Methods for correcting projected images, projectors, and storage media

Abstract

This invention discloses a method for correcting a projected image, a projector, and a storage medium. The method includes the steps of: correcting the shape of the projected image; and further includes the step of: reducing the brightness of pixels in the side areas of the projected image based on the side pixel information of the projected image after shape correction, so as to reduce edge jaggedness, wherein the brightness reduction of the side area pixels is less than 100%. This invention adjusts the brightness of the corresponding sides of the projected image after trapezoidal correction, making the jagged edges visually blurred, so that the user will not noticeably perceive the jaggedness on those sides. This invention first performs deformation judgment on each side, and only performs anti-aliasing processing on sides that meet the conditions, effectively solving the problem of slight jaggedness that is not visually perceptible without sacrificing too much image edge information. This invention provides quantitative brightness control methods for the degree of edge deformation after trapezoidal correction, making the effect of eliminating edge jaggedness more stable.

Description

Technical Field

[0001] This invention relates to the field of projection technology, and in particular to a method for correcting projected images, a projector, and a storage medium. Background Technology

[0002] A projector, also known as a projector, is a device that can project images or videos onto a screen. It can be connected to computers, VCD players, DVD players, BD players, game consoles, DV players, etc., through different interfaces to play corresponding video signals.

[0003] When the projector projects an image onto a flat wall, it will generally display a regular rectangular image if no changes are made. However, if the projector 104 is placed at an angle relative to the wall, the projected image will appear as a trapezoidal shape 101, such as... Figure 1 As shown, although the projected image can be adjusted by software to visually revert to a rectangle 102, the edges of the adjusted rectangular projected image (as indicated by the arrow) will produce jagged edges, affecting the viewing experience of the audience 103. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for correcting projected images, a projector, and a storage medium to solve the problem of jagged edges on the corrected projected images.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A method for correcting a projected image includes the steps of: correcting the shape of the projected image; and further including the steps of: reducing the brightness of the side region pixels of the projected image based on the side pixel information of the projected image after shape correction, so as to reduce edge jaggedness, wherein the brightness reduction of the side region pixels is less than 100%.

[0007] In one embodiment, the side region where the side region pixel is located includes an adjacent outermost region and a transition layer region. The step of reducing the brightness of the side region pixels of the projected image based on the side pixel information of the projected image after shape correction, to reduce edge jaggedness, wherein the brightness reduction of the side region pixels is less than 100%, includes:

[0008] Based on the side pixel information of the corrected projected image, the pixel brightness of the outermost region is reduced to 20% to 40% of the original brightness, and the pixel brightness of the transition layer region is reduced to 40% to 90% of the original brightness.

[0009] In one embodiment, the side region containing the side region pixels includes at least two sub-pixel regions arranged sequentially from the inner layer to the outer layer and corresponding to different brightness reduction magnitudes. The step of reducing the brightness of the side region pixels of the projected image based on the side pixel information of the projected image after shape correction, to reduce edge jaggedness, wherein the brightness reduction magnitude of the side region pixels is less than 100%, includes:

[0010] Based on the corrected side pixel information of the projected image, the brightness of the adjacent outer sub-pixel region is reduced to 50% to 70% of the brightness of the inner sub-pixel region, and the brightness reduction of each sub-pixel region is less than 100%.

[0011] In one embodiment, the side pixel information of the projected image after shape correction, reducing the brightness of the side region pixels of the projected image to reduce edge jaggedness, wherein the step of reducing the brightness of the side region pixels by less than 100% includes:

[0012] Based on the degree of misalignment of the side region pixels of the projected image in the X or Y direction after the step of correcting the shape of the projected image, the brightness of the side region pixels is reduced, and the brightness reduction of the side region pixels is less than 100%.

[0013] In one embodiment, the step of reducing the brightness of the side region pixels based on the degree of misalignment of the side region pixels in the X or Y direction after the step of correcting the shape of the projected image, wherein the brightness reduction of the side region pixels is less than 100%, includes:

[0014] Based on the shape of the corrected projection image, a shape-corrected projection image is obtained;

[0015] Obtain the pixel bit difference value of the vertex of the edge of the projected image on one side in the X or Y direction in the X or Y direction;

[0016] When the pixel difference is greater than a first preset value, the brightness of the side region pixels corresponding to the edge is reduced, and the brightness reduction of the side region pixels is less than 100%.

[0017] In one embodiment, the side region where the side region pixel is located includes at least two sub-pixel regions arranged sequentially from the inner layer to the outer layer and corresponding to different brightness reduction magnitudes;

[0018] The step of reducing the brightness of the side pixel information of the projected image after shape correction, thereby reducing edge jaggedness, wherein the brightness reduction of the side pixel is less than 100%, includes:

[0019] Based on the degree of misalignment of the side region pixels of the projected image in the X or Y direction after the step of correcting the shape of the projected image, the pixel row or column corresponding to each sub-pixel region is determined.

