Image splitting methods and image display methods

Abstract

This invention provides an image segmentation method applied in a display device, wherein the display device forms a projected image on a projection screen. The image segmentation method includes the following steps: obtaining an image to be displayed, wherein the resolution of the image to be displayed is a first resolution; segmenting each frame of the image to be displayed into multiple low-resolution sub-frame images with a second resolution, wherein the second resolution is less than the first resolution; calculating the pixel grayscale value of each low-resolution sub-frame image based on the grayscale value of each image to be displayed and the display time duty cycle of the multiple low-resolution sub-frame images, thereby obtaining the modulation data of each low-resolution sub-frame image; this invention also provides an image display method including the above-described image segmentation method.

Description

[0001] This application is based on a divisional application filed on April 30, 2019, with application number 201910360885.9 and the invention title "Image Segmentation Method and Image Display Method". Technical Field

[0002] This invention relates to the field of display technology, and more particularly to an image splitting method and an image display method. Background Technology

[0003] This section is intended to provide background or context for the specific embodiments of the invention set forth in the claims. The description herein is not an admission that it is prior art simply because it is included in this section.

[0004] For image display devices such as projectors, high resolution means more distinguishable details, which has always been a goal pursued in the display industry. When displaying images formed by spatial light modulators such as Digital Micro-mirror Devices (DMDs), Thin-Film-Transistor Liquid Crystal Displays (TFT-LCDs), or Liquid Crystal on Silicon (LCoS), the number of pixels of the displayed image on the screen is usually the same as the number of pixels of the spatial light modulator. The higher the resolution of the spatial light modulator, the higher the resolution of the displayed image, but the corresponding manufacturing cost and the cost of the corresponding optical engine and projection components will increase significantly.

[0005] As an alternative, even without improving the intrinsic resolution of the spatial light modulator, the high-resolution image to be displayed can be split into multiple low-resolution sub-frame images, each composed of multiple low-resolution sub-frame pixels. The imaging positions of the multiple low-resolution sub-frame images are offset from each other by a non-integer number of low-resolution sub-frame pixels. The multiple low-resolution sub-frame images are then superimposed to obtain the high-resolution image to be displayed (i.e., the reconstructed image), thereby significantly improving the display resolution.

[0006] There are two common algorithms for splitting a high-resolution image into multiple low-resolution subframes: weighted averaging and internal sampling. The core idea of ​​weighted averaging is to assign a weighted average (usually using pixel area ratio as the weight) of the grayscale values ​​of several adjacent high-resolution pixels to the corresponding pixel in the low-resolution subframe. Internal sampling directly samples a high-resolution pixel from the original high-resolution signal source. In essence, internal sampling averages the grayscale values ​​of two adjacent high-resolution pixels along the diagonal to obtain the low-resolution subframe pixel.

[0007] Please see Figure 1A, Figure 1B and Figure 1C ,in Figure 1A The original image was obtained by superimposing multiple low-resolution subframe images using an internal sampling method. Figure 1B The reconstructed image, from Figure 1C As can be seen, the reconstructed image obtained by the internal sampling method has significantly reduced sharpness compared to the original image. Sharp edges have been filtered out, meaning that high-frequency spatial information has been selectively filtered out. The internal sampling method is essentially a spatial low-pass filtering operation, and the difference between it and the original image includes high-frequency edge components.

[0008] Please see Figure 1D and Figure 1E , Figure 1D It is based on Figure 1A The original image shown is a reconstructed image obtained using the weighted average method. Since each low-resolution subframe pixel in the weighted average method is the result of averaging the four adjacent high-resolution pixels at that pixel location, it is also a form of spatial low-pass filtering. Figure 1E As can be seen, the difference between the reconstructed image obtained by the weighted average method and the original image also lies in the sharp changes in high-frequency edge information. Summary of the Invention

[0009] This invention provides an image segmentation method and an image display method, applied in a display device, wherein the display device forms a projected image on a projection screen, and the image segmentation method includes the following steps:

[0010] Obtain the image to be displayed, wherein the resolution of the image to be displayed is a first resolution;

[0011] Each frame of the image to be displayed is divided into multiple low-resolution sub-frame images with a second resolution, which is smaller than the first resolution. The pixel grayscale value of each low-resolution sub-frame image is calculated based on the grayscale value of the pixel to be displayed in each image and the display time duty cycle of the multiple low-resolution sub-frame images, thereby obtaining the modulation data of each low-resolution sub-frame image.

[0012] An image display method includes the steps of the image segmentation method described above. After obtaining the modulation data of each low-resolution subframe image, the image display method further includes the following steps:

[0013] During the display cycle of each frame of the image to be displayed, the image light of the plurality of low-resolution subframe images is emitted to the projection screen according to the modulation data of each low-resolution subframe image. The row directions of the plurality of low-resolution subframe images are controlled to be parallel to each other. In the plurality of low-resolution subframe images obtained by splitting any frame of the image to be displayed, the imaging position of any two low-resolution subframe images is offset by 1 / n low-resolution subframe pixels in the row direction and / or column direction, where n>1.

[0014] An image display method includes the steps of the image segmentation method described above.

[0015] The first resolution is twice the second resolution.

[0016] The step of splitting each frame of the image to be displayed into multiple low-resolution sub-frames with a second resolution specifically involves:

[0017] Each frame of the image to be displayed is split into four low-resolution sub-frames with a second resolution;

[0018] After obtaining the modulation data of each low-resolution subframe image, the image display method further includes the following steps:

[0019] During the display cycle of each frame of the image to be displayed, the image light of the plurality of low-resolution subframe images is emitted to the projection screen according to the modulation data of each low-resolution subframe image in a timing sequence. The row directions of the plurality of low-resolution subframe images are controlled to be parallel to each other. The imaging positions of any two low-resolution subframe images in the plurality of low-resolution subframe images obtained by splitting any frame of the image to be displayed are controlled to be offset by 1 / 2 low-resolution subframe pixels in the row direction and / or column direction.

[0020] An image display method includes the steps of the image segmentation method described above.

[0021] The first resolution is twice the second resolution.

[0022] The step of splitting each frame of the image to be displayed into multiple low-resolution sub-frames with a second resolution specifically involves:

[0023] Each frame of the image to be displayed is split into two low-resolution sub-frames with a second resolution.

[0024] After obtaining the modulation data of each low-resolution subframe image, the image display method further includes the following steps:

[0025] During the display cycle of each frame of the image to be displayed, the image light of the two low-resolution subframe images is emitted to the projection screen according to the modulation data of each low-resolution subframe image. The row directions of the two low-resolution subframe images are controlled to be parallel to each other. In the multiple low-resolution subframe images obtained by splitting any frame of the image to be displayed, the imaging position of any two low-resolution subframe images is offset by 1 / 2 low-resolution subframe pixels in the row and column directions.

[0026] The method of calculating the modulation data of low-resolution subframe images by taking the pixel grayscale value of each pixel to be displayed and the display time duty cycle of the multiple low-resolution subframe images can better reproduce high-resolution images to be displayed. The reconstructed image obtained by superimposing multiple low-resolution subframe images is less different from the original image, and can effectively avoid the high-frequency filtering phenomenon generated during the image splitting and reassembly process. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments / methods of the present invention, the drawings used in the description of the embodiments / methods will be briefly introduced below. Obviously, the drawings described below are some embodiments / methods of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1A This is the original image.

