Projection correction method and projection device

Abstract

The application relates to a projection correction method and a projection device. The method comprises the following steps: acquiring each detection point information corresponding to a detection range; performing regional division on the detection point information to obtain each current extraction region, and performing planar processing on each current extraction region to obtain a current extraction plane of each corresponding extraction region; processing each current extraction plane to obtain a target projection plane; obtaining an attitude angle according to the target projection plane, and correcting a current projection picture based on the attitude angle to obtain a corrected picture, thereby realizing projection correction, obtaining a target projection plane to be projected through accurate processing, determining an accurate attitude angle of a projector relative to the target projection plane, and then obtaining an accurate trapezoidal corrected picture, so that correction error is reduced, and trapezoidal correction accuracy is improved.

Description

Technical Field

[0001] This application relates to the field of image processing technology, and in particular to a projection correction method and projection device. Background Technology

[0002] A projector, also known as a projection machine, is a device that projects images or videos onto a screen or wall. To achieve a better user experience, the projected image is typically corrected to a rectangular shape. For example, when a projector is tilted towards a target projection surface such as a screen or wall, the image projected onto that surface will appear trapezoidal. In this case, it needs to be corrected back to a matrix shape to avoid affecting the user's viewing experience.

[0003] In existing projection trapezoidal correction methods, a triangular model in space is usually established using depth and angle data from three detection points. The tilt angle of the projector relative to the wall is then calculated based on the triangular model.

[0004] During the implementation process, the inventors discovered that the traditional technology has at least the following problems: In the existing projection trapezoidal correction method, when there is a wall corner between any two detection points, the wall corner cannot be taken into account, resulting in inaccurate calculated attitude angles, large correction errors, and affecting the accuracy of the final trapezoidal correction. Summary of the Invention

[0005] Therefore, it is necessary to address the problems existing in the above-mentioned existing projection trapezoidal correction methods by providing a projection correction method and projection device that can accurately process and obtain the target projection plane, determine the precise attitude angle of the projector relative to the target projection plane, and thus obtain an accurate trapezoidal corrected image, thereby reducing correction errors and improving the accuracy of trapezoidal correction.

[0006] In a first aspect, this application provides a projection correction method, comprising the following steps: Obtain information on each detection point within the corresponding detection range; The information of each detection point is divided into regions to obtain each current extraction region, and each current extraction region is processed by plane to obtain the current extraction plane of each corresponding extraction region; Process each currently extracted plane to obtain the target projection plane; Based on the target projection plane, the attitude angle is obtained, and the current projected image is corrected based on the attitude angle to obtain the corrected image.

[0007] Optionally, each current extraction plane can be divided into a current intermediate extraction plane and several current auxiliary extraction planes; The steps for processing each currently extracted plane to obtain the target projection plane include: Obtain the first normal of the current intermediate extraction plane and the second normal of each corresponding current subordinate extraction plane; Calculate the included angles between the first normal and each of the second normals to obtain the included angles of each normal. When each normal corner falls within the first preset range, the current intermediate extraction plane is identified as the target projection plane.

[0008] Optionally, after calculating the angles between the first normal and each of the second normals to obtain the angles between each normal, the method further includes: When the corners of each normal are within the second preset range, the current intermediate extraction plane is identified as the target projection plane; any value of the second preset range is greater than any value of the first preset range.

[0009] Optionally, each current extraction region is divided into a current intermediate extraction region corresponding to the current intermediate extraction plane and several current subordinate extraction regions corresponding to the current subordinate extraction plane; After calculating the angles between the first normal and each of the second normals to obtain the angles between each normal, the following steps are included: When at least one normal angle does not fall within the first preset range and the second preset range, the current auxiliary extraction area corresponding to the at least one normal angle not falling within is identified as the auxiliary extraction area to be adjusted, and the current intermediate extraction area is identified as the intermediate extraction area to be adjusted. Based on the preset width increment value, the width of the auxiliary extraction area to be adjusted is adjusted to obtain the adjusted auxiliary extraction area and the adjusted middle extraction area. The adjusted secondary extraction region and the adjusted intermediate extraction region are processed by plane to obtain the adjusted secondary extraction plane and the adjusted intermediate extraction plane; When the difference between the adjusted intermediate extraction plane and the corresponding intermediate extraction plane of the area to be adjusted is greater than a preset threshold, the adjusted intermediate extraction plane is confirmed as the target projection plane.

[0010] Optionally, the step of dividing the information of each detection point into regions to obtain each currently extracted region includes: Based on the preset vertical division rules, the information of each detection point is divided into regions to obtain the current first middle extraction region, the current first side auxiliary extraction region, and the current second side auxiliary extraction region; The steps for performing planar processing on each currently extracted region to obtain the current extraction plane for each corresponding extracted region include: Planar processing is performed on the current first intermediate extraction region, the current first side auxiliary extraction region, and the current second side auxiliary extraction region to obtain each current extraction plane.

[0011] Optionally, the step of dividing the information of each detection point into regions to obtain each currently extracted region also includes: Based on the preset horizontal division rules, the information of each detection point is divided into regions to obtain the current second intermediate extraction region, the current third side auxiliary extraction region, and the current fourth side auxiliary extraction region; The steps for performing planar processing on each currently extracted region to obtain the current extraction plane for each corresponding extracted region include: Perform planar processing on the current second intermediate extraction region, the current third side auxiliary extraction region, and the current fourth side auxiliary extraction region to obtain each current extraction plane.

[0012] Optionally, the step of performing planar processing on each currently extracted region to obtain the current extraction plane for each corresponding extracted region includes: Based on the least squares algorithm, plane fitting is performed on each currently extracted region to obtain each currently extracted plane.

