Handwriting erasing method, device, interactive tablet, and storage medium

Abstract

This application discloses a handwriting erasing method, device, interactive tablet, and storage medium, in which the touch response accuracy of the touch frame on the interactive tablet is within a predetermined accuracy range. The method includes the steps of: displaying a display interface including the handwriting to be erased on a display; receiving a handwriting erasing command generated by a user's trigger to enter a handwriting erasing mode; acquiring touch point information fed back by the touch frame when a touch object operated and controlled by the user touches and moves on the surface of the display; analyzing the acquired touch point information and the handwriting to be erased, and erasing the handwriting to be erased in the interface with an erasing geometric form matching the touch object. The method can ensure that the erasing response to the handwriting to be erased in the interface is more consistent with the erasing geometric form for the touch object used by the user, and can flexibly adjust the erasing area during the erasing process, thereby improving the erasing efficiency from the interactive tablet.

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims priority to a Chinese patent application bearing application number 202110554083.9, filed with the China Patent Office on May 20, 2021, the entire contents of which are incorporated herein by reference.

[0002] The present application relates to the technical field of touch writing in electronic devices, and in particular to a handwriting erasing method, device, interactive tablet, and storage medium. [Background technology]

[0003] The touch frame is an important hardware component of an interactive tablet, and is mainly used to respond to the touch operation on the interactive tablet by the user. Most of the touch frames used in interactive tablets on the market are non-precise touch frames, and such non-precise touch frames mainly have the following defects: It is difficult to determine the type of pen; It is difficult to ensure that the touch area generated by writing with the same pen is the same; It is difficult to determine whether the touch medium is a pen, a finger, or an eraser; and It is also difficult to determine the touch rotation angle.

[0004] In the process of achieving the present application, the inventors find that there are currently the following defects: the interactive tablet cannot fully utilize the touch point information fed back by the touch frame at the software level, and as a result, there is no obvious improvement in the performance and effect related to touch on the interactive tablet (such as the erasing effect when erasing the formed writing trace). Summary of the Invention [Problem to be solved by the invention]

[0005] The embodiments of the present application provide a handwriting erasing method, device, interactive tablet, and storage medium that improve the effect of erasing handwriting on an interactive tablet. [Means for solving the problem]

[0006] In a first aspect, an embodiment of the present application is a handwriting erasing method for an interactive tablet, in which a touch response accuracy of a touch frame on the interactive tablet falls within a predetermined accuracy range, comprising: displaying a display interface including the handwriting to be erased on a display; receiving a handwriting erasing command generated by a user trigger to enter a handwriting erasing mode; When a touch object operated and controlled by a user touches and moves on the surface of the display, obtaining touch point information fed back by the touch frame; analyzing the acquired touch point information and the target handwriting to be erased, and erasing the target handwriting in the interface with an erasing geometric form that matches the touch object; The erasing geometry matching the touch object is expressed as a touch area of ​​the touch object acting on the display; The erasing geometries provide a way to erase handwriting including rounded rectangles, circles and any irregular shape.

[0007] Furthermore, the above step of obtaining touch point information fed back by the touch frame further comprises: identifying, by the touch frame hardware circuitry, each touch signal generated as the touch object moves across the display; obtaining touch point information fed back by the touch frame for each of the touch signals according to a HID standard protocol of human-computer interaction; One touch point information corresponds to one touch point, and the touch point information includes: touch point coordinates, touch point height and width, and touch rotation angle.

[0008] Furthermore, after obtaining the touch point information fed back by the touch frame, The method further includes processing each of the touch point information so that each of the touch point information has a uniform unit format and data structure.

[0009] Furthermore, the above step of processing each of the touch point information further comprises: converting the units of each piece of data information in the touch point information into a unified predetermined unit format according to the acquired size information of the touch frame and screen resolution information; and recording the touch point information in a data structure corresponding to the predetermined unit format.

[0010] Further, the step of analyzing the acquired touch point information and the target handwriting to be erased, and erasing the target handwriting in the interface with an erasing geometric form matching the touch object, includes: determining an erasure geometry matching the moving touch object based on the acquired touch point information, and determining a moving contour geometry formed by the moving adjacent touch point pair with the erasure geometry; analyzing each handwriting point included in the erasure target handwriting, performing a hit test between each of the handwriting points and the moving contour geometric figure, and determining a target erasure target handwriting that falls within the moving contour geometric figure; Erasing the target erasure target handwriting on the display interface.

[0011] Furthermore, the above steps of determining an erasure geometry matching the moving touch object based on the acquired touch point information, and determining a moving contour geometry formed by the moving adjacent touch point pair with the erasure geometry, are further comprised of: extracting important touch point information, which is touch point information of a touch point generated when the touch object first contacts the display during movement, and obtaining an important touch area in the important touch point information; determining an area threshold range and an area shape to which the significant touch area belongs, searching for a target shape that matches the area shape among geometric shapes corresponding to the area threshold range to which the significant touch area belongs, and determining the target shape as a geometric shape for erasure that matches the touch object; for each pair of adjacent touch points of the touch object being moved, analyzing touch point information for the pair of adjacent touch points to determine significant geometric information of each touch point in the pair of adjacent touch points relative to the erasure geometry; determining a movement contour geometry formed by said adjacent touch point pairs relative to said erasure geometry based on each of said key geometric information.

[0012] Furthermore, when the geometric shape for erasure is a rounded rectangle, the rounded rectangle includes a rectangle and a chamfer with each vertex of the rectangle as a circle center; The step of analyzing touch point information for the adjacent touch point pairs to determine significant geometric information of each touch point in the adjacent touch point pairs relative to the erasure geometry includes: determining the rounded rectangle as a first geometric shape to be constructed by each of the adjacent touch points in the pair of touch points; For each touch point in the adjacent touch point pair, combine the touch point coordinates, touch width, touch height and touch rotation angle in the relevant touch point information with a predetermined chamfer radius to determine the center point coordinates of a rectangle in the first geometric figure to be constructed, the circle center coordinates of each chamfer and the coordinates of each important junction, and the coordinates of the connection points of the two figures; and determining the coordinates of the center point of the rectangle, the coordinates of the circle centers of the chamfers, the coordinates of the important junctions, and the coordinates of the connection points of the two figures as important geometric information of the touch points for the first geometric figure to be constructed; Each chamfer of the first geometrical figure to be constructed includes two critical junctions, each critical junction being a corresponding junction when the chamfer and an adjacent chamfer are connected by tangent lines.

[0013] Furthermore, the step of determining a moving contour geometry formed by the adjacent touch point pairs on the erasure geometry based on each of the significant geometric information further comprises: According to the key geometric information of the adjacent touch point pairs, extracting the chamfer circle center coordinates of the corresponding rounded rectangle, and selecting the key circle center points required to construct the circumscribing contour; obtaining important circular areas determined based on each of the important circle center points; According to the important geometric information of the adjacent touch point pairs, extracting the rectangle vertex coordinates and center point coordinates of the corresponding rounded rectangle, and selecting the important connection point pairs required to construct the circumscribing contour; obtaining a circumscribed rectangular area determined based on each pair of important connection points, and a vertex-connected closed area determined based on each of the rectangular vertex coordinates; combining each of the important circular regions, each of the circumscribing rectangular regions and the vertex-connected closed regions to form a first moving contour figure formed by the adjacent touch point pairs relative to the rounded rectangle.

[0014] Furthermore, the above step of analyzing each handwriting point included in the erasure target handwriting, performing a hit test between each of the handwriting points and the moving contour geometric figure, and determining a target erasure target handwriting that falls within the moving contour geometric figure, decomposing the first moved contour figure to obtain the vertex-connected closed region and a corresponding number of circumscribing rectangular regions and important circular regions; performing a first hit test for each handwriting point included in the handwriting to be erased, between the handwriting point, the vertex-connected closed region, and each of the circumscribed rectangular regions; if the first hit test is successful, adding the handwritten point to a first set of target points, and if the first hit test is unsuccessful, performing a second hit test between the handwritten point and each of the important circular regions; adding the handwriting point to the first set of target points if the second hit test is successful; determining a handwriting formed by each handwriting point in the first target point set as a target handwriting to be erased that falls within the moving contour geometric figure.

[0015] Furthermore, the step of performing a first hit test between the handwriting point and each of the circumscribing rectangular regions includes: combining the vertex-connected closed region with each of the circumscribing rectangular regions to obtain a corresponding convex polygon region, and obtaining each of the region vertices constituting the convex polygon region; connecting the handwriting points to each of the region vertices respectively to obtain triangles having the same number as the region vertices; determining an angle value of an apex angle formed by the handwritten points in each of the triangles; and determining that a first hit test of the handwritten point is successful if the sum of the angle values ​​is 360 degrees.

[0016] Furthermore, the step of performing a second hit test on the handwriting points and each of the important circular regions includes: obtaining a region center and a region radius of each of the important circular regions, and determining a length of a connecting line between the handwriting point and each of the region centers; and determining that the second hit test of the handwritten point is successful if there is a connecting line whose length is less than the region radius.

[0017] and determining an erasing geometry matching the moving touch object based on the acquired touch point information. determining that the erasure geometry is a rounded rectangle and if the touch object is monitored to not move within a set time, determining a static touch point that corresponds to when the touch object contacts the display within the set time; determining a static rounded rectangle for the static touch point based on touch point information of the static touch point; The method further includes a step of performing a hit test between each handwriting point included in the handwriting to be erased and the static rounded rectangle, and erasing the handwriting to be erased that falls within the static rounded rectangle in the interface.

[0018] Furthermore, the static rounded rectangle includes two static rectangular regions and four static circular regions; In this case, the step of performing a hit test between each handwriting point included in the handwriting to be erased and the static rounded rectangle, and erasing the handwriting to be erased that falls within the static rounded rectangle in the interface, performing a hit test for each handwriting point in the handwriting to be erased between the handwriting point and each of two static rectangular regions and four circular regions; adding the handwritten point to a static point set if the handwritten point satisfies a condition for passing the hit test; and erasing the handwriting formed based on each handwriting point in the static point set.

[0019] Moreover, when the erasure geometry is a circle, the step of analyzing touch point information for the adjacent touch point pairs to determine significant geometric information of each touch point in the adjacent touch point pairs relative to the erasure geometry further comprises: determining the circular shape as a second geometric shape to be constructed by each of the adjacent touch points in the pair of touch points; determining a circle center coordinate and each important intersection coordinate of the corresponding second geometric figure to be constructed according to the touch point coordinate, touch width, and touch height in the touch point information of each touch point in the adjacent touch point pair; and determining the circle center coordinates and the important intersection coordinates corresponding to each touch point as important geometric information corresponding to the second geometric figure to be constructed.

[0020] Furthermore, the step of determining the circle center coordinates and each important intersection coordinate of the corresponding second geometric figure to be constructed according to the touch point coordinates, touch width, and touch height in the touch point information of each touch point in the adjacent touch point pair includes: determining a circle center coordinate of a corresponding second circle to be constructed according to the touch point coordinate, the touch width and the touch height in the touch point information for each touch point in the adjacent touch point pair; Connecting the circle center coordinates of the two corresponding circles to obtain a connecting line of the circle centers; and drawing straight lines perpendicular to the circle center connecting lines based on the circle center coordinates of each of the circles, and obtaining important intersection coordinates determined by intersecting each straight line with the corresponding second circle to be constructed.

[0021] Furthermore, the step of determining a moving contour geometry formed by the adjacent touch point pairs on the erasure geometry based on each of the significant geometric information includes: Extracting circular center coordinates from the significant geometric information of the adjacent touch points; obtaining a second geometric region to be constructed based on the coordinates of each of the circular centers; Extracting respective significant intersection coordinates from the significant geometric information of the adjacent touch points; obtaining an important intersection connection area determined based on each of the important intersection coordinates; combining each of the second construction target geometric figures with the important intersection connection regions to form a second moving contour figure formed by the adjacent touch point pairs with respect to the circular shape.

[0022] Furthermore, the above step of analyzing each handwriting point included in the target handwriting to be removed, performing a hit test between each of the handwriting points and the moving contour geometric figure, and determining a target handwriting to be removed that falls within the moving contour geometric figure, Decomposing the second moving contour figure to obtain one important intersection connection region and two second construction target geometric figures; performing a third hit test for each handwriting point included in the handwriting to be erased between the handwriting point and the important intersection connection region; if the third hit test is successful, adding the handwritten point to a second target point set, and if not successful, performing a fourth point-to-circular region hit test for the handwritten point and each of the second construction target geometric figures; adding the handwriting point to the second set of target points if the fourth hit test is successful; determining a handwriting formed based on each handwriting point in the second target point set as a target handwriting to be erased that falls within the moving contour geometric figure.

[0023] Furthermore, the step of performing a third hit test on the handwriting point and the important intersection connection region includes: if it is determined that the important intersection connection region is a rectangular region, selecting one vertex from the rectangular region to form two rectangular side vectors, and comparing the handwritten point with each of the rectangular side vectors to perform a hit test between the handwritten point and the rectangular region; If the region is not a rectangle, a step of determining, based on each vertex of the important intersection connection region, a number of comparison target vectors equal to the number of vertices of the important intersection connection region; and performing a hit test between the handwritten points and the rectangular region by comparing the handwritten points with each of the comparison target vectors.

[0024] Moreover, when the erasure geometry is an arbitrary irregular shape, the step of analyzing touch point information for the adjacent touch point pairs to determine significant geometric information of each touch point in the adjacent touch point pairs relative to the erasure geometry may further include: determining combination graphic information included in the third geometric figure to be constructed by determining the arbitrary irregular shape as a third geometric figure to be constructed by each touch point in the adjacent touch point pair; for each touch point in the adjacent touch point pair, combining touch point information with the combined graphic information to determine significant locus points of the third geometric figure to be constructed relative to the touch point and graphic display information of the third geometric figure to be constructed; and determining the graphic display information of each of the combined graphics and each of the important trajectory points as important geometric information of the touch points for the third geometric graphic to be constructed.

[0025] Furthermore, the step of combining touch point information with the combined graphic information to determine significant trajectory points of the third geometric figure to be constructed relative to the touch points and graphic display information of the third geometric figure to be constructed further comprises: analyzing the combined graphic information; if it is determined that the third geometric figure to be constructed includes only a broken line or a polygon, determining an important trajectory point existing with respect to the touch point of the broken line or the polygon based on touch point information related thereto, and acquiring first figure display information representing the broken line or the polygon; When it is determined that the third geometric figure to be constructed includes a broken line / polygon and a target circle, determining important trajectory points in the broken line / polygon and important circle based on touch point information related thereto, and obtaining second figure display information representing the broken line / polygon and important circle.

[0026] Furthermore, the step of determining an important trajectory point existing for the touch point of the broken line / polygon based on touch point information related to the broken line / polygon and acquiring first graphic display information representing the broken line / polygon, determining a center point coordinate of a polygonal line and a vertex coordinate of each polygonal line, which is the first graphic display information, based on a touch point coordinate, a touch height, and a touch width in the touch point information related to the polygonal line; and selecting important trajectory points that satisfy a selection condition for trajectory points from among the vertex coordinates of each of the polygonal lines based on the polygonal line center point coordinates and related touch point information.

[0027] Further, the step of determining important trajectory points on the polygonal line and the important circle based on touch point information related thereto, and obtaining second graphic display information representing the polygonal line and the important circle, further includes: determining the coordinates of the center point of the polygonal line and the coordinates of each vertex of the polygonal line and the coordinates of the center point of the important circle and the circle radius of the important circle based on the touch point coordinates, the touch height and the touch width in the touch point information related to the polygonal line and the important circle, and setting them as the second figure display information; and selecting important trajectory points that satisfy a trajectory point selection condition from among the vertex coordinates of each of the polygonal lines and on the circumference of the important circle based on the polygonal line center point coordinate, the circle center point coordinate, the circle radius and related touch point information.

[0028] Furthermore, the step of determining a moving contour geometry formed by the adjacent touch point pairs with respect to the erasure geometry based on each of the significant geometric information includes: respectively extracting first graphic representation information or second graphic representation information from the significant geometric information of the adjacent touch point pairs; obtaining a combined geometric figure determined based on the corresponding first or second graphic representation information, respectively; respectively extracting significant trajectory points from the significant geometric information of the adjacent touch point pairs; obtaining an important trajectory region formed by connecting each of the important trajectory points; combining each of the combined geometric figures with the significant locus region to form a third moving contour figure formed by the adjacent touch point pairs for the arbitrary irregular shape.

[0029] Furthermore, the above step of analyzing each handwriting point included in the erasure target handwriting, performing a hit test between each handwriting point and the moving contour geometric figure, and determining a target erasure target handwriting that falls within the moving contour geometric figure, decomposing the third moving contour figure to obtain the significant trajectory region and each of the combined geometric figures; For each handwriting point included in the handwriting to be erased, if the combination geometric figure is only a broken line or a polygon, a rotation angle hit test is performed between the handwriting point and each of the broken lines or polygons by a rotation angle method; or If the combination geometric figure includes a broken line, a polygon and an important circle, a distance hit test is performed between the writing point and each of the broken line, the polygon and the important circle by a distance method; adding the handwritten point to a third target point set if the rotation angle hit test or the distance hit test is successful, and otherwise performing a vector hit test between the handwritten point and the significant trajectory region, and adding the handwritten point to a third target point set if the vector hit test is successful; determining a handwriting formed based on each handwriting point in the third target point set as a target handwriting to be erased that falls within the moving contour geometric figure.

