Writing track smoothing method and device, equipment and medium

Abstract

The invention discloses a writing track smoothing method and device, equipment and a medium, and the method comprises the steps: obtaining induction coordinates of a plurality of track points which are sequentially generated through writing operation on a touch display screen, the induction coordinates of the plurality of track points comprise an induction coordinate of a target track point and induction coordinates of n-1 track points before the target track point, and n is an integer greater than 2; performing smoothing calculation on the induction coordinates of the plurality of track points to obtain smoothing parameters, wherein the smoothing parameters are filtering smoothing on the target track point; obtaining a smooth coordinate of the target track point by using the smooth parameter; and displaying a writing track on the touch display screen by using the smooth coordinate of the target track point. The writing track smoothing method and device, the equipment and the medium have the advantages of being good in real-time performance, chirality and smoothness.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of touch writing technology, and in particular to a writing trajectory smoothing method, device, equipment, and medium. Background Art

[0002] In various applications of touch control technology, users often want devices to understand their various touch operations, so they can understand their intent and quickly respond accordingly, providing them with more convenient and intelligent services. A common touch operation is sliding a touch object, such as a finger or stylus, across a touch detection surface. In this case, the device analyzes the object's trajectory on the touchscreen display to determine the user's intended action. Accurately tracking the object's trajectory is crucial to the device's ability to respond to user operations, so accurately capturing, tracking, and displaying the object's trajectory on the touchscreen display is crucial.

[0003] When identifying the motion trajectory of a touch object, the device identifies a series of discrete trajectory points based on frame-by-frame scan data. The trajectory points from previous and subsequent frames are then linked to form the object's motion trajectory. Due to the influence of touch hardware, the device cannot obtain high-precision position information of the trajectory points. This results in a certain deviation between the acquired position information and the actual touch position, resulting in jagged, uneven rendered trajectory that affects the user's visual experience. In related technologies, the trajectory is often interpolated and smoothed to produce a smoother writing trajectory.

[0004] However, the writing trajectory after the above interpolation and smoothing process lags behind the moving trajectory of the touch object and cannot meet the hand tracking requirement. Summary of the Invention

[0005] The purpose of the embodiments of the present application is to provide a writing trajectory smoothing method, device, equipment and medium, which can solve the problem that the writing trajectory after interpolation and smoothing lags behind the moving trajectory of the touch object and cannot meet the hand tracking requirements.

[0006] To achieve the above-mentioned purpose, one aspect of an embodiment of the present application provides a writing trajectory smoothing method, including: obtaining the sensing coordinates of multiple trajectory points generated in sequence by a writing operation on a touch display screen, the sensing coordinates of the multiple trajectory points including the sensing coordinates of a target trajectory point and the sensing coordinates of n-1 trajectory points before the target trajectory point, where n is an integer greater than 2; smoothing the sensing coordinates of the multiple trajectory points to obtain a smoothing parameter, wherein the smoothing parameter is used to filter and smooth the target trajectory point; using the smoothing parameter to obtain the smoothed coordinates of the target trajectory point; and using the smoothed coordinates of the target trajectory point to display the writing trajectory on the touch display screen.

[0007] The writing trajectory smoothing method provided in the embodiments of the present application obtains the sensing coordinates of multiple trajectory points, smoothes the sensing coordinates of the multiple trajectory points to obtain smoothing parameters, uses the smoothing parameters to obtain the smoothed coordinates of the target trajectory point, and uses the smoothed coordinates to display the writing trajectory on the touch screen. The smoothing parameters are used to filter and smooth the target trajectory point. Compared with related interpolation smoothing, this method has the advantages of real-time performance, good hand tracking, and good smoothing effect.

[0008] Optionally, the smoothing calculation of the sensed coordinates of the multiple trajectory points to obtain smoothing parameters includes: substituting the sensed coordinates of the multiple trajectory points into a preset polynomial to obtain n polynomial equations; using the least squares method to solve the n polynomial equations to obtain a smoothing relationship matrix; using the least squares method to solve the n polynomial equations to obtain a smoothing relationship matrix; and using the nth row vector of the smoothing relationship matrix as the smoothing parameter.

[0009] In this way, the least squares method can determine the parameters of the best fitting line or curve by minimizing the sum of squared errors, so that the signal change information can be more effectively preserved while filtering and smoothing.