[0029] Figure 1B The image is a reconstructed image obtained using the internal sampling method.

[0030] Figure 1C for Figure 1A and Figure 1B The difference between corresponding pixels.

[0031] Figure 1D The image is a reconstructed image obtained using the weighted average method.

[0032] Figure 1E for Figure 1A and Figure 1D The difference between corresponding pixels.

[0033] Figure 2A This is a schematic diagram illustrating the correspondence between four adjacent pixels to be displayed and the corresponding pixels of the first low-resolution subframe in the first embodiment of the present invention.

[0034] Figure 2B for Figure 2A The diagram shows the correspondence between four adjacent pixels to be displayed and the corresponding low-resolution subframe pixels.

[0035] Figure 3AThis is the first low-resolution subframe image in this embodiment.

[0036] Figure 3B This is the second low-resolution subframe image in this embodiment.

[0037] Figure 3C This is the third low-resolution subframe image in this embodiment.

[0038] Figure 3D This is the fourth low-resolution subframe image in this embodiment.

[0039] Figure 4 This is a schematic diagram of the display device.

[0040] Figure 5A This is the original image.

[0041] Figure 5B To utilize Figures 3A-3D The resulting reconstructed image.

[0042] Figure 5C for Figure 5A and Figure 5B The difference between corresponding pixels.

[0043] Figure 6A This is a schematic diagram illustrating the correspondence between four adjacent pixels to be displayed and the corresponding pixels of the first low-resolution subframe in the second embodiment.

[0044] Figure 6B for Figure 6A The diagram shows the correspondence between four adjacent pixels to be displayed and the corresponding low-resolution subframe pixels.

[0045] Figure 7A For Figure 5A The image shown is the original image, and the first low-resolution subframe image obtained in this embodiment after limiting the grayscale value.

[0046] Figure 7B For Figure 5A The image shown is the original image, and the second low-resolution subframe image obtained in this embodiment after limiting the grayscale values.

[0047] Figure 7C To be Figure 7A and Figure 7B The reconstructed image obtained by overlaying.

[0048] Figure 7D for Figure 7C The difference between this image and the original image.

[0049] Figure 8A This is the original image.

[0050] Figure 8BThis is the first low-resolution subframe image obtained in this embodiment using the grayscale values ​​of the pixels to be displayed at diagonal and off-diagonal positions.

[0051] Figure 8C This is the second low-resolution subframe image obtained in this embodiment using the grayscale values ​​of the pixels to be displayed at diagonal and off-diagonal positions.

[0052] Figure 8D According to Figure 8B and Figure 8C The reconstructed image obtained by the image splitting method and image display method provided in this embodiment.

[0053] Figure 8E For 8A and Figure 8D The difference.

[0054] Explanation of main component symbols

[0055] First display area p First low-resolution subframe pixels a Second low-resolution subframe pixels b Third low-resolution subframe pixels c Fourth low-resolution subframe pixels d Display devices 100 Light source system 101 Optical modulation device 102 Optical path translation system 103 Projection optical system 104 Projection screen 105

[0056] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0057] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0058] Numerous specific details are set forth in the following description to provide a thorough understanding of the invention. The described embodiments are only a part of, and not all, of the embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0059] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0060] This invention provides an image segmentation method and an image display method incorporating the image segmentation method, applied in a display device. The image light emitted from the display device forms a projected image on a projection screen. The image segmentation method provided by this invention is used to improve the resolution of the display device. It can promote the breakthrough of spatial light modulation devices in overcoming the limitations of the research and development cycle to achieve higher resolution during the image display process. It can also be used when high-resolution spatial light modulation devices cannot be purchased due to budget constraints. The method provided by this invention can be used to segment each frame of the display image into multiple low-resolution sub-frame images, and then superimpose the multiple low-resolution sub-frame images to obtain a high-resolution image to be displayed. This method is beneficial to improving the resolution of the display device, which will greatly promote the development of the projection industry and bring huge economic benefits.

[0061] First Implementation Method

[0062] The display device emits image light based on the original image data (such as video source) of the image to be displayed and forms a series of continuously displayed multi-frame projected images on the projection screen. In this invention, the method for splitting and displaying one frame of the multi-frame projected images is described as an example. Specifically, the image splitting method provided by this invention includes the following steps:

[0063] S101: Obtain the image to be displayed, which includes multiple pixels of pixel distribution to be displayed, and the resolution of the image to be displayed is a first resolution.

[0064] Please see Figure 2A The image to be displayed is composed of pixels distributed in a pixel-like manner. Generally, multiple pixels to be displayed are arranged in a rectangle along the row and column directions. Different pixels to be displayed are distinguished by addresses. For example, if the image to be displayed is a standard 4K format image, then the first resolution is 4096*2160. The row address of each pixel is represented by m, and the column address is represented by n. Then the pixel address is (m, n), where m and n are both integers, and 0≤m<4096, 0≤n<2160.

[0065] In addition, the original image data of the image to be displayed includes the grayscale values ​​of various primary colors for each pixel to be displayed. Generally, the grayscale values ​​of various primary colors in the original image data are in RGB format, and include the grayscale values ​​of each of the three primary colors. Taking a certain pixel to be displayed as an example, 50, 100, and 150 are the grayscale values ​​of the three primary colors of that pixel. In this invention, the grayscale value of the pixel to be displayed is denoted as H. m，n, It should be noted that the grayscale value of each pixel to be displayed can be the grayscale value of any primary color of the pixel to be displayed, or a combination of the grayscale values of multiple primary colors of the pixel to be displayed. The addresses of four adjacent pixels to be displayed in a "field" distribution can be respectively expressed as (2i - 1, 2j - 1), (2i - 1, 2j), (2i, 2j - 1), (2i, 2j). The grayscale values of the pixels to be displayed corresponding to the above four addresses are respectively denoted as H 2i-1，2j-1 , H 2i-1，2j , H 2i，2j-1 , H 2i，2j .

[0066] S102: Split each frame of the image to be displayed into multiple sub-frame images with a second resolution, where the second resolution is less than the first resolution. Each of the multiple sub-frame images with a low resolution includes multiple sub-frame pixels with a pixel distribution. Each pixel to be displayed in the image to be displayed is in a display area on the projection screen. According to the pixel grayscale value of each pixel to be displayed and the display time duty ratio of the multiple sub-frame images with a low resolution obtained by splitting each pixel to be displayed, calculate the pixel grayscale value of any sub-frame pixel in each sub-frame image with a low resolution, so as to obtain the modulation data of each sub-frame image with a low resolution.

[0067] Furthermore, calculating the pixel grayscale value of any sub-frame pixel in each sub-frame image with a low resolution includes:[[]]

[0068] Solve the weighted grayscale value of the corresponding sub-frame pixel with a low resolution according to the pixel grayscale value of each pixel to be displayed. Using the weighted grayscale value of the corresponding sub-frame pixel with a low resolution and the display time duty ratio of the sub-frame image with a low resolution to which the corresponding sub-frame pixel with a low resolution belongs, calculate the pixel grayscale value of the corresponding sub-frame pixel with a low resolution.