[0020] Based on the brightness reduction magnitude corresponding to each sub-pixel region, the brightness of pixels in the corresponding pixel row or column of each sub-pixel region is reduced to weaken edge jaggedness, wherein the brightness reduction magnitude of pixels in each sub-pixel region is less than 100%; and the brightness reduction magnitude of pixels in the same sub-pixel region is the same; the brightness reduction magnitude of pixels differs between pixel rows or columns corresponding to different sub-pixel regions.

[0021] In one embodiment, determining the pixel row or column corresponding to each sub-pixel region based on the degree of misalignment of the side region pixels of the projected image in the X or Y direction after correction of the shape of the projected image includes:

[0022] The side region pixels include three brightness reduction levels A1, A2, and A3, and the three brightness reduction levels A1, A2, and A3 correspond to different sub-pixel regions from the outside to the inside of the projected image.

[0023] In the side region pixels of the projected image on one side in the X or Y direction, when 20 pixels ≤ diff-p < (1 / 6)P, the three brightness reduction amplitudes A1, A2, and A3 each correspond to one pixel row or column; when (1 / 6)P ≤ diff-p < (1 / 4)P, brightness reduction amplitude A1 corresponds to two pixel rows or columns, while brightness reduction amplitudes A2 and A3 each correspond to one pixel row or column; when (1 / 4)P ≤ diff-p, brightness reduction amplitudes A1 and A2 each correspond to two pixel rows or columns, while brightness reduction amplitude A3 corresponds to one pixel row or column.

[0024] Where diff-p represents the pixel difference between the two vertices of the edge p on one side of the projected image in the X or Y direction after the step of correcting the shape of the projected image; P is the total pixel value of the projected image in the X or Y direction.

[0025] In one embodiment, the side region pixels have a spatial gradient brightness difference after adjustment, so that the brightness of the pixels gradually increases along the direction from the edge of the screen to the center of the screen.

[0026] The present invention also adopts the following technical solution:

[0027] A projector includes a processor and a memory, the memory storing a computer program that can be read and executed to implement any of the above-described methods for correcting projected images.

[0028] A storage medium storing a computer program, wherein the computer program is configured to be run by a processor to perform the correction method for any of the above-described projected images.

[0029] The present invention has the following beneficial effects:

[0030] This invention adjusts the brightness of the corresponding side of the projected image after trapezoidal correction, making the jagged edges visually blurred so that users will not notice the jaggedness on that side.

[0031] In addition, some embodiments also have the following beneficial effects:

[0032] 1. This invention first performs deformation judgment on each side, and only the side that meets the conditions is processed for anti-aliasing, which effectively solves the problem of slight jaggedness that cannot be perceived by the visual and does not sacrifice too much edge information of the image.

[0033] 2. This invention provides a quantitative brightness control method for the degree of edge deformation after trapezoidal correction, making the effect of eliminating edge jaggedness more stable. Attached Figure Description

[0034] Figure 1 This is a schematic diagram illustrating the jagged edges produced by an existing projector after image calibration.

[0035] Figure 2 This is a flowchart of the projector projection method in an embodiment of the present invention;

[0036] Figure 3a This is a schematic diagram of the projected image shape before and after correction in an embodiment of the present invention;

[0037] Figure 3b This is a schematic diagram of the projector's pre-projection screen before and after correction in an embodiment of the present invention;

[0038] Figure 4 This is a schematic diagram illustrating the principle of correcting the shape of the projected image in an embodiment of the present invention;

[0039] Figure 5 This is a schematic diagram illustrating the principle of determining whether the edges of each image need to be de-aliased in an embodiment of the present invention;

[0040] Figure 6 This is a brightness value division diagram when both adjacent sides need to be de-aliased in an embodiment of the present invention;

[0041] Figure 7a This is a distribution diagram of four stepped brightness levels inward from the side edge in an embodiment of the present invention;

[0042] Figure 7b This is the second distribution diagram of four stepped brightness levels inward from the side edge in this embodiment of the invention;

[0043] Figure 7c This is the third distribution diagram of four stepped brightness levels inward from the side edge in this embodiment of the invention;

[0044] Figure 8 This is a schematic diagram of the projected image when a bulge or pit appears on the wall surface in an embodiment of the present invention;

[0045] Figure 9 This is a schematic diagram illustrating the principle of flatness correction and anti-aliasing of the projected image in an embodiment of the present invention.

[0046] Figure 10a This is a schematic diagram of the projected image before edge jaggedness is eliminated after correction, according to an embodiment of the present invention.