[0013] Optionally, the steps for obtaining the attitude angles based on the target projection plane include: The yaw angle is obtained from the angle between the third normal of the target projection plane and the X-axis in the spatial coordinate system; and / or The pitch angle is obtained by the angle between the third normal of the target projection plane and the Y-axis in the spatial coordinate system.

[0014] Optionally, the detection point information includes angle information and distance information; Before obtaining the attitude angles based on the target projection plane, the following steps are included: Acquire information from various angles and distances; Plane fitting is performed based on the angle and distance information to obtain the target projection plane.

[0015] Secondly, this application provides a projection device, including a detection module and a processor, wherein the detection module is connected to the processor; the detection module is used to obtain information of each detection point in the corresponding detection range based on the detection light output to the detection range; the processor is used to execute the steps of any of the projection correction methods described above.

[0016] One of the above technical solutions has the following advantages and beneficial effects: In the aforementioned projection correction method, information on each detection point within the corresponding detection range is acquired; the information on each detection point is divided into regions to obtain current extraction regions; each current extraction region is processed to obtain a current extraction plane; each current extraction plane is processed to obtain a target projection plane; the attitude angle is obtained based on the target projection plane; and the current projected image is corrected based on the attitude angle to obtain a corrected image, thereby achieving projection correction. This invention obtains a large amount of depth and angle data from detection points, performs segmented extraction calculations on these detection points in space, that is, fits multiple planes based on segmented regions within the detection range, and then determines the target projection plane from these, thereby determining a more precise attitude angle of the projector relative to the target projection plane. This helps to accurately execute subsequent correction steps, resulting in an accurate corrected image. It achieves precise processing to obtain the target projection plane, determines the precise attitude angle of the projector relative to the target projection plane, and thus obtains an accurate trapezoidal correction image, reducing correction errors and improving trapezoidal correction accuracy. Attached Figure Description

[0017] Figure 1 This is a schematic diagram illustrating the application scenario of the projection correction method in the embodiments of this application; Figure 2 This is a schematic diagram of the first process of the projection correction method in the embodiments of this application; Figure 3 This is a schematic diagram of the first process of obtaining the target projection plane in an embodiment of this application; Figure 4 This is a schematic diagram of the second process of obtaining the target projection plane in an embodiment of this application; Figure 5 This is a schematic diagram of the second process of the projection correction method in the embodiments of this application; Figure 6 This is a schematic diagram of the third process of the projection correction method in the embodiments of this application; Figure 7 This is a schematic diagram of the detection range of the projection correction method in the embodiments of this application; Figure 8 This is a schematic diagram illustrating the division of the detection range area of ​​the projection correction method in this embodiment of the application; Figure 9 This is a schematic diagram showing the area to be adjusted in the projection correction method of this application embodiment; Figure 10 This is a schematic diagram showing the adjusted detection range area of ​​the projection correction method in this embodiment of the application; Figure 11 This is a schematic diagram of the attitude angle adjustment of the projection correction method in the embodiments of this application; Figure 12This is a schematic diagram illustrating the establishment of the spatial coordinate system for the projection correction method in the embodiments of this application; Figure 13 This is a schematic diagram of the tilted plane S2 established by the projection correction method in the embodiments of this application; Figure 14 This is a schematic diagram illustrating the establishment of plane K in the projection correction method of this application embodiment; Figure 15 This is a schematic diagram illustrating the establishment of the trapezoidal region S3 in the projection correction method of this application embodiment; Figure 16 This is a schematic diagram illustrating the establishment of the rectangular region S4 in the projection correction method of this application embodiment; Figure 17 This is a schematic diagram of the rectangular region S5 established in the projection correction method of this application embodiment; Figure 18 This is a schematic diagram illustrating the establishment of the projection area S6 in the projection correction method of this application embodiment; Figure 19 This is a schematic diagram of the projection device in the embodiments of this application. Detailed Implementation

[0018] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0019] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0020] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0021] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0022] In addition, the term "multiple" should mean two or more.

[0023] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0024] The projection correction method provided in this application can be applied to, for example... Figure 1 In the application environment shown, the processing device may include a processor 102 and a detection module 104. The processor 102 is connected to the detection module 104 and can be used to acquire information of each detection point within the corresponding detection range; divide the information of each detection point into regions to obtain each current extraction region; perform planar processing on each current extraction region to obtain the current extraction plane of each corresponding extraction region; process each current extraction plane to obtain the target projection plane; obtain the attitude angle based on the target projection plane; and correct the current projected image based on the attitude angle to obtain the corrected image. The detection module 104 can be used to obtain information of each detection point within the corresponding detection range based on the detection light rays output to the detection range. The processing device may be a projection device, the processor 102 may be the main processor 102 of the projector, and the detection module 104 may be a lidar module, for example, a high-array lidar ranging radar module.

[0025] In one embodiment, such as Figure 2 As shown, a projection correction method is provided, which is applied to... Figure 1 Taking the processor in the example, the following steps are included: Step S210: Obtain information on each detection point within the corresponding detection range.

[0026] The detection module can be used to project a detection array onto a wall or screen. The detection module may include millimeter-wave radar, infrared light, ultrasound, etc. Distance measurement uses ITOF and DTOF methods, hereinafter referred to as TOF (Time of Flight) sensors. Taking the infrared light emission method as an example, the TOF sensor emits modulated near-infrared light, which is reflected upon encountering an object. The TOF sensor calculates the distance to the object being photographed by calculating the time difference or phase difference between the emission and reflection of the light, thus generating depth information.

[0027] A Time-of-Flight (TOF) sensor emits a large number of detection rays within its detection range. A TOF array is the collection of all the detection rays projected from the TOF sensor, with each ray representing a detection point. Each detection point has corresponding emission angle information, and the TOF sensor can calculate the distance to the object detected by each point. This allows the sensor to determine the information of each reflected detection point and transmit this information to the processor. The processor then obtains the information of each detection point within the corresponding detection range. For example, the detection point information can be the spherical coordinates (r, φ, θ). Based on the spherical coordinates of each detection point, a rough outline of the detection range can be formed in a spatial coordinate system. The more detection points there are, the more detailed the outline information.