[0069] The weighted grayscale value of the sub-frame pixel with a low resolution in the present invention can be the weighted grayscale value of one primary color of the sub-frame pixel with a low resolution, or a combination of the weighted grayscale values of multiple primary colors of the sub-frame pixel with a low resolution. The weighted grayscale value of the sub-frame pixel with a low resolution is related to the grayscale value of the corresponding primary color of the sub-frame pixel with a low resolution and the display time duty ratio of the sub-frame pixel with a low resolution. The display time duty ratio of the sub-frame pixel with a low resolution is the display time duty ratio of the sub-frame image with a low resolution to which the sub-frame pixel with a low resolution belongs. Specifically, the weighted grayscale value of the sub-frame pixel with a low resolution in the present invention is equal to the product of the grayscale value of the corresponding primary color of the sub-frame pixel with a low resolution and the display time duty ratio of the corresponding sub-frame image with a low resolution.

[0070] According to the principle of conservation of luminous flux, the weighted gray value of the corresponding low-resolution subframe pixel is obtained by solving the pixel gray value of each pixel to be displayed. Specifically, the pixel gray value of each pixel to be displayed is equal to the sum of the weighted gray values ​​of the corresponding low-resolution subframe pixels in multiple low-resolution subframe images.

[0071] Theoretically, the offset of the imaging positions of any adjacent low-resolution subframe images can be equal. For example, adjacent low-resolution subframe images can be offset by 1 / n low-resolution subframe pixels. In this embodiment, n=2, meaning that when the high-resolution image to be displayed is determined, multiple low-resolution subframe images with offset imaging positions can be superimposed to achieve the same display effect as the high-resolution image. It is understood that n does not need to be a fixed integer; a larger n indicates fewer low-resolution subframe pixels are needed, resulting in lower costs. However, this leads to more difficult image splitting and higher chip reliability requirements. Another type is non-equidistant offset, where adjacent low-resolution subframe images are offset by different distances.

[0072] The image segmentation method provided by this invention calculates the pixel grayscale value of any low-resolution subframe pixel in each low-resolution subframe image based on the pixel grayscale value of each pixel to be displayed and the display time duty cycle of the multiple low-resolution subframe images. This method can better reproduce the high-resolution image to be displayed. The reconstructed image obtained by superimposing multiple low-resolution subframe images is less different from the original image. The reconstructed image is obtained by superimposing multiple low-resolution subframe images obtained by the image segmentation method provided by this invention, and the resolution of the reconstructed image is the same as the resolution of the image to be displayed.

[0073] This method employs a principle based on luminous flux conservation to divide a high-resolution image to be displayed into multiple low-resolution sub-frames matching the resolution of the display device. The second resolution can be the intrinsic resolution of the display device, and it is less than the first resolution. This means the resolution of the image to be displayed is higher than the intrinsic resolution of the display device. If the display device does not process the original image data of the image to be displayed, but directly modulates the primary color light based on the original image data of each frame to obtain a projected image, then the resolution of the projected image is the same as the intrinsic resolution of the display device. Consequently, the high resolution of the original image data is not utilized to achieve a high-definition display of the projected image, thus limiting the widespread application of the display device. It is understandable that the second resolution can also be less than the intrinsic resolution of the display device, and the resolution of the reconstructed image is equal to the first resolution.

[0074] Please see Figure 2A and Figure 2B, in this embodiment, the first resolution is twice the second resolution. That is, on the projection screen, each low-resolution sub-frame pixel and four adjacent to-be-displayed pixels distributed in a "field" shape are irradiated onto the same display area on the projection screen. That is, the area of each low-resolution sub-frame pixel is 4 times that of each to-be-displayed pixel. In this embodiment, taking the example of splitting each frame of the to-be-displayed image into four low-resolution sub-frame images with the second resolution, it can be understood that each frame of the to-be-displayed image can also be split into other numbers of low-resolution sub-frame images other than four.

[0075] Specifically, the four low-resolution sub-frame images are respectively the first low-resolution sub-frame image, the second low-resolution sub-frame image, the third low-resolution sub-frame image, and the fourth low-resolution sub-frame image. The first low-resolution sub-frame image, the second low-resolution sub-frame image, the third low-resolution sub-frame image, and the fourth low-resolution sub-frame image respectively include a plurality of first low-resolution sub-frame pixels, second low-resolution sub-frame pixels, third low-resolution sub-frame pixels, and fourth low-resolution sub-frame pixels with pixel distributions. Four to-be-displayed pixels with addresses (2i - 1, 2j - 1), (2i - 1, 2j), (2i, 2j - 1), and (2i, 2j) are displayed on the first display area p on the projection screen. That is, the first display area p is used to display the images of the four to-be-displayed pixels with addresses (2i - 1, 2j - 1), (2i - 1, 2j), (2i, 2j - 1), and (2i, 2j). The first display area p is also used to receive the light rays of the first low-resolution sub-frame pixel a, the second low-resolution sub-frame pixel b, the third low-resolution sub-frame pixel c, and the fourth low-resolution sub-frame pixel d. That is, the first low-resolution sub-frame pixel a, the second low-resolution sub-frame pixel b, the third low-resolution sub-frame pixel c, and the fourth low-resolution sub-frame pixel d are superimposed to obtain the images of the four to-be-displayed pixels with addresses (2i - 1, 2j - 1), (2i - 1, 2j), (2i, 2j - 1), and (2i, 2j). Since the superimposing method of the multiple low-resolution sub-frame images obtained by splitting each frame of the to-be-displayed image affects the specific image splitting method and the expression form of the gray values of the to-be-displayed pixels, the image display method adopted in this embodiment is described here, specifically involving the superimposing method of the above-mentioned multiple low-resolution sub-frame images. It can be understood that within the spirit or basic features of the present invention, the image splitting method provided by the present invention is also applicable to other image superimposing methods. Based on the method of using other low-resolution sub-frame images for superimposing to obtain a high-resolution to-be-displayed image, the expression form of the gray value of each to-be-displayed pixel obtained by using the image splitting method provided by the present invention will be different.

[0076] In this embodiment, the image display method includes the steps of the image segmentation method described above. After calculating the modulation data of each low-resolution subframe image, during the display period of each frame of the image to be displayed, the image light of the plurality of low-resolution subframe images is emitted to the projection screen according to the timing of the modulation data of each low-resolution subframe image. The row directions of the plurality of low-resolution subframe images obtained from the segmentation of each frame of the image to be displayed are controlled to be parallel to each other. Furthermore, the imaging positions of any two low-resolution subframe images obtained from the segmentation of any frame of the image to be displayed are controlled to be offset by 1 / n low-resolution subframe pixels in the row direction and / or column direction, where n > 1, thereby ensuring that the imaging positions of the plurality of low-resolution subframe images have an overlapping portion. In this embodiment, n = 2. Further, the emission timing of the plurality of low-resolution subframe images can also be controlled. For example, in this embodiment, the imaging positions of any two consecutively emitted low-resolution subframe images are controlled to be offset by 1 / n low-resolution subframe pixels in the row direction or column direction.