[0047] Figure 10b This is a schematic diagram of the projected image after correction and removal of jagged edges according to an embodiment of the present invention;

[0048] Figure 11a This is a schematic diagram of the projected image before edge jaggedness is eliminated after correction, according to an embodiment of the present invention.

[0049] Figure 11b This is a schematic diagram of the projected image after correction and removal of jagged edges according to an embodiment of the present invention;

[0050] Figure 12a This is a schematic diagram of the projected image before edge jaggedness is eliminated after correction, according to an embodiment of the present invention.

[0051] Figure 12b This is a schematic diagram of the projected image after correction and removal of jagged edges in an embodiment of the present invention. Detailed Implementation

[0052] The embodiments of the present invention will be described in detail below. It should be emphasized that the following description is merely exemplary and not intended to limit the scope and application of the present invention.

[0053] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of the present invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0054] Before introducing the specific implementation of the present invention, let me briefly introduce the idea of ​​the present invention: The present invention reduces the brightness of the corresponding side of the projected image after trapezoidal correction in a non-zero and gradient manner, so that the jagged edges are visually blurred, so that the user will not obviously feel the jaggedness of the side, and at the same time, it will not sacrifice too much image edge information. The technical solution proposed by this idea includes the following important technical features: (1) the brightness value of the outermost pixel of the side is non-zero; (2) gradient brightness change; (3) first determine which side needs to be reduced edge jaggedness (anti-aliasing) processing, and then only process the corresponding side.

[0055] This invention provides a method for correcting a projected image, comprising the following steps: correcting the shape of the projected image; adjusting the brightness of the pixels in the side region based on the side pixel information to reduce edge jaggedness, wherein the brightness reduction of the pixels in the side region is less than 100%.

[0056] The side pixel information includes the pixel brightness information of the side region of the projected image after correcting the shape of the projected image, and / or the degree of misalignment of the side region pixels in the X or Y direction after correction. The reduction in pixel brightness is the adjustment range of the reduced pixel brightness compared to the original brightness, which can be a constant or a proportional value. A brightness reduction of less than 100% means that when the pixel brightness is not zero, the brightness of that pixel remains non-zero after the reduction steps described above.

[0057] The brightness of pixels in the side region is adjusted according to the degree of misalignment. The degree of misalignment refers to the extent to which pixel information originally located in the same row or column is misaligned in the X or Y direction due to correction. The brightness of the side region pixels changes in a gradient from the outside to the inside after adjustment. The side region includes an outermost region and a transition layer region. The brightness ratio of the pixels in the outermost region is greater than 20%, and the brightness ratio of the pixels in the adjacent transition layer region is 50% to 70% of the brightness ratio of the pixels in the inner region. This brightness ratio is the ratio of actual brightness to maximum brightness. Preferably, the degree of misalignment is detected.

[0058] This invention also provides a projector, including a processor and a memory, wherein the memory stores a computer program that can be read and executed to implement the above-described method for correcting the projected image.

[0059] This invention also provides a storage medium storing a computer program, wherein the computer program is configured to be run by a processor to perform the correction method for the projected image described above.

[0060] Example 1

[0061] refer to Figure 2 This invention provides a projection method using a projector, comprising the following steps:

[0062] F1: Corrects the shape of the projected image;

[0063] F2. Based on the degree of correction of the sides of the image, determine whether the edge jaggedness of each image needs to be reduced;

[0064] F3. Determine the pixel brightness of that side in the corrected image based on the degree of correction of the side of the image.

[0065] F4: Output projected image.

[0066] The function, working order, and working content of each step in the method of this embodiment will be explained in detail below.

[0067] Step F1 works using a keystone correction method. If the projector's lens optical axis is tilted relative to the wall, resulting in a trapezoidal projected image, the system corrects the default image shape to obtain the corrected, expected projected image shape. The projected image shapes before and after correction are shown below. Figure 3a As shown, the solid line represents the shape of the projected image before correction (trapezoidal), and the dashed line represents the shape of the projected image after correction (rectangular). The projector's pre-projected images before and after correction are shown below. Figure 3b As shown, the solid line represents the default projection shape (rectangle) of the system before correction, and the dashed line represents the image shape (trapezoidal) that the system expects to project after correction.

[0068] Specifically, the following two correction methods are included:

[0069] (1) Capture images using a projector or mobile phone camera, transmit the captured images back to the projector's system for analysis and processing, and then obtain results such as... Figure 3b The shape of the image to be projected is shown.

[0070] (2) The distance and tilt angle of the projector relative to the wall can be detected by depth detection modules such as TOF (Time of flight) and structured light. Based on these positional information and preset relationships, the tilt degree of the projector relative to the wall can be determined. Then, it can be directly determined how to adjust the default shape of the image to be projected, and thus obtain the expected shape of the image to be projected.