[0030] In a second aspect, an embodiment of the present application provides a handwriting erasing device disposed on an interactive tablet, the handwriting erasing device having a touch response accuracy of a touch frame on the interactive tablet within a predetermined accuracy range, comprising: a display module for displaying a display interface including the handwriting to be erased on a display; a trigger module for receiving a handwriting erasing command generated by a user trigger to enter a handwriting erasing mode; an acquisition module for acquiring touch point information fed back by the touch frame when a touch object operated and controlled by a user touches and moves on the surface of the display; an erasing module for analyzing the acquired touch point information and the handwriting to be erased, and erasing the handwriting to be erased in the interface with an erasing geometric form matching the touch object.

[0031] In a third aspect, the present embodiment further comprises: a touch frame having a touch response accuracy within a predetermined accuracy range and responding to a touch operation by a touch object through a hardware circuit; a display that is covered by the touch frame to form a touch screen and displays interaction content; one or more processors; a storage device storing one or more programs; The one or more programs, when executed by the one or more processors, cause the one or more processors to implement a method according to the first aspect of the present application.

[0032] In a fourth aspect, embodiments of the present application further provide a storage medium comprising computer-executable instructions, the computer-executable instructions, when executed by a computer processor, for performing a method according to the first aspect. Effect of the Invention

[0033] In the above-mentioned handwriting erasing method, device, interactive tablet, and storage medium, the method may be performed by an interactive tablet, and the touch response accuracy of the touch frame on the interactive tablet is within a predetermined accuracy range. The method first displays a display interface including the handwriting to be erased on a display, then receives a handwriting erasing command to enter a handwriting erasing mode, and then obtains touch point information fed back by the touch frame when a touch object touches and moves on the surface of the display, and finally analyzes the obtained touch point information and the handwriting to be erased to erase the handwriting in the interface with an erasing geometric form matching the touch object. In the above-mentioned technology of the present embodiment, in the case of an interactive tablet with a high-precision touch frame arranged as a hardware structure, the method of the present embodiment can optimize the function at a software application level for the arranged high-precision touch frame, and compared with the interactive tablet of the prior art without optimization at a software level, the method of the present embodiment can ensure that the erasing response to the handwriting to be erased in the interface is more aligned with the erasing geometric form for the touch object used by the user, and can flexibly adjust the erasing area during the erasing process, thereby improving the erasing efficiency from the interactive tablet. [Brief description of the drawings]

[0034] [Figure 1] 1 shows a schematic flow diagram of a handwriting erasing method according to a first embodiment of the present application. [Figure 1a] FIG. 2 is a schematic diagram showing a response effect of a touch frame on a touch object in the handwriting erasing method according to the first embodiment of the present application; [Figure 1b] FIG. 2 shows an effect diagram representing an erasing geometric form in the handwriting erasing method according to the first embodiment of the present application. [Figure 1c]FIG. 2 shows an effect display diagram of a moving contour geometric figure as an erasure area in the handwriting erasing method according to the first embodiment of the present application; [Diagram 2] 4 shows a schematic flow diagram of a handwriting erasing method according to Example 2 of the present application. [Figure 2a] FIG. 4 is a diagram showing the effect of the handwriting erasing method according to the second embodiment of the present invention; [Figure 2b] 13 shows a flow chart of an example of implementation of determining an erasure pattern and a contour figure in the handwriting erasing method according to the second embodiment of the present application. [Figure 2c] 2c to 2h are schematic diagrams illustrating the determination of important geometric information when the geometric form for erasing is a rectangle with rounded corners in the handwriting erasing method according to the second embodiment of the present application. [Figure 2d] 2c to 2h are schematic diagrams illustrating the determination of important geometric information when the geometric form for erasing is a rectangle with rounded corners in the handwriting erasing method according to the second embodiment of the present application. [Figure 2e] 2c to 2h are schematic diagrams illustrating the determination of important geometric information when the geometric form for erasing is a rectangle with rounded corners in the handwriting erasing method according to the second embodiment of the present application. [Figure 2f] 2c to 2h are schematic diagrams illustrating the determination of important geometric information when the geometric form for erasing is a rectangle with rounded corners in the handwriting erasing method according to the second embodiment of the present application. [Figure 2g] 2c to 2h are schematic diagrams illustrating the determination of important geometric information when the geometric form for erasing is a rectangle with rounded corners in the handwriting erasing method according to the second embodiment of the present application. [Figure 2h] 2c to 2h are schematic diagrams illustrating the determination of important geometric information when the geometric form for erasing is a rectangle with rounded corners in the handwriting erasing method according to the second embodiment of the present application. [Figure 2i] 2i to 2m show schematic diagrams for explaining the determination of important geometric information when the geometric form for erasing is a circle in the handwriting erasing method according to the second embodiment of the present application. [Figure 2j]2i to 2m show schematic diagrams for explaining the determination of important geometric information when the geometric form for erasing is a circle in the handwriting erasing method according to the second embodiment of the present application. [Figure 2k] 2i to 2m show schematic diagrams for explaining the determination of important geometric information when the geometric form for erasing is a circle in the handwriting erasing method according to the second embodiment of the present application. [Figure 2l] 2i to 2m show schematic diagrams for explaining the determination of important geometric information when the geometric form for erasing is a circle in the handwriting erasing method according to the second embodiment of the present application. [Figure 2m] 2i to 2m show schematic diagrams for explaining the determination of important geometric information when the geometric form for erasing is a circle in the handwriting erasing method according to the second embodiment of the present application. [Figure 2n] FIG. 13 is a diagram showing the effect of the handwriting erasing method according to the second embodiment of the present invention when the erasing geometric shape is an arbitrary irregular shape. [Figure 2o] 2o to 2q are schematic diagrams illustrating the determination of important geometric information when the geometric form for erasing in the handwriting erasing method according to the second embodiment of the present application is of an arbitrary irregular shape and includes only polygonal geometric figures. [Figure 2p] 2o to 2q are schematic diagrams illustrating the determination of important geometric information when the geometric form for erasing in the handwriting erasing method according to the second embodiment of the present application is of an arbitrary irregular shape and includes only polygonal geometric figures. [Figure 2q] 2o to 2q are schematic diagrams illustrating the determination of important geometric information when the geometric form for erasing in the handwriting erasing method according to the second embodiment of the present application is of an arbitrary irregular shape and includes only polygonal geometric figures. [Figure 2r] FIG. 13 shows a schematic diagram of determining important geometric information when the geometric form for erasing in the handwriting erasing method according to the second embodiment of the present application is an arbitrary irregular shape. [Figure 2s]FIG. 13 shows a schematic diagram of determining important geometric information when the geometric form for erasing in the handwriting erasing method according to the second embodiment of the present application is an arbitrary irregular shape. [Figure 2t] 13 illustrates a flow chart of an example of implementation of determining a target erasure target handwriting in the handwriting erasing method according to the second embodiment of the present application; [Diagram 3] FIG. 13 shows a schematic diagram of an implementation of a hit test used when the geometric form for erasure is a rounded rectangle in the handwriting erasing method according to the second embodiment of the present application. [Figure 4] FIG. 13 shows a schematic diagram of an implementation of a hit test used when the geometric form for erasure is a rounded rectangle in the handwriting erasing method according to the second embodiment of the present application. [Diagram 5] 13 illustrates a flowchart of another implementation of determining a target erasure target handwriting in the handwriting erasing method according to Example 2 of the present application. [Figure 6] FIG. 13 shows a schematic diagram of an example implementation of a hit test used when the geometric form for erasure is a circle in the handwriting erasing method according to the second embodiment of the present application; [Figure 7] FIG. 13 shows a schematic diagram of an example implementation of a hit test used when the geometric form for erasure is a circle in the handwriting erasing method according to the second embodiment of the present application; [Figure 8] 13 illustrates a flowchart of yet another implementation of determining a target erasure target handwriting in the handwriting erasing method according to Example 2 of the present application; [Figure 9] 13 is a diagram showing the effect of a static rounded rectangle in the handwriting erasing method according to the second embodiment of the present application; [Figure 10] FIG. 11 is a structural block diagram of a handwriting erasing device according to a third embodiment of the present invention. [Figure 11] FIG. 11 is a structural schematic diagram of an interactive tablet according to Example 4 of the present application. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0036] In the following description, when the drawings are referred to, the same numerals in different drawings represent the same or similar elements unless otherwise stated. The embodiments described in the following illustrative examples do not represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the claims.

[0037] In the description of this application, the terms "first", "second", "third", etc. are used only to distinguish between similar objects, are not used to describe a particular order or priority, and should not be understood as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of the above terms in this application depending on the context. Furthermore, in the description of this application, unless otherwise stated, "plurality" means two or more. "And / or" describes the related relationship of related objects and indicates that there are three relationships. For example, A and / or B indicates that A exists alone, A and B exist simultaneously, and B exists alone. The symbol " / " generally indicates that the related objects before and after are in an "or" relationship.

[0038] In practical application, the hardware part of an interactive tablet is composed of parts such as a display, an intelligent processing system, etc., which are coupled by an overall structural member and supported by a dedicated software system.

[0039] Among them, the display may specifically include a light emitting diode (LED) display, an organic light-emitting diode (OLED) display, a liquid crystal display (LCD), etc. By providing optical touch sensors on both sides of the surface of the display, a touch frame can be configured to form a touch display. The optical touch sensor constituting the touch frame can scan a touch object such as a user's finger or a touch pen on the surface of the display using an optical signal. It is understood that a cover glass is provided on the surface of the display to protect the display from scratches caused by touch. Therefore, in the embodiments of this specification, the surface of the display refers to the surface of the cover glass of the display.

[0040] When a touch object touches the display and triggers a certain interface on the display, an operation such as location determination is performed, and the touch frame responds to the above touch operation and transmits corresponding touch operation information to an application-level intelligent processing system, so that various interactive applications can be realized through the intelligent processing system.

[0041] Taking one of the optical touch sensors constituting the touch frame as an example, the touch frame will be described from the perspective of technical principle.

[0042] Specifically, the optical touch sensor includes an infrared transmitter for transmitting an infrared signal and an infrared receiver for receiving the infrared signal, and can form a light beam grid using the infrared signals densely arranged in various directions to identify the location of the touch point. A bezel with a circuit board is attached to the display, which serves to arrange the infrared transmitters and infrared receivers around the display and form a beam grid touch frame that crosses vertically and horizontally.

[0043] If the display is equipped with the above touch frame, when the touch object blocks the infrared signal, the photometric value will be weakened at the corresponding infrared receiver, so that the position of the touch point on the screen can be determined.

[0044] Specifically, an infrared transmitter is attached to a first side of a display bezel, and an infrared receiver is attached to a second side of the display bezel, and the first and second sides are positioned opposite each other, i.e., the infrared receiver is within the scanning range of the infrared transmitter, so that the infrared signal transmitted by the infrared transmitter is received by the infrared receiver.

[0045] The shape of the display varies according to the needs of various businesses, for example, rectangular, hexagonal, circular, etc., and the shape of the bezel also varies according to the shape of the display, for example, rectangular, hexagonal, circular, etc., and when the bezel shape is different, the arrangement of the infrared transmitter and infrared receiver in each infrared module also differs.

[0046] Generally, the conventional touch frame arranged on the interactive tablet often has a touch response accuracy within a general range when responding to a touch signal by a touch object. Meanwhile, for a non-high-precision touch frame with a touch response accuracy within a general range, it may be difficult to recognize the size of the touch area of ​​the touch object on the display, so that in the touch writing mode, it is difficult to determine what type of touch object the user used to write or what touch medium (finger, writing pen) the user used to touch; and in the touch erasing mode, it is difficult to determine what type of touch object the user used to erase, so that erasing can only be performed based on the conventional erasing form. In addition, it is also difficult for a non-high-precision touch frame to ensure that the same type of touch object expresses the same touch area during touching.

[0047] In the present embodiment, the interactive tablet adopts a high-precision touch frame having a higher touch response accuracy than a touch frame within a general range of touch response accuracy due to its hardware configuration, and the so-called high touch response accuracy is considered to mean that the touch response accuracy is within a predetermined accuracy range limited to a higher accuracy than the general accuracy range. According to such a touch frame adopted in the present embodiment, more detailed touch information such as the touch area of ​​the touch object, more accurate touch point coordinates, and the rotation angle of the touch object during touching can be provided to a higher application level.

[0048] In addition, the intelligent processing system in the interactive whiteboard can include a host processor, which is the processor of the interactive tablet, and the software built into the host processor can realize various functional applications, display the screen through the display, and create vivid AV effects.

[0049] Here, the host processor is a high performance computing module.

[0050] For example, the host processor is an Android module that can install the Android system and place components such as a central processing unit (CPU), a graphics processing unit (GPU), random access memory (RAM), and read-only memory (ROM). For example, in the Android 7.0 version, the CPU is a dual-core A72 and a quad-core A53, the GPU is a Mali T860, the RAM is 4GB, and the ROM is 32GB.

[0051] Also, for example, the host processor may be a personal computer (PC) module in which components such as a CPU, GPU, memory, and hard disk can be arranged. For example, in the case of a plug-in Intel Core series modular computer, the CPU is Intel Core i5 / i7, the GPU is Core Display Intel HD Graphics, the memory is DDR4 8G / 16G, and the hard disk is 128G / 256G.

[0052] Example 1 FIG. 1 is a flow diagram of a handwriting erasing method according to a first embodiment of the present application. This embodiment is applicable to erasing handwriting existing on an interface in an erasing mode. The method may be performed by a handwriting erasing device, which may be implemented by software and / or hardware, and may be disposed in an interactive tablet, particularly a processor of the interactive tablet, which may be a host processor of an intelligent processing system. In addition, the touch frame in the interactive tablet has a touch response accuracy within a predetermined accuracy range, and the touch frame is also electrically connected to a display.

[0053] As shown in FIG. 1, the handwriting erasing method according to the first embodiment of the present invention specifically includes steps S101 to S104.

[0054] S101: A display interface including handwriting to be erased is displayed on a display.

[0055] It can be understood that the interactive tablet, which is the subject of the method according to the present embodiment, is further provided with a graphics processor (GPU: Graphics Processing Unit) that can provide video processing functions, specifically, the GPU can receive information from the host processor, store it in a frame memory, and generate serial display data and scanning control timing required for the display for the video signal according to the partition driving method. Based on the above operations, the display provided on the interactive tablet can reproduce frame data information according to the serial display data and scanning control timing, and display various screens on the display.

[0056] In this embodiment, the display interface is considered to be an interface displayed on the display after the user writes or edits in a writing or editing mode. Specifically, the element information displayed on the display interface includes at least the handwriting to be erased formed by the user's operation. It can be understood that the handwriting to be erased may be the handwriting displayed by the user performing a writing operation in the writing mode, where the color, thickness, etc. of the handwriting may all be selected by the user, and the displayed handwriting style may also represent the user's writing style.

[0057] In general, the display interface may be an independent interface; as an example, an interactive tablet provides an electronic whiteboard, a user triggers a control operation on the interactive tablet to display the electronic whiteboard, and the interactive tablet receives the control operation and displays the electronic whiteboard as a display interface for element representations.

[0058] In addition, the display interface may be an interface with a background, as an example, an interactive tablet displays local courseware, data such as a screen image of a source device (e.g., a laptop) transmitted by a screen sharing device (USB dongle), and the user triggers an annotation operation on the interactive tablet, and the interactive tablet receives the annotation operation and freezes the courseware, screen image, etc. data and makes them the background, i.e., maintains the display of the current frame screen of the courseware, screen image, etc. data, and generates a mask layer on top of the courseware, screen image, etc. data, which becomes the currently represented display interface.

[0059] Here, the so-called courseware can refer to a curriculum document that is created through steps such as determining teaching objectives, analyzing teaching contents and tasks, and designing the structure and interface of teaching activities according to teaching requirements. For example, it may be a file in a common format such as a Word document or PowerPoint (PPT), or it may be a custom page created by combining elements such as text, tables, and figures, but this embodiment is not limited to this.

[0060] S102: Receive a handwriting erasing command triggered by a user and enter a handwriting erasing mode.

[0061] In this embodiment, from the user's point of view, the user can perform touch trigger operations on the display, i.e., on the displayed display interface, and the touch operations may be tap, long press touch, and moving touch. Among these, tap is often used to trigger any button or icon in the display interface, long press touch is often used to drag an element, and moving touch is used to write or erase handwriting, among which moving touch is often displayed in the form of a trajectory.

[0062] Generally, the control operations on the display interface of the interactive tablet include, but are not limited to, touch operations, key board operations, mouse operations, and physical key board operations. In this embodiment, the operation of generating the handwriting erasure command may also be a touch operation, a mouse operation, and a key board operation, etc.

[0063] As an example, the preceding operation of performing this step can be described as follows: the display interface includes a function button, such as an erase button, for entering an erase mode, and when a user taps the erase button, the touch frame of the interactive tablet responds to the touch signal of the tap operation and feeds back the touch information related to the touch signal to the upper layer of the interactive tablet (e.g., the main processor of the intelligent processing system). Thus, this step can receive a handwriting erase command generated by the upper layer, and respond to the handwriting erase command to enter the handwriting erase mode.

[0064] In this embodiment, the handwriting erasure mode may be understood as granting the interactive whiteboard the authority to erase elements displayed on the display interface when the mode is turned on, i.e., when entering the erasure mode, the display interface can treat handwriting expressed in the writing mode as an object to be erased, and has the authority to erase the erased handwriting.

[0065] S103: When a touch object operated and controlled by a user touches and moves on the surface of the display, obtain touch point information fed back by the touch frame.

[0066] In this embodiment, the touch object may be specifically a user's finger, an active stylus, a passive stylus, etc., and the user can operate and control the touch object to move on the display surface of the interactive tablet, where the moving state represented by the moving touch object can be used to erase the writing trace in the erasing mode. For example, the touch object for erasing may be a dedicated physical eraser (such as a touch blackboard eraser) that matches the interactive tablet, or a part of the user's body such as a hand.