[0010] Optionally, obtaining the smoothed coordinates of the target trajectory point by using the smoothing parameter includes: performing inner product summation on the smoothing parameter and the sensed coordinates of the plurality of trajectory points to obtain the smoothed coordinates of the target trajectory point.

[0011] Optionally, n is an odd number greater than 2.

[0012] To achieve the above-mentioned purpose, another aspect of an embodiment of the present application further provides a writing trajectory smoothing device, including: an acquisition module, used to acquire the sensing coordinates of multiple trajectory points generated in sequence by a writing operation on a touch display screen; the sensing coordinates of the multiple trajectory points include the sensing coordinates of the target trajectory point and the sensing coordinates of the first n-1 trajectory points of the target trajectory point, where n is an integer greater than 2; a processing module, used to smooth the sensing coordinates of the multiple trajectory points to obtain a smoothing parameter, and the smoothing parameter is used to filter and smooth the target trajectory point; the processing module is used to use the smoothing parameter to obtain the smoothed coordinates of the target trajectory point.

[0013] Optionally, the processing module is used to smooth the sensing coordinates of the multiple trajectory points to obtain smoothing parameters, including: the processing module is used to substitute the sensing coordinates of the multiple trajectory points into a preset polynomial to obtain n polynomial equations; the processing module is used to solve the n polynomial equations using the least squares method to obtain a smoothing relationship matrix; the processing module is used to use the nth row vector of the smoothing relationship matrix as the smoothing parameter.

[0014] Optionally, the processing module is used to obtain the smoothed coordinates of the target trajectory point using the smoothing parameter, including: the processing module is used to perform inner product summation on the smoothing parameter and the sensing coordinates of the multiple trajectory points to obtain the smoothed coordinates of the target trajectory point.

[0015] To achieve the above-mentioned purpose, another aspect of an embodiment of the present application further provides an interactive tablet, comprising a memory and a processor; the memory is used to store instructions executable by the processor; wherein the processor is configured to execute the writing trajectory smoothing method as described above.

[0016] To achieve the above-mentioned purpose, another aspect of an embodiment of the present application further provides a computer storage medium, in which computer-readable storage medium is stored computer execution instructions, and when the computer execution instructions are executed by a processor, they are used to implement the writing trajectory smoothing method described above.

[0017] To achieve the above-mentioned purpose, another aspect of an embodiment of the present application further provides a computer program product, including a computer program, which implements the writing trajectory smoothing method as described above when executed by a processor. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0019] Figure 1 A schematic diagram of smoothing processing in related technology;

[0020] Figure 2 A schematic structural diagram of a writing trajectory smoothing method, apparatus, device, and medium provided in an embodiment of the present application;

[0021] Figure 3 A schematic diagram of the structure of an interactive tablet provided in an embodiment of the present application;

[0022] Figure 4 A schematic diagram of a writing trajectory smoothing device provided in an embodiment of the present application;

[0023] Figure 5 A schematic diagram of an interactive tablet provided in an embodiment of the present application. DETAILED DESCRIPTION

[0024] As described in the background technology, the writing trajectory after the interpolation and smoothing processing of the related technology has the problem of lagging behind the moving trajectory of the touch object and failing to meet the hand tracking requirements. Specifically, the related interpolation and smoothing processing method may include inserting supplementary points between two adjacent trajectory points according to an algorithm, and generating a writing trajectory based on the trajectory points and the supplementary points. The trajectory points are the user touch coordinate points recognized by the device, and the supplementary points are the points added by the device according to the relevant algorithm. For example, Figure 1 In the figure, the device recognizes trajectory point 10 and trajectory point 20, and adds supplementary point 11 and supplementary point 12 between point 10 and point 20 according to the algorithm; the device recognizes trajectory point 20 and trajectory point 30, and adds supplementary point 21 between point 20 and point 30 according to the algorithm.

[0025] As can be seen from the above, the supplementary points are generated according to the algorithm after the user touches them. For example, when the user moves to track point 20, the writing track completes the calculation of supplementary points 11 and 12; when the user moves to track point 30, the writing track completes the calculation of supplementary point 21. In addition, when drawing the writing track, it is necessary to pass through the supplementary points first and then pass through the downstream track points. For example, when drawing the writing track C1, it is necessary to pass through track point 10, supplementary point 11, supplementary point 12 and track point 20 in sequence; when drawing the writing track C2, it is necessary to pass through track point 20, supplementary point 21 and track point 30 in sequence. In summary, the writing track lags behind the moving track for a long time and has poor tracking properties.