[0077] Specifically, both row and column directions include positive and negative directions, such as... Figure 2A As shown, the row direction is the horizontal direction in the figure, the column direction is the vertical direction in the figure, the positive direction of the row is the horizontal direction to the right in the figure, the negative direction of the row is the horizontal direction to the left in the figure, the positive direction of the column is the vertical direction downward in the figure, and the negative direction of the column is the vertical direction upward in the figure. In this embodiment, a light modulation device periodically emits a first low-resolution subframe image, a second low-resolution subframe image, a third low-resolution subframe image, and a fourth low-resolution subframe image. The imaging position of the second low-resolution subframe image is controlled to be offset by 1 / 2 low-resolution subframe pixel relative to the imaging position of the first low-resolution subframe image in the positive direction of the row direction. The imaging position of the third low-resolution subframe image is controlled to be offset by 1 / 2 low-resolution subframe pixel relative to the imaging position of the second low-resolution subframe image in the positive direction of the column direction. The imaging position of the fourth low-resolution subframe image is controlled to be offset by 1 / 2 low-resolution subframe pixel relative to the imaging position of the third low-resolution subframe image in the negative direction of the row direction. In other words, the imaging position of the fourth low-resolution subframe image is offset by 1 / 2 low-resolution subframe pixel relative to the imaging position of the first low-resolution subframe image in the positive direction of the row direction. In one implementation, the number of low-resolution subframe pixels offset by the successively emitted low-resolution subframe images is not equal. For example, the imaging position of the second low-resolution subframe image is controlled to be offset by 1 / 2 low-resolution subframe pixel relative to the imaging position of the first low-resolution subframe image in the positive direction of the row direction; the imaging position of the third low-resolution subframe image is controlled to be offset by 1 / 4 low-resolution subframe pixel relative to the imaging position of the second low-resolution subframe image in the positive direction of the column direction.

[0078] Based on the image display method described above, the image segmentation method mentioned in this invention will be further explained. According to the principle of luminous flux conservation, the weighted gray values ​​of the pixels corresponding to the first, second, third, and fourth low-resolution sub-frames in the four low-resolution sub-frame images are calculated based on the pixel gray value of each pixel to be displayed. Further, the pixel gray value of each pixel to be displayed is equal to the sum of the weighted gray values ​​of the pixels corresponding to the first, second, third, and fourth low-resolution sub-frames projected onto the first display area p in the aforementioned four low-resolution sub-frame images. The weighted gray value of each low-resolution sub-frame pixel is equal to the display time duty cycle DT of its respective low-resolution sub-frame image and the pixel gray value L of that low-resolution sub-frame pixel. mn The product of.

[0079] Specifically, the relationship between the grayscale value of each pixel to be displayed and the weighted grayscale value of the corresponding low-resolution subframe pixel satisfies formula 1-4:

[0080] H 2i-1,2j-1 =L 1 i,j DT 1 (Formula 1),

[0081] H 2i-1,2j =L 1 i,j DT 1 +L 2 i,j DT 2 (Formula 2),

[0082] H 2i,2j-1 =L 1 i,j DT 1 +L 4 i,j DT 4 (Formula 3),

[0083] H 2i,2j =L 1 i,j DT 1 +L 2 i,j DT 2 +L 3 i,j DT 3 +L 4 i,j DT 4 (Formula 4).

[0084] Among them, L k i,j This represents the grayscale value of the pixel at address (i, j) in the k-th low-resolution subframe image. Specifically, L 1 i,j L represents the grayscale value of the pixel at address (i, j) in the first low-resolution subframe image. 2 i,j L represents the grayscale value of the pixel at address (i, j) in the second low-resolution subframe image. 3 i,j L represents the grayscale value of the pixel at address (i, j) in the third low-resolution subframe image. 4 i,j This represents the grayscale value of the pixel at address (i, j) in the fourth low-resolution subframe image.

[0085] DT k This represents the display time duty cycle of the k-th low-resolution subframe image. Specifically, DT 1 DT 2 DT 3 With DT 4 These represent the display time duty cycles of the first, second, third, and fourth low-resolution subframe images, respectively. In this embodiment, the display time of each low-resolution subframe image is the same, therefore DT... 1 =DT 2 =DT 3 =DT 4 =1 / 4, in other implementations, the display time of each low-resolution subframe image can be different, i.e., DT 1 DT 2 DT 3 With DT 4 The proportional data can be set to be not exactly equal as needed.

[0086] L k i,j *DT k This represents the weighted gray value of the pixel at address (i, j) in the k-th low-resolution subframe image.

[0087] Formulas 1-4 are only strictly true when i = j = 1, because when i > 1 or j > 1, The low-resolution subframe pixels corresponding to (k=2,3,4) will be displayed in other display areas adjacent to the first display area p. Therefore, the influence between adjacent low-resolution subframe pixels needs to be considered. The above formulas 1-4 can be generally expressed as formulas 5-8:

[0088] H 2i-1,2j-1 -L 2 i,j-1 DT 2 -L 3 i-1,j-1 DT 3 -L 4 i-1,j DT 4 = L 1 i,j DT 1 = K 2i-1,2j-1 (Formula 5),

[0089] H 2i-1,2j -L 3 i-1,j DT 3 -L 4 i-1,j DT 4 = L 1 i,j DT 1 + L 2 i,j DT 2 = K 2i-1,2j (Formula 6),

[0090] H 2i,2j-1 -L 2 i-1,j DT 2 -L 3 i,j-1 DT 3 = L 1 i,j DT 1 + L 4 i,j DT 4 = K 2i,2j-1 (Formula 7),

[0091] H 2i,2j = L 1 i,j DT 1 + L 2 i,j DT 2 + L 3 i,j DT 3 + L 4 i,j DT 4 = K 2i,2j (Formula 8).

[0092] The representation of Equations 1-8 is closely related to the superposition method of multiple low-resolution subframes. When other image superposition / display methods are used, the representation of Equations 1-8 will be different.

[0093] Formula 5-8 defines a correction factor, denoted as K, that corresponds one-to-one with each pixel to be displayed. By limiting the range of values ​​for the correction factor, it is possible to ensure that the grayscale value of each low-resolution subframe pixel is within the range of 0-1. Let L... 0,0 =L 0,j =L i,0 =0 (0≤j<2048, 0≤j<1080), solve for the correction factor K in sequence. 2i-1,2j-1 K 2i-1,2j K 2i,2j-1 With K 2i,2j If K 2i-1,2j-1 K 2i-1,2j K 2i,2j-1 or K 2i,2j If any one of them is 0, then set its value to 0, thereby increasing the grayscale value L of the low-resolution subframe pixels in the low-resolution subframe image. i，j The probability of ≥0.

[0094] According to the correction factor (K) corresponding to each pixel to be displayed 2i-1,2j-1 K 2i-1,2j K 2i,2j-1 With K 2i,2j The minimum value of ) and the display time duty cycle DT of the first low-resolution subframe image. 1 The pixel grayscale value L of the first low-resolution subframe pixel corresponding to each pixel to be displayed is calculated. 1 i,j This is beneficial for solving the problem of L. 2 i,j L 3 i,j L 4 i,j All are non-negative numbers.