[0071] The working principle of step F2 is as follows: Figure 4 and Figure 5 As shown, the degree of edge jaggedness reduction on the corresponding side of the projected image is determined based on the difference between the default projection image size and the keystone-corrected projection image size. (Reference) Figure 4The top and bottom edges of the corrected projection image are calculated using diff-x1 and diff-x2, while the left and right edges are calculated using diff-y1 and diff-y2. If the diff value of a corresponding edge is greater than 20 pixels, edge aliasing reduction is applied to that edge; if it is less than 20 pixels, edge aliasing reduction is not required. Specifically, the diff for a given edge is the absolute value of the pixel difference between the two vertices of that edge in that direction. For example, diff-x1 for the top edge is the absolute value of the pixel difference between the two vertices of the top edge in the width (X) direction; diff-x2 for the bottom edge is the absolute value of the pixel difference between the two vertices of the bottom edge in the width (X) direction; diff-y1 for the left edge is the absolute value of the pixel difference between the two vertices of the left edge in the length (Y) direction; and diff-y2 for the right edge is the absolute value of the pixel difference between the two vertices of the right edge in the length (Y) direction.

[0072] The pixel information of the image, which was originally arranged in rows and columns according to a regular pattern, needs to be rearranged to adapt to the shape of the projected image after trapezoidal correction. At this time, the pixel information that was originally located in the same row or column needs to be misaligned in the X or Y direction, which will create jagged edges on the image. The greater the degree of misalignment (characterized by the diff value), the stronger the jaggedness. However, when the diff value is greater than 20, it indicates that the shape of the corrected image has undergone a large deformation compared to the original default shape, and edge jaggedness reduction processing is required. Therefore, in this embodiment, based on the side pixel information, the brightness of the side region pixels is reduced to reduce edge jaggedness, wherein the brightness reduction of the side region pixels is less than 100%, the step of reducing the brightness of the side region pixels is as follows: based on the degree of misalignment of the side region pixels of the projected image after correction in the X or Y direction after the step of correcting the shape of the projected image, the brightness reduction of the side region pixels is less than 100%. More specifically:

[0073] Based on the steps of correcting the shape of the projected image, the shape-corrected projected image is obtained;

[0074] Obtain the pixel bit difference in the X or Y direction of the vertex of the edge on one side of the projected image;

[0075] When the pixel difference is greater than a first preset value, the brightness of the pixels in the side region corresponding to the edge is reduced, and the brightness reduction of the pixels in the side region is less than 100%.

[0076] The definition of pixel bit difference here can be found in the previous explanation of the meaning of diff-x1, diff-x2, diff-y1, and diff-y2.

[0077] The working principle of step F3 is as follows: the greater the degree of correction, the greater the diff on the side of the corresponding image, and the more obvious the jagged edges. Therefore, the brightness of the outermost pixel needs to be adjusted to a lower level. At the same time, the brightness of the image gradually increases to the normal level as it gets closer to the center of the image. The brightness changes in a gradient and is not zero.

[0078] The side region containing the pixels includes the adjacent outermost region and the transition layer region. The range of values ​​for adjusting the pixel brightness of the outermost region and the transition layer region includes:

[0079] In one X or Y direction, the brightness value of the pixels in the outermost region of the shape-corrected projected image is between 20% and 40% of their original brightness value;

[0080] In the X or Y direction, the pixel brightness of the transition layer region is between 40% and 90% of the original brightness. For example, the transition layer region includes two sub-pixel regions, where the outermost region corresponds to the penultimate layer of pixels in the projected image in the X or Y direction, one sub-pixel region corresponds to the penultimate layer of pixels in the projected image in the X or Y direction, and the other sub-pixel region corresponds to the penultimate layer of pixels in the projected image in the X or Y direction.

[0081] The brightness value of the second-to-last pixel is between 40% and 60% of its original brightness value;

[0082] The brightness value of the third-to-last pixel is between 70% and 90% of its original brightness value.

[0083] For the default image to be projected, in the X direction, the outermost layer of pixels refers to the pixels in the outermost pixel row in that X direction, the second-to-last layer of pixels refers to the pixels adjacent to the outermost pixel row in that X direction, and so on. The X direction includes the +X direction and the -X direction. The pixels in the side region of the projected image in the +X direction are the pixels in the upper edge of the image and several nearby pixel rows; the pixels in the side region of the projected image in the -X direction are the pixels in the lower edge of the image and several nearby pixel rows. The meanings of the outermost layer of pixels, the second-to-last layer of pixels, etc., in the Y direction of the projected image are similar to those described above and will not be repeated here.