[0026] To address the above technical issues, the inventors of this application envisioned a method for directly obtaining smooth points at corresponding locations based on trajectory points, without resorting to interpolation. Connecting two adjacent smooth points would yield a smooth writing curve. Based on this idea, the inventors realized that if a smooth relationship between trajectory points and smooth points could be determined, then substituting the trajectory points into the smooth relationship, smooth points could be easily obtained. This smooth relationship can be derived from the target trajectory point and the n historical data points preceding it.

[0027] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments.

[0028] Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0029] Figure 2A flow chart of a writing trajectory smoothing method provided in an embodiment of the present application is given. The writing trajectory smoothing method provided in an embodiment of the present application can be performed by a writing trajectory smoothing device, which can be implemented by hardware and / or software and integrated in an interactive tablet. The interactive tablet can be composed of two or more physical entities, or it can be composed of one physical entity. For example, the interactive tablet can be a mobile phone, a conference teaching tablet (which can be large-sized), an industrial control computer, an intelligent interactive tablet for conference scenes (which can be large-sized), etc., which is used to realize the content display and interactive response in the human-computer interaction process. For ease of understanding, the embodiment uses the conference teaching tablet as the actual carrier to exemplarily describe the detailed process of detecting touch operations, judging touch operations, and displaying responses to touch operations when the annotation control method is implemented. The interactive tablet with the conference teaching tablet as the carrier can be an integrated device that uses touch technology to control the content displayed on the display tablet and realize human-computer interaction operations, which integrates one or more functions such as a projector, an electronic whiteboard, a screen, an audio system, a television, and a video conferencing terminal.

[0030] Figure 3 This is a schematic diagram of the structure of an interactive tablet provided in an embodiment of the present application. Figure 3 As shown, the interactive tablet includes at least one touch screen. The touch screen can be an infrared screen, a capacitive screen, a resistive screen or an electromagnetic screen, etc. On the touch screen, the user can implement touch operations by touching the screen with a finger or an intelligent writing pen, a hard pen, a soft pen (such as a brush), etc. as a writing pen. Accordingly, the interactive tablet can detect the touch position and respond according to the touch position to implement the touch function. Typically, the interactive tablet is installed with at least one operating system, wherein the operating system includes but is not limited to Android system, Linux system and Windows system. Furthermore, the interactive tablet can install at least one application with a writing function. Among them, the application can be an application that comes with the operating system, and at the same time, an application downloaded from a third-party device or server is also installed. Optionally, in addition to the writing function based on touch operation, the application also has other editing functions, such as inserting tables, inserting pictures, inserting graphics, drawing tables, drawing graphics, etc.

[0031] The graphical interface displayed on the interactive tablet's display screen also serves as the touch interface for detecting user operations, meaning the graphical interface and the touch interface essentially overlap. When a touch operation is performed on this touch interface, such as when a stylus touches the display screen, the display's touch module can sense changes in infrared light, current, voltage, or magnetic flux (corresponding to the specific settings of the infrared display, capacitive display, resistive display, or electromagnetic display), generating a touch signal containing the coordinates of the touch position and the trigger time of the touch signal. Based on the coordinates of the touch position and the trigger time of the touch signal, trajectory data for each writing trajectory input by the stylus during the process of pressing down to write and lifting up to stop writing can be obtained. Based on this trajectory data, the user's input writing trajectory is displayed in real time on the graphical interface of the lower video screen. Of course, the writing process is not limited to writing; any input process for displaying an operation trajectory implemented on the interactive tablet's display screen can be considered a writing process. Furthermore, depending on the display element where the touch operation occurs, the touch operation can be responded to as a user click, drag, or other operation. These different response methods utilize the same underlying coordinate processing method, ultimately resulting in visual changes in the image displayed on the display screen. Based on the hardware implementation of basic functions such as touch and display, various interactive display designs of interactive tablets can be realized.

[0032] refer to Figure 2 The writing trajectory smoothing method provided in the embodiment of the present application may include the following steps:

[0033] S101: Acquire sensing coordinates of a plurality of trajectory points sequentially generated by a writing operation on a touch screen.

[0034] Specifically, the interactive tablet may have a touch screen display that allows the user to write on it and can also be used to display the smoothing results of the writing trajectory on it for the user to view. In some embodiments, the interactive tablet may not have a touch screen display, but may be connected to another device with a touch screen display to obtain information collected by the touch screen display and send the smoothing results to the device for display after smoothing is completed.