[0028] Step S220: Divide the information of each detection point into regions to obtain each current extraction region, and perform planar processing on each current extraction region to obtain the current extraction plane of each corresponding extraction region.

[0029] The processor receives information from each detection point and divides the area into extraction regions, thus obtaining each current extraction region. Based on the coordinates of the detection points in each current extraction region, the processor fits a plane corresponding to each extraction region in a spatial coordinate system, thus obtaining the current extraction plane for each corresponding extraction region.

[0030] For example, such as Figure 7 and Figure 8As shown, the detection range is set as a rectangle, preferably divided into three extraction regions: left, middle, and right. The width of the left extraction region is DL1, the width of the right extraction region is DR1, DL2 is the distance from the left edge of the projection range to the left edge of the detection range, and DR2 is the distance from the right edge of the projection range to the right edge of the detection range. The total width of the detection range is D0, and the width of the middle extraction region is D0-DL1-DR1. After dividing the detection range into three regions, the coordinates of each detection point in the left extraction region are fitted to a left plane, i.e., the current extraction plane corresponding to the left extraction region is the left plane; the coordinates of each detection point in the middle extraction region are fitted to a middle plane, i.e., the current extraction plane corresponding to the middle extraction region is the middle plane; and the coordinates of each detection point in the right extraction region are fitted to a right plane, i.e., the current extraction plane corresponding to the right extraction region is the right plane.

[0031] For example, the detection range can be divided into three extraction regions: upper, middle, and lower. The width of the upper extraction region is DU1, the width of the lower extraction region is DD1, DU2 is the distance from the upper edge of the projection range to the upper edge of the detection range, and DD2 is the distance from the lower edge of the projection range to the lower edge of the detection range. After dividing the detection range into three regions, the coordinates of each detection point in the upper extraction region are fitted to an upper plane, i.e., the current extraction plane for the upper extraction region is the upper plane; the coordinates of each detection point in the middle extraction region are fitted to a middle plane, i.e., the current extraction plane for the middle extraction region is the middle plane; and the coordinates of each detection point in the lower extraction region are fitted to a lower plane, i.e., the current extraction plane for the lower extraction region is the lower plane.

[0032] Step S230: Process each currently extracted plane to obtain the target projection plane.

[0033] The target projection plane is the plane that the projection device wants to project onto.

[0034] The processor processes each current extraction plane, determines whether the current extraction planes corresponding to each extraction region are the same plane, and obtains the target projection plane.

[0035] For example, the processor can construct a plane equation for each currently extracted plane in a spatial coordinate system (e.g., Based on the plane equation, the normal vector of the corresponding currently extracted plane can be obtained. By determining whether the included angle of the normals of each currently extracted plane meets the preset conditions, it is further determined whether each currently extracted plane belongs to the same plane, and then whether there are wall corners between each currently extracted plane. If each currently extracted plane belongs to the same plane, it is determined that there are no wall corners between each currently extracted plane, and thus the target projection plane is obtained, such as confirming the intermediate extracted plane as the target projection plane.

[0036] Step S240: Obtain the attitude angle based on the target projection plane, and correct the current projection image based on the attitude angle to obtain the corrected image.

[0037] Attitude angles can include yaw, pitch, and roll. Yaw and pitch angles can be determined based on the angle between the target projection plane and the X-axis or Y-axis, while roll angle can be determined using a gyroscope.

[0038] For example, the plane equation of the target projection plane can be set as follows: The normal vector of the plane is The processor then obtains the corresponding attitude angle based on the plane equation and plane normal vector of the target projection plane, and then corrects the current projected image based on the attitude angle to obtain the corrected image. For example, the processor can determine the tilt of the projected image of the projection device in the spatial coordinate system based on the attitude angle and perform trapezoidal correction on the image to obtain the corrected image.

[0039] In the above embodiments, information on each detection point within the corresponding detection range is acquired; the information on each detection point is divided into regions to obtain each current extraction region; each current extraction region is processed to obtain the current extraction plane of each corresponding extraction region; each current extraction plane is processed to obtain the target projection plane; the attitude angle is obtained based on the target projection plane; and the current projected image is corrected based on the attitude angle to obtain the corrected image, thereby achieving projection correction. This invention obtains a large amount of depth and angle data from detection points, performs segmented extraction calculations on these detection points in space, that is, fits multiple planes based on segmented regions within the detection range, and then determines the target projection plane from them, thereby determining a more precise attitude angle of the projector relative to the target projection plane. This helps to accurately execute subsequent correction steps, resulting in an accurate corrected image. It can accurately process and obtain the target projection plane, determine the precise attitude angle of the projector relative to the target projection plane, and thus obtain an accurate trapezoidal correction image, reducing correction errors and improving trapezoidal correction accuracy.

[0040] In one embodiment, such as Figure 3As shown, each current extraction plane is divided into a current intermediate extraction plane and several current subordinate extraction planes. The steps for processing each current extraction plane to obtain the target projection plane include: Step S310: Obtain the first normal of the current intermediate extraction plane and the second normal of each corresponding current subordinate extraction plane.

[0041] Each current extraction plane can be divided into a current intermediate extraction plane and several current subordinate extraction planes. A current subordinate extraction plane refers to the extraction plane adjacent to the current intermediate extraction plane. For example, based on the division of left, middle, and right extraction regions, each current extraction plane can be divided into a current left extraction plane corresponding to the left extraction region, a current middle extraction plane corresponding to the middle extraction region, and a current right extraction plane corresponding to the right extraction region.