[0067] Regarding the touch of the display by the touch object and information feedback, it is clear from the above description in the embodiment of the present application that the interactive tablet also has a touch frame combined with the display, and the touch frame can specifically be a frame made of an optical touch sensor and fitted on the edge of the display. In this step, the touch frame can generate a touch signal according to its optical touch sensor when the touch object moves on the display, and identify the relevant touch point information in response to the touch signal.

[0068] Specifically, Fig. 1a is a display diagram of the response effect of the touch frame to the touch object in the handwriting erasing method according to the first embodiment of the present application. As shown in Fig. 1a, one or more optical touch sensors 120 are attached to both sides of the edge of the display 110 of the interactive tablet to form a touch frame. The moving state of the touch object (for example, the user's finger is the touch object used for erasing) operated and controlled by the user on the display 110 can be represented by finger states 131-135.

[0069] Following the above description, while the interactive tablet is activated and working, the processor activates the optical touch sensor 120, the optical touch sensor 120 scans the optical signal on the display surface of the interactive tablet, and detects whether a touch object appears on the display surface according to the transmission of the optical signal, and generates a corresponding touch signal in real time during the moving process of the touch object when the touch object is detected. In addition, the touch frame can feed back the touch point data identified after the response to the upper layer of the interactive tablet (for example, the main processor of the intelligent processing system) in response to the generated touch signal, and in this embodiment, the touch point data is referred to as touch point information.

[0070] In this embodiment, the touch frame used in this embodiment is considered to be a high-precision touch frame, considering that the touch response accuracy of the touch frame arranged on the interactive tablet to the touch object falls within a certain accuracy range. In the above steps, the touch point information fed back by the touch frame is superior to the touch point information fed back by the conventional touch frame in both accuracy and information detail. As an example, the touch point information fed back by the touch frame to the upper layer of the interactive tablet includes at least the touch point coordinates of the touch point, the touch point height and width and touch area of ​​the touch signal generated by the touch object, and the corresponding touch rotation information when the touch object rotates.

[0071] S104: Analyzing the acquired touch point information and the handwriting to be erased, and erasing the handwriting to be erased in the interface with an erasing geometric form matching the touch object.

[0072] In this embodiment, from the user's perspective, the user touches to enter the erase mode, which indicates that the user intends to erase an element on the display interface. The element that satisfies the erase condition may be handwriting that has been arbitrarily written in advance by the user. In this embodiment, the handwriting displayed on the display interface is called handwriting to be erased.

[0073] In addition, in the implementation of erasing in the related art, when entering the erasing mode by touching, the geometric shape of the eraser for the erasing operation is often preset by the user, for example, it may be circular or rectangular, and the erasing dimensions of the eraser are also the same as the size of the eraser. In the case of erasing in the related art, the geometric shape of the eraser, especially the shape and erasing dimensions after rotating the eraser, cannot change according to the change in the shape or dimensions of the touch object, and usually need to be set manually. Therefore, when erasing with the erasing method in the related art, there is a problem that erasing takes a long time because the size of the eraser is too small.

[0074] In this embodiment, when a user wants to personalize handwriting erasure or improve the efficiency of handwriting erasure on an interactive tablet, it is necessary to obtain data information that can represent the shape of a touch object used by the user, and then process the data information to determine an erasing geometric form that matches the touch object when erasing handwriting. Finally, the determined erasing geometric form can be used to represent the shape and dimensions of an eraser, and the represented eraser can be used to erase the handwriting to be erased. This diversifies the geometric forms represented as erasers in the handwriting erasing operation, and improves the erasing efficiency of the handwriting erasing operation.

[0075] It should be noted that the determination of the erasing geometric shape corresponding to the touch object mainly depends on the touch area in the touch point information, and generally, different touch areas correspond to different erasing geometric shapes, that is, the erasing geometric shape matching the touch object is expressed by the touch area of ​​the touch object acting on the display. In this embodiment, the touch area in the touch point information may be analyzed to determine a geometric shape matching the touch area, and the geometric shape may be the erasing geometric shape corresponding to the touch object. Here, the erasing geometric shape determined in this step may include at least three shapes, namely, a circle, a rounded rectangle, and any irregular shape.

[0076] For example, the correspondence between the touch area and the geometric shape for erasing is mainly determined by the shape and size of the touch area. For example, if the touch object is a finger, and the touch area in the touch point information can represent the area covered by the finger, and the shape of the touch area is approximately circular, erasing using the touch object is considered to be erasing a small area range, and therefore, a circle having the same area as the touch area is the geometric shape for erasing of the touch object, and an eraser having the geometric shape for erasing (circular) is represented in the erasing mode to perform handwriting erasure.

[0077] Also, for example, if the touch object is the back of a hand, and the touch area in the touch point information can substantially represent the area touched and covered by the back of the hand, and the shape of the touch area is approximately a chamfered rectangle, erasing using the touch object is considered to be erasing a large area range, and therefore a rounded rectangle that matches the area of ​​the area covered by the back of the hand may be formed as the erasing geometric shape of the touch object.

[0078] Furthermore, for example, if the touch object is the underside of a fist (i.e., the position on the pinky finger side), the touch area in the touch point information may substantially represent the area touched and covered by the underside of the fist, in which case the shape of the touch area is a combination of two geometric figures, for example, a polygon and a circle, and thus the combination of a polygon and a circle may be the erasing geometric shape of the touch object, and such a combination shape may be considered as any irregular shape.

[0079] In this embodiment, the touch frame generally feeds back touch point information every collection period, and the fed back touch point information generally includes data information of touch points corresponding to each touch signal received within the collection period. In the erasing mode, during the process of erasing handwriting by moving the touch object on the display, the touch object is in contact with the display, that is, the touch object is not separated from the display, and during this process, the interactive tablet can continuously erase handwriting by moving the touch object. Therefore, under the above premise, to determine the erasing geometry of the touch object, it is sufficient to only use the touch point information of the touch point generated when the touch object first contacts the display, not the touch area in all the touch point information, that is, the erasing geometry of the touch object only needs to be determined once while the touch object is not separated from the display.

[0080] In this step, the specific implementation of erasing the handwriting to be erased with the determined geometric shape for erasure is analyzed as follows: First, for the touch points generated by the touch object in the touch frame at a specific time, an eraser pattern is formed to match the geometric shape for erasure; then, considering that the touch object moves while touching on the display, the eraser pattern formed above is also represented discretely and continuously, so that when each represented eraser pattern is connected, a continuous geometric closed figure is formed, that is, a moving outline geometric figure formed by the moving touch object. Furthermore, the formed moving outline geometric figure becomes the area to be erased in the display interface; finally, each handwriting to be erased in the area to be erased is determined, and these handwriting to be erased are erased.

[0081] Regarding the eraser pattern represented as an erasing geometric shape, FIG. 1b shows an effect diagram representing an erasing geometric shape in the handwriting erasing method according to the first embodiment of the present application, and as shown in FIG. 1b, FIG. 1b includes a first eraser pattern 140 represented as a rounded rectangle and a second eraser pattern 150 represented as a circle.

[0082] Based on the continuous closed geometric figure formed during the movement of the touch object, FIG. 1c shows an effect display diagram of the moving contour geometric figure as the erasure area in the handwriting erasure method according to the first embodiment of the present application, and as shown in FIG. 1c, FIG. 1c includes a moving contour geometric figure 160 formed when a rounded rectangle is used as the erasure geometric form.

[0083] In the specific implementation of this step, a moving contour geometric figure needs to be constructed during the movement of the touch object, and the analysis result shows that the continuous moving contour geometric figure is substantially equivalent to an area formed by expressing each touch point with a geometric shape for erasure, so in determining the moving contour geometric figure, it is sufficient to actually determine a figure that connects the geometric shapes for erasure expressed by two adjacent touch points. However, since the geometric shapes for erasure are different, the manner of forming the moving contour geometric figure based on the shapes of the adjacent geometric shapes for erasure is also different, so that the erasure operation can be normally performed, it is necessary to construct a corresponding moving contour geometric figure for each geometric shape for erasure in this step.

[0084] As an example, when the geometric form for erasure is a rounded rectangle, a contour construction method corresponding to the rounded rectangle is required. Specifically, after determining the graphic representation of two rounded rectangles, several points are respectively selected in the two rounded rectangles to expand and connect the areas, so that the closed area formed based on the two rounded rectangles can be formed as a moving contour geometric form corresponding to the rounded rectangle.

[0085] Also, for example, when the geometric form for erasure is a circle, a contour construction method corresponding to the circle is required. Specifically, after determining the graphic representation of two circles, two connection points on the two circles are respectively selected and connected, so that the closed area formed based on the two circles can be formed as a moving contour geometric form corresponding to the circle.

[0086] The handwriting erasing method according to the first embodiment of the present application may be performed by an interactive tablet, and the touch response accuracy of the touch frame on the interactive tablet is within a predetermined accuracy range. In the method, a display interface including the handwriting to be erased is first displayed on a display, a handwriting erasing command is then received to enter a handwriting erasing mode, and then when a touch object touches and moves on the surface of the display, touch point information fed back by the touch frame is obtained, and finally, the obtained touch point information and the handwriting to be erased are analyzed to erase the handwriting to be erased in the interface with an erasing geometric form matching the touch object. The interactive tablet, which is the execution subject of the method, has a high-precision touch frame arranged in the hardware structure, and the arranged high-precision touch frame is optimized in function at the software application level by the method according to the present embodiment. Compared with the interactive tablet of the related art that is not optimized at the software level, the method according to the present embodiment can ensure that the erasing response to the handwriting to be erased in the interface is more aligned with the erasing geometric form for the touch object used by the user, and can flexibly adjust the erasing area during the erasing process, thereby improving the erasing efficiency from the interactive tablet.

[0087] As a preferred embodiment of the present application's embodiment 1, in this preferred embodiment, after obtaining the touch point information fed back by the touch frame, the method may further include processing each of the touch point information, so that each of the touch point information has a unified unit format and data structure.

[0088] In addition, in this embodiment, the handwriting expression operation may be mainly performed by the intelligent processing system, specifically, the host processor, which is the upper layer of the interactive tablet, and the touch point information required for the handwriting expression is mainly fed back by the touch frame at the hardware level of the interactive tablet. In this embodiment, the touch point information fed back by the touch frame may be treated as input information required for the upper layer.

[0089] If the touch frame disposed on the interactive tablet is made by different manufacturers, there will be differences in the execution parameters of the touch frame, so that there will be differences in the display format of the touch information fed back by the touch frame, which may adversely affect the normal execution of the handwriting erasing method. In order to ensure that the data information is unified in the execution flow represented by the handwriting, the information processing operation described in this preferred embodiment is added based on the above embodiment 1.

[0090] For example, in this preferred embodiment, the production information and batch information of the touch frame are analyzed to determine the original information format of the touch point information fed back by the touch frame, and then the unit format and data structure of the touch point information are processed to ensure that the data input to the upper layer of the interactive tablet has a unified information format. In the processed touch point information, other than the unit format related to the manufacturer and batch of the touch frame, for example, the feedback touch area unit in the touch point information of the original information format is approximately the number of the shielded optical trigger sensor of the touch frame as the touch width unit and touch height unit, but in this preferred embodiment, they can be converted into a unified software abstract unit, such as pixel unit.

[0091] Based on the above optimization, in this embodiment, the processing of each of the touch point information may be embodied as follows:

[0092] According to the acquired size information of the touch frame and screen resolution information, the unit of each data information in the touch point information is converted into a unified predetermined unit format, and the touch point information is recorded in a data structure corresponding to the predetermined unit format.

[0093] In the specific implementation of this preferred embodiment, in order to obtain relatively accurate data information from inside the touch frame, the size of the touch frame currently possessed by the interactive tablet and the screen resolution information of the display are required, and these information can be obtained by communicating with the touch frame hardware or reading from the intelligent processing system, respectively.

[0094] Regarding the specific processing items of the touch point information, in this preferred embodiment, the data information such as the touch point coordinates, the height and width of the touch point, or the geometric figure vertices formed when touching, which are marked by the touch frame in the original information format, may be unified and converted into relatively abstract unit values ​​at the software level, such as coordinate points, width or height values ​​expressed by pixels.

[0095] Similarly, another advantage of the high-precision touch frame is that it can also capture the rotation operation during touch of the touch object to determine the rotation angle of the touch rotation, and in such a case, according to the processing method of the present preferred embodiment, the initially obtained rotation angle may be processed in a unified radian unit.

[0096] In the above-mentioned preferred embodiment of the first embodiment of the present application, specifically, a processing operation is added to the touch point information fed back by the touch frame, and the processing operation enables the touch point information to be input in a unified manner, so as to avoid the touch point information being unable to be exchanged in the subsequent execution process due to the difference in the attribute parameter information of the touch frame itself, and effectively improve the execution efficiency of handwriting erasure.

[0097] Example 2 FIG2 shows a flow diagram of a handwriting erasing method according to the second embodiment of the present application, and this embodiment is further subdivided based on the above embodiment. In this embodiment, the step of obtaining touch point information fed back by the touch frame is specifically subdivided as follows: the hardware circuit of the touch frame identifies each touch signal generated by the touch object moving on the display, and the touch frame obtains touch point information fed back for each touch signal according to a Human Interface Device (HID) standard protocol, where one touch point information corresponds to one touch point, and the touch point information includes touch point coordinates, touch point height and width, and touch rotation angle.

[0098] In addition, in this embodiment, the step of analyzing the acquired touch point information and the handwriting to be erased and erasing the handwriting to be erased in the interface with an erasure geometric form matching the touch object may be specifically subdivided as follows: determining an erasure geometric form matching the moving touch object based on the acquired touch point information, determining a moving outline geometric form formed by a pair of moving adjacent touch points in the erasure geometric form, analyzing each handwriting point included in the handwriting to be erased, performing a hit test between each handwriting point and the moving outline geometric form, determining a target handwriting to be erased that falls within the moving outline geometric form, and erasing the target handwriting to be erased in the display interface.

[0099] As shown in FIG. 2, the handwriting erasing method according to the second embodiment of the present application specifically includes the following operations:

[0100] S201: A display interface including the handwriting to be erased is displayed on a display.

[0101] As an example, a user may trigger entry into a display interface having element information such as handwriting, or a display interface having element information such as handwriting to be erased may be triggered by an associated scene (e.g., a courseware display scene).

[0102] S202: Receive a handwriting erasing command triggered by a user and enter a handwriting erasing mode.

[0103] As an example, a user may receive a handwriting erasing command by triggering an erase button in the display interface, thereby entering a handwriting erasing mode and turning on the authority to erase handwriting in the display interface.

[0104] S203: When a touch object touches and moves on a surface of the display, a hardware circuit of the touch frame identifies each touch signal generated by the touch object moving on the display.

[0105] In this embodiment, the angle of the touch frame is used to analyze the operation of the touch object touching the display and the operation of the touch object moving on the display. Specifically, the optical touch sensor can be regarded as the core component that constitutes the touch frame. After the interactive tablet is started up and operated, and the optical touch sensor is controlled to be powered on, the optical touch sensor (e.g., an infrared transmitter on one side and an infrared receiver on the other side) on the edge of the display can detect whether a touch object exists on the surface of the display according to whether the beam grid formed by the infrared signals densely distributed in each direction is blocked.

[0106] If there is a touch object, when the touch object blocks the normally emitted infrared signal, a touch signal corresponding to the corresponding position will be generated, and then the hardware circuit provided in the touch frame can identify the touch signal, for example by identifying the high and low levels of the touch signal, thereby determining the coordinate information of the position where the touch signal is located, which is represented by hardware level data, the width information, height information corresponding to when the touch object blocks the beam grid, the touch area information and rotation information of the touch object, etc.

[0107] It is envisioned that as the touch object moves across the display, a set of touch signals is generated, and the hardware circuitry of the touch frame can effectively identify touch information associated with each touch signal in the set, and the pressure applied by the touch object to the touch frame hardware circuitry can determine pressure sensitivity information at each touch point of the touch object.

[0108] S204: Obtain touch point information that the touch frame feeds back for each touch signal according to the HID standard protocol of human-computer interaction.

[0109] Following the above description, it can be understood that considering that the touch frame is a hardware structure of an interactive tablet, the touch point information identified for each touch point by the hardware circuit of the touch frame is difficult to directly input to the upper layer software processing module, so according to the dedicated human-computer interaction HID standard protocol used in this step, the touch point information identified at the hardware level can be converted to obtain readable touch point information at the software level.

[0110] In the handwriting erasing operation realized according to the present embodiment, each touch point information fed back by the touch frame specifically represents one touch point triggered by a touch object, and the desired touch point information at least includes the touch point coordinates, the touch point height and width, and the touch rotation angle.

[0111] Specifically, the touch point coordinates are basic information of the touch, the height and width of the touch point represent the size of the optical sensor of the touch frame covered when the user manipulates and controls the touch object to move, the touch area represents the coverage area of ​​the touch signal generated for the touch frame when the user manipulates and controls the touch object to move, and the erasing geometric form matching the touch object can be determined by the above information. Similarly, the touch rotation angle represents rotation information when the touch object rotates during movement, and the rotation information can be the basic information required to determine the movement outline geometric form corresponding to the erasing geometric form.

[0112] According to the above steps of this embodiment, the touch point information fed back by the touch frame during the movement of the touch object can be obtained in real time, so that in this embodiment, the handwriting to be erased can be erased on the display interface by the following steps S205 to S207.

[0113] S205: Based on the acquired touch point information, a geometric form for erasure matching the moving touch object is determined, and a moving outline geometric figure formed by the moving adjacent touch point pair is determined by the geometric form for erasure.