[0035] When a user writes on a touchscreen display, the device can use the touchscreen to collect the user's track points on the touchscreen. Specifically, while the user is writing, the device collects the coordinates of the user's current touch location on the touchscreen at preset intervals as the sensed coordinates of the track points, thereby acquiring the sensed coordinates of multiple track points. The sensed coordinates of the track points include both X-axis values ​​and Y-axis values.

[0036] In addition, the multiple trajectory points mentioned in step S101 may include the coordinates of the target trajectory point and the first n trajectory points of the target trajectory point, where n is an integer greater than 2. For example, if the trajectory point at time t is used as the target trajectory point, the interval time is 1. Then the multiple trajectory points mentioned above are: n trajectory points between time t-n+1 and time t. That is to say, between time t-n+1 and time t, the device collects the sensing coordinates of n trajectory points. In addition, n can be an integer greater than 2, and the value of n should not be too small. If it is too small, the accuracy of the fitted trajectory is not high. Although the higher the value of n, the more data needs to be fitted and the smoother the trajectory, the precise coordinate information may be lost. Optionally, n can be an odd number greater than 2.

[0037] S102 , performing smoothing calculation on the sensing coordinates of the plurality of trajectory points to obtain smoothing parameters, where the smoothing parameters are used to perform filtering and smoothing on the target trajectory points.

[0038] In related technologies, writing trajectories can be smoothed using methods such as Savitzky-Golay filtering, Kalman filtering, Loess smoothing algorithm, and Butterworth filtering. These methods can all generate smoothing relationships based on historical real data and, based on these smoothing relationships, obtain target smoothed coordinates corresponding to the target true value.

[0039] However, the inventors discovered that the smoothed coordinates obtained using these smoothing methods exhibit lag. The inventors discovered that this lag occurs because the related art smoothing methods assign a higher weight to historical coordinates and a lower weight to the current touch point coordinates. This results in a greater emphasis on historical information during smoothing, and the current smoothed coordinates significantly lag behind the true coordinates, failing to meet hand tracking requirements and severely impacting the user experience. In light of this, the present invention provides an improved smoothing method based on existing smoothing methods.

[0040] The improved smoothing method is described below using Savitzky Golay filtering as an example.

[0041] Exemplarily, step S102 may include:

[0042] S1021, the sensed coordinates of the multiple track points are substituted into a preset polynomial to obtain n polynomial equations. Specifically, in step S1021, the sensed coordinates of the multiple track points are substituted into a K-order polynomial for fitting, and the fitting method is:

[0043] x t =α0+α1*t+α2*t 2 +…α k *t k

[0044] y t=β0+β1*t+β2*t 2 +…β k *t k

[0045] Among them, x t represents the X-axis coordinate at time t, α0 represents the X-axis polynomial fitting constant, α1,…,α k Represents the coefficients of the X-axis polynomial from 1st to kth order; y t represents the Y-axis coordinate at time t, β0 represents the Y-axis polynomial fitting constant, β1,…,β k Represents the coefficients of the Y-axis polynomial from order 1 to order k. In addition, K represents the polynomial order, which is used to fit the degree of the polynomial. A higher order indicates a better curve fitting effect, which will introduce more complex curve trends, retain more information of the original trajectory, and have poorer smoothness.

[0046] By fitting the sensing coordinates of each trajectory point from time t-n+1 to time t, we can get n polynomial equations, which can be converted into matrix form as shown below:

[0047]

[0048]

[0049] Simplify the above matrix:

[0050] X=TA

[0051] Y=TB

[0052] Where X represents the X-axis coordinates of multiple trajectory points from time t-n+1 to time t, and T represents multiple A represents the X-axis fitting polynomial coefficient matrix; Y represents the Y-axis coordinates of multiple trajectory points from time t-n+1 to time t, T represents the polynomial matrix, and B represents the Y-axis fitting polynomial coefficient matrix.

[0053] S1022. Solve n polynomial equations using the least squares method to obtain a smooth relationship matrix. S1023. Use the nth row vector of the smooth relationship matrix as a smoothing parameter.

[0054] Specifically, the polynomial coefficients are solved using the least squares method to obtain the X-axis polynomial fitting coefficient matrix A = (T'·T) -1 ·T'·X,Y axis polynomial fitting coefficient matrix is ​​B=(T'·T) -1 ·T'·Y. Where T' represents the transpose of matrix T, (T'·T) -1 represents the inverse of the matrix T'·T.