[0042] The processor can construct a corresponding plane equation in the spatial coordinate system for the current intermediate extraction plane and several current subordinate extraction planes (e.g., Based on the plane equation, the normal vector of the corresponding plane can be obtained. This allows us to obtain the first normal of the current intermediate extraction plane and the second normal of each corresponding current subordinate extraction plane.

[0043] Step S320: Calculate the included angles between the first normal and each of the second normals to obtain the included angles of each normal.

[0044] The processor can calculate the angle between the first normal and each of the second normals, calculate the size of the angle between the first normal and each of the second normals, and then obtain the angle between each normal.

[0045] Step S330: When the corners of each normal line are within the first preset range, the current intermediate extraction plane is confirmed as the target projection plane.

[0046] For example, the first preset range can be set to -10° to 10°. The processor can determine whether the included angles of each normal fall within the first preset range. If the included angles of each normal fall within the first preset range, the current intermediate extraction plane is confirmed as the target projection plane.

[0047] For example, the first normal is the normal corresponding to the current intermediate extraction plane, and there are two second normals: one corresponding to the current left extraction plane and the other corresponding to the current right extraction plane. When the angle between the first normal and each of the second normals falls within a first preset range, it is considered that the current left extraction plane and the current intermediate extraction plane belong to the same plane, and the current right extraction plane and the current intermediate extraction plane belong to the same plane, with no wall corner between them. Therefore, the current intermediate extraction plane is identified as the target projection plane. Furthermore, the processor determines a more precise attitude angle of the projector relative to the target projection plane and corrects the current projected image based on this attitude angle, thereby obtaining an accurate corrected image. This enables precise processing to obtain the target projection plane, determines the precise attitude angle of the projector relative to the target projection plane, and thus obtains an accurate trapezoidal correction image, reducing correction errors and improving trapezoidal correction accuracy.

[0048] Furthermore, the first normal is the normal corresponding to the current intermediate extraction plane, and there are two second normals: one corresponding to the current upper extraction plane and the other corresponding to the current lower extraction plane. When the angle between the first normal and each of the second normals falls within the first preset range, it is considered that the current upper extraction plane and the current intermediate extraction plane belong to the same plane, and the current lower extraction plane and the current intermediate extraction plane belong to the same plane. There is no ceiling or ground between them, so the current intermediate extraction plane is identified as the target projection plane. This enables precise processing to obtain the target projection plane, determine the precise attitude angle of the projector relative to the target projection plane, and obtain an accurate trapezoidal correction image, reducing correction errors and further improving the accuracy of trapezoidal correction.

[0049] In one example, step S320 is followed by: When the corners of each normal are within the second preset range, the current intermediate extraction plane is identified as the target projection plane; any value of the second preset range is greater than any value of the first preset range.

[0050] The second preset range can be set to 80° to 100°.

[0051] The processor can determine whether the included angle of each normal falls within the second preset range. If the included angle of each normal falls within the second preset range, the current intermediate extraction plane is confirmed as the target projection plane.

[0052] For example, the first normal is the normal corresponding to the current intermediate extraction plane, and there are two second normals: one corresponding to the current left extraction plane and the other corresponding to the current right extraction plane. When the angle between the first normal and each of the second normals falls within a second preset range, the wall corner is considered to be near the left or right extraction boundary, within the allowable range of projection correction error. Therefore, the current intermediate extraction plane is confirmed as the target projection plane. Furthermore, the processor determines a more precise attitude angle of the projector relative to the target projection plane and corrects the current projected image based on this attitude angle, thereby obtaining an accurate corrected image. This enables precise processing to obtain the target projection plane, determines the precise attitude angle of the projector relative to the target projection plane, and thus obtains an accurate trapezoidal correction image, reducing correction errors and improving trapezoidal correction accuracy.

[0053] Furthermore, the first normal is the normal corresponding to the current intermediate extraction plane, and there are two second normals: one corresponding to the current upper extraction plane and the other corresponding to the current lower extraction plane. When the angle between the first normal and each of the second normals falls within the second preset range, the ceiling or ground is considered to be near the left or right extraction boundary, within the allowable range of projection correction error. Thus, the current intermediate extraction plane is confirmed as the target projection plane, enabling precise processing to obtain the target projection plane and determine the precise attitude angle of the projector relative to the target projection plane. This results in an accurate trapezoidal correction image, reducing correction error and further improving the accuracy of trapezoidal correction.

[0054] In one embodiment, such as Figure 4 As shown, each current extraction region is divided into the current intermediate extraction region corresponding to the current intermediate extraction plane and several current subordinate extraction regions corresponding to the current subordinate extraction plane.

[0055] After calculating the angles between the first normal and each of the second normals to obtain the angles between each normal, the following steps are included: Step S410: When at least one normal angle does not fall into the first preset range and the second preset range, the current auxiliary extraction area corresponding to the at least one normal angle not falling into is identified as the auxiliary extraction area to be adjusted, and the current intermediate extraction area is identified as the intermediate extraction area to be adjusted.

[0056] Each current extraction region can be divided into a current intermediate extraction region corresponding to the current intermediate extraction plane and several current subordinate extraction regions corresponding to the current subordinate extraction plane. The current subordinate extraction region refers to the extraction region corresponding to the current intermediate extraction region. For example, based on the division of left-middle-right extraction regions, each current extraction region can be divided into a current left-side extraction region corresponding to the left side, a current intermediate extraction region corresponding to the middle side, and a current right-side extraction region corresponding to the right side.