[0095] Determine the pixel grayscale value L of the first low-resolution subframe. 1 i,j If the value is greater than 1, then set the pixel grayscale value L of the first low-resolution subframe pixel. 1 i,j =1. Based on this, solve L sequentially. 2 i,j L 3 i,j With L 4 i,j And determine the pixel grayscale value L of each low-resolution subframe pixel. i，jIf the value is greater than 1, then set the pixel grayscale value L for each low-resolution subframe pixel. i，j The value is 1. Please refer to [link / reference]. Figures 3A-3D According to the above method, the pixel grayscale value of each low-resolution subframe pixel in the multiple low-resolution subframe images is within the physical constraint of [0,1].

[0096] Based on the above steps, the pixel grayscale value of each low-resolution subframe pixel in each low-resolution subframe image is calculated, thereby obtaining the modulation data of each low-resolution subframe image. The modulation data consists of the pixel grayscale values ​​of all low-resolution subframe pixels that constitute the corresponding low-resolution subframe pixel image.

[0097] During image display, based on the modulation data of each low-resolution subframe image, the first low-resolution subframe image, the second low-resolution subframe image, the third low-resolution subframe image, and the fourth low-resolution subframe image are sequentially projected onto the projection screen, or the fourth low-resolution subframe image, the third low-resolution subframe image, the second low-resolution subframe image, and the first low-resolution subframe image are sequentially projected onto the projection screen.

[0098] In practical applications, based on the modulation data of each low-resolution subframe image, multiple low-resolution subframe images can be sequentially emitted to the projection screen using an optical modulation device with intrinsic resolution.

[0099] Please see Figure 4 The display device 100 includes a light source system 101, a light modulation device 102, a light path translation system 103, a projection optics system 104, and a projection screen 105. The light source system 101 generates various primary color lights. The intrinsic resolution of the light modulation device 102 is the intrinsic resolution of the display device 100. The light modulation device 102 modulates the primary color lights according to the modulation data of each low-resolution subframe image to obtain the image light of each low-resolution subframe image. The light path translation system 103 adjusts the transmission direction of the image light of each low-resolution subframe image in a sequential manner, so that the imaging positions of the different low-resolution subframe images obtained from splitting a frame of image to be displayed on the projection screen 105 maintain a preset offset. The preset offset is 1 / n low-resolution subframe pixels, such as 1 / 2 low-resolution subframe pixels in this embodiment. The projection optics system 104 maps the light field with a two-dimensional grayscale distribution emitted from the light path translation system 103 onto the projection screen 105. The projection optics system 104 can be a projection lens.

[0100] Based on the modulation data of each low-resolution subframe image obtained from the above solution process, the primary color light is modulated using the optical modulation device 102 to obtain the image light of different low-resolution subframe images.

[0101] In one implementation, before step S102 of the image splitting method, each frame of the image to be displayed is split into multiple primary color sub-frame images, each primary color sub-frame image including primary color sub-frame pixels with pixel distribution, such as splitting each frame of the image to be displayed into red, green and blue primary color sub-frame images.

[0102] Based on multiple primary color subframe images obtained from the image to be displayed, each primary color subframe image is split into multiple low-resolution subframe images. Each primary color subframe pixel in each primary color subframe image and its corresponding low-resolution pixel in the split low-resolution subframe images are displayed in the same display area on the projection screen. The multiple low-resolution subframe images obtained from the split primary color subframe image are superimposed to obtain the reconstructed image of the corresponding primary color subframe image. The pixel grayscale value of each pixel to be displayed in each image to be displayed is equal to the combination of the primary color grayscale values ​​of the corresponding primary color subframe pixels in the multiple primary color subframe images. For example, if the three primary color grayscale values ​​of a pixel to be displayed are 50, 100, and 150, then the grayscale values ​​of the corresponding primary color subframe pixels in the red, green, and blue primary color subframe images of this pixel to be displayed are 50, 100, and 150, respectively. The weighted gray value and gray value of each low-resolution subframe pixel in each primary color subframe image are calculated based on the primary color gray value of each primary color subframe pixel in each primary color subframe image (according to formula 5-8), thereby obtaining the modulation data of multiple low-resolution subframe images obtained by splitting each primary color subframe image.

[0103] In the display device 100, the light source system 101 emits red, green, and blue primary colors, or combinations of other primary colors. During the time period when each primary color light illuminates the light modulation device 102, the same primary color light is modulated according to the modulation data of multiple low-resolution sub-frame images obtained by splitting each primary color sub-frame image to obtain multiple low-resolution sub-frame images corresponding to one primary color. The light modulation device 102 is controlled to modulate the low-resolution sub-frame images corresponding to different primary color sub-frame images in a time-division manner, that is, the light modulation device 102 is controlled to emit only one low-resolution sub-frame image obtained by splitting one primary color sub-frame image at any given time.

[0104] The optical path translation system 103 uses timing adjustment to adjust the transmission direction of the image light emitted from the optical modulation device 102, and guides the image light of different low-resolution subframe images to different positions on the projection screen 105. For clarity, Figure 4 The figure shows two beams of image light, Ray1 and Ray2, corresponding to two low-resolution subframe images, illuminating different imaging positions on the projection screen 105. The image light corresponding to the other two low-resolution subframe images in this embodiment is not shown in the figure.

[0105] To achieve the mutual offset imaging positions of multiple low-resolution subframe images corresponding to a single frame of an image to be displayed on the projection screen 105, multiple display devices can be used for simultaneous display. Each display device outputs one low-resolution subframe image corresponding to a single frame of the image to be displayed. Alternatively, multiple optical modulation devices can be installed in the same display device for simultaneous display. In this embodiment, the optical modulation device 102 outputs multiple low-resolution subframe images corresponding to a single frame of the image to be displayed in a time-division manner. That is, multiple low-resolution subframe images are displayed in a time-division manner using the same optical modulation device 102 within the display cycle of a single frame of the image to be displayed. From a cost perspective, using the same optical modulation device 102 for time-division display is more advantageous because there are relatively low-cost methods for optically shifting the entire image pixels. These methods can be broadly classified into mechanical, birefringent, and hybrid methods.

[0106] Mechanical methods often employ adjusting the deflection angle of a transparent plate relative to the image light. Because the refractive index of the transparent plate (often made of glass) differs from that of air, light undergoes multiple refractions as it passes through the plate, causing a slight shift in the exit point of the image light relative to the incident point. The amount of this shift depends on the plate's refractive index and the deflection angle. Birefringent methods often combine polarization control. When image light is incident on a birefringent material with its crystal axis aligned to a specific orientation, light of different polarization states will be deflected from its exit point. Therefore, the position of the exit light can be controlled by sequentially controlling the polarization direction of the incident polarized light. Consequently, these components often include electrically controlled polarization conversion elements, which can be nonlinear optical crystals or liquid crystals. Hybrid methods utilize rotating transparent plates with different refractive indices, causing image light from different low-resolution subframes to illuminate these plates, resulting in different imaging positions of the low-resolution subframes on the projection screen 105.