[0055] Among them, the least squares method is one of the most common curve fitting methods. It seeks the best function matching for the data by minimizing the sum of squares of errors. It is widely used in many disciplines of data processing such as error estimation, uncertainty, system identification, prediction, and forecasting.

[0056] For a given set of data (xi,yi) (i=0,1,2,...,m), we need to find the functional relationship y=F(x) between the independent variable x and the dependent variable y. However, since the observed data is often inaccurate, we do not require that y=F(x) pass through all points (xi,yi). Instead, we only require that the error δi=F(xi)-yi (i=0,1,2,...,m) at a given point xi be minimized according to some standard. If δ=(δ0,δ1,...,δm)T, then we are asking for the minimum norm of the vector δ. The Euclidean norm ‖δ‖2, which is relatively simple to calculate, is often used as a measure of error. This is the general least squares approximation, or, in geometric terms, the least squares method of curve fitting.

[0057] In addition, the fitting value of the polynomial curve at each coordinate point, that is, the smoothed coordinate, can be obtained based on the fitting polynomial coefficient matrix.

[0058] The smoothed coordinate of the X-axis is

[0059] The smoothed coordinate of the Y axis is

[0060] From this we can get the smooth relationship matrix S = T·(T'·T) -1 T'. The smooth relationship matrix can represent the relationship between the sensing coordinates of multiple trajectory points and multiple smooth coordinates. The smooth coordinates of the X axis The smoothed coordinate of the Y axis is

[0061] Based on this, the X-axis coordinate smoothing coordinate at time t Y-axis smoothing coordinate at time t Among them, S[n] is the smoothing parameter, which is the n-th row vector of the smoothing relationship matrix S.

[0062] Continue to refer Figure 2 , S103, using the smoothing parameters to obtain the smoothed coordinates of the target trajectory points.

[0063] Specifically, the smoothed coordinates of the target trajectory point are obtained by performing inner product summation on the smoothing parameter and the sensing coordinates of multiple trajectory points.

[0064] For example, n is 5, K is 1, and the X-axis coordinates are [1, 2, 3, 4, 5.2]. The deviation of the 5th coordinate point is large, so the 5th coordinate is smoothed. Through step S102, the smoothing parameter can be calculated as [-0.2, 0, 0.2, 0.4, 0.6]. The inner product of the coordinate and the smoothing parameter is obtained to obtain the smoothed coordinate of the 5th point as 5.12. Compared with the sensed X-axis coordinate 5.2, the smoothed X-axis coordinate 5.12 reduces the deviation distance by 0.08 units, effectively improving the abruptness. Among them, 5.12 is obtained by 1*(-0.2)+2*0+3*0.2+4*0.4+5.2*0.6.

[0065] It's worth noting that the existing Savitzky-Golay filter essentially uses the least squares curve fitting method for smoothing. This method primarily calculates the smoothing relationship matrix S using n and K, and uses the (n-1) / 2th row of the smoothing relationship matrix S as the smoothing parameter. The inner product of the smoothing parameter and the coordinates is equivalent to weighted smoothing of the sensed coordinates of the n trajectory points. However, this introduces a certain amount of hysteresis, primarily due to the selection of the (n-1) / 2th row of the smoothing relationship matrix S as the smoothing parameter, which is used to filter and smooth the intermediate coordinate points within the window.

[0066] Based on the hysteresis characteristics of the existing Savitzky-Golay filter, this solution improves the Savitzky-Golay filter, which also uses the least squares curve fitting method for smoothing and calculates the smoothing relationship matrix S using n and K. However, the method provided in the embodiment of the present application uses the nth row of the smoothing relationship matrix S as the smoothing parameter to smooth the coordinates of the last point, eliminating the influence of hysteresis and achieving real-time smoothing.

[0067] It should be noted that existing Savitzky-Golay filtering is generally used in applications requiring high precision, and therefore uses the (n-1) / 2th row of the smoothing relationship matrix S as the smoothing parameter. However, the present embodiment is applied in the field of touch writing, where precision requirements are lower but real-time performance and hand tracking are more important. Therefore, the method provided in the present embodiment uses the nth row of the smoothing relationship matrix S as the smoothing parameter.