[0057] The processor can calculate the angles between the first normal and each of the second normals, and thus obtain the angles of each normal. The processor can determine whether each normal angle falls within a first preset range and a second preset range. If at least one normal angle does not fall within the first preset range or the second preset range, it is considered that the current subordinate extraction plane and the current intermediate extraction plane do not belong to the same plane, and it is determined that there is a wall corner (such as...) between the current left extraction area (or the current right extraction area) and the current intermediate extraction area. Figure 9 As shown), the current subordinate extraction region that does not fall within at least one normal angle is identified as the subordinate extraction region to be adjusted, and the current intermediate extraction region is identified as the intermediate extraction region to be adjusted.

[0058] For example, the first normal is the normal corresponding to the current intermediate extraction plane, that is, the first normal is the normal corresponding to the current intermediate extraction region. There are two second normals: one second normal corresponds to the current left extraction plane, that is, this second normal corresponds to the current left extraction region; the other second normal corresponds to the current right extraction plane, that is, this second normal corresponds to the current right extraction plane. When the angle between the first normal and the second normal corresponding to the current left extraction region does not fall within a first preset range and a second preset range, the processor identifies the current left extraction region corresponding to which the angle does not fall as the left extraction region to be adjusted, and identifies the current intermediate extraction region as the intermediate extraction region to be adjusted. Similarly, when the angle between the first normal and the second normal corresponding to the current right extraction region does not fall within a first preset range and a second preset range, the processor identifies the current right extraction region corresponding to which the angle does not fall as the right extraction region to be adjusted, and identifies the current intermediate extraction region as the intermediate extraction region to be adjusted.

[0059] Step S420: Based on the preset width increment value, adjust the width of the auxiliary extraction area to be adjusted to obtain the adjusted auxiliary extraction area and the adjusted middle extraction area.

[0060] The preset width increment value can be obtained according to the system preset.

[0061] The processor can adjust the width of the auxiliary extraction area to be adjusted based on a preset width increment value, thereby increasing the width of the auxiliary extraction area to be adjusted and decreasing the width of the intermediate extraction area to be adjusted, thus obtaining the adjusted auxiliary extraction area and the adjusted intermediate extraction area.

[0062] For example, in the case of left-center-right region division, the widths of the current left-side extraction region and the current right-side extraction region can be further widened to form a structure like... Figure 10 The adjusted current left and right extraction regions are shown, where DL3 is greater than DL1 and DR3 is greater than DR1.

[0063] It should be noted that, for the case of upper, middle, and lower region division, the auxiliary extraction regions to be adjusted are the current upper extraction region and the current lower extraction region; the auxiliary extraction regions after adjustment are the adjusted lower extraction region and the adjusted upper extraction region. The processor can widen the current upper extraction region and the current lower extraction region to obtain the adjusted upper extraction region, the adjusted lower extraction region, and the adjusted middle extraction region.

[0064] Step S430: Perform planar processing on the adjusted auxiliary extraction region and the adjusted intermediate extraction region to obtain the adjusted auxiliary extraction plane and the adjusted intermediate extraction plane.

[0065] The processor fits the coordinates of the detection points in the adjusted auxiliary extraction region and the adjusted intermediate extraction region into a spatial coordinate system to obtain the plane corresponding to each extraction region, thus obtaining the adjusted auxiliary extraction plane and the adjusted intermediate extraction plane.

[0066] Step S440: When the difference between the adjusted auxiliary extraction plane and the auxiliary extraction plane of the corresponding auxiliary extraction area to be adjusted is greater than a preset threshold, the adjusted intermediate extraction plane is confirmed as the target projection plane.

[0067] The processor can perform difference processing on the adjusted auxiliary extraction plane and the auxiliary extraction plane of the corresponding auxiliary extraction region to be adjusted. Based on the processing result, when the difference between the adjusted auxiliary extraction plane and the auxiliary extraction plane of the corresponding auxiliary extraction region to be adjusted is greater than a preset threshold, the adjusted intermediate extraction plane is confirmed as the target projection plane.

[0068] For example, in the case of left-center-right region division, if the difference between the plane fitted by the probe points in the adjusted left-side extracted region and the old plane is greater than a preset threshold (e.g., 10%), then the wall corner is considered to exist between DL3 and DL1. Subsequently, the middle plane fitted by the probe points in the adjusted middle extracted region is considered the target projection plane. Similarly, if the difference between the plane fitted by the probe points in the adjusted right-side extracted region and the old plane is greater than a preset threshold (e.g., 10%), then the wall corner is considered to exist between DR3 and DR1. Subsequently, the middle plane fitted by the probe points in the adjusted middle extracted region is confirmed as the target projection plane. Furthermore, the processor determines a more precise attitude angle of the projector relative to the target projection plane, and corrects the current projected image based on the attitude angle to obtain an accurate corrected image. This enables precise processing to obtain the target projection plane to be projected, determines the precise attitude angle of the projector relative to the target projection plane, and thus obtains an accurate trapezoidal correction image, reducing correction errors and improving trapezoidal correction accuracy.

[0069] Furthermore, regarding the division of upper, middle, and lower regions, if the difference between the plane fitted by the probe points in the adjusted upper extraction region and the old plane is greater than a preset threshold (e.g., 10%), then the ceiling or ground is considered to exist in the adjusted upper extraction plane, and the middle plane fitted by the probe points in the adjusted middle extraction region is then considered the target projection plane; or if the difference between the plane fitted by the probe points in the adjusted lower extraction region and the old plane is greater than a preset threshold (e.g., 10%), then the ceiling or ground is considered to exist between the adjusted lower extraction regions, and the middle plane fitted by the probe points in the adjusted middle extraction region is then confirmed as the target projection plane.

[0070] In one embodiment, such as Figure 5 As shown, a projection correction method is provided, which is applied to... Figure 1 Taking the processor in the example, the following steps are included: Step S510: Obtain information on each detection point within the corresponding detection range.

[0071] For a detailed explanation of step S510, please refer to the description of the above embodiments, which will not be repeated here.