[0114] In this embodiment, this step specifically determines two important pieces of information required for the erasure operation: one is the erasure geometric form of touch object matching, and the other is the moving contour geometric form that two adjacent touch points can form with the determined erasure geometric form.

[0115] It is apparent from the description in the above embodiment that when determining the erasure geometry, only the touch point information of the touch point generated when the touch object first contacts the display in the current movement is sufficient, and the touch area in the touch point information can be used to determine a geometry matching the touch area, so that the matching geometry can be the erasure geometry that the current erasure can represent.

[0116] Similarly, it is apparent from the description of the above embodiments that the erasing geometric shape includes at least a rounded rectangle, a circle, and any irregular shape, and based on the touch point information of each touch point fed back, an eraser pattern that matches the erasing geometric shape may be represented for each touch point, and the eraser patterns of two adjacent touch points may be connected in some manner, and the connected closed area may be a moving contour geometric shape corresponding to the two adjacent touch points.

[0117] As an example, if the eraser patterns of two adjacent touch points are rounded rectangles, each rounded rectangle corresponds to a rectangle with multiple apex angles modified into chamfers, i.e., a rounded rectangle may be considered to include at least the side length of a rectangle and a portion of a circular arc.

[0118] For two rounded rectangles represented in the above form, first obtain the important points constituting each rounded rectangle, then select and connect some connection points from the important points of the two rounded rectangles, obtain the areas of the two rounded rectangles themselves and the connected closed area, and combine the areas of the two rounded rectangles with the closed area to form a moving contour geometric figure corresponding to two adjacent touch points when the erasing geometric form is a rounded rectangle.

[0119] In addition, when the erasing geometric form is a circle or any irregular shape, there is also a method for determining the corresponding moving contour geometric form. In short, no matter what shape the erasing geometric form is, first determine the graphic display information of the figure itself corresponding to the erasing geometric form, then select the connection points required for connection based on the obtained graphic display information, and form a combination closed area based on the connection points and the figure itself corresponding to the erasing geometric form, which is the corresponding moving contour geometric form.

[0120] In addition, in this embodiment, a rounded rectangle and a circle are considered as two special cases of an arbitrary irregular shape, and when determining the moving contour geometric figure for these two special cases, other possible determination methods may be used instead of the determination method corresponding to an arbitrary irregular shape. Therefore, in this embodiment, a rounded rectangle and a circle may be treated as two independent shapes other than an arbitrary geometric combination image, and respective corresponding determination methods are provided for determining the moving contour geometric figure.

[0121] S206: Analyze each handwriting point included in the erasure target handwriting, and perform a hit test between each of the handwriting points and the moving contour geometric figure to determine a target erasure target handwriting that falls within the moving contour geometric figure.

[0122] The above S205 corresponds to determining an erasure target area (moving outline geometric figure) that has the erasure authority and is formed by the movement of the touch object during the erasure operation. This step mainly determines how to determine which handwritings in the display interface fall within the moving outline geometric figure. If there are handwritings that fall within the moving outline geometric figure, these handwritings are considered to be handwritings that can be currently erased, and in this embodiment, they are marked as target handwritings to be erased.

[0123] In this embodiment, the handwritings to be erased in the display interface can be understood as the contents written by a user in some manner on the interface in writing or editing mode. These handwritings to be erased may be represented by corresponding handwriting information, and the important information in the handwriting information is the handwriting point coordinates of the handwriting points constituting these handwritings to be erased, and in this step, the handwriting point coordinates representing each handwriting point of the handwriting to be erased can be directly obtained.

[0124] In this step, the operation of determining which handwriting to be erased falls within the moving contour geometric figure may be changed to an operation of determining whether each handwriting point representing the handwriting to be erased falls within the moving contour geometric figure. The determination of whether a handwriting point falls within the moving contour geometric figure may be performed by performing a hit test between the handwriting point and the moving contour geometric figure.

[0125] The hit test between the handwritten point and the moving contour geometric figure corresponds to determining whether the handwritten point is within the closed area of ​​the moving contour geometric figure. The determination of whether the handwritten point is within the closed area represented by the moving contour geometric figure corresponds to determining the data information representing the closed area. It can be understood that the moving contour geometric figure may have an irregular geometric form, which is difficult to directly represent with data information. Therefore, in this embodiment, the moving contour geometric figure is decomposed, for example, the moving contour geometric figure is decomposed into a combination of geometric figures that are easy to represent, such as a circle or a polygon, and then, using the hit test method to determine whether the handwritten point is within the closed area corresponding to each geometric figure obtained by decomposition.

[0126] When the shape of a geometric figure is different, the method of hit testing the handwritten points may also be different. For example, in the case of a circular area, the hit test may be realized by determining whether the distance between the handwritten point and the center of the circle is less than the radius. For example, in the case of a convex polygon area, the hit test may be realized by determining whether the sum of the angles of the handwritten point and the corresponding vertex angles is 360 degrees when the handwritten point falling within the area forms a triangle with each vertex of the convex polygon. Furthermore, for example, in the case of a rectangular area, a hit test using a vector method may be used.

[0127] In this embodiment, the moving contour geometric figure can be decomposed and a hit test can be performed between the handwriting point and each sub-figure region, and if it is determined that the handwriting point exists within a certain region, the handwriting represented by the handwriting point can be determined as the target handwriting to be erased.

[0128] S207: The target erasure target handwriting is erased on the display interface.

[0129] In this embodiment, after the target handwriting to be erased is determined by the above steps, the target handwriting to be erased can be erased by this step.

[0130] The movement of an eraser, which is represented by a touch object in a geometric shape for erasing, on the display interface is visualized and represented, and handwriting edited or written by a user on the interface is hidden at a position where the eraser has passed.

[0131] FIG. 2a shows an effect display diagram of the handwriting erasing method according to Example 2 of the present application. As shown in FIG. 2a, a display interface 21 displays handwriting 22 to be erased, and a touch object controlled by a user is displayed as an erasing geometric form of a circle 23 on the display interface 21. In the area where the circle moves, the previously displayed handwriting becomes hidden and is displayed as a blank area.

[0132] In the handwriting erasing method according to the second embodiment of the present application, a feedback form of touch point information is embodied, and an erasing method of handwriting erasing is also embodied. The implementation of the method is premised on the touch frame having a touch response accuracy within a certain accuracy range on the interactive tablet. Compared with the interactive tablet with a conventional touch frame, in this embodiment, a high-precision touch frame is arranged on the interactive tablet at the hardware level, and the high-precision touch frame can feed back more accurate touch point information containing more effective information to the application layer. Thus, when combined with the method according to the present embodiment, it can ensure that the erasing response to the handwriting to be erased in the interface is more aligned with the erasing geometric form for the touch object used by the user, and the erasing area can be flexibly adjusted during the erasing process, thereby improving the erasing efficiency from the interactive tablet.

[0133] As for the specific determination of the erasing geometric form and the moving outline geometric form, as the first preferred embodiment of the present embodiment 2, Fig. 2b shows an implementation flow chart of determining the erasing form and the outline geometric form in the handwriting erasing method according to the embodiment 2 of the present application. As shown in Fig. 2b, in the first preferred embodiment, the above step S205 of determining the erasing geometric form matching the moving touch object according to the acquired touch point information, and determining the moving outline geometric form formed by the moving adjacent touch point pair in the erasing geometric form is further divided into the following steps:

[0134] S2051: Extract important touch point information, which is touch point information of a touch point generated when the touch object first comes into contact with the display during movement, and obtain an important touch area from the important touch point information.

[0135] As an example, the important touch point information can be specifically understood as information of important touch points for determining an erasure geometric form among the touch point information fed back by a touch frame, and the important touch point information also includes a touch area generated when a touch object contacts a display as an important touch area.

[0136] In this embodiment, the touch object does not leave the display throughout the process of the user controlling the touch object to contact the display and move on the display, and therefore the shape of the touch object used by the user does not change throughout the process, i.e., the erasing geometric shape matching the touch object does not change throughout the movement process.

[0137] In order to simplify the operation of determining the geometric form for erasure, in this embodiment, it is not necessary to determine the geometric form for erasure of the touch object for each piece of touch point information related to each touch point, and the geometric form for erasure of the touch object can be determined by simply selecting this one piece of touch point information. In this embodiment, the determination operation is performed using the touch point information of the touch point generated when the touch object first contacts the display, and the touch point information is considered to be important touch point information.

[0138] It can be understood that in this embodiment, the important touch point information can be the touch point information related to the first contact, but is not limited thereto.

[0139] S2052: An area threshold range and an area shape to which the significant touch area belongs are determined, a target shape that matches the area shape is searched for among the geometric shapes corresponding to the area threshold range to which the significant touch area belongs, and the target shape is determined as a geometric shape for erasure that matches the touch object.

[0140] In this embodiment, the area value of the significant touch area may be within a preset area threshold range, and in this embodiment, for each area threshold range, multiple geometric shapes matching the range are also preset, for example, one area threshold range may match multiple geometric shapes, for example, the matching shapes include a circle, a combination of a circle and a rectangle, a combination of a circle and an ellipse, etc.

[0141] Once the area shape is known, from each geometric figure corresponding to the area threshold range, a target shape that matches the area shape is determined, for example, if the area shape is a rectangle with radians, the critical touch area may be matched to a rounded rectangle, and finally, the rounded rectangle may be the geometric shape for erasing the touch object.

[0142] S2053: For each adjacent touch point pair of the touch object being moved, analyze touch point information for the adjacent touch point pair to determine significant geometric information of each touch point in the adjacent touch point pair relative to the erasure geometry.

[0143] In this embodiment, the touch frame discretely feeds back touch point information in real time during the movement of the touch object, and each touch point information corresponds to one touch point, and two adjacent touch points may be considered as one touch point pair. Considering that the touch object plays the role of handwriting erasure in this embodiment, each touch point generated during the movement of the touch object represents a possible erasure area in the above-determined erasure geometric form, and the important geometric information of each touch point for the erasure geometric form can be specifically understood as mathematical expression information representing the erasure area represented by the touch point, and mathematical expression information of the related closed area connecting the erasure areas represented by the two adjacent touch points. Here, the determined important geometric information may include at least vertex information or circle center information and radius information of the erasure area represented by the erasure geometric form.

[0144] In this embodiment, the important geometric information of each touch point for the erasing geometric form can be obtained by combining the relevant touch point information with the above determined erasing geometric form. In general, when the touch point coordinates, the height and width of the touch point, and the touch rotation angle of the touch point are known, the data information required for various graphic representations can be determined by performing mathematical operations.

[0145] First, when the geometric shape for erasing is a rounded rectangle, the rounded rectangle includes one rectangle and chamfers each of the vertices of the rectangle as a circle center, and the implementation of the first preferred embodiment of the above step S2053 is specifically described as follows:

[0146] a1: The rounded rectangle is the first geometric figure to be constructed by each touch point in the adjacent touch point pair.

[0147] In this embodiment, preferably, the erasure area represented on the display by each touch point erasing handwriting is the geometric figure to be constructed corresponding to the touch point, and in this embodiment, when the erasure geometric form is a rounded rectangle, the corresponding geometric figure to be constructed is the first geometric figure to be constructed.

[0148] b1: For each touch point in the adjacent touch point pair, combine the touch point coordinates, touch width, touch height and touch rotation angle in the relevant touch point information with a predetermined chamfer radius to determine the center point coordinate of a rectangle in the first geometric figure to be constructed, the circle center coordinates of each chamfer and the coordinates of each important junction, and the coordinates of the connection points of the two figures.

[0149] As an example, in this embodiment, from the perspective of mathematical calculation, the determination of important geometric information corresponding to a touch point when the geometric form for erasure is a rectangle with rounded corners is specifically described, where Figures 2c to 2h show schematic explanatory diagrams for determining important geometric information when the geometric form for erasure is a rectangle with rounded corners in the handwriting erasing method according to Example 2 of the present application.

[0150] Considering that the interactive tablet according to the present embodiment also has a response to the rotation operation performed during the movement of the touch object, in this embodiment, the rounded rectangle is displayed as one rotated rectangle and four chamfered corners, where the rotated rectangle is considered as a rectangle with an angle offset with respect to the horizontal and vertical directions of the display interface. Also, for ease of calculation, in this embodiment, the top left corner of the display interface is preferably the zero-zero coordinate, the horizontal coordinate increases from left to right, and the vertical coordinate increases from top to bottom, as shown in FIG. 2c.

[0151] FIG. 2c includes an effect display of a first object shape to be constructed corresponding to one touch point, namely, a rounded rectangle, where points A, B, C and D constitute a rotated rectangle of the rounded rectangle, and points A, B, C and D are respectively the centers of the four chamfers included in the rounded rectangle, and a combined shape formed by connecting two adjacent chamfers at a tangent point is regarded as the object shape to be constructed, and in FIG. 2c, the radius of the chamfer is a configurable parameter, and the value of the parameter may be predetermined, in addition, the length of side length AC plus the diameter of the chamfer corresponds to the height of the rounded rectangle, and the length of side length CD converted to the diameter of the chamfer corresponds to the width of the rounded rectangle.

[0152] It can be understood that for each touch point in the adjacent touch point pair, there is a corresponding rounded rectangle to be constructed, and considering that the geometric form of the rounded rectangle corresponding to each touch point is the same, the implementation manner of determining the corresponding geometric information of each rounded rectangle is the same. Meanwhile, expressing the required geometric information for the rounded rectangle corresponds to determining each vertex coordinate and each contact coordinate in the above FIG. 2c.

[0153] Specifically, the problem of calculating geometric information related to a rounded rectangle can be transformed into the following mathematical problem:

[0154] First, the coordinates of point O1 are determined according to the touch point coordinates, and the height and width of the rounded rectangle are determined according to the height and width of the touch point, and the touch rotation angle and chamfer radius Radius can be obtained, where the touch rotation angle is considered to be the angle of rotation relative to the horizontal and vertical axes of the above-mentioned predetermined coordinate system. That is, when the data problem is transformed, when O1, the rotation angle θ, the chamfer radius Radius, and the width and height of the rounded rectangle are known, it corresponds to how to obtain the vertex coordinates of the rotated rectangle in the rounded rectangle.

[0155] Considering that the rounded rectangle has a rotation angle with respect to the above coordinate system, for ease of explanation, the vertex coordinates of the rounded rectangle may be determined first assuming that the rotation angle is 0.

[0156] Specifically, this may be done with a rounded rectangle as shown in FIG. 2d, where O1 is known and the coordinates of point A relative to O1 are calculated using the following formula:

[0157] O1.X = foo + Width / 2 AX = foo + Radius AX-O1.X = X coordinate of point A relative to O1 = foo + Radius - (foo + Width / 2) = Radius - Width / 2 On the other hand, after the coordinates of point A are determined as described above, calculations are performed for the case of a rounded rectangle shown in FIG. 2e based on the results of the above calculations.

[0158] Specifically, the rounded rectangle in Figure 2d is expressed as the figure shown in Figure 2e after rotation by θ. In this case, the coordinates of point A and the rotation angle θ are known, which corresponds to finding the coordinates of points A, B, C, and D after rotation by θ with respect to O1.

[0159] According to the new point formula (mainly shown in Fig. 2e) obtained by rotating a point at a specific point, the coordinate of point A rotated relative to O1 can be calculated. In order to make point A relative to the zero point, point A is transformed from the coordinate relative to O1 to the coordinate relative to the zero point, that is, the specific implementation is to convert the coordinate of O1, and finally, the coordinate of point A after rotation is obtained.

[0160] Similarly, the B, C, and D points in the rounded rectangle to be constructed may be calculated in the same manner as above. The coordinates of each vertex of the rotated rectangle in the rounded rectangle, that is, the coordinates of the center of each chamfer, are obtained as described above.

[0161] For the geometric information of the rounded rectangle, it is also necessary to obtain the coordinates of the junctions used when connecting two adjacent chamfers, and these junctions are A1, A2, B1 and B2, etc., shown in Figure 2c.

[0162] Specifically, point A1 corresponds to the ordinate of point A before rotation minus the radius of the chamfer, and point A2 corresponds to the abscissa of point A before rotation minus the radius of the chamfer. Therefore, the coordinates of two points A1 and A2 may be calculated by the equation of a new point obtained by rotating a certain point around a specific point, and the coordinates of B1, B2, etc. may be calculated in the same manner.

[0163] According to the above method, the coordinates of each point required for each touch point in the adjacent touch point pair to represent the rounded rectangle to be constructed can be calculated. Next, we will explain how to calculate the geometric information of each connected area connecting two rounded rectangles.

[0164] As shown in FIG. 2f, assuming that the rectangle has no chamfer, the working locus of the two rectangles is connected, where the following scheme may be used to connect the two rectangles.

[0165] The vertices of the two rectangles are combined with connecting lines to obtain two lines that do not intersect with the rectangles themselves, and a line connecting the center points of the two rectangles. The line connecting the center points of the two rectangles is used to verify whether the two lines that do not intersect with the obtained rectangles themselves are appropriate, and if the two lines are appropriate, they are both parallel to the line connecting the center points of the two rectangles.

[0166] When connected in the above manner, the connection state diagram shown in Figure 2g is obtained.

[0167] After completing the calculation of the connecting lines between the two rectangles without chamfers above, we will now explain how to calculate the coordinates of each key point involved when connecting two rounded rectangles with chamfers added.

[0168] First, the connection effect diagram of two rounded rectangles with added chamfers is shown in Figure 2h.

[0169] As shown in FIG. 2h, the B1C2 line segment corresponding to the line segment BC is substantially equivalent to horizontally shifting the BC line segment by a predetermined distance, where the shift distance is the radius of the chamfer and the shift direction is outward.