[0107] In one embodiment, the light modulation device 102 is disposed on a preset imaging surface inside the display device 100. The preset imaging surface includes a first position and a second position. During the display cycle of each frame of the image to be displayed, the light modulation device 102 is controlled to be in either the first position or the second position, and the light modulation device 102 is controlled to modulate at least one low-resolution subframe image at both the first position and the second position. In other embodiments, the light modulation device 102 can also be controlled to emit image light of at least one low-resolution subframe image from more than two different positions on the preset imaging surface. In embodiments where the positions of different low-resolution subframe images are different by using the timing control of the position of the light modulation device 102, an optical path translation system 103 can be used, or the optical path translation system 103 can be omitted.

[0108] Please see Figures 5A-5CAs can be seen from the figure, the reconstructed image obtained by the image splitting method and image display method in this embodiment is less different from the original image. The method of obtaining the modulation data of the low-resolution subframe image based on the principle of light flux conservation in this invention can better reproduce the high-resolution image to be displayed, and can effectively avoid the high-frequency filtering phenomenon generated during the image splitting and reconstructing process.

[0109] Technically, by superimposing multiple low-resolution subframe images with 1 / n (where n > 1) low-resolution subframe pixel offsets, the reconstructed image resolution can be significantly improved. From a cost perspective, only a low-cost optical path translation system 103 needs to be added to the original display device to significantly improve the resolution of the emitted image; therefore, this solution has a good return on investment.

[0110] Understandably, in practical applications, each frame of the image to be displayed can be split into multiple low-resolution subframe images, and the imaging positions of the multiple low-resolution subframe images on the projection screen can be offset from each other by a non-integer number of low-resolution subframe pixels other than 1 / 2.

[0111] It should be noted that the step numbers S101 and S102 are used to distinguish each step and to make reference easier. The step numbers S101 and S102 are not used to limit the order in which the steps are performed.

[0112] Second Implementation Method

[0113] The main difference between the image display method provided in this embodiment and the image display method provided in the first embodiment is that the phrase "the imaging positions of any two low-resolution subframe images are offset by 1 / n low-resolution subframe pixels in the row direction and / or column direction, where n > 1" is replaced with "the imaging positions of any two low-resolution subframe images are offset by 1 / n low-resolution subframe pixels in the row direction and / or column direction, where n > 1".

[0114] Accordingly, in one embodiment, step S102 in the image splitting method specifically involves splitting each frame of the image to be displayed into two low-resolution sub-frame images with a second resolution, namely a first low-resolution sub-frame image and a second low-resolution sub-frame image. The first low-resolution sub-frame image includes a plurality of first low-resolution sub-frame pixels with pixel distribution, and the second low-resolution sub-frame image includes a plurality of second low-resolution sub-frame pixels with pixel distribution.

[0115] Please see Figures 6A-6B, since the second resolution is twice the first resolution, each first / second low-resolution sub-frame pixel corresponds to four adjacent pixels to be displayed distributed in a "field" shape. The second low-resolution sub-frame image is offset by a non-integer number of low-resolution sub-frame pixels in the diagonal direction of the low-resolution sub-frame pixels relative to the first low-resolution sub-frame image. In this embodiment, it is controlled that the imaging positions of the two low-resolution sub-frame images obtained by splitting each frame of the image to be displayed are offset by 1 / n low-resolution sub-frame pixels in both the row direction and the column direction, where n>1, that is, the second low-resolution sub-frame image is offset by 1 / n low-resolution sub-frame pixels in the diagonal direction of the low-resolution sub-frame pixels relative to the first low-resolution sub-frame image. In this embodiment, n = 2. In other embodiments, it can be controlled that the imaging positions of multiple low-resolution sub-frame images obtained by splitting each frame of the pixels to be displayed are offset by other non-integer numbers of low-resolution sub-frame pixels other than 1 / 2 in both the row direction and the column direction, that is, the second low-resolution sub-frame image is offset by other non-integer numbers of low-resolution sub-frame pixels other than 1 / 2 in the diagonal direction of the low-resolution sub-frame pixels relative to the first low-resolution sub-frame image. In one embodiment, the number of low-resolution sub-frame pixels by which the imaging position of the second low-resolution sub-frame image is offset relative to the first low-resolution sub-frame in the row direction and the column direction is not equal, that is, the second low-resolution sub-frame image is offset in the non-diagonal direction of the first low-resolution sub-frame image.

[0116] According to the principle of light flux conservation, the sum of the weighted gray values of the corresponding first low-resolution sub-frame pixels and the weighted gray values of the corresponding second low-resolution sub-frame pixels in the two low-resolution sub-frame images is calculated based on the pixel gray value of each pixel to be displayed. The weighted gray value of each low-resolution sub-frame pixel is equal to the product of the display time duty ratio DT of the low-resolution sub-frame image to which it belongs and the pixel gray value L [[ID=V4]] m，n of this low-resolution sub-frame pixel.

[0117] Specifically, the relationship between the gray value of each pixel to be displayed and the corresponding low-resolution sub-frame pixel satisfies formulas 9-10:

[0118] H 2i-1,2j-1 =L 1 i,j DT 1 (Formula 9),

[0119] H 2i,2j =L 1 i,j DT 1 +L 2 <( i,j DT 2 (Formula 10). Where L k i,jThis represents the grayscale value of the pixel at address (i, j) in the k-th low-resolution subframe image. Specifically, L 1 i,j L represents the grayscale value of the pixel at address (i, j) in the first low-resolution subframe image. 2 i,j This represents the grayscale value of the pixel at address (i, j) in the second low-resolution subframe image.

[0120] DT k This represents the display time duty cycle of the k-th low-resolution subframe image. Specifically, DT 1 With DT 2 These represent the display time duty cycles of the first and second low-resolution subframe images, respectively. In this embodiment, the display time of the two low-resolution subframe images is the same, therefore DT... 1 =DT 2 =1 / 2. It is understood that in other implementations, the display time of multiple low-resolution subframe images may be different, that is, the duty cycle of the display time of different low-resolution subframe images may be different.

[0121] Formula 9-10 is only strictly true when i = j = 1, because when i > 1 or j > 1, The low-resolution subframe pixels corresponding to (k=2) will be displayed in the adjacent display area of ​​the first display area p. Therefore, the influence between adjacent low-resolution subframe pixels needs to be considered. Equation 9-10 can be generally expressed as Equation 11-12.

[0122] H 2i-1,2j-1 -L 2 i-1,j-1 DT 2 =L 1 i,j DT 1 =K 2i-1,2j-1 (Formula 11),

[0123] H 2i,2j =L 1 i,j DT 1 +L 2 i,j DT 2 =K 2i,2j (Formula 12).

[0124] Formulas 11 and 12 define a correction factor, denoted as K, that corresponds one-to-one with the pixels to be displayed, and let L... 0,0 =L 0,j =L i,0=0 (0≤j<2048, 0≤j<1080), solve for the correction factor K in sequence. 2i-1,2j-1 With K 2i,2j Based on the solution obtained by K 2i-1,2j-1 With K 2i,2j The grayscale value of each low-resolution pixel in the low-resolution subframe image can be calculated using formulas 11-12.