[0072] Step S520: Based on the preset vertical division rules, the information of each detection point is divided into regions to obtain the current first intermediate extraction region, the current first side auxiliary extraction region, and the current second side auxiliary extraction region.

[0073] The preset vertical division rule can be to set two extraction boundary lines (such as a left extraction boundary line and a right extraction boundary line). The information of each detection point within the detection range is divided into regions using the left and right extraction boundary lines, thus obtaining the current first intermediate extraction region, the current first side auxiliary extraction region, and the current second side auxiliary extraction region. The current first side auxiliary extraction region can be the current left-side extraction region located at the left extraction boundary line, and the current second-side auxiliary extraction region can be the current right-side extraction region located at the right extraction boundary line.

[0074] Step S530: Perform planar processing on the current first intermediate extraction region, the current first side auxiliary extraction region, and the current second side auxiliary extraction region to obtain each current extraction plane.

[0075] If the current first-side auxiliary extraction region is the current left extraction region, then the coordinates of each detection point in the current left extraction region are fitted into a left plane in the spatial coordinate system, thus obtaining the current left extraction plane corresponding to the current left extraction region; the coordinates of each detection point in the current first middle extraction region are fitted into a middle plane, thus obtaining the current first middle extraction plane corresponding to the current first middle extraction region; if the current second-side auxiliary extraction region is the current right extraction region, then the coordinates of each detection point in the current right extraction region are fitted into a right plane, thus obtaining the current right extraction plane corresponding to the current right extraction region.

[0076] Step S540: Process each currently extracted plane to obtain the target projection plane.

[0077] For a detailed explanation of step S540, please refer to the description of the above embodiments, which will not be repeated here.

[0078] Step S550: Obtain the attitude angle based on the target projection plane, and correct the current projection image based on the attitude angle to obtain the corrected image.

[0079] For a detailed explanation of step S550, please refer to the description of the above embodiments, which will not be repeated here.

[0080] In the above embodiments, by obtaining a large amount of depth and angle data of detection points, and based on preset vertical division rules, these detection points are extracted and calculated in a segmented manner in space. That is, multiple planes are fitted based on the segmented regions within the detection range, and then the target projection plane to be projected is determined from them. This leads to a more accurate attitude angle of the projector relative to the target projection plane, which helps to accurately execute subsequent correction steps and obtain an accurate corrected image. This enables precise processing to obtain the target projection plane to be projected, determine the accurate attitude angle of the projector relative to the target projection plane, and obtain an accurate trapezoidal correction image, thereby reducing correction errors and improving the accuracy of trapezoidal correction.

[0081] In one embodiment, such as Figure 6 As shown, a projection correction method is provided, which is applied to... Figure 1 Taking the processor in the example, the following steps are included: Step S610: Obtain information on each detection point within the corresponding detection range.

[0082] For a detailed explanation of step S610, please refer to the description of the above embodiments, which will not be repeated here.

[0083] Step S620: Based on the preset horizontal division rules, the information of each detection point is divided into regions to obtain the current second intermediate extraction region, the current third side auxiliary extraction region, and the current fourth side auxiliary extraction region.

[0084] The preset horizontal division rule can be to set two extraction boundary lines (such as an upper extraction boundary line and a lower extraction boundary line). These lines divide the information of each detection point within the detection range into regions, thus obtaining the current second intermediate extraction region, the current third-side auxiliary extraction region, and the current fourth-side auxiliary extraction region. Specifically, the current third-side auxiliary extraction region can be the current upper extraction region located on the upper extraction boundary line, and the current fourth-side auxiliary extraction region can be the current lower extraction region located on the lower extraction boundary line.

[0085] Step S630: Perform planar processing on the current second intermediate extraction region, the current third side auxiliary extraction region, and the current fourth side auxiliary extraction region to obtain each current extraction plane.

[0086] If the current third-side auxiliary extraction region is the current upper extraction region, then the coordinates of each detection point in the current upper extraction region are fitted into an upper plane in the spatial coordinate system, thus obtaining the current upper extraction plane corresponding to the current upper extraction region; the coordinates of each detection point in the current second intermediate extraction region are fitted into an intermediate plane, thus obtaining the current second intermediate extraction plane corresponding to the current second intermediate extraction region; if the current fourth-side auxiliary extraction region is the current lower extraction region, then the coordinates of each detection point in the current lower extraction region are fitted into a lower plane, thus obtaining the current lower extraction plane corresponding to the current lower extraction region.

[0087] Step S640: Process each currently extracted plane to obtain the target projection plane.

[0088] For a detailed explanation of step S640 above, please refer to the description of the above embodiments, which will not be repeated here.

[0089] Step S650: Obtain the attitude angle based on the target projection plane, and correct the current projection image based on the attitude angle to obtain the corrected image.

[0090] For a detailed explanation of step S650, please refer to the description of the above embodiments, which will not be repeated here.

[0091] In the above embodiments, by obtaining a large amount of depth and angle data of detection points, and based on preset horizontal division rules, these detection points are extracted and calculated in a segmented manner in space. That is, multiple planes are fitted based on the segmented regions within the detection range, and then the target projection plane to be projected is determined from them. This leads to a more accurate attitude angle of the projector relative to the target projection plane, which helps to accurately execute subsequent correction steps and obtain an accurate corrected image. This enables precise processing to obtain the target projection plane to be projected, determine the accurate attitude angle of the projector relative to the target projection plane, and obtain an accurate trapezoidal correction image, thereby reducing correction errors and improving the accuracy of trapezoidal correction.

[0092] In one embodiment, steps S520 and S530 can be executed before step S620, thereby determining whether there is a wall corner in the projection range from the left and right directions, and whether there is a ceiling and ground in the current intermediate extraction plane from the up and down directions, so as to determine whether the current intermediate extraction plane can be left and right target projection plane.