[0084] Furthermore, while reducing the brightness of the side region pixels, the brightness of adjacent outer layer pixels is maintained at 50% to 70% of the brightness of the inner layer pixels, preferably 60%. The side region where the side region pixels of the projected image are located includes at least two sub-pixel regions arranged sequentially from the inner layer to the outer layer, and different sub-pixel regions correspond to different brightness reduction rates. At this time, based on the side pixel information, the brightness of the side region pixels is reduced to weaken edge jaggedness, wherein the step of reducing the brightness of the side region pixels by less than 100% includes:

[0085] Based on the side pixel information, the brightness of adjacent outer sub-pixel regions is reduced to 50% to 70% of the brightness of inner sub-pixel regions. That is, in the direction from the center of the projected image to any of the four edges, adjacent sub-pixel regions can be divided into inner and outer sub-pixel regions, with the outer sub-pixel regions closer to the edge of the projected image in this direction. For example, the outer sub-pixel region corresponds to the region corresponding to the penultimate layer of pixels, and the inner sub-pixel region corresponds to the region corresponding to the penultimate layer of pixels; or, the outer sub-pixel region can correspond to the region corresponding to the penultimate layer of pixels, and the inner sub-pixel region corresponds to the region corresponding to the third-to-last layer of pixels. However, it should be noted that each sub-pixel region can correspond to only one layer of pixels, i.e., one row or one column of pixels, or each sub-pixel region can correspond to two or more layers of pixels.

[0086] Based on the above range of values ​​for adjusting the brightness of the outermost pixel, the brightness of the outermost pixel is then determined according to the range of the side diff values:

[0087] (1)20pixel<diff<150pixel;

[0088] Outermost parallel pixels (e.g.) Figure 4 The brightness ratio of the pixel in index 1 is reduced to 40% of the original brightness value;

[0089] The second to last layer of parallel pixels (e.g.) Figure 4 The brightness ratio of the pixel in index 2 is reduced to 60% of the original brightness value;

[0090] The third-to-last layer of parallel pixels (e.g.) Figure 4 The brightness ratio of the pixels in index 3 is reduced to 90% of the original brightness value;

[0091] (like Figure 4 The misaligned pixels marked 1 are displayed at 40% brightness, the pixels marked 2 are displayed at 60% brightness, and the pixels marked 3 are displayed at 90% brightness.

[0092] (2) 150 pixels ≤ diff < 300 pixels

[0093] The brightness ratio of the outermost parallel pixels is reduced to 30% of the original brightness value.

[0094] The brightness ratio of the second-to-last layer of parallel pixels is reduced to 50% of the original brightness value.

[0095] The brightness ratio of the third-to-last parallel pixels is reduced to 70% of the original brightness value.

[0096] (3) 300 pixels ≤ diff

[0097] The brightness ratio of the outermost parallel pixels is reduced to 20% of the original brightness value.

[0098] The brightness ratio of the second-to-last layer of parallel pixels is reduced to 40% of the original brightness value.

[0099] The brightness ratio of the third-to-last parallel pixels is reduced to 70% of the original brightness value.

[0100] (4) When both adjacent sides need to be treated to reduce edge jaggedness, some pixel rows / columns will overlap. Theoretically, each of these overlapping pixels may have two different brightness values ​​(see reference). Figure 6 The first side is given a brightness value (X1\X2\X3) when the edge jaggedness is reduced, and the adjacent side is given another brightness value (Y1\Y2\Y3) when the edge jaggedness is reduced. At this time, the brightness of the pixel will be selected from the lowest brightness value. For example, the pixel in the corner will select the minimum value of X1 and Y1.

[0101] The working principle of step F4 is referenced. Figure 4 After reducing the jagged edges of the corresponding side of the image to be projected (gradually reducing brightness), the image is projected based on the brightness-adjusted image.

[0102] The above four steps constitute the complete process of reducing jagged edges after projector image correction. When the system performs keystone correction again (e.g., when the projector is moved), steps F2 and F3 above will be executed again.

[0103] After adjusting the pixel brightness in the side area using the method of this embodiment, there is a spatial gradient brightness difference, that is, the pixel brightness gradually increases along the direction from the edge of the screen to the center of the screen.

[0104] Example 2

[0105] The difference between this embodiment and Embodiment 1 is that step F3 employs the following working principle: Depending on the range of the diff values ​​of each side, the number of pixel rows / columns corresponding to each gradient brightness on the side requiring edge aliasing reduction also varies. The larger the diff of the corresponding side, the more pixel rows / columns are corresponding to the outermost gradient brightness of that side.