[0125] By limiting the range of correction factor values, it is ensured that the grayscale values ​​of each low-resolution subframe pixel are within the range of 0-1, thereby improving the quality of image reconstruction. For L... i，j Amplitude limiting is applied; specifically, it checks if at least one correction factor is less than 0. If so, the correction factor less than 0 is set to 0. Specifically, if K... 2i-1,2j-1 or K 2i,2j If any of the values ​​in the set variable is less than 0, then set its value to 0, thereby increasing the grayscale value L of the low-resolution subframe pixels in the low-resolution subframe image. i，j The probability of K being ≥0. In one implementation, only K is determined. 2i-1,2j-1 If it is less than 0, then set it to 0.

[0126] In one implementation, based on the correction factor (K) corresponding to each pixel to be displayed 2i-1,2j-1 With K 2i,2j The minimum value of ) and the display time duty cycle DT of the first low-resolution subframe image. 1 The pixel grayscale value L of the first low-resolution subframe pixel corresponding to each pixel to be displayed is calculated. 1 i,j This is beneficial for solving the problem of L. 2 i,j It is a non-negative number.

[0127] In one implementation, the pixel grayscale value L of the first low-resolution subframe pixel can be determined. 1 i,j If the value is greater than 1, then set the pixel grayscale value L of the first low-resolution subframe pixel. 1 i,j =1. Based on this, solve for L using formula 12. 2 i,j And determine the pixel grayscale value L of the second low-resolution subframe. 2 i,j If the value is greater than 1, then set the pixel grayscale value L of the second low-resolution subframe. 2 i,j =1.

[0128] Please see Figures 7A-7D Based on the above method for solving grayscale values, the following is obtained: Figure 7A and Figure 7B The two low-resolution subframe images shown will Figure 7A and Figure 7B After offsetting along the diagonal direction and then superimposing, the reconstructed image shown in Figure 7C is obtained. Figure 7D It can be seen that the reconstructed image has obvious defects on both sides of the diagonal compared to the original image. The reason for these defects is that the aforementioned solution process only considered the pixels to be displayed located at the diagonal position (pixel address (i, j)) in the image to be displayed. 2i-1,2j and H 2i,2j-1 The corresponding pixel to be displayed is actually a composite of two low-resolution subframe pixels. If the low-resolution subframe pixel values ​​are not chosen appropriately, there will be a large discontinuity between the recombined pixels to be displayed, resulting in image defects. To further solve the problem of image defects, it is necessary to consider the grayscale values ​​of high-resolution pixels in the off-diagonal positions of the image to be displayed.

[0129] Specifically, according to formulas 11-12 and 13-14 below, the grayscale values ​​of the corresponding low-resolution subframe pixels are calculated using the grayscale values ​​of the pixels to be displayed at diagonal and off-diagonal positions.

[0130] H 2i-1,2j -L 2 i-1,j DT 2 =L 1 i,j DT 1 =K 2i-1,2j (Formula 13),

[0131] H 2i,2j-1 -L 2 i,j-1 DT 2 =L 1 i,j DT 1 =K 2i,2j-1 (Formula 14).

[0132] According to formulas 11-14, that is, according to the correction factors K corresponding to the pixels to be displayed at the diagonal and off-diagonal positions respectively. 2i-1,2j-1 K 2i-1,2j K 2i,2j-1 Specifically, it utilizes the correction factor K corresponding to the pixels to be displayed at diagonal and off-diagonal positions. 2i-1,2j-1 K 2i-1,2j K 2i,2j-1 The average value, compared with the display time duty cycle DT of the first low-resolution subframe image. 1 The pixel grayscale value L of the corresponding first low-resolution subframe pixel for each pixel to be displayed is calculated. 1 i,jThe correction factor K is used to represent the pixels to be displayed at the diagonal and off-diagonal positions, respectively. 2i-1,2j-1 K 2i-1,2j K 2i,2j-1 The pixel grayscale value L of the first low-resolution subframe is obtained by calculating the average value. 1 i,j During the process, the influence of low-resolution subframe pixels in off-diagonal positions on adjacent display areas is considered, which helps to avoid image defects such as discontinuities in the grayscale values ​​of high-resolution pixels to be displayed in the reconstructed image. It is understandable that in solving L... 1 i,j With L 2 i,j During the process, L can be used 1 i,j With L 2 i,j The method described in this embodiment is used for amplitude limiting, so that L 1 i,j With L 2 i,j All are within the range [0,1].

[0133] Based on the above steps, the pixel grayscale value of each low-resolution subframe pixel in the two low-resolution subframe images is obtained, thus obtaining the modulation data of each low-resolution subframe image. The modulation data consists of the pixel grayscale values ​​of all low-resolution subframe pixels that constitute the corresponding low-resolution subframe pixel image.

[0134] The structure of the display device in this embodiment is the same as that of the display device 100 in the first embodiment, and as follows: Figure 4 As shown. In this embodiment, during the display cycle of each frame of the image to be displayed, the timing control optical path translation system 103 is used to guide the image light corresponding to the two different low-resolution sub-frame images emitted by the optical modulation device 102 to different positions on the projection screen 105. The specific implementation of the optical path translation system 103 is the same as that in the first embodiment, and will not be described in detail here.

[0135] Please see Figures 8A-8E ,from Figure 8E As can be seen from the figure, the reconstructed image obtained by using the gray values ​​of the pixels to be displayed at the diagonal and off-diagonal positions in this embodiment has a small difference from the original image. The method of obtaining the modulation data of the low-resolution subframe image based on the principle of light flux conservation in this invention can better reproduce the high-resolution image to be displayed, and can effectively avoid the high-frequency filtering phenomenon generated during the image splitting and reassembly process. The reconstruction effect is good, and the gray value continuity of adjacent high-resolution pixels in the reconstructed image is good.

[0136] It should be noted that, within the scope of the spirit or basic features of this invention, the specific solutions applicable to different embodiments can also be applied to each other. To save space and avoid repetition, they will not be described in detail here.

[0137] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be embraced within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims. Furthermore, it is clear that the word "comprising" does not exclude other elements or steps, and the singular does not exclude the plural. Multiple devices recited in the apparatus claims may also be implemented by the same device or system in software or hardware. The terms "first," "second," etc., are used to indicate names and do not indicate any particular order.

[0138] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. An image splitting method applied to a display device that forms a projection picture on a projection screen, characterized by, The image splitting method comprises the following steps: obtaining a to-be-displayed image, the resolution of the to-be-displayed image being a first resolution; splitting each frame of the to-be-displayed image into a plurality of low-resolution sub-frame images with a second resolution, the second resolution being smaller than the first resolution, calculating a pixel gray value of each low-resolution sub-frame image according to a gray value of a to-be-displayed pixel of each to-be-displayed image and a display time duty cycle of the plurality of low-resolution sub-frame images, the display time duty cycles of the plurality of low-resolution sub-frame images being the same, and obtaining modulation data of each low-resolution sub-frame image.