[0093] In one embodiment, the step of performing planar processing on each currently extracted region to obtain the current extraction plane of each corresponding extracted region includes: Based on the least squares algorithm, plane fitting is performed on each currently extracted region to obtain each currently extracted plane.

[0094] Based on the coordinates of the probe points in each current extraction region, the processor processes the coordinates of the probe points in each current extraction region using the least squares algorithm, and then fits the plane corresponding to each extraction region in the spatial coordinate system to obtain the current extraction plane of each corresponding extraction region.

[0095] In one example, the steps to obtain the attitude angles based on the target projection plane include: The yaw angle is obtained from the angle between the third normal of the target projection plane and the X-axis in the spatial coordinate system; and / or the pitch angle is obtained from the angle between the third normal of the target projection plane and the Y-axis in the spatial coordinate system.

[0096] like Figure 11 As shown, the projection device includes three attitude angles: yaw angle Y, pitch angle P, and roll angle R. The yaw angle Y can be determined based on the angle between the target projection plane and the X-axis, the pitch angle P can be determined based on the angle between the target projection plane and the Y-axis, and the roll angle R can be determined by a gyroscope. For example, the plane equation of the target projection plane can be defined as: The normal vector of the plane is Then the formula for calculating the yaw angle Y is: The formula for calculating the pitch angle P is: The numerical units in the calculation formula are degrees.

[0097] In one embodiment, based on three attitude angles, the tilt of the projected image is determined in a spatial coordinate system, and trapezoidal correction is achieved. The specific image correction process is as follows: Figure 12 As shown, a spatial coordinate system is initially formed in the projection device. The spatial coordinate system has an initial projection image S1 under an ideal scene. The size of S1 is, for example, a rectangle with a length of 1920 * a height of 1080.

[0098] like Figure 13 As shown, the three attitude angles are then substituted into the rotation matrix M1 to obtain the tilted plane S2. The formula for calculating the rotation matrix M1 is: .

[0099] Where Y is the yaw angle, P is the pitch angle, and R is the roll angle. The angle values ​​in this calculation formula are in radians.

[0100] like Figure 14 As shown, a plane K is formed, perpendicular to the Z-axis and close to the origin. Plane K is used to characterize the wall surface. Figure 15As shown, connecting the origin to the four corner points of S2 determines the intersection points of these four lines with plane K. The shape of the trapezoidal region S3 enclosed by these four intersection points represents the shape of the actual projected image on the wall due to the tilted projection. Figure 16 As shown, a rectangular region S4 (preferably the largest rectangle) is formed within the region S3 defined by the four intersection points. Figure 17 As shown, mapping this rectangular region S4 to the plane containing S2 based on the origin yields S5. Figure 18 As shown, based on the coordinates of the four vertices in S5 and the inverse matrix operation of M1, the coordinates of the four vertices in S1 are obtained (which can form S6). Finally, these four vertices in S6 are input to the image driver, which can shrink the display area from the original projection area S1 to S6. The projector projects based on S6, and the final image projected onto the wall or screen will become a rectangle again.

[0101] In one embodiment, the probe point information includes angle information and distance information. Prior to the step of obtaining the attitude angle based on the target projection plane, the following steps are included: Acquire angle and distance information; perform plane fitting based on angle and distance information to obtain the target projection plane.

[0102] Specifically, the detection point information includes angle information and distance information. The detection module can emit a large number of detection rays within the detection range and receive the reflected detection point information, transmitting it to the processor. The processor then obtains the detection point information for the corresponding detection range. The processor can analyze the detection point information to obtain the angle and distance information.

[0103] The processor can perform plane fitting on the corresponding angle and distance information of each detection point to obtain the target projection plane. For example, the processor can use the least squares method to perform plane fitting on the corresponding angle and distance information of each detection point to obtain the target projection plane. The processor can process the plane equation and plane normal vector of the target projection plane to obtain the corresponding attitude angle. Then, the processor corrects the current projection image based on the attitude angle to obtain the corrected image, thus achieving projection correction. This invention obtains a large amount of distance and angle information from detection points, fits this information to determine the target projection plane, and then determines a more accurate attitude angle of the projector relative to the target projection plane. This helps to accurately execute subsequent correction steps, thereby obtaining an accurate corrected image. It can accurately process and obtain the target projection plane, determine the accurate attitude angle of the projector relative to the target projection plane, and obtain an accurate trapezoidal correction image, reducing correction errors and improving trapezoidal correction accuracy.

[0104] It should be understood that, although Figures 2 to 6 The steps in the flowchart are shown sequentially as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order in which these steps are executed, and they can be performed in other orders. Figures 2 to 6 At least some of the steps in the process may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least some of the sub-steps or stages of other steps.

[0105] In one embodiment, such as Figure 19 As shown, a projection device is also provided, including a detection module 120 and a processor 110. The detection module 120 is connected to the processor 110. The detection module 120 is used to obtain the detection point information corresponding to the detection range based on the detection light output to the detection range. The processor 110 is used to execute the steps of any of the projection correction methods described above.

[0106] The projection device can be a projector, the processor 110 can be the main processor 110 of the projector, and the detection module 120 can be a lidar module, for example, a high-array lidar ranging module. The detection module 120 may include a TOF sensor. For specific details regarding the projection correction method, etc., please refer to the description of the above embodiments; they will not be repeated here.