[0068] In addition, the embodiment of the present application adopts the least square method to solve the polynomial coefficients and then obtain the smoothing parameters. The fixed smoothing parameter method can be used to avoid the adaptive calculation of the coefficients at each moment and improve the operation efficiency. In addition, the embodiment of the present application adopts the fitting method to smooth the sensing coordinate points to obtain smoothed coordinate points, which will change the position of the sensing coordinate points and can smooth the abrupt trajectory points. The Bezier curve interpolation method inserts a supplementary point in the middle area between two adjacent sensing coordinate points, which will not change the position of the original point and cannot smooth the abrupt contact points.

[0069] S104: Display the writing track on the touch screen using the smoothed coordinates of the target track point.

[0070] Specifically, a line may be drawn between the coordinates of the previous track point of the target track point and the smoothed coordinates of the target track point, and the line may be displayed on the touch screen. The line is a portion of the writing track. The coordinates of the previous track point of the target track point may be the sensed coordinates of the previous track point of the target track point or the smoothed coordinates of the previous track point of the target track point.

[0071] It is understandable that every time a user starts writing or drawing on the interactive tablet, the first n-1 reported points may not be smoothed, but drawn and displayed using the sensing coordinates. Obviously, in the initial stage of each writing or drawing, since the number of historical trajectory points may be less than n-1, smoothing is not performed. Instead, smoothing is performed when the number of historical reported points meets n-1. It is understandable that the interactive tablet can collect approximately more than 300 sensing coordinates. Therefore, for example, 30 reported points can be collected in only about 100 milliseconds. If the value of n is 10, it will be completed in just over 30 milliseconds. For the user, this is very short, even imperceptible, and will not cause a serious delay experience.

[0072] Based on this, when the target trajectory point is the nth point acquired by the device, the number of historical trajectory points for that target trajectory point is n-1. The point immediately preceding that target trajectory point is the n-1th point acquired by the device, and the number of historical trajectory points for that target trajectory point is n-2. Since n-2 is less than n-1, steps S101, S102, and S103 are not performed for the n-1th point acquired by the device. Thus, when performing step S104, a line can be drawn between the sensed coordinates of the previous point of the target trajectory point and the smoothed coordinates of the target trajectory point.

[0073] For example, n=30, the target track point is the 30th track point acquired by the device, and the previous track point of the target track point is the 29th track point acquired by the device. The sensing coordinates of the 30th track point can be used to obtain the smoothed coordinates of the 30th track point through steps S101, S102, and S103. In step S104, a line is drawn between the sensing coordinates of the 29th track point and the smoothed coordinates of the 30th track point, and the line is displayed on the touch screen. In the process of forming a writing track by the first 29 track points, a line can be drawn between every two adjacent track points in the first 29 track points, and the line can be displayed on the touch screen.

[0074] Furthermore, when the target trajectory point is the n+m (m is an integer greater than zero) point acquired by the device, the number of historical trajectory points for this target trajectory point is n+m-1. The previous point of this target trajectory point is the n+m-1 point acquired by the device, and the number of historical trajectory points for this target trajectory point is n+m-2, where n+m-2 is greater than or equal to n-1. Therefore, when performing step S104, a line can be drawn between the smoothed coordinates of the previous point of the target trajectory point and the smoothed coordinates of the target trajectory point.

[0075] For example, if n = 30, the target trajectory point is the 50th trajectory point acquired by the device, and the previous trajectory point is the 49th trajectory point acquired by the device. The sensed coordinates of the 50th trajectory point can be processed through steps S101, S102, and S103 to obtain the smoothed coordinates of the 50th trajectory point; and the sensed coordinates of the 49th trajectory point can be processed through steps S101, S102, and S103 to obtain the smoothed coordinates of the 49th trajectory point. In step S104, a line is drawn between the smoothed coordinates of the 49th trajectory point and the smoothed coordinates of the 50th trajectory point, and the line is displayed on the touch screen.

[0076] It should be noted that to further reduce hysteresis, after obtaining the smoothed coordinates of the target trajectory point, a prediction method can be used to obtain one or more future coordinates. A line is then drawn between the smoothed coordinates of the target trajectory point and the future coordinates, and this line is displayed on the touch screen. Various prediction methods exist in the prior art, and they will not be listed here.

[0077] refer to Figure 4 The present application also provides a writing trajectory smoothing device, which may include an acquisition module and a processing module. The acquisition module may be used to acquire the sensed coordinates of multiple trajectory points generated by a writing operation on a touch screen display. The sensed coordinates of the multiple trajectory points may include the sensed coordinates of a target trajectory point and the sensed coordinates of the n-1 trajectory points preceding the target trajectory point. Here, n may be an integer greater than 2; alternatively, n may be an odd number greater than 2.