2. The image splitting method of claim 1, wherein, The to-be-displayed image comprises a plurality of to-be-displayed pixels with pixel distribution, and the plurality of low-resolution sub-frame images each comprise a plurality of low-resolution sub-frame pixels with pixel distribution, each to-be-displayed pixel in the to-be-displayed image and a corresponding low-resolution sub-frame pixel in the plurality of low-resolution sub-frame images are displayed in the same display area on the projection screen; The calculation of the pixel gray value of any low-resolution sub-frame pixel in each low-resolution sub-frame image comprises: solving a weighted gray value of the corresponding low-resolution sub-frame pixel according to the pixel gray value of each to-be-displayed pixel, and calculating the pixel gray value of the corresponding low-resolution sub-frame pixel by using the weighted gray value of the corresponding low-resolution sub-frame pixel and the display time duty cycle of the low-resolution sub-frame image to which the corresponding low-resolution sub-frame pixel belongs.

3. The image splitting method of claim 2, wherein, The solving of the weighted gray value of the corresponding low-resolution sub-frame pixel according to the pixel gray value of each to-be-displayed pixel comprises: the pixel gray value of each to-be-displayed pixel is equal to the sum of the weighted gray values of the corresponding low-resolution sub-frame pixels in the plurality of low-resolution sub-frame images.

4. The image splitting method of claim 2, wherein The solving of the weighted gray value of the corresponding low-resolution sub-frame pixel according to the pixel gray value of each to-be-displayed pixel comprises: judging whether a correction factor related to the weighted gray value of at least one low-resolution sub-frame pixel is less than 0, and if yes, setting the correction factor as 0.

5. The image splitting method of claim 4, wherein, The calculation of the pixel gray value of the corresponding low-resolution sub-frame pixel comprises: judging whether the pixel gray value of each low-resolution sub-frame pixel is greater than 1, and if yes, setting the pixel gray value of each low-resolution sub-frame pixel as 1.

6. The image splitting method of claim 5, wherein, The calculation of the pixel gray value of the corresponding low-resolution sub-frame pixel comprises: calculating the pixel gray value of the corresponding low-resolution sub-frame pixel in one low-resolution sub-frame image according to a minimum value or an average value of a plurality of correction factors and the display time duty cycle of the one low-resolution sub-frame image.

7. The image splitting method according to any one of claims 1 to 6, wherein The first resolution is twice the second resolution, The splitting of each frame of the to-be-displayed image into the plurality of low-resolution sub-frame images with the second resolution specifically comprises: splitting each frame of the to-be-displayed image into two or four low-resolution sub-frame images with the second resolution.

8. The image splitting method of any one of claims 1-6, wherein before the splitting of each frame of the to-be-displayed image into the plurality of low-resolution sub-frame images with the second resolution, the method further comprises: splitting each frame of the to-be-displayed image into a plurality of primary color sub-frame images, each primary color sub-frame image comprising a primary color sub-frame pixel of pixel distribution; the splitting each frame of the to-be-displayed image into a plurality of low-resolution sub-frame images with the second resolution comprises: according to the plurality of primary color sub-frame images obtained from the to-be-displayed image, splitting each primary color sub-frame image into a plurality of low-resolution sub-frame images, each primary color sub-frame pixel in each primary color sub-frame image and a corresponding low-resolution pixel in a split low-resolution sub-frame image are displayed in the same display area on the projection screen; the calculating the pixel grayscale value of any low-resolution sub-frame pixel in each low-resolution sub-frame image comprises: obtaining, according to the pixel grayscale value of each to-be-displayed pixel in each to-be-displayed image, the primary color grayscale value of each primary color sub-frame pixel in the plurality of primary color sub-frame images and the weighted grayscale value of the corresponding low-resolution sub-frame pixel of each primary color sub-frame pixel.

9. An image display method characterized by The image display method comprises the steps of the image splitting method of any one of claims 1-8, and after the modulation data of each low-resolution sub-frame image is obtained, the image display method further comprises the following steps: in the display period of each frame of the to-be-displayed image, the image light of the plurality of low-resolution sub-frame images is sequentially emitted to the projection screen according to the modulation data of each low-resolution sub-frame image, the row direction of the plurality of low-resolution sub-frame images is controlled to be parallel to each other, and the imaging positions of any two low-resolution sub-frame images in the plurality of low-resolution sub-frame images split from any frame of the to-be-displayed image are offset by 1 / n low-resolution sub-frame pixels in the row direction and / or the column direction, n>1.

10. The image display method of claim 9, wherein, the sequentially emitting the image light of the plurality of low-resolution sub-frame images to the projection screen according to the modulation data of each low-resolution sub-frame image comprises: modulating the primary color light by using the light modulation device according to the modulation data of each low-resolution sub-frame image, and obtaining the image light of different low-resolution sub-frame images; sequentially adjusting the transmission direction of the image light emitted by the light modulation device by using the optical path translation system, and guiding the image light of the plurality of low-resolution sub-frame images split from any frame of the to-be-displayed image to different positions on the projection screen.

11. The image display method of claim 10, wherein, the light modulation device is arranged on a preset imaging surface inside the display device, the preset imaging surface comprises a first position and a second position, the modulating the primary color light by using the light modulation device according to the modulation data of each low-resolution sub-frame image, and obtaining the image light of different low-resolution sub-frame images, comprises: in the display period of each frame of the to-be-displayed image, the light modulation device is controlled to be in the first position or the second position, and the light modulation device is controlled to modulate at least one low-resolution sub-frame image in both the first position and the second position.

12. An image display method characterized by the image splitting method comprises the steps of any one of claims 1-6 or 8, the first resolution is twice the second resolution, the splitting each frame of the to-be-displayed image into a plurality of low-resolution sub-frame images with the second resolution specifically comprises: splitting each frame of the image to be displayed into four low-resolution sub-frame images having the second resolution; after obtaining the modulation data of each low-resolution sub-frame image, the image display method further comprises the following steps: in the display period of each frame of the image to be displayed, the image light of the multiple low-resolution sub-frame images is sequentially emitted to the projection screen according to the modulation data of each low-resolution sub-frame image, the row direction of the multiple low-resolution sub-frame images is controlled to be parallel to each other, and the imaging positions of any two low-resolution sub-frame images in the row direction and / or the column direction are offset by 1 / 2 low-resolution sub-frame pixels.

13. An image display method characterized by comprising: comprising the steps of the image splitting method as claimed in any one of claims 1-6 or 8, the first resolution is twice the second resolution, the splitting each frame of the image to be displayed into multiple low-resolution sub-frame images having the second resolution specifically comprises: splitting each frame of the image to be displayed into two low-resolution sub-frame images having the second resolution; after obtaining the modulation data of each low-resolution sub-frame image, the image display method further comprises the following steps: in the display period of each frame of the image to be displayed, the image light of the two low-resolution sub-frame images is sequentially emitted to the projection screen according to the modulation data of each low-resolution sub-frame image, the row direction of the two low-resolution sub-frame images is controlled to be parallel to each other, and the imaging positions of any two low-resolution sub-frame images in the row direction and / or the column direction are offset by 1 / 2 low-resolution sub-frame pixels.

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