[0107] The detection module 120 can emit a large number of detection rays within the detection range and receive the reflected detection point information, transmitting the detection point information to the processor 110. The processor 110 acquires the detection point information within the corresponding detection range; divides the detection point information into regions to obtain current extraction regions; performs planar processing on each current extraction region to obtain the current extraction plane of each corresponding extraction region; processes each current extraction plane to obtain the target projection plane; obtains the attitude angle based on the target projection plane; and corrects the current projected image based on the attitude angle to obtain the corrected image, thereby achieving projection correction. This invention obtains depth and angle data from a large number of detection points, and performs segmented extraction calculations on these detection points in space. That is, based on the segmented regions within the detection range, multiple planes are fitted, and then the target projection plane to be projected is determined from them. This allows for a more precise determination of the projector's attitude angle relative to the target projection plane, which helps to accurately execute subsequent correction steps, thereby obtaining an accurate corrected image. This invention enables precise processing to obtain the target projection plane to be projected, determines the precise attitude angle of the projector relative to the target projection plane, and thus obtains an accurate trapezoidal correction image, reducing correction errors and improving trapezoidal correction accuracy.

[0108] In one embodiment, this application provides a computer storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of any of the above-described projection correction methods.

[0109] In one example, when a computer program is executed by a processor, it performs the following steps: By acquiring information about each detection point within the corresponding detection range; dividing the information of each detection point into regions to obtain each current extraction region; performing planar processing on each current extraction region to obtain the current extraction plane of each corresponding extraction region; processing each current extraction plane to obtain the target projection plane; obtaining the attitude angle based on the target projection plane; and correcting the current projection image based on the attitude angle to obtain the corrected image, thereby achieving projection correction.

[0110] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the division operations described above. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0111] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0112] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A projection correction method, characterized in that, Includes the following steps: Obtain information on each detection point within the corresponding detection range; wherein the detection range covers the projection range; The information of each detection point is divided into regions to obtain each current extraction region, and each current extraction region is processed by plane to obtain the current extraction plane corresponding to each current extraction region; The current extracted planes are processed to obtain the target projection plane; Based on the target projection plane, the attitude angle is obtained, and the current projected image is corrected based on the attitude angle to obtain the corrected image; Each of the current extraction planes is divided into a current intermediate extraction plane and several current auxiliary extraction planes; The step of processing each of the currently extracted planes to obtain the target projection plane includes: Obtain the first normal of the current intermediate extraction plane and the second normal of each of the current subordinate extraction planes; Calculate the included angles between the first normal and each of the second normals to obtain the included angles of each normal; When each of the aforementioned normals falls within the first preset range, the current intermediate extraction plane is identified as the target projection plane.

2. The projection correction method according to claim 1, characterized in that, The step of calculating the angle between the first normal and each of the second normals to obtain the angle between each normal also includes: When each of the normals is within the second preset range, the current intermediate extraction plane is confirmed as the target projection plane; any value of the second preset range is greater than any value of the first preset range.

3. The projection correction method according to claim 2, characterized in that, Each of the current extraction regions is divided into a current intermediate extraction region corresponding to the current intermediate extraction plane and several current auxiliary extraction regions corresponding to the current auxiliary extraction plane; The step of calculating the angle between the first normal and each of the second normals to obtain the angle between each normal includes: When at least one normal angle does not fall within the first preset range and the second preset range, the current auxiliary extraction area corresponding to the at least one normal angle that does not fall within the first preset range and the second preset range is identified as an auxiliary extraction area to be adjusted, and the current intermediate extraction area is identified as an intermediate extraction area to be adjusted. Based on a preset width increment value, the width of the auxiliary extraction area to be adjusted and the intermediate extraction area to be adjusted are adjusted to obtain the adjusted auxiliary extraction area and the adjusted intermediate extraction area. The adjusted auxiliary extraction region and the adjusted intermediate extraction region are subjected to planar processing to obtain the adjusted auxiliary extraction plane and the adjusted intermediate extraction plane; When the difference between the adjusted auxiliary extraction plane and the auxiliary extraction plane corresponding to the auxiliary extraction area to be adjusted is greater than a preset threshold, the adjusted intermediate extraction plane is confirmed as the target projection plane.

4. The projection correction method according to any one of claims 1 to 3, characterized in that, The step of dividing the information of each detection point into regions to obtain each currently extracted region includes: Based on the preset vertical division rules, the information of each detection point is divided into regions to obtain the current first middle extraction region, the current first side auxiliary extraction region, and the current second side auxiliary extraction region; The step of performing planar processing on each of the current extracted regions to obtain the current extracted plane corresponding to each of the current extracted regions includes: The current first intermediate extraction region, the current first side auxiliary extraction region, and the current second side auxiliary extraction region are subjected to planar processing to obtain each current extraction plane.

5. The projection correction method according to any one of claims 1 to 3, characterized in that, The step of dividing the information of each detection point into regions to obtain each currently extracted region further includes: Based on the preset horizontal division rules, the information of each detection point is divided into regions to obtain the current second intermediate extraction region, the current third side auxiliary extraction region, and the current fourth side auxiliary extraction region; The step of performing planar processing on each of the current extracted regions to obtain the current extracted plane corresponding to each of the current extracted regions includes: The current second intermediate extraction region, the current third side auxiliary extraction region, and the current fourth side auxiliary extraction region are subjected to planar processing to obtain each current extraction plane.

6. The projection correction method according to claim 1, characterized in that, The step of performing planar processing on each of the current extracted regions to obtain the current extracted plane corresponding to each of the current extracted regions includes: Based on the least squares algorithm, plane fitting is performed on each of the current extraction regions to obtain each of the current extraction planes.

7. The projection correction method according to claim 1, characterized in that, The step of obtaining the attitude angle based on the target projection plane includes: The yaw angle is obtained based on the angle between the third normal of the target projection plane and the X-axis in the spatial coordinate system; and / or The pitch angle is obtained based on the angle between the third normal of the target projection plane and the Y-axis in the spatial coordinate system.

8. A projection device, characterized in that, It includes a detection module and a processor, wherein the detection module is connected to the processor; The detection module is used to obtain information about each detection point in the detection range based on the detection light rays output to the detection range. The processor is used to perform the steps of the projection correction method as described in any one of claims 1 to 7.

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