[0106] In this embodiment of the invention, step F3 serves the following purpose: When the shape of the projected image differs significantly from the shape of the default rectangular projected image after image correction, the side with the greatest difference not only suffers from severe pixel misalignment in the outermost two or three rows / columns, resulting in jagged edges, but this jaggedness also affects the fourth and fifth rows / columns inward. If only the outermost two or three rows of pixels are treated to reduce edge jaggedness, it will still be insufficient to visually reduce the jaggedness caused by the fourth or fifth row / column. Therefore, it is necessary to selectively reduce the degree of edge jaggedness based on the actual degree of deformation of the image sides after trapezoidal correction.

[0107] The side region containing the side region pixels includes at least two sub-pixel regions arranged sequentially from the inner layer to the outer layer, corresponding to different brightness reduction magnitudes. The number of pixel rows or columns corresponding to different sub-pixel regions may not be completely identical, thus allowing the number of pixel rows or columns corresponding to different sub-pixel regions to be determined based on the degree of misalignment of the side region pixels in the X or Y direction after correction. Specifically, based on the side pixel information, the brightness of the side region pixels is reduced to weaken edge jaggedness, wherein the step of reducing the brightness of the side region pixels by less than 100% includes:

[0108] Based on the degree of misalignment of the side region pixels of the projected image in the X or Y direction after the step of correcting the shape of the projected image, the pixel row or column corresponding to each sub-pixel region is determined.

[0109] Based on the brightness reduction rate corresponding to each sub-pixel region, the brightness of the pixels in the corresponding pixel row or column of each sub-pixel region is reduced to weaken edge jaggedness. The brightness reduction rate of the pixels in each sub-pixel region is less than 100%; and the brightness reduction rate of the pixels in the corresponding pixel row or column of the same sub-pixel region is the same; the brightness reduction rate of the pixels in the corresponding pixel row or column of different sub-pixel regions is different.

[0110] by Figure 4 For example, in the processor of the projector, the uncorrected projection image 501 has the maximum resolution. The projection image 502, which is shape-corrected to achieve trapezoidal correction, changes shape relative to the image 501. The regular pixel rows originally located in the image 501 are converted into slanted pixel rows in the projection image 502. The set of pixels marked 1, 2, and 3 in the projection image 502 constitutes the side area pixels of the projection image in the +X direction. The pixel marked 1 is the outermost pixel in this direction, which can also be called the outermost pixel row; the pixel marked 2 is the second to last pixel in this direction; and the pixel marked 3 is the third to last pixel in this direction.

[0111] Taking the side area of ​​the projected image corresponding to any direction of +X, -X, +Y, -Y as an example, there are a total of four gradient brightness levels. The pixels in the middle area of ​​the image are pixels with normal brightness. The side area pixels include three brightness reduction levels A1, A2, and A3. The three brightness reduction levels A1, A2, and A3 correspond to different sub-pixel areas from the outside to the inside of the projected image.

[0112] In the side region pixels of the projected image on one side in the X or Y direction, when 20 pixels ≤ diff-p < (1 / 6)P, the three brightness reduction amplitudes A1, A2, and A3 each correspond to one pixel row or column; when (1 / 6)P ≤ diff-p < (1 / 4)P, the brightness reduction amplitude A1 corresponds to two pixel rows or columns, while the brightness reduction amplitudes A2 and A3 each correspond to one pixel row or column; when (1 / 4)P ≤ diff-p, the brightness reduction amplitudes A1 and A2 each correspond to two pixel rows or columns, while the brightness reduction amplitude A3 corresponds to one pixel row or column.

[0113] Where diff-p represents the pixel difference in the X or Y direction between two vertices of the edge p on one side of the projected image after the step of correcting the shape of the projected image; P is the total pixel value of the projected image in the X or Y direction. In addition, diff-p can be used to characterize any of the parameters diff-x1, diff-x2, diff-y1, and diff-y2 in Embodiment 1.

[0114] Taking the side area of ​​the projected image in the +X or -X direction as an example, there are a total of four brightness gradients. The four brightness steps from the edge of this side area inward are X1, X2, X3, and normal, with the brightness increasing sequentially. Wherein:

[0115] ①.Reference Figure 7a When 20pixel≤diff-x<(1 / 6)X, X is the total pixel value of the image to be projected in the X direction by default. The brightness values ​​of X1, X2, and X3 on this side each correspond to only one pixel row.

[0116] ②.Reference Figure 7b When (1 / 6)X≤diff-x<(1 / 4)X, the brightness value of X1 on this side corresponds to two pixel rows, while the brightness values ​​of X2 and X3 each correspond to only one pixel row.

[0117] ③、Reference Figure 7c When (1 / 4)X≤diff-x, the brightness values ​​of X1 and X2 on this side correspond to two pixel rows respectively, while the brightness value of X3 corresponds to only one pixel row.