[0170] If the coordinates of points B and C are known, the BC line segment can be calculated using the mathematical methods in the related art, and if the line segment is moved horizontally in a certain direction by a known distance, it can also be calculated using the mathematical calculation methods in the related art. The coordinates of each vertex shown in Figure 2h can be calculated in the same way. The calculated coordinates of each vertex in Figure 2h correspond to the connection point coordinates of two figures connecting rounded rectangles for adjacent touch point pairs, and Figure 2h also shows the effect of the moving contour geometric figure formed by connecting two rounded rectangles.

[0171] c1: The coordinates of the center point of the rectangle, the coordinates of the circle centers of each chamfer, the coordinates of each important junction point, and the coordinates of the connection point between the two figures are set as important geometric information of the touch point for the first geometric figure to be constructed.

[0172] Here, each chamfer of the first geometric figure to be constructed includes two important junctions, and each important junction is a junction that corresponds to a chamfer when the chamfer and an adjacent chamfer are connected by a tangent line.

[0173] The above mainly describes the specific implementation of determining important geometric information when the erasing geometric form is a rounded rectangle in step S2053.

[0174] Next, when the erasing geometric shape is a circle, the implementation of the second preferred embodiment of the above step S2053 is specifically described as follows.

[0175] a2: The circle is the second geometric shape to be constructed by each touch point in the adjacent touch point pair.

[0176] For ease of distinction, in the preferred embodiment, the erasure region where the erasure geometry to be constructed is a circle is the second to-be-constructed geometry.

[0177] b2: Determine the circle center coordinates and each important intersection coordinate of the corresponding second geometric figure to be constructed according to the touch point coordinates, touch width, and touch height in the touch point information for each touch point in the adjacent touch point pair.

[0178] In this step, when determining geometric information about the circle to be constructed, the touch point information of each touch point in the adjacent touch point pair is also required. Here, in this step, when determining important geometric information, a model of the two connected circles is first constructed, and then each necessary important geometric information is calculated based on some geometric characteristics of the circle itself.

[0179] Preferably, in this embodiment, the above-mentioned step b1 of determining the circular center coordinates and each important intersection coordinate of the corresponding second geometric figure to be constructed based on the touch point coordinates, touch width, and touch height in the touch point information for each touch point in the adjacent touch point pair may be specifically as follows:

[0180] Based on the touch point coordinates, touch width and touch height in the touch point information for each touch point in the adjacent touch point pair, the circle center coordinates of the corresponding second circle to be constructed are determined, the circle center coordinates of the corresponding two circles are connected to obtain a circle center connection line, and straight lines perpendicular to the circle center connection line are respectively drawn based on the circle center coordinates of each circle, and important intersection coordinates are determined by intersecting each straight line with the corresponding second circle to be constructed.

[0181] As an example, this embodiment also explains the determination of important geometric information regarding the above-mentioned circle by converting it into a mathematical problem, where Figures 2i to 2m show schematic explanatory diagrams regarding the determination of important geometric information when the geometric form for erasure in the handwriting erasing method according to embodiment 2 of the present application is a circle.

[0182] First, as shown in Fig. 2i, the connection of two circles is included, so obtaining the important geometric information of the two circles can be converted into obtaining each vertex of the line segment that is parallel to the touch movement direction and intersects with the circle when the two circles are connected according to the touch movement direction.

[0183] In the above explanation, the abstracted mathematical problem may be as follows: It is known that the centers of two circles are two points P1 and P2, the radii are lengths r1 and r2, the line segment AB is perpendicular to the line segment P1P2, and the line segment CD is perpendicular to the line segment P1P2, the intersections of the line segment AB with the circle are two points A and B, and the intersections of the line segment CD with the circle are two points C and D. Find the coordinates of the four points A, B, C, and D.

[0184] In addition, after the touch point information of the adjacent touch point pair is known, the coordinates of the circle centers P1 and P2 and the radii r1 and r2 can be calculated in a normal manner, and the touch movement direction can also be determined in real time according to the two touch point coordinates. The coordinate calculation of the above four points is specifically described as follows:

[0185] Since the two circles themselves can be considered independent, first perform calculations for one of the circles, and then create an auxiliary line perpendicular to the abscissa as shown in Figure 2j. It can be seen that the straight line P1P2 in the direction of the motion locus of the circle passing through the center of the circle and the auxiliary line form an angle of θ. From the triangle calculation formula, it is clear that since the line segment AB is perpendicular to the line P1P2, the angle P2P1B is a right angle, and therefore the angle of angle B is also an angle of θ.

[0186] The above problem corresponds to how to calculate the angle θ. As shown in Figure 2j, by adopting the calculation shown in Figure 2j, when two points P1 and P2 are known, the angle θ can be calculated from these two points. After calculating the angle θ, the coordinate of point B can be calculated, specifically, as shown in Figure 2k. Similarly, the coordinate of point A can be calculated by adopting the calculation method shown in Figure 2l. Since the calculation methods for the two circles are different, the coordinates of points C and D can also be calculated by the method in Figure 2m.

[0187] In this step, the calculation method is converted into a mathematical problem, and the circle center coordinates corresponding to each touch point are determined. In this embodiment, this is the circle center coordinate. The coordinates of each important intersection formed by connecting two circles can also be calculated.

[0188] c2: The circle center coordinates and the important intersection coordinates corresponding to each touch point are regarded as important geometric information corresponding to the second geometric figure to be constructed.

[0189] It is envisaged that each of the coordinate point information determined above may be important geometric information for the case where the erasure geometry is circular.

[0190] The above describes a specific implementation of determining important geometric information in step S2053 when the geometric form for erasure is a rounded rectangle. Furthermore, when the erasing geometric form is an arbitrary irregular shape, the implementation of the execution of the third preferred embodiment of the above step S2053 is specifically described as follows.

[0191] a3: The arbitrary irregular shape is set as a third geometric figure to be constructed by each touch point in the adjacent touch point pair, and combination graphic information included in the third geometric figure to be constructed is determined.

[0192] In this embodiment, the arbitrary irregular shape can be understood as a combined aggregate figure consisting of broken lines and / or arc lines, and in this embodiment, preferably, the arbitrary irregular shape is a graphical representation of the erased areas associated with each touch point in the adjacent touch point pair, which is the third geometric figure to be constructed in this embodiment.

[0193] Depending on the representation format of the irregular shape, it is possible to determine what specific graphical information is included in the irregular shape. For example, the irregular shape may include broken line figures, arc figures, etc., and all of this determined information may be considered as combined graphical information.

[0194] As an example, FIG. 2n shows an effect display diagram when the erasing geometric form in the handwriting erasing method according to Example 2 of the present application is an arbitrary irregular shape, and as shown in FIG. 2n, the arbitrary irregular shape 24 may be a combination of a polygon and a circle.

[0195] b3: For each touch point in the adjacent touch point pair, combine the relevant touch point information with the combined graphic information to determine significant trajectory points of the third geometric figure to be constructed that exist with respect to the touch point and graphic display information of the third geometric figure to be constructed.

[0196] In this embodiment, specifically, the important geometric information corresponding to the irregular shape may be determined as follows. Preferably, in this embodiment, the step of combining the related touch point information with the combined graphic information to determine the important trajectory points existing with respect to the touch points in the third geometric figure to be constructed and the graphic display information of the third geometric figure to be constructed may be specifically as follows:

[0197] b31: Analyzing the combined graphic information.

[0198] In this embodiment, by analyzing the combined graphic information, it is possible to determine what shapes are specifically included in the arbitrary irregular shape, which may include, for example, a broken line / polygon, an arc shape, or a circle, or both a broken line / polygon and a circle.

[0199] b32: When it is determined that the third geometric figure to be constructed includes only a broken line / polygon, an important trajectory point that exists with respect to the touch point among the broken line / polygon is determined based on touch point information related thereto, and a first figure display information representing the broken line / polygon is obtained.

[0200] In this step b32, several cases are described, such as when only broken lines / polygons are included, the implementation of determining the graphic display information (first graphic display information) related to the broken lines / polygons and the important trajectory points that exist when each broken line / polygon corresponding to two touch points is connected.

[0201] Based on the optimization, the step of determining important trajectory points existing for the touch points of the broken line / polygon based on the relevant touch point information and acquiring first graphic display information representing the broken line / polygon includes the steps of: determining a broken line center point coordinate and a vertex coordinate of each broken line of the broken line / polygon, which is the first graphic display information, based on the touch point coordinates, touch height, and touch width in the relevant touch point information; and selecting an important trajectory point that satisfies a selection condition for trajectory points from among the broken line vertex coordinates based on the broken line center point coordinates and the relevant touch point information.

[0202] Specifically, in this embodiment, the above problem may be converted into a mathematical problem for calculation. Here, when the irregular shape is only a broken line or polygon, first, a central axis line in the touch movement direction that can be determined by the touch point coordinates of two touch points is obtained, then the distances of all vertices of the broken line or polygon from the central axis line are obtained, and then the vertices farthest from the central axis line are considered to be important locus points that need to be calculated for the broken line or polygon.

[0203] As an example, Figures 2o to 2q show schematic diagrams for determining important geometric information when the geometric form for erasure in the handwriting erasure method according to Example 2 of the present application is of an arbitrary irregular shape and includes only polygonal geometric figures.

[0204] As shown in Fig. 2o, the above calculation process may be abstracted as the following mathematical problem: If the polygonal lines A and B and the touch movement direction AB are known, and the polygonal line A changes to the polygonal line B along the movement direction, find the movement trajectory from the polygonal line A to the polygonal line B. Here, the essential problem of the above calculation is to find two vertices of each of the two polygonal lines in the AB direction and connect the corresponding vertices. Each vertex for connection corresponds to an important trajectory point.

[0205] Since each geometric figure is independent, the calculation can be performed separately. In addition, since the touch movement direction is a vector, the vector does not have coordinates. For any polyline / polygon, find the vertices available for any touch movement direction. Since the characteristics of the vertices need to be known and the vector does not have coordinates, the vector of the touch movement direction may be moved horizontally arbitrarily in the calculation implementation. Also, most preferably, the vector is moved horizontally to the center point of the polyline / polygon.

[0206] In this case, the above problem can also be transformed into a problem of finding the two vertices of the broken line-polygon that are the furthest from the line corresponding to the vector, and these two vertices are located on both sides of the line. In the case of the broken line-polygon shown in Figure 2p, it is clear that the distances of points b and d from the line segment AB are the furthest points on both sides of the line segment. Therefore, points b and d are considered to be two important locus points in the broken line-polygon shown in Figure 2p.

[0207] As can be understood, by using the same method as above to find the corresponding important trajectory points of the broken line / polygon corresponding to the multiple touch points in the adjacent touch point pair, and connecting each corresponding vertex, a closed area consisting of two broken line / polygons is obtained, and a schematic diagram of the formed closed area is shown in Figure 2q, that is, Figure 2q also includes an effect display of the moving contour geometric figure formed by connecting two broken line / polygons.

[0208] b33: When it is determined that the third geometric figure to be constructed includes a broken line / polygon and a target circle, important trajectory points are determined in the broken line / polygon and important circle based on touch point information related thereto, and second figure display information representing the broken line / polygon and important circle is obtained.

[0209] This step b33 mainly describes another case in which, when a circle (in this embodiment, a target circle) is included in addition to a broken line / polygon, the implementation of determining the graphic display information (second graphic display information) related to this irregular shape (combination of a broken line / polygon and a circle) and the important trajectory points that exist when connecting each irregular shape corresponding to two touch points is performed.

[0210] Based on the above embodiment, the above step of determining important trajectory points on the broken line / polygon and important circle based on the relevant touch point information and obtaining second graphic display information representing the broken line / polygon and important circle specifically includes determining the broken line center point coordinates and each broken line vertex coordinates of the broken line / polygon, and the circle center point coordinates and circle radius of the important circle based on the touch point coordinates, touch height and touch width in the relevant touch point information, which are taken as second graphic display information, and selecting important trajectory points that satisfy trajectory point selection conditions on the circumference of the important circle and from each of the broken line vertex coordinates based on the broken line center point coordinates, circle center point coordinates, circle radius and the relevant touch point information.

[0211] As an example, in this embodiment, the determination of important geometric information regarding the above circle is similarly explained by converting it into a mathematical problem, where Figures 2r and 2s show schematic explanatory diagrams regarding the determination of important geometric information when the erasure geometric form in the handwriting erasure method according to embodiment 2 of the present application is an arbitrary irregular shape.

[0212] First, the effect display of the irregular shape may include a circle and a broken line / polygon, as shown in Figure 2r. Also, the specific implementation of this part may be abstracted as a mathematical problem, that is, the calculation method is to judge whether a certain tangent of a circle matches the important locus point. The judgment method is to first judge the distance between the circle center and the line segment AB in Figure 2r, and then the distance plus the radius of the circle is the farthest distance from the line segment of the circle. If this distance meets the maximum distance, the tangent on the circle may be met as the important locus point.

[0213] The determination of the important trajectory point described above will be explained as follows: Specifically, as shown in Fig. 2s, if there is an important trajectory point on the current circle, the important trajectory point of the circle can be obtained by first obtaining the intersection point between the auxiliary line CD passing through the circle center and perpendicular to the line AB and the circle, and the point b far from AB is the important trajectory point.

[0214] c3: The graphic display information of each of the combined graphics and each of the important trajectory points are regarded as important geometric information of the touch points for the third geometric graphic to be constructed.

[0215] It is envisaged that the three sub-steps included in b3 above may be used to determine important trajectory points based on the combined graphic information, and the determined important trajectory points and graphic display information of each combined graphic may be taken as important geometric information of the third geometric graphic to be constructed.

[0216] In this embodiment, the graphic display information of the above-mentioned combined figure may generally be determined by combining given touch point information with several parameter information, and the graphic display information mainly includes the center point and vertex coordinates, or the circle center coordinates and circle radius information of the combined figure.

[0217] S2054: Based on each of the significant geometric information, a moving contour geometric figure formed by the adjacent touch point pairs is determined for the erasure geometric form.

[0218] In this embodiment, the important geometric information determined above is equivalent to including the graphic display information of the geometric figure to be constructed corresponding to each of the two touch points in the adjacent touch point pair, and the geometric information of the closed area formed by connecting the two corresponding graphic display information. Therefore, the desired moving contour geometric figure can be constructed according to the important geometric information.

[0219] Since the moving contour geometry is also related to the erasure geometry, the present embodiment also describes an implementation of determining the moving contour geometry corresponding to each of the different erasure geometries.

[0220] First, as can be understood, based on the fact that the geometric shape for erasure is a rounded rectangle and the important geometric information is determined by the execution step of the first preferred embodiment in S2053 above, the determination of the moving contour geometric figure in S2054 may be specifically performed by the first preferred embodiment described below.

[0221] a4: Based on the important geometric information of the adjacent touch point pair, extract the chamfer circle center coordinates of the corresponding rounded rectangle, and select the important circle center points required to construct the circumscribing contour.

[0222] b4: Obtain important circular areas determined based on each of the important circle center points.

[0223] c4: Based on the important geometric information of the adjacent touch point pairs, extract the rectangle vertex coordinates and center point coordinates of the corresponding rounded rectangle, and select the important connection point pairs needed to construct the circumscribing contour.

[0224] d4: Obtain a circumscribed rectangular region determined based on each of the important connection point pairs, and a vertex-connected closed region determined based on each of the rectangular vertex coordinates.

[0225] e4: Each of the important circular regions, each of the circumscribing rectangular regions and the vertex-connected closed regions are combined to form a first moving contour figure constituted by the adjacent touch point pairs with respect to the rounded rectangle.

[0226] From the above exemplary description of determining important geometric information when the erasing geometric form is a rounded rectangle, it is clear that the given Fig. 2h includes a first moving contour figure, which is a moving contour geometric figure corresponding to a rounded rectangle. In Fig. 2h, the first moving contour figure includes eight circular regions (specifically, corresponding to the important circular regions determined in the above two steps a4 and b4), and also includes each filling rectangular region to perform filling display (specifically, corresponding to the circumscribed rectangular region determined in the above two steps c4 and d4), such as rectangle ABA1B2, rectangle AFA2F1, etc., and the important connection point pairs selected when determining in the above two steps c4 and d4 may include A1B2, AB, AF, A2F1, F2E1, EF, BC and B2C2, etc.

[0227] In addition, according to the above two steps c4 and d4, a vertex-connected closed region, for example a polygonal region constructed based on points ABCDEF in Figure 2h, may also be determined, and this polygonal region is also included in Figure 2h as part of the first moving contour figure.

[0228] Similarly, if the erasure geometry is circular and based on determining the important geometric information by the execution step of the second preferred embodiment in S2053 above, the determination of the moving contour geometry in S2054 may be specifically performed by the second preferred embodiment described below.

[0229] a5: Extract the circular center coordinates from the important geometric information of the adjacent touch points.

[0230] b5: Obtaining a second geometrical figure region to be constructed, which is determined based on the coordinates of the centers of the circles.

[0231] c5: Extract the coordinates of each important intersection from the important geometric information of the adjacent touch points.

[0232] d5: Obtain an important intersection connection area determined based on each of the important intersection coordinates.

[0233] e5: Combine each of the second construction target geometric figures with the important intersection connection regions to form a second moving contour figure that is configured by the adjacent touch point pairs with respect to the circle.

[0234] From the above exemplary description of determining important geometric information when the erasing geometric form is a circle, it is clear that the given Fig. 2i includes a second moving contour figure, which is a moving contour geometric figure corresponding to a circle. In Fig. 2i, the second moving contour figure includes two circular regions (specifically, corresponding to the second construction target geometric figure region determined in the above two steps a5 and b5), and also includes a quadrilateral region formed by connecting vertices ABCD (specifically, corresponding to the important intersection connection region determined in the above two steps c5 and d5). In Fig. 2i, the combination of the circular region and the important intersection connection region becomes the second moving contour figure.