[0078] The processing module can be used to smooth the sensed coordinates of multiple trajectory points to obtain smoothing parameters, which are used to filter and smooth the target trajectory points; the processing module is used to use the smoothing parameters to obtain the smoothed coordinates of the target trajectory points; the processing module can also be used to use the smoothed coordinates of the target trajectory points to display the writing trajectory on the touch display screen.

[0079] Optionally, the processing module may be configured to smooth the sensed coordinates of the plurality of trajectory points to obtain a smoothing parameter, including: the processing module being configured to substitute the sensed coordinates of the plurality of trajectory points into a preset polynomial to obtain n polynomial equations; the processing module being configured to solve the n polynomial equations using a least squares method to obtain a smoothing relationship matrix; and the processing module being configured to use the nth row vector of the smoothing relationship matrix as the smoothing parameter.

[0080] Optionally, the processing module being configured to obtain the smoothed coordinates of the target trajectory point using the smoothing parameter may include: the processing module being configured to perform inner product summation of the smoothing parameter and the sensed coordinates of the plurality of trajectory points to obtain the smoothed coordinates of the target trajectory point.

[0081] The embodiment of the present application also provides an interactive tablet, which can be integrated with the writing trajectory smoothing device provided in the embodiment of the present application. Figure 5 This is a schematic diagram of the structure of an interactive tablet provided by an embodiment of the present application. Figure 5 The interactive tablet may include: an input device 330, an output device 340, a memory 320, and one or more processors 310. The memory 320 may be used to store one or more programs. When one or more programs are executed by one or more processors 310, the one or more processors 310 implement the writing trajectory smoothing method provided in the above embodiment. The input device 330, the output device 340, the memory 320, and the processor 310 may be connected via a bus or other means. Figure 5 The bus connection is taken as an example.

[0082] Memory 320, as a computing device-readable storage medium, can be used to store software programs, computer-executable programs, and modules, such as program instructions / modules corresponding to the writing trajectory smoothing method of any embodiment of the present application (e.g., the acquisition module 210 and the processing module 220 in the writing trajectory smoothing device). Memory 320 may primarily include a program storage area and a data storage area. The program storage area may store an operating system and at least one application required for a function; the data storage area may store data generated based on the use of the device. Furthermore, memory 320 may include high-speed random access memory and non-volatile memory, such as at least one disk storage device, flash memory device, or other non-volatile solid-state memory device. In some instances, memory 320 may further include memory remotely located relative to processor 310, and such remote memory may be connected to the device via a network. Examples of such networks include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0083] The input device 330 may be used to receive input digital or character information and generate key signal input related to user settings and function control of the device. The output device 340 may include a display device such as a display screen.

[0084] The processor 310 executes various functional applications and data processing of the device by running the software programs, instructions and modules stored in the memory 320, that is, implements the above-mentioned writing trajectory smoothing method.

[0085] The writing trajectory smoothing device, equipment and computer provided above can be used to execute the writing trajectory smoothing method provided in any of the above embodiments, and have corresponding functions and beneficial effects.

[0086] An embodiment of the present application also provides a storage medium containing computer-executable instructions. When the computer-executable instructions are executed by a computer processor, they are used to execute the writing trajectory smoothing method provided in the above embodiment. The writing trajectory smoothing method includes: obtaining the sensing coordinates of multiple trajectory points generated by a writing operation on a touch display screen; smoothing the sensing coordinates of the multiple trajectory points to obtain smoothing parameters, where the smoothing parameters are used to filter and smooth the target trajectory points; and using the smoothing parameters to obtain the smoothed coordinates of the target trajectory points.

[0087] Storage medium - any of various types of memory devices or storage devices. The term "storage medium" is intended to include: installation media, such as CD-ROMs, floppy disks, or tape drives; computer system memory or random access memory, such as DRAM, DDR RAM, SRAM, EDO RAM, Rambus RAM, etc.; non-volatile memory, such as flash memory, magnetic media (such as hard disks or optical storage); registers or other similar types of memory elements, etc. Storage media may also include other types of memory or combinations thereof. In addition, the storage medium may be located in the first computer system in which the program is executed, or it may be located in a different second computer system that is connected to the first computer system via a network (such as the Internet). The second computer system can provide program instructions to the first computer for execution. The term "storage medium" may include two or more storage media that can reside in different locations (e.g., in different computer systems connected via a network). The storage medium can store program instructions (e.g., embodied as a computer program) that can be executed by one or more processors.