[0118] Example 3

[0119] This invention provides a method for reducing edge jaggedness after projector image flatness correction. Specifically, for image flatness correction performed on the sides of a projected image on a wall due to localized deformation, edge jaggedness reduction is applied to the corrected sides. Specifically, edge jaggedness reduction is applied to each side individually, and only to the sides requiring edge jaggedness reduction; while the sides that have undergone flatness correction are treated as a whole.

[0120] refer to Figure 8 , 9 When there are bumps or depressions on the wall, the image projected onto that area will bulge outwards or concave inwards accordingly. Figure 8 The concave 801 is used as an example for explanation.

[0121] The method of this invention includes the following steps:

[0122] G1, The camera on the projector captured this locally distorted image;

[0123] G2. The system program inside the projector will perform flatness correction processing.

[0124] Specifically, the default image to be projected in the system is appropriately reduced in size, and targeted reverse deformation is performed in the area corresponding to the deformation position. However, this will cause the deformed area 902 to have jagged edges when it is re-projected onto the wall (after reverse deformation, the concave phenomenon caused by the pit can be offset when it is subsequently projected onto the wall, and the projected image will visually return to a rectangular shape 901).

[0125] G3. For the sides that have undergone reverse deformation correction, directly apply the aforementioned edge-reducing sawtooth treatment as a whole (affecting 1, 1.1, 2, 2.1, 3, 3.1); or

[0126] refer to Figure 9 The aforementioned edge reduction processing is only applied to the pixels on the side that have undergone reverse deformation (affecting only 1.1, 2.1, and 3.1). That is, the brightness of the pixel marked 1.1 is X1, the brightness of the pixel marked 2.1 is X2, and the brightness of the pixel marked 3.1 is X3.

[0127] G4, Output projected image.

[0128] Example 4

[0129] The difference between this embodiment and Embodiment 1 is that, for steps F1 and F2, the system can directly determine in advance which side will require a higher degree of correction than expected based on the previously measured position (angle + distance) information between the projector and the wall. Then, the side that meets the conditions for reducing edge jaggedness is processed in step F3. This method eliminates the need for coordinate calculation and analysis of the corrected projected image's sides to determine the degree of correction for each side, thus accelerating the response speed for reducing edge jaggedness.

[0130] Example 5

[0131] Embodiment 5 of the present invention discloses a storage medium storing a computer program, wherein the computer program is configured to be run by a processor to perform the steps in any of the above method embodiments.

[0132] Optionally, the aforementioned storage media may include, but are not limited to, USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks, and other media capable of storing computer programs.

[0133] Experimental results

[0134] like Figures 10a-12b As shown, the experimental results of this embodiment of the invention effectively verify the effect of reducing edge jaggedness in this embodiment. Among them, Figure 10a , Figure 10b The results of the first group of experiments, Figure 11a , Figure 11b The results of the second group of experiments, Figure 12a , Figure 12b This is the result of the third group of experiments. Figure 10a , Figure 11a , Figure 12a This represents the projected image before the jagged edges are reduced. Figure 10b , Figure 11b , Figure 12b This represents the projected image after reducing edge jaggedness. By comparing the results before and after reducing edge jaggedness, the effect of the method for reducing edge jaggedness after projector image correction provided in this embodiment of the invention is clearly evident.

[0135] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0136] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0137] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0138] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0139] The above description provides a further detailed explanation of the present invention in conjunction with specific / preferred embodiments, and it should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various substitutions or modifications can be made to these described embodiments without departing from the concept of the present invention, and all such substitutions or modifications should be considered within the scope of protection of the present invention. In the description of this specification, the reference to terms such as "an embodiment," "some embodiments," "preferred embodiment," "example," "specific example," or "some examples," etc., indicates that the specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples. Without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification and the features of different embodiments or examples. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions, and modifications can be made herein without departing from the scope of protection of the patent application.