[0235] In addition, when the erasing geometric form is an arbitrary irregular shape, and based on determining the important aggregate information by the execution step of the third preferred embodiment in the above S2053, the determination of the moving contour aggregate figure in S2054 may be specifically performed by the third preferred embodiment described below.

[0236] a6: Extracting first graphic display information or second graphic display information from the important geometric information of the adjacent touch point pair, respectively.

[0237] Here, the first graphic display information is preferably graphic display information of a broken line / polygon, and the second graphic display information is preferably graphic display information of a combination of a broken line / polygon and a circular phase.

[0238] b6: Obtaining a combined geometric figure determined based on the corresponding first graphic display information or second graphic display information, respectively.

[0239] Here, the determined combination geometric figure is a combination of a broken line / polygon, or a combination of a broken line / polygon and a circle.

[0240] c6: Extracting important trajectory points from the important geometric information of each of the adjacent touch point pairs.

[0241] d6: Obtain an important trajectory region formed by connecting each of the important trajectory points.

[0242] e6: Combine each of the combined geometric figures with the significant locus region to form a third moving contour figure formed by the adjacent touch point pairs for the arbitrary irregular shape.

[0243] Following the above exemplary description of determining important geometric information when the geometric form for elimination is an arbitrary irregular shape, the corresponding moving contour geometric figure may be taken as an example in Fig. 2q when the irregular shape contains only a broken line / polygon. In Fig. 2q, the first graphic display information may be used to obtain two broken line / polygon regions, and the important trajectory points may be used to obtain a closed region connecting the two broken line / polygons, which corresponds to the important trajectory region.

[0244] In addition, the specific determination of the target erasure handwriting may be further subdivided based on the above-mentioned first preferred embodiment as the second preferred embodiment of this embodiment 2. Specifically, based on the above-mentioned S205 determining that the erasure geometric form is a rounded rectangle, determining the important geometric information according to the first preferred embodiment corresponding to S2053, and determining the moving outline geometric figure according to the first preferred embodiment corresponding to S2054, in this second preferred embodiment, the target erasure handwriting is determined according to the flow shown in Fig. 2b.

[0245] Here, Fig. 2t shows an implementation flow chart of an example of determining a target erasure target handwriting in the handwriting erasure method according to the embodiment 2 of the present application. As shown in Fig. 2t, in the second preferred embodiment, the above step S206 of analyzing each handwriting point included in the erasure target handwriting, performing a hit test between each of the handwriting points and the moving contour geometric figure, and determining a target erasure target handwriting that falls within the moving contour geometric figure is specifically further divided into the following steps:

[0246] S2061: The first moved contour figure is decomposed to obtain the vertex-connected closed region and a corresponding number of circumscribing rectangular regions and important circular regions.

[0247] From the above exemplary description of determining important geometric information when the erasing geometric form is a rounded rectangle, it is apparent that in given FIG. 2h, a moving contour geometric figure corresponding to a rounded rectangle is included, and when the figure included in FIG. 2h is decomposed, it includes a vertex-connected closed region, a number of circumscribed rectangular regions formed based on each important connection point pair, and eight important circular regions.

[0248] S2062: For each handwriting point included in the handwriting to be erased, a first hit test is performed between the handwriting point, the vertex-connected closed region, and each of the circumscribed rectangular regions.

[0249] In this embodiment, the specific implementation of performing a first hit test on the handwritten points and each of the circumscribed rectangular regions may preferably include combining the vertex-connected closed region and each of the circumscribed rectangular regions to obtain a corresponding convex polygon region and obtaining each of the region vertices that constitute the convex polygon region, connecting the handwritten points to each of the region vertices respectively to obtain the same number of triangles as the region vertices, determining the angle value of the vertex angle formed by the handwritten points in each of the triangles, and determining that the first hit test of the handwritten points is successful if the sum of the angle values ​​is 360 degrees.

[0250] As an example, Figures 3 and 4 show schematic diagrams of the implementation of the hit test used when the geometric form for erasure in the handwriting erasing method according to the second embodiment of the present application is a rounded rectangle. As shown in Figure 3, if it is assumed that the first point 25 is a handwriting point to be hit tested and the first polygon 26 is a contour corresponding to the abstracted first moving contour figure, the first point 25 and each vertex of the first polygon 26 are connected to form the first connection diagram 27 shown in Figure 4, then the angle value of the first point 25 in each triangle shown in Figure 4 is determined, and finally, it is calculated whether the sum of the angle values ​​is 360 degrees, and if it is 360 degrees, it may be determined that the first hit test is successful.

[0251] S2063: If the first hit test is successful, add the handwritten point to a first target point set, and if not successful, perform a second hit test between the handwritten point and each of the important circular regions.

[0252] In this embodiment, the specific implementation of performing a second hit test on the handwritten point and each of the important circular areas preferably includes obtaining the area center and area radius of each of the important circular areas, determining the length of a connecting line between the handwritten point and each of the area centers, and determining that the second hit test of the handwritten point is successful if there is a connecting line whose length is less than the area radius.

[0253] S2064: If the second hit test is successful, the handwriting point is added to the first target point set.

[0254] S2065: The handwriting formed by each handwriting point in the first target point set is determined as a target handwriting to be erased that falls within the moving contour geometric figure.

[0255] It can be understood that the first target point set includes all handwriting points that have successfully passed the hit test with the first moving contour figure, and based on these handwriting points, it is possible to reconstruct which handwritings to be erased are within the first moving contour figure on the display interface, and these handwritings to be erased are set as target handwritings to be erased.

[0256] Similarly, the specific determination of the target erasure handwriting may be subdivided based on the above-mentioned first preferred embodiment as the third preferred embodiment of this embodiment 2. Specifically, based on the above-mentioned S205 determining that the erasure geometric form is a circle, the second preferred embodiment corresponding to S2053 determining the important geometric information, and the second preferred embodiment corresponding to S2054 determining the moving contour geometric figure, the third preferred embodiment determines the target erasure handwriting according to the flow shown in FIG.

[0257] Fig. 5 shows a flow chart of another implementation of determining a target erasure target handwriting in the handwriting erasure method according to embodiment 2 of the present application. As shown in Fig. 5, in the third preferred embodiment, the above step S206 of analyzing each handwriting point included in the erasure target handwriting, performing a hit test between each handwriting point and the moving contour geometric figure, and determining a target erasure target handwriting that falls within the moving contour geometric figure is specifically further divided into the following steps:

[0258] S2601: The second moving contour figure is decomposed to obtain one important intersection connection region and two second geometric figures to be constructed.

[0259] From the above exemplary description of determining important geometric information when the erasing geometric form is a rounded rectangle, it is clear that in given Fig. 2i, a moving contour geometric figure corresponding to a rounded rectangle is included. When the second moving contour figure included in Fig. 2i is decomposed, there are two circular regions and an important intersection connection region.

[0260] S2602: For each handwriting point included in the handwriting to be erased, a third hit test is performed between the handwriting point and the important intersection connection region.

[0261] Here, in this embodiment, the step of performing the third hit test on the handwriting point and the important intersection connection area specifically includes: when it is determined that the important intersection connection area is a rectangular area, selecting one vertex from the rectangular area to form two rectangular side vectors, and performing a hit test on the handwriting point and the rectangular area by comparing the handwriting point with each of the rectangular side vectors; when it is not a rectangular area, determining the same number of comparison target vectors as the number of vertices based on each vertex of the important intersection connection area, and performing a hit test on the handwriting point and the rectangular area by comparing the handwriting point with each of the comparison target vectors.

[0262] In this embodiment, the important intersection connection area is preferably a rectangular area (for example, two circles with the same radius), but it may not be a rectangular area (for example, two circles with different radii). In this embodiment, the implementation of the hit test in these two cases is described. As an example, FIGS. 6 and 7 show schematic explanatory diagrams of the implementation using one of these hit tests when the geometric shape for erasure in the handwriting erasure method according to Embodiment 2 of the present application is circular.

[0263] When the important intersection connection area is a rectangular area, the problem of the hit test may be converted to determining whether it is inside the rectangle. As shown in FIG. 6, the vertices A, B, C, and D of the rectangle are known, and it is determined whether the M point of the handwriting point is inside the rectangle. Next, as shown in FIG. 7, three vectors, namely vectors AB, AC, and AM, are created. Finally, it is determined whether the handwriting point is inside the rectangle according to the following formula (0 < AM · AB < AB · AB) ∧ (0 < AM · AC < AC · AC). If it is inside the rectangle, it is assumed that the handwriting point satisfies the third hit test.

[0264] In addition, when the important intersection connection area is an irregular polygon, it can be converted into a mathematical problem by first connecting each vertex of the polygon in the order of their adjacency to form a vector, and how to determine a certain direction in the vector of a point is essentially to determine the angle made by two vectors, and to create two vectors for each of the geometrically adjacent points and points that need to be determined, thereby determining the angle made by the two vectors.

[0265] The judgment is made based on one characteristic of vectors, namely, the cross product of vectors. Specifically, a point on a geometric edge is selected, and a clockwise or counterclockwise direction is arbitrarily selected, and the point is connected to the next adjacent point to form a vector, and then the point is combined with the point to be judged to form a vector, and the value of the cross product of the two vectors is obtained.

[0266] If the cross products of all the vectors are in the same direction, then the point is on the same side of the set of line segments consisting of all geometrically adjacent edges, i.e., the handwritten point is inside the irregular polygon. On the other hand, the determination that the cross products of the vectors are all in the same direction may be made based on whether the numerical values ​​of the cross products are greater than zero, and if the numerical values ​​of all the cross products are greater than zero or less than zero, then the handwritten point is inside the irregular polygon. If there is a cross product with a numerical value of zero, it indicates that the handwritten point is on an edge of the irregular polygon.

[0267] S2063: If the third hit test is successful, add the handwritten point to a second target point set; if not successful, perform a fourth hit test between the handwritten point and each of the second construction target geometric figures and a point and a circular region.

[0268] As can be seen, the fourth hit test is similarly a test of whether the writing point is within a circular region.

[0269] S2064: If the fourth hit test is successful, add the handwriting point to the second target point set.

[0270] S2065: The handwriting formed based on each handwriting point in the second target point set is determined as a target handwriting to be erased that falls within the moving contour geometric figure.

[0271] Similarly, the second target point set summarizes all handwriting points that have been successfully hit tested with the second moving contour figure, and based on these handwriting points, it is possible to restore which handwriting to be erased falls within the second moving contour figure in the display interface, and these handwriting to be erased can be set as target handwriting to be erased.

[0272] In addition, the specific determination of the target handwriting to be erased may be subdivided based on the above-mentioned first preferred embodiment as the fourth preferred embodiment of this embodiment 2. Specifically, based on the above-mentioned S205 determining that the geometric form for erasure is an arbitrary irregular shape, the third preferred embodiment corresponding to S2053 determining the important geometric information, and the third preferred embodiment corresponding to S2054 determining the moving contour geometric figure, the fourth preferred embodiment determines the target handwriting to be erased according to the flow shown in FIG.

[0273] Fig. 8 shows a flow chart of yet another implementation of determining a target erasure target handwriting in the handwriting erasing method according to the embodiment 2 of the present application. As shown in Fig. 8, in the third preferred embodiment, the above step S206 of analyzing each handwriting point included in the erasure target handwriting, performing a hit test between each handwriting point and the moving contour geometric figure, and determining a target erasure target handwriting that falls within the moving contour geometric figure is specifically further divided into the following steps:

[0274] S261: The third moving contour figure is decomposed to obtain the important trajectory region and each of the combined geometric figures.

[0275] Following the exemplary description of determining important geometric information when the above erasing geometric form is an arbitrary irregular shape, the above Fig. 2q may be taken as an example to determine a corresponding moving contour geometric figure when the irregular shape contains only a broken line / polygon. In Fig. 2q, when the third moving contour figure is decomposed, an important trajectory region formed by two broken line / polygon regions and important trajectory points is obtained.

[0276] S262: For each handwriting point included in the handwriting to be erased, if the combined geometric figure is only a broken line or a polygon, a rotation angle hit test is performed between the handwriting point and each of the broken lines or polygons using a rotation angle method, or if the combined geometric figure includes a broken line, a polygon and an important circle, a distance hit test is performed between the handwriting point and each of the broken lines, polygons and important circles using a distance method.

[0277] As can be understood, the rotation angle hit test can be understood as an implementation of the hit test described in this embodiment based on Figures 3 and 4. The distance hit test can be understood as an implementation of the hit test between the handwriting point and the circular area described in this embodiment.

[0278] S263: If the rotation angle hit test or the distance hit test is successful, add the handwritten point to a third target point set; if not, perform a vector hit test between the handwritten point and the significant trajectory region, and if the vector hit test is successful, add the handwritten point to the third target point set.

[0279] Similarly, as can be understood, the vector hit test can be understood as an implementation of a hit test based on determining vectors of points and irregular polygons when discussing the third hit test above in this embodiment.

[0280] S264: The handwriting formed based on each handwriting point in the third target point set is determined as a target handwriting to be erased that falls within the moving contour geometric figure.

[0281] Similarly, the third target point set summarizes all handwriting points that have been successfully hit-tested with the third moving contour figure, and based on these handwriting points, it is possible to reconstruct which handwritings to be erased fall within the third moving contour figure in the display interface, and these handwritings to be erased are set as target handwritings to be erased.

[0282] In this embodiment 2, a special case implementation of the provided handwriting erasing method is described as a fifth preferred embodiment of this embodiment 2. This fifth preferred embodiment may be subdivided based on the above first preferred embodiment. Specifically, in this fifth preferred embodiment, after performing the operation of determining an erasing geometric form matching the moving touch object based on the acquired touch point information by the above S205, the following operation may be further added:

[0283] It should be noted that this special case can be understood as when the erasing geometric form is a rounded rectangle, the touch object does not move on the display and contacts the display in a stationary state. In this case, the touch point information fed back by the touch frame is touch point information generated when the touch object contacts the display, and a to-be-constructed erasing area whose erasing geometric form is a rounded rectangle is formed according to the touch point, and the to-be-constructed erasing area corresponds to a static rounded rectangle. Therefore, in this case, the specific implementation of the fifth preferred embodiment is as follows:

[0284] a: determining that the erasing geometric shape is a rounded rectangle and, if it is monitored that the touch object does not move within a set time, determining a corresponding static touch point when the touch object contacts the display within the set time;

[0285] Here, the static touch point can be understood as a touch point corresponding to a touch signal generated when a touch object first contacts the display, and in this step, touch point information of the static touch point can be obtained.

[0286] b: Determine a static rounded rectangle for the static touch point based on touch point information of the static touch point.

[0287] It is clear from the description of the rounded rectangle in the above embodiment that once the touch point information of the static touch point is known, the relevant geometric information representing the static rounded rectangle can be determined. Figure 9 shows the effect display diagram of the static rounded rectangle in the handwriting erasing method according to the second embodiment of the present application. As shown in Figure 9, the static rounded rectangle can be considered to include two rectangles (two filled rectangular areas) and four circular areas. That is, in this embodiment, the static rounded rectangle preferably includes two static rectangular areas and four static circular areas.

[0288] Therefore, the determination of the static rounded rectangle corresponds to the determination of the geometric information related to the two rectangles and the four circles. Meanwhile, the determination operation of each vertex coordinate related to the diagonal rounded rectangle in this embodiment can also determine the vertex coordinates of the two rectangles and the center coordinates and radius information of the four circles, which corresponds to obtaining a display related to the static rounded rectangle.

[0289] c: A hit test is performed between each handwriting point included in the handwriting to be erased and the static rounded rectangle, and the handwriting to be erased that falls within the static rounded rectangle in the interface is erased.

[0290] Based on the above optimization, the above step of performing a hit test between each handwriting point included in the handwriting to be erased and the static rounded rectangle, and erasing the handwriting to be erased that falls within the static rounded rectangle in the interface includes the steps of: for each handwriting point in the handwriting to be erased, performing a hit test between the handwriting point and each of the two static rectangular regions and four circular regions; if the handwriting point satisfies the condition for the hit test to be successful, adding the handwriting point to a static point set; and erasing the handwriting formed based on each handwriting point in the static point set.

[0291] Specifically, the test between the handwritten points and the static rounded rectangle is assumed to include a hit test between the handwritten points and a rectangular region and a hit test between the handwritten points and a circular region. The test of the rectangular region may be performed as described above for the rectangle hit test (vector method hit test), and the test of the circular region may be performed as described above for the circle hit test (distance method hit test).

[0292] Example 3 10 is a structural block diagram of a handwriting erasing device according to a third embodiment of the present application, the handwriting erasing device can be integrated into an interactive tablet, and the touch response accuracy of the touch frame on the interactive tablet is within a predetermined accuracy range. The device can specifically include a display module 31, a trigger module 32 and an erasing module 34.

[0293] The display module 31 displays a display interface including the handwriting to be erased on a display.

[0294] The trigger module 32 receives a handwriting erasing command generated by a user trigger to enter the handwriting erasing mode.

[0295] The acquisition module 33 acquires touch point information fed back by the touch frame when a touch object operated and controlled by a user touches and moves on the surface of the display.

[0296] The erasing module 34 analyzes the acquired touch point information and the handwriting to be erased, and erases the handwriting to be erased in the interface with an erasing geometric form matching the touch object.

[0297] Example 3 of the present application provides a handwriting erasing device, and the interactive tablet, which is the execution body of the device, is arranged with a high-precision touch frame in terms of hardware structure, and the arranged high-precision touch frame has its function optimized at the software application level through the method of this embodiment. Compared with the interactive tablets of related art that are not optimized at the software level, in Example 3, a handwriting erasing device is integrated into the interactive tablet, and the device can ensure that the erasure response to the handwriting to be erased in the interface is more aligned with the erasing geometric form for the touch object used by the user, and enable flexible adjustment of the erasing area during the erasing process, thereby improving the erasing efficiency from the interactive tablet.