[0088] Of course, the storage medium containing computer-executable instructions provided in an embodiment of the present application, whose computer-executable instructions are not limited to the above-mentioned writing trajectory smoothing method, can also execute related operations in the writing trajectory smoothing method provided in any embodiment of the present application.

[0089] The writing trajectory smoothing device, equipment and storage medium provided in the above embodiments can execute the writing trajectory smoothing method provided in any embodiment of the present application. For technical details not described in detail in the above embodiments, please refer to the writing trajectory smoothing method provided in any embodiment of the present application.

[0090] The above are only preferred embodiments of the present application and the technical principles employed. The present application is not limited to the specific embodiments described herein, and any obvious changes, readjustments, and substitutions that are apparent to those skilled in the art will not depart from the scope of protection of the present application. Therefore, although the present application has been described in detail through the above embodiments, the present application is not limited to the above embodiments and may include many other equivalent embodiments without departing from the scope of the present application. The scope of the present application is determined by the scope of the claims.

Claims

1. A writing trajectory smoothing method, characterized in that: include: Acquire the sensed coordinates of a plurality of track points sequentially generated by a writing operation on the touch display screen, the sensed coordinates of the plurality of track points including the sensed coordinates of a target track point and the sensed coordinates of n-1 track points preceding the target track point, where n is an integer greater than 2; Smoothing the sensed coordinates of the plurality of trajectory points to obtain smoothing parameters, wherein the smoothing parameters are used to filter and smooth the target trajectory points; Obtaining smoothed coordinates of the target trajectory point using the smoothing parameter; The writing track is displayed on the touch display screen using the smoothed coordinates of the target track point.

2. The method according to claim 1, characterized in that The step of performing smoothing calculation on the sensing coordinates of the plurality of trajectory points to obtain smoothing parameters comprises: Substitute the sensed coordinates of multiple trajectory points into a preset polynomial to obtain n polynomial equations; Solving the n polynomial equations using the least squares method to obtain a smooth relationship matrix; The nth row vector of the smooth relationship matrix is ​​used as a smoothing parameter.

3. The method according to claim 2, characterized in that The obtaining of the smoothed coordinates of the target trajectory point by using the smoothing parameter comprises: The smoothing parameter and the sensing coordinates of the plurality of trajectory points are summed by inner product to obtain the smoothing coordinates of the target trajectory point.

4. The method according to claim 1, wherein n is an odd number greater than 2.

5. A writing trajectory smoothing device, characterized in that: include: an acquisition module, configured to acquire the sensed coordinates of a plurality of track points sequentially generated by a writing operation on the touch display screen; the sensed coordinates of the plurality of track points include the sensed coordinates of a target track point and the sensed coordinates of n-1 track points preceding the target track point, where n is an integer greater than 2; The processing module is used to smooth the sensed coordinates of the multiple trajectory points to obtain smoothing parameters, and the smoothing parameters are used to filter and smooth the target trajectory points; the processing module is used to use the smoothing parameters to obtain the smoothed coordinates of the target trajectory points; the processing module also uses the smoothed coordinates of the target trajectory points to display the writing trajectory on the touch screen.

6. The device according to claim 5, characterized in that The processing module is configured to perform smoothing calculation on the sensing coordinates of the plurality of trajectory points to obtain smoothing parameters, including: The processing module is used to substitute the sensed coordinates of multiple trajectory points into a preset polynomial to obtain n polynomial equations; the processing module is used to solve the n polynomial equations using the least squares method to obtain a smooth relationship matrix; the processing module is used to use the nth row vector of the smooth relationship matrix as a smoothing parameter.

7. The device according to claim 5, characterized in that The processing module is configured to obtain the smoothed coordinates of the target trajectory point using the smoothing parameter, including: The processing module is used to perform inner product summation on the smoothing parameter and the sensing coordinates of the plurality of trajectory points to obtain the smoothed coordinates of the target trajectory point.

8. An interactive tablet, characterized in that: including memory and processor; The memory is a memory for storing instructions executable by the processor; The processor is configured to execute the writing trajectory smoothing method according to any one of claims 1 to 4.

9. A computer storage medium, characterized in that The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the writing trajectory smoothing method according to any one of claims 1 to 4.

10. A computer program product, characterized in that The invention comprises a computer program, which implements the writing trajectory smoothing method according to any one of claims 1 to 4 when executed by a processor.

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