Claims

1. A method of correcting a projected image, comprising the step of: correcting a shape of the projected image; characterized in that, The method further comprises the following steps: reducing the brightness of the side edge region pixels of the projection picture based on the side edge pixel information of the projection picture after the shape correction, so as to weaken the edge jaggies, wherein the reduction amplitude of the brightness of the side edge region pixels is less than 100%; the side edge region where the side edge region pixels are located comprises at least two sub-pixel regions arranged from the inner layer to the outer layer in sequence and corresponding to different reduction amplitudes of the brightness; The step of reducing the brightness of the side edge region pixels of the projection picture based on the side edge pixel information of the projection picture after the shape correction, so as to weaken the edge jaggies, wherein the reduction amplitude of the brightness of the side edge region pixels is less than 100%, comprises: According to the degree of misalignment of the side edge region pixels of the projection picture in the X or Y direction after the shape correction, the pixel row or column corresponding to each sub-pixel region is determined; According to the reduction amplitude of the brightness corresponding to each sub-pixel region, the brightness of the pixels in the pixel row or column corresponding to each sub-pixel region is reduced, so as to weaken the edge jaggies, wherein the reduction amplitude of the brightness of the pixels in each sub-pixel region is less than 100%; the reduction amplitude of the brightness of the pixels in the pixel row or column corresponding to the same sub-pixel region is the same; the reduction amplitude of the brightness of the pixels between the pixel rows or columns corresponding to different sub-pixel regions is different; and the step of determining the pixel row or column corresponding to each sub-pixel region according to the degree of misalignment of the side edge region pixels of the projection picture in the X or Y direction after the shape correction, comprises: The side edge region pixels comprise three reduction amplitudes A1, A2 and A3 of the brightness, and the three reduction amplitudes A1, A2 and A3 correspond to different sub-pixel regions from the outside to the inside of the projection picture; In the side edge region pixels on one side of the projection picture in the X or Y direction, when 20 pixels≤diff-p<(1 / 6)P is satisfied, the three reduction amplitudes A1, A2 and A3 correspond to one pixel row or column respectively; when (1 / 6)P≤diff-p<(1 / 4)P is satisfied, the reduction amplitude A1 corresponds to two pixel rows or columns, and the reduction amplitudes A2 and A3 correspond to one pixel row or column respectively; and when (1 / 4)P≤diff-p is satisfied, the reduction amplitudes A1 and A2 correspond to two pixel rows or columns respectively, and the reduction amplitude A3 corresponds to one pixel row or column; Wherein, diff-p represents the pixel position difference value of two vertices of an edge p on one side of the projection picture in the X or Y direction after the shape correction of the projection picture; and P is the total pixel value of the projection picture in the X or Y direction.

2. The method of claim 1, wherein, The side edge region where the side edge region pixels are located comprises adjacent outermost region and transition layer region, and the step of reducing the brightness of the side edge region pixels of the projection picture based on the side edge pixel information of the projection picture after the shape correction, so as to weaken the edge jaggies, wherein the reduction amplitude of the brightness of the side edge region pixels is less than 100%, comprises: The step of reducing the brightness of the side edge region pixels of the projection picture based on the side edge pixel information of the projection picture after the shape correction, so as to weaken the edge jaggies, wherein the brightness reduction amplitude of the side edge region pixels is less than 100%, comprises:

3. The method of claim 1, wherein the step of correcting the projected image comprises the step of: The step of reducing the brightness of the side edge region pixels of the projection picture based on the side edge pixel information of the projection picture after the shape correction, so as to weaken the edge jaggies, wherein the brightness reduction amplitude of the side edge region pixels is less than 100%, comprises: The step of reducing the brightness of the side edge region pixels of the projection picture based on the side edge pixel information of the projection picture after the shape correction, so as to weaken the edge jaggies, wherein the brightness reduction amplitude of the side edge region pixels is less than 100%, comprises:

4. The method of claim 1, wherein the step of correcting the projected image comprises the step of: The step of reducing the brightness of the side edge region pixels of the projection picture based on the side edge pixel information of the projection picture after the shape correction, so as to weaken the edge jaggies, wherein the brightness reduction amplitude of the side edge region pixels is less than 100%, comprises: The step of reducing the brightness of the side edge region pixels of the projection picture based on the side edge pixel information of the projection picture after the shape correction, so as to weaken the edge jaggies, wherein the brightness reduction amplitude of the side edge region pixels is less than 100%, comprises:

5. The method of claim 4, wherein the step of correcting the projected image comprises the step of: The step of reducing the brightness of the side edge region pixels of the projection picture based on the side edge pixel information of the projection picture after the shape correction, so as to weaken the edge jaggies, wherein the brightness reduction amplitude of the side edge region pixels is less than 100%, comprises: The step of reducing the brightness of the side edge region pixels of the projection picture based on the side edge pixel information of the projection picture after the shape correction, so as to weaken the edge jaggies, wherein the brightness reduction amplitude of the side edge region pixels is less than 100%, comprises: The side edge region pixels have a spatial gradient type of brightness difference after the adjustment, that is, the brightness of the pixels gradually increases along the direction from the picture edge to the picture center. The device comprises a processor and a memory, and the memory stores a computer program which can be read to execute the method according to any one of claims 1-6.

6. The method of claim 1, wherein the step of correcting the projected image comprises the step of: The storage medium stores a computer program, and the computer program is configured to be executed by the processor to execute the projection picture correction method according to any one of claims 1-6.

7. A projector characterized by comprising: ​ 8. A storage medium, characterized by ​

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