[0298] Further, the erasing geometry matching the touch object is expressed as a touch area that the touch object exerts on the display, and the erasing geometry includes a rounded rectangle, a circle, and any irregular shape.

[0299] In addition, the acquisition module 33 specifically identifies, when a touch object touches and moves on the surface of the display, each touch signal generated by the touch object moving on the display through a hardware circuit of the touch frame, and acquires touch point information fed back by the touch frame for each touch signal according to a HID standard protocol for human-computer interaction, where one touch point information corresponds to one touch point, and the touch point information may include touch point coordinates, touch point height and width, and touch rotation angle.

[0300] Further, the device may further include an input processing module, which, after obtaining the touch point information fed back by the touch frame, processes each of the touch point information, so that each of the touch point information has a unified unit format and data structure.

[0301] Based on the above optimization, a specific implementation of the input processing module processing each of the touch point information may include: converting the unit of each data information in the touch point information into a unified predetermined unit format based on the size information and screen resolution information of the acquired touch frame; and recording the touch point information in a data structure corresponding to the predetermined unit format.

[0302] In addition, the erasure module 34 may specifically include: a shape contour determination unit for determining an erasure geometric form matching the moving touch object based on the acquired touch point information, and determining a moving contour geometric form formed by the moving adjacent touch point pairs in the erasure geometric form; a target handwriting determination unit for analyzing each handwriting point included in the erasure target handwriting, performing a hit test between each of the handwriting points and the moving contour geometric form, and determining a target erasure target handwriting that falls within the moving contour geometric form; and an erasure execution unit for erasing the target erasure target handwriting on the display interface.

[0303] Based on the above optimization, the form contour determination unit may specifically include: an information acquisition subunit for extracting important touch point information, which is touch point information of a touch point generated when the touch object first contacts the display during movement, and acquiring an important touch area from the important touch point information; a form determination subunit for determining an area threshold range and an area shape to which the important touch area belongs, searching for a target shape matching the area shape from among the geometric shapes corresponding to the area threshold range to which the important touch area belongs, and determining the target shape as a geometric shape for erasure matching the touch object; a geometric information determination subunit for each adjacent touch point pair of the moving touch object, analyzing touch point information related to the adjacent touch point pair, and determining important geometric information of each touch point in the adjacent touch point pair with respect to the geometric shape for erasure; and a contour determination subunit for determining a movement contour geometric figure formed by the adjacent touch point pair with respect to the geometric shape for erasure based on each of the important geometric information.

[0304] Based on the above optimization, when the geometric form for erasing is a rounded rectangle, the rounded rectangle includes a rectangle and chamfers with each vertex of the rectangle as a circle center, and the geometric information determination subunit specifically takes the rounded rectangle as a first geometric figure to be constructed by each touch point in the adjacent touch point pair, and for each touch point in the adjacent touch point pair, combines the touch point coordinates, touch width, touch height and touch rotation angle in the touch point information related to the touch point with a predetermined chamfer radius to determine the center point coordinate of the rectangle, the circle center coordinate of each chamfer and the coordinate of each important junction, and the coordinate of the connection point of the two figures in the first geometric figure to be constructed, and regards the center point coordinate of the rectangle, the circle center coordinate of each chamfer and the coordinate of each important junction, and the coordinate of the connection point of the two figures as the important geometric information of the touch point for the first geometric figure to be constructed, and each chamfer of the first geometric figure to be constructed includes two important junctions, and each important junction is a junction corresponding to the chamfer and its adjacent chamfer when the chamfer is connected by a tangent line.

[0305] Further, the contour determination subunit may specifically extract, based on the important geometric information of the adjacent touch point pairs, the chamfered circle center coordinates of the corresponding rounded rectangle, select important circle center points required to construct a circumscribing contour, obtain important circular areas determined based on each of the important circle center points, extract rectangular vertex coordinates and center point coordinates of the corresponding rounded rectangle based on the important geometric information of the adjacent touch point pairs, select important connection point pairs required to construct a circumscribing contour, obtain circumscribing rectangular areas determined based on each of the important connection point pairs, and vertex-connected closed areas determined based on each of the rectangular vertex coordinates, and combine each of the important circular areas, each of the circumscribing rectangular areas, and the vertex-connected closed areas to form a first moving contour figure formed by the adjacent touch point pairs for the rounded rectangle.

[0306] Based on the above embodiment, the target handwriting determination unit may specifically decompose the first moving contour figure to obtain the vertex-connected closed region and a corresponding number of circumscribing rectangular regions and important circular regions, and for each handwriting point included in the to-be-erased handwriting, perform a first hit test between the handwriting point and the vertex-connected closed region and each of the circumscribing rectangular regions, and if the first hit test is successful, add the handwriting point to a first target point set, and if not successful, perform a second hit test between the handwriting point and each of the important circular regions, and if the second hit test is successful, add the handwriting point to the first target point set, and determine the handwriting formed by each handwriting point in the first target point set as a target to-be-erased handwriting that falls within the moving contour geometric figure.

[0307] Furthermore, specific execution steps of performing a first hit test on the handwritten points, the vertex-connected closed region, and each of the circumscribed rectangular regions include the steps of combining the vertex-connected closed region with each of the circumscribed rectangular regions to obtain a corresponding convex polygonal region and obtaining each of the region vertices that constitute the convex polygonal region; connecting the handwritten points to each of the region vertices to obtain the same number of triangles as the region vertices; determining the angle value of the vertex angle formed by the handwritten points in each of the triangles; and determining that the first hit test of the handwritten points is successful if the sum of the angle values ​​is 360 degrees.

[0308] Furthermore, specific execution steps of performing a second hit test on the handwritten point and each of the important circular areas include a step of obtaining the area center and area radius of each of the important circular areas and determining the length of a connecting line between the handwritten point and each of the area centers, and a step of determining that the second hit test of the handwritten point is successful if there is a connecting line whose length is less than the area radius.

[0309] Based on the above embodiment, the erasure module 34 may further include a static erasure implementation unit, which may specifically include: a static point determination subunit for determining an erasure geometric form that matches the moving touch object based on the acquired touch point information, and then determining that the erasure geometric form is a rounded rectangle; and when it is monitored that the touch object does not move within a set time, determining a static touch point corresponding to when the touch object contacts the display within the set time; a static rectangle determination subunit for determining a static rounded rectangle for the static touch point based on the touch point information of the static touch point; and a static hit test subunit for performing a hit test between each handwriting point included in the erasure target handwriting and the static rounded rectangle, and erasing the erasure target handwriting that falls within the static rounded rectangle in the interface.

[0310] Furthermore, the static rounded rectangle may include two static rectangular regions and four static circular regions, and in this case, the static hit test subunit may specifically perform a hit test between each handwriting point in the handwriting to be erased and each of the two static rectangular regions and four circular regions, and if the handwriting point satisfies a condition for a successful hit test, add the handwriting point to a static point set and erase the handwriting formed based on each handwriting point in the static point set.

[0311] Furthermore, the geometric information determination subunit may, specifically, when the geometric form for erasure is a circle, determine the circle as a second geometric figure to be constructed by each touch point in the adjacent touch point pair, and determine the circle center coordinates and each important intersection coordinates of the corresponding second geometric figure to be constructed based on the touch point coordinates, touch width, and touch height in the touch point information for each touch point in the adjacent touch point pair, and determine the circle center coordinates and each important intersection coordinates corresponding to each touch point as important geometric information corresponding to the second geometric figure to be constructed.

[0312] Based on the above optimization, specific implementation steps of determining the circle center coordinates and each important intersection coordinate of the corresponding second to be constructed geometric figure based on the touch point coordinates, touch width, and touch height in the touch point information for each touch point in the adjacent touch point pair may include: determining the circle center coordinates of the corresponding second to be constructed circle based on the touch point coordinates, touch width, and touch height in the touch point information for each touch point in the adjacent touch point pair; connecting the circle center coordinates of the corresponding two circles to obtain a circle center connecting line; drawing straight lines perpendicular to the circle center connecting line based on the circle center coordinates of each circle, and obtaining the determined important intersection coordinates by intersecting each straight line with the corresponding second to be constructed circle.

[0313] Furthermore, the contour determination subunit may, specifically, extract circular center coordinates contained in the important geometric information of the adjacent touch points based on the important geometric information of the adjacent touch points, obtain a second construction target geometric figure area determined based on each of the circular center coordinates, extract each important intersection coordinate contained in the important geometric information of the adjacent touch points, obtain an important intersection connection area determined based on each of the important intersection coordinates, and combine each of the second construction target geometric figures and the important intersection connection area to form a second moving contour figure formed by the adjacent touch point pair with respect to the circle.

[0314] Based on the above optimization, the target handwriting determination unit may specifically decompose the second moving contour figure to obtain one important intersection connection area and two second construction target geometric figures, and for each handwriting point included in the erasure target handwriting, perform a third hit test between the handwriting point and the important intersection connection area, and if the third hit test is successful, add the handwriting point to a second target point set, and if not successful, perform a fourth hit test between the handwriting point and each of the second construction target geometric figures, and if the fourth hit test is successful, add the handwriting point to the second target point set, and determine the handwriting formed based on each handwriting point in the second target point set as the target erasure target handwriting that falls within the moving contour geometric figure.

[0315] Furthermore, the specific execution steps of performing a third hit test on the handwritten point and the important intersection connecting area include: if it is determined that the important intersection connecting area is a rectangular area, selecting one vertex from the rectangular area to form two rectangular side vectors, and performing a hit test between the handwritten point and the rectangular area by comparing the handwritten point with each of the rectangular side vectors; if it is not a rectangular area, determining a number of comparison target vectors equal to the number of vertices based on each vertex of the important intersection connecting area; and performing a hit test between the handwritten point and the rectangular area by comparing the handwritten point with each of the comparison target vectors.

[0316] Furthermore, the geometric information determination subunit may, specifically, further be configured to, when the erasing geometric form is an arbitrary irregular shape, set the arbitrary irregular shape as a third geometric figure to be constructed by each touch point in the adjacent touch point pair, determine combined graphic information included in the third geometric figure to be constructed, and for each touch point in the adjacent touch point pair, combine touch point information related to each touch point with the combined graphic information to determine important trajectory points existing with respect to the touch points in the third geometric figure to be constructed and graphic display information of the third geometric figure to be constructed, and set the graphic display information of each of the combined graphics and each of the important trajectory points as important geometric information of the touch points for the third geometric figure to be constructed.

[0317] Further, specific execution steps of combining the relevant touch point information with the combined graphic information to determine important locus points existing at the touch points in the third geometric graphic to be constructed and graphic display information of the third geometric graphic to be constructed may include: analyzing the combined graphic information; when it is determined that the third geometric graphic to be constructed includes only a broken line / polygon, determining important locus points existing at the touch points in the broken line / polygon based on the relevant touch point information, and obtaining first graphic display information representing the broken line / polygon; when it is determined that the third geometric graphic to be constructed includes a broken line / polygon and a target circle, determining important locus points in the broken line / polygon and the important circle based on the relevant touch point information, and obtaining second graphic display information representing the broken line / polygon and the important circle.

[0318] Furthermore, specific execution steps of determining important trajectory points existing for the touch points of the broken line / polygon based on the relevant touch point information and acquiring first graphic display information representing the broken line / polygon may include a step of determining a broken line center point coordinate and a vertex coordinate of each broken line of the broken line / polygon, which is the first graphic display information, based on the touch point coordinates, touch height and touch width in the relevant touch point information, and a step of selecting important trajectory points that satisfy a selection condition for trajectory points from the broken line vertex coordinates based on the broken line center point coordinates and the relevant touch point information.

[0319] Further, specific execution steps of determining important trajectory points on the broken line / polygon and important circle based on the relevant touch point information and obtaining second graphic display information representing the broken line / polygon and important circle may include: determining a broken line center point coordinate and each broken line vertex coordinate of the broken line / polygon and a circle center point coordinate and circle radius of the important circle based on the touch point coordinates, touch height and touch width in the relevant touch point information, and setting them as second graphic display information; and selecting important trajectory points that satisfy a trajectory point selection condition on the circumference of the important circle and from each of the broken line vertex coordinates based on the broken line center point coordinates, circle center point coordinates, circle radius and the relevant touch point information.

[0320] Based on the above optimization, the contour determination subunit may specifically extract first graphic display information or second graphic display information from the important geometric information of the adjacent touch point pairs, respectively, obtain a combined geometric figure determined based on the corresponding first graphic display information or second graphic display information, respectively extract important trajectory points from the important geometric information of the adjacent touch point pairs, respectively, obtain an important trajectory area formed by connecting each of the important trajectory points, and combine each of the combined geometric figures and the important trajectory area to form a third moving contour figure formed by the adjacent touch point pairs for the arbitrary irregular shape.

[0321] Based on the above embodiment, the target handwriting determination unit may specifically decompose the third moving contour figure to obtain the important trajectory region and each of the combined geometric figures; for each handwriting point included in the target handwriting to be erased, if the combined geometric figure is only a broken line / polygon, perform a rotation angle hit test by a rotation angle method between the handwriting point and each of the broken line / polygon; or if the combined geometric figure includes a broken line / polygon and an important circle, perform a distance hit test by a distance method between the handwriting point and each of the broken line / polygon and the important circle; if the rotation angle hit test or the distance hit test is successful, add the handwriting point to a third target point set; if not successful, perform a vector hit test between the handwriting point and the important trajectory region; if the vector hit test is successful, add the handwriting point to a third target point set; and determine the handwriting formed based on each handwriting point in the third target point set as a target handwriting to be erased that falls within the moving contour geometric figure.

[0322] Example 4 Fig. 11 is a structural schematic diagram of an interactive tablet according to Example 4 of the present application. The interactive tablet includes a processor 40, a memory 41, a display 42, an input device 43, an output device 44, and a touch frame 45. The number of processors 40 of the interactive tablet may be one or more, and Fig. 11 illustrates one processor 40. The number of memories 41 of the interactive tablet may be one or more, and Fig. 11 illustrates one memory 41. The processor 40, memory 41, display 42, input device 43, output device 44, and touch frame 45 of the interactive tablet may be connected by a bus or other methods, and Fig. 11 illustrates the connection by a bus.

[0323] The memory 41 can store software programs, computer executable programs and modules as a computer readable storage medium, such as program instructions / modules corresponding to the interactive tablet described in any embodiment of the present application (e.g., the display module 31, the trigger module 32, the acquisition module 33 and the erasure module 34 of the handwriting erasure device). The memory 41 may mainly include a program storage area and a data storage area, where the program storage area may store an operating system, an application program required for at least one function, and the data storage area may store data generated according to the use of the device, etc. In addition to this, the memory 41 may include a high-speed random access memory, a non-volatile memory, such as at least one magnetic disk storage device, a flash memory device, or other non-volatile solid-state storage device. In some examples, the memory 41 may further include a memory located remotely with respect to the processor 40, and these remote memories may be connected to the device via a network. Examples of the above-mentioned networks include, but are not limited to, the Internet, a corporate intranet, a local area network, a mobile communication network, and combinations thereof.

[0324] The display 42 may be covered by a touch frame 45 (such covering relationship is not shown in FIG. 11) and configured on top of a touch screen to display interaction content; generally, the display 42 displays data according to instructions from the processor 40, accepts touch operations acting on the display 42, and transmits corresponding signals to the processor 40 or other devices.

[0325] The input device 43 may be used to receive input numeric or character information and generate important signal inputs related to user settings and function control of the display device, and may be a camera for acquiring graphics and a pickup device for acquiring audio data. The output device 44 may include an audio device such as a speaker. Note that the specific configurations of the input device 43 and the output device 44 can be set according to the actual situation.

[0326] The touch frame 45 has a touch response accuracy within a predetermined accuracy range, and responds to a touch operation by a touch object through a hardware circuit.

[0327] The processor 40 runs the software programs, instructions and modules stored in the memory 41 to execute various functional applications and data processing of the device, thereby realizing the above-mentioned handwriting erasing method.

[0328] The interactive tablet provided above may be used to implement the handwriting erasing method according to any of the above embodiments, and has corresponding functions.

[0329] Example 5 Example 5 of the present application further provides a storage medium including computer-executable instructions, which, when executed by a computer processor, performs a handwriting erasing method, including: displaying a display interface including the handwriting to be erased on a display; receiving a handwriting erasing command generated by a user trigger to enter a handwriting erasing mode; obtaining touch point information fed back by the touch frame when a touch object operated and controlled by a user touches and moves on a surface of the display; analyzing the obtained touch point information and the handwriting to be erased, and erasing the handwriting to be erased in the interface with an erasing geometric form matching the touch object.

[0330] Of course, in a storage medium including computer-executable instructions according to an embodiment of the present application, the computer-executable instructions are not limited to the handwriting erasure method operations described above, but may also perform related operations in the handwriting erasure method according to any embodiment of the present application and have corresponding functionality.

[0331] From the above description of the embodiments, those skilled in the art can clearly understand that the present application may be realized by software and necessary general-purpose hardware, and of course, may be realized by hardware, but in many cases, the former is a more preferred embodiment. Based on this understanding, the essential or relevant part of the technical solution of the present application may be embodied in the form of a software product that can be stored in a computer-readable storage medium such as a computer floppy disk, read-only memory (ROM), random access memory (RAM), flash memory (FLASH), hard disk, or optical disk, and the computer software product includes some instructions for an interactive tablet (which may be a robot, a personal computer, a server, or a network device, etc.) to execute the handwriting erasing method described in any embodiment of the present application.

[0332] In addition, each unit or module included in the handwriting erasing device is only divided by functional logic, and is not limited to the above division, as long as the corresponding function can be realized. In addition, the specific names of each functional unit are given only to make it easier to distinguish them from each other, and are not intended to limit the scope of the patent of this application.

[0333] It should be noted that various parts of the present application may be implemented in hardware, software, firmware, or a combination thereof. In the above embodiment, a number of steps or methods may be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, when implemented in hardware, as in the other embodiments, the method may be implemented in any one of the technologies known to those skilled in the art, such as a discrete logic circuit having logic gate circuits for implementing a logical function of a data signal, an application specific integrated circuit having an appropriate combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), or a combination thereof.

Claims

1. A handwriting erasing method for an interactive tablet, the handwriting erasing method comprising: displaying a display interface including the handwriting to be erased on a display; receiving a handwriting erasing command generated by a user trigger to enter a handwriting erasing mode; When a touch object operated and controlled by a user touches and moves on the surface of the display, obtaining touch point information fed back by the touch frame; Analyzing the acquired touch point information and the target handwriting to be erased, and erasing the target handwriting in the interface with an erasing geometric form that matches the touch object and an erasing area range that corresponds to the erasing geometric form; The erasing geometry matching the touch object is expressed as a touch area of ​​the touch object acting on the display; the touch object being one of a plurality of different parts of the user's hand; The erasure geometric shapes include rounded rectangles, circles and any irregular shape; if the touch object is the user's finger, the erasing geometry matching the touch object is the circle; if the touch object is the back of the user's hand, the erasing geometry matching the touch object is the rounded rectangle; When the touch object is a lower portion of the user's fist, an erasing geometric shape matching the touch object is the arbitrary irregular shape.

2. The step of obtaining touch point information fed back by the touch frame includes: identifying, by the touch frame hardware circuitry, each touch signal generated as the touch object moves across the display; obtaining touch point information fed back by the touch frame for each of the touch signals according to a HID standard protocol of human-computer interaction; The method of claim 1 , wherein one touch point information corresponds to one touch point, and the touch point information includes: touch point coordinates, touch point height and width, and touch rotation angle.

3. After obtaining the touch point information fed back by the touch frame, The method of claim 1 , further comprising processing each of the touch point information such that each of the touch point information has a uniform unit format and data structure.

4. The step of processing each of the touch point information includes: converting the units of each piece of data information in the touch point information into a unified predetermined unit format according to the acquired size information of the touch frame and screen resolution information; and recording the touch point information in a data structure corresponding to the predetermined unit format.

5. The step of analyzing the acquired touch point information and the handwriting to be erased and erasing the handwriting to be erased in the interface with an erasing geometric form matching the touch object includes: determining an erasure geometry matching the moving touch object based on the acquired touch point information, and determining a moving contour geometry formed by the moving adjacent touch point pair using the erasure geometry; analyzing each handwriting point included in the erasure target handwriting, performing a hit test between each of the handwriting points and the moving contour geometric figure, and determining a target erasure target handwriting that falls within the moving contour geometric figure; and erasing the target erasure target handwriting in the display interface.

6. The step of determining an erasure geometry matching the moving touch object based on the acquired touch point information, and determining a moving outline geometry formed by the moving adjacent touch point pair using the erasure geometry, includes: extracting important touch point information, which is touch point information of a touch point generated when the touch object first contacts the display during movement, and obtaining an important touch area in the important touch point information; determining an area threshold range and an area shape to which the significant touch area belongs, searching for a target shape that matches the area shape among geometric shapes corresponding to the area threshold range to which the significant touch area belongs, and determining the target shape as a geometric shape for erasure that matches the touch object; for each pair of adjacent touch points of the touch object being moved, analyzing touch point information for the pair of adjacent touch points to determine significant geometric information of each touch point in the pair of adjacent touch points relative to the erasure geometry; and determining, based on each of the significant geometric information, a moving contour geometry formed by the adjacent touch point pairs relative to the erasure geometry.

7. When the erasure geometric shape is a rounded rectangle, the rounded rectangle includes a rectangle and a chamfer with each vertex of the rectangle as a circle center; Analyzing touch point information for the adjacent touch point pairs to determine significant geometric information of each touch point in the adjacent touch point pairs relative to the erasure geometry includes: determining the rounded rectangle as a first geometric figure to be constructed by each of the adjacent touch points in the pair of touch points; For each touch point in the adjacent touch point pair, combine the touch point coordinates, touch width, touch height and touch rotation angle in the relevant touch point information with a predetermined chamfer radius to determine the center point coordinates of a rectangle in the first geometric figure to be constructed, the circle center coordinates of each chamfer, the coordinates of each important junction, and the coordinates of the connection points of the two figures; a step of determining the coordinates of the center point of the rectangle, the coordinates of the circle centers of the chamfers, the coordinates of the important junctions, and the coordinates of the connection points of the two figures as important geometric information of the touch point for the first geometric figure to be constructed; 7. The method of claim 6, wherein each chamfer of the first construction geometric figure includes two critical junctions, each critical junction being a corresponding junction when the chamfer and an adjacent chamfer are connected by a tangent line.

8. determining a movement contour geometry formed by the adjacent touch point pairs on the erasure geometry based on each of the significant geometric information, According to the key geometric information of the adjacent touch point pairs, extracting the chamfer circle center coordinates of the corresponding rounded rectangle, and selecting the key circle center points required to construct the circumscribing contour; obtaining important circular areas determined based on each of the important circle center points; According to the important geometric information of the adjacent touch point pairs, extracting the rectangle vertex coordinates and center point coordinates of the corresponding rounded rectangle, and selecting the important connection point pairs required to construct the circumscribing contour; obtaining a circumscribed rectangular area determined based on each pair of important connection points, and a vertex-connected closed area determined based on each of the rectangular vertex coordinates; and combining each of the important circular regions, each of the circumscribing rectangular regions, and the vertex-connected closed regions to form a first moving outline shape composed of the adjacent touch point pairs for the rounded rectangle.

9. The step of analyzing each handwriting point included in the erasure target handwriting, performing a hit test between each of the handwriting points and the moving contour geometric figure, and determining a target erasure target handwriting that falls within the moving contour geometric figure, decomposing the first moved contour figure to obtain the vertex-connected closed region and a corresponding number of circumscribing rectangular regions and important circular regions; performing a first hit test for each handwriting point included in the handwriting to be erased, between the handwriting point, the vertex-connected closed region, and each of the circumscribed rectangular regions; if the first hit test is successful, adding the handwritten point to a first set of target points, and if the first hit test is not successful, performing a second hit test between the handwritten point and each of the important circular regions; adding the handwriting point to the first set of target points if the second hit test is successful; and determining a handwriting formed by each handwriting point in the first set of target points as a target handwriting to be erased that falls within the moving contour geometric figure.

10. The step of performing a first hit test between the handwriting point and each of the circumscribing rectangular regions includes: combining the vertex-connected closed region with each of the circumscribing rectangular regions to obtain a corresponding convex polygon region, and obtaining each of the region vertices constituting the convex polygon region; connecting the handwriting points to each of the region vertices respectively to obtain triangles having the same number as the region vertices; determining an angle value of an apex angle formed by the handwritten points in each of the triangles; and determining that the first hit test of the handwritten point is successful if the sum of the angle values ​​is 360 degrees.

11. The step of performing a second hit test on the handwriting points and each of the important circular regions includes: obtaining a region center and a region radius of each of the important circular regions, and determining a length of a connecting line between the handwriting point and each of the region centers; and determining that the second hit test of the handwritten point is successful if there is a connecting line whose length is less than the region radius.

12. determining an erasing geometry matching the moving touch object based on the acquired touch point information; determining that the erasure geometry is a rounded rectangle and if the touch object is monitored to not move within a set time, determining a static touch point that corresponds to when the touch object contacts the display within the set time; determining a static rounded rectangle for the static touch point based on touch point information of the static touch point; The method of claim 5 , further comprising: performing a hit test between each handwriting point included in the handwriting to be erased and the static rounded rectangle; and erasing the handwriting to be erased that falls within the static rounded rectangle in the interface.

13. the static rounded rectangle includes two static rectangular regions and four static circular regions; In this case, the step of performing a hit test between each handwriting point included in the handwriting to be erased and the static rounded rectangle, and erasing the handwriting to be erased that falls within the static rounded rectangle in the interface, performing a hit test for each handwriting point in the handwriting to be erased between the handwriting point and each of two static rectangular regions and four circular regions; adding the handwritten point to a static point set if the handwritten point satisfies a condition for passing the hit test; and erasing handwriting formed based on each handwriting point in the static point set.

14. If the erasure geometry is a circle, analyzing touch point information for the adjacent touch point pairs to determine significant geometric information of each touch point in the adjacent touch point pairs relative to the erasure geometry includes: a second geometric shape to be constructed by each of the adjacent touch points in the pair of adjacent touch points; determining a circle center coordinate and each important intersection coordinate of the corresponding second geometric figure to be constructed according to the touch point coordinate, touch width, and touch height in the touch point information of each touch point in the adjacent touch point pair; The method of claim 6 , further comprising: determining the circular center coordinates corresponding to each touch point and the important intersection coordinates as important geometric information corresponding to the second geometric figure to be constructed.

15. determining a circle center coordinate and each important intersection coordinate of the corresponding second geometric figure to be constructed according to the touch point coordinate, the touch width, and the touch height in the touch point information of each touch point in the adjacent touch point pair; determining a circle center coordinate of a corresponding second circle to be constructed according to the touch point coordinate, the touch width and the touch height in the touch point information for each touch point in the adjacent touch point pair; connecting the circle center coordinates of the two corresponding circles to obtain a connecting line of the circle centers; The method according to claim 14 , further comprising drawing straight lines perpendicular to the circle center connecting lines based on the circle center coordinates of each of the circles, and obtaining important intersection coordinates determined by intersecting each straight line with the corresponding second target circle to be constructed.

16. determining a movement contour geometry formed by the adjacent touch point pairs on the erasure geometry based on each of the significant geometric information, Extracting circular center coordinates from the significant geometric information of the adjacent touch points; obtaining a second geometric region to be constructed based on the coordinates of each of the circular centers; Extracting respective significant intersection coordinates from the significant geometric information of the adjacent touch points; obtaining an important intersection connection area determined based on each of the important intersection coordinates; and combining each of the second construction geometric figures with the significant intersection connection regions to form a second moving contour figure of the adjacent touch point pairs relative to the circular shape.

17. The step of analyzing each handwriting point included in the erasure target handwriting, performing a hit test between each of the handwriting points and the moving contour geometric figure, and determining a target erasure target handwriting that falls within the moving contour geometric figure, decomposing the second moving contour figure to obtain one important intersection connection region and two second construction target geometric figures; performing a third hit test for each handwriting point included in the handwriting to be erased between the handwriting point and the important intersection connection region; if the third hit test is successful, adding the handwritten point to a second target point set, and if not successful, performing a fourth point-to-circular region hit test for the handwritten point and each of the second construction target geometric figures; adding the handwriting point to the second set of target points if the fourth hit test is successful; and determining a handwriting formed based on each handwriting point in the second set of target points as a target handwriting to be erased that falls within the moving contour geometric figure.

18. The step of performing a third hit test on the handwriting point and the important intersection connection region includes: if it is determined that the important intersection connection region is a rectangular region, selecting one vertex from the rectangular region to form two rectangular side vectors, and comparing the handwritten point with each of the rectangular side vectors to perform a hit test between the handwritten point and the rectangular region; If the region is not a square region, a step of determining, based on each vertex of the important intersection connection region, a number of comparison target vectors equal to the number of vertices of the important intersection connection region; and performing a hit test between the handwritten point and the rectangular region by comparing the handwritten point with each of the comparison vectors.

19. If the erasure geometry is an arbitrary irregular shape, analyzing touch point information for the adjacent touch point pairs to determine significant geometric information of each touch point in the adjacent touch point pairs relative to the erasure geometry includes: determining a third geometric figure to be constructed by each touch point in the adjacent touch point pair, the arbitrary irregular shape being determined; and determining combined geometric information included in the third geometric figure to be constructed; for each touch point in the adjacent touch point pair, combining touch point information with the combined graphic information to determine significant locus points of the third geometric figure to be constructed relative to the touch point and graphic display information of the third geometric figure to be constructed; and determining each of the significant locus points and each of the graphic display information of the combined graphic as significant geometric information of the touch points for the third geometric graphic to be constructed.

20. The step of combining the related touch point information with the combined graphic information to determine important trajectory points of the third geometric figure to be constructed relative to the touch points and graphic display information of the third geometric figure to be constructed includes: analyzing the combined graphic information; if it is determined that the third geometric figure to be constructed includes only a broken line / polygon, determining important trajectory points that exist with respect to the touch points of the broken line / polygon based on touch point information related thereto, and acquiring first figure display information representing the broken line / polygon; 20. The method of claim 19, further comprising: when it is determined that the third geometric figure to be constructed includes a broken line / polygon and a target circle, determining important trajectory points in the broken line / polygon and important circle based on touch point information related thereto, and obtaining second graphic display information representing the broken line / polygon and important circle.

21. determining significant trajectory points of the polygonal line / polygon that exist with respect to the touch points based on the related touch point information, and obtaining first graphic display information representing the polygonal line / polygon; determining the coordinates of the center point of the polygonal line and the coordinates of the vertices of each polygonal line, which is the first graphic display information, based on the touch point coordinates, the touch height, and the touch width in the touch point information related to the polygonal line and the polygonal line; The method of claim 20 , further comprising: selecting important trajectory points that satisfy a selection condition for trajectory points from among the polygonal line vertex coordinates according to the polygonal line center point coordinates and related touch point information.

22. determining important trajectory points on the polygonal line, polygonal line, and important circle based on the related touch point information, and obtaining second graphic display information representing the polygonal line, polygonal line, and important circle; determining the coordinates of the center point of the polygonal line and the coordinates of each vertex of the polygonal line and the coordinates of the center point of the important circle and the circle radius of the important circle based on the touch point coordinates, the touch height and the touch width in the touch point information related to the polygonal line and the important circle, and setting them as second graphic display information; The method of claim 20, further comprising: selecting important trajectory points that satisfy a trajectory point selection condition on the circumference of the important circle and from among the coordinates of each of the polygonal line vertices according to the polygonal line center point coordinate, the circle center point coordinate, the circle radius and related touch point information.

23. determining a moving contour geometry formed by the adjacent touch point pairs relative to the erasure geometry based on each of the significant geometric information, respectively extracting first graphic representation information or second graphic representation information from the significant geometric information of the adjacent touch point pairs; obtaining a combined geometric figure determined based on the corresponding first or second graphic representation information, respectively; respectively extracting significant trajectory points from significant geometric information of the adjacent touch point pairs; obtaining an important trajectory region formed by connecting each of the important trajectory points; The method of claim 20 , further comprising combining each of the combined geometric figures with the significant locus region to form a third moving contour figure formed by the adjacent touch point pairs for the given irregular shape.

24. The step of analyzing each handwriting point included in the erasure target handwriting, performing a hit test between each of the handwriting points and the moving contour geometric figure, and determining a target erasure target handwriting that falls within the moving contour geometric figure, decomposing the third moving contour figure to obtain the significant trajectory region and each of the combined geometric figures; For each handwriting point included in the handwriting to be erased, if the combined geometric figure is only a broken line / polygon, a rotation angle hit test is performed between the handwriting point and each of the broken lines / polygons by a rotation angle method, or if the combined geometric figure includes a broken line / polygon and an important circle, a distance hit test is performed between the handwriting point and each of the broken lines / polygons and important circles by a distance method; adding the handwritten point to a third target point set if the rotation angle hit test or the distance hit test is successful, and performing a vector hit test between the handwritten point and the significant trajectory region if the rotation angle hit test or the distance hit test is not successful, and adding the handwritten point to the third target point set if the vector hit test is successful; and determining a handwriting formed based on each handwriting point in the third target point set as a target handwriting to be erased that falls within the moving contour geometric figure.

25. A handwriting erasing device disposed on an interactive tablet, the handwriting erasing device having a touch response accuracy of a touch frame on the interactive tablet within a predetermined accuracy range, comprising: a display module for displaying a display interface including the handwriting to be erased on a display; a trigger module for receiving a handwriting erasing command generated by a user trigger and entering a handwriting erasing mode; an acquisition module for acquiring touch point information fed back by the touch frame when a touch object operated and controlled by a user touches and moves on the surface of the display; an erasing module for analyzing the acquired touch point information and the handwriting to be erased, and erasing the handwriting to be erased in the interface in an erasing geometric form that matches the touch object and an erasing area range corresponding to the erasing geometric form; The erasing geometry matching the touch object is expressed as a touch area of ​​the touch object acting on the display; the touch object being one of a plurality of different parts of the user's hand; The erasure geometric shapes include rounded rectangles, circles and any irregular shape; if the touch object is the user's finger, the erasing geometry matching the touch object is the circle; if the touch object is the back of the user's hand, the erasing geometry matching the touch object is the rounded rectangle; When the touch object is a lower portion of the user's fist, an erasing geometric shape matching the touch object is the arbitrary irregular shape.

26. An interactive tablet, a touch frame having a touch response accuracy within a predetermined accuracy range and responding to a touch operation by a touch object through a hardware circuit; A display that is covered by the touch frame to form a touch screen and displays interaction content; one or more processors; a storage device that stores one or more programs; An interactive tablet, wherein said one or more programs when executed by said one or more processors cause said one or more processors to implement a method according to any one of claims 1 to 24.

27. A storage medium containing computer-executable instructions, comprising: A storage medium, the computer-executable instructions which, when executed by a computer processor, perform the method of any one of claims 1 to 24.

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