A method for repairing seams on-site of LED display screen

Abstract

The present invention relates to an on-site seam repair method for an LED display screen. The method continuously extrapolates and searches from the center area of ​​the display screen and judges the similarity between the next light spot and the current normal light spot image until the positions of similar light spots at each edge are determined, thereby obtaining the left and right column coordinates and the up and down row coordinates of the screen, thereby calculating the positions of the gaps between modules, modules, and boxes and the seam repair ratio. The on-site seam repair of the entire display screen can be performed under the conditions of turning on the light and the presence of various stray lights.

Description

Technical Field

[0001] The invention belongs to the technical field of LED display optical collection and correction, and relates to a method for compensating dark lines and bright lines of a splicing gap of an LED display screen module, a module, and a box. Background Art

[0002] Currently, display screen seam repair is usually performed in a darkroom. The light spot matrix is ​​collected from top to bottom and from left to right in the camera window to determine the screen position, thereby calculating the location of the gaps between modules, modules, and cabinets. The standard pixel spacing and non-standard pixel spacing near the gap are collected, the seam repair ratio is calculated, and the dark and bright lines of the splicing gap are compensated. However, the on-site environment is usually very complex, and it is even impossible to turn off the lights to create conditions similar to a darkroom. At this time, the image information collected in the camera field of view includes both the normal display pixel dot matrix information of the display pixels, as well as a variety of complex interfering optical images such as the installation frame, lighting source, window, doorway, and human shadow, making it difficult to perform display screen seam repair. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide an on-site seam repair method for an LED display screen, which can perform the entire on-site seam repair under the conditions of turning on the light and the presence of various stray lights.

[0004] In order to solve the above technical problems, the on-site seam repair method of the LED display screen of the present invention is as follows:

[0005] The display screen uses every Gh column every Gh row display mode to display Gh 2 sequence images and take pictures with the camera;

[0006] For any image, take a horizontal strip area A in the middle of its longitudinal position, with a width D = (1.3-1.7) × D0, a length equal to the horizontal length of the image, and D0 equal to the spot row spacing; calculate a series of envelopes formed by the average brightness of the camera pixels in the horizontal strip area; take the envelope corresponding to the spot in the middle of the horizontal strip area as the reference envelope, and gradually extrapolate to both sides to search for the next complete envelope centered on the envelope peak point column coordinates; take the envelope with a correlation coefficient r>0.7 with the reference envelope each time as the new reference envelope and adjust its peak point column coordinates to x1′;

[0007] x′1=x0×w0+x1×w1

[0008] Where x0 is the reference envelope peak point column coordinate, x1 is the currently searched envelope peak point column coordinate; w0 is the reference envelope weight, w0=75%~95%, w1 is the currently searched envelope weight, w1=5%~25%, w0+w1=1; record the first and last envelope peak point column coordinates whose correlation coefficient with the reference envelope is greater than 0.7 and whose adjusted envelope peak point column coordinates meet the integer multiple of the standard spot spacing, and use them as the leftmost and rightmost envelope peak point column coordinates of the image respectively; similarly, obtain the row coordinates of the top and bottom envelope peak points of the image;

[0009] Take the column coordinates of the leftmost envelope peak point with the smallest column coordinates, the column coordinates of the rightmost envelope peak point with the largest column coordinates, the column coordinates of the top envelope peak point with the smallest row coordinates, and the row coordinates of the bottom envelope peak point with the largest row coordinates in all pictures as the left end column coordinates L0, the right end column coordinates L1, the top end row coordinates C0, and the bottom end row coordinates C1 of the display screen respectively; determine the column coordinates of each vertical seam and the row coordinates of the horizontal seam according to L0, L1, C0, C1 and the number of module columns and rows on the display screen;

[0010] Calculate the repair ratio of each vertical seam and horizontal seam and multiply it by the original correction coefficient of the display pixels on both sides of the vertical seam and the horizontal seam to obtain the corrected correction coefficient, and complete the on-site repair of the LED display.

[0011] Furthermore, Gh=2~8.

[0012] Further, each sequence of images lights up sub-pixels of a single primary color every Gh columns and every Gh rows.

[0013] Furthermore, when shooting the sequence of images, 80% of the camera's field of view is used as the effective area to shoot the display screen image.

[0014] Furthermore, before shooting the sequence of images, the camera is adjusted so that the brightness peak of the light spot in the camera field of view is greater than 93% of the maximum grayscale.

[0015] Furthermore, take the light spot in the middle of the horizontal strip area and 3 to 5 nearby vertical light spot areas, calculate the average camera pixel brightness for each light spot area, and obtain 3 to 5 envelopes; take the average value of the peak point column coordinates of these envelopes as the peak point column coordinate x0 of the initial reference envelope.

[0016] Furthermore, during the extrapolation search process, w0 gradually increases and w1 gradually decreases.

[0017] Preferably, when the coordinates of the new reference envelope peak point are adjusted by the first extrapolation search, w0=85%, w1=15%, and when the coordinates of the new reference envelope peak point are adjusted by the last extrapolation search, w0=95%, w1=5%.

[0018] Further, each sequence of images simultaneously lights up the red, green and blue tube cores of the display pixels in every other Gh columns and every other Gh rows.

[0019] Furthermore, all the single-primary-color sub-pixels of the LED display screen are lit up at the same time, or one column on the left side and two columns on the right side of the vertical seam, and one row on the upper side and two rows on the lower side of the horizontal seam are lit up at the same time, and a picture of the display screen is taken with a camera; for the vertical seam between any two adjacent modules, 90% of the vertical seam height is taken in the middle, and the brightness of the three columns of light spots on both sides is vertically integrated to obtain three envelopes, and the spacing between the first and second envelope peak points is used as the non-standard spacing of the horizontal light spots; the spacing between the second and third envelope peak points is used as the standard spacing of the horizontal light spots; the non-standard spacing of the horizontal light spots is divided by the standard spacing of the horizontal light spots to obtain the vertical seam repair ratio; and the horizontal seam repair ratios are obtained in the same way.

[0020] Beneficial effects:

[0021] 1. The present invention continuously extrapolates and searches from the center area of ​​the display screen and determines the similarity between the next light spot and the current normal light spot image, thereby obtaining the left and right column coordinates and the up and down row coordinates of the screen, thereby calculating the location of the gaps between modules, modules, and boxes and the repair ratio, and can perform on-site repair of the entire display screen under the conditions of turning on the light and the presence of various stray lights.

[0022] 2. When calculating the column (or) row coordinates of the new reference envelope peak point, the envelope currently searched by extrapolation accounts for a small proportion, so as to avoid the abnormal new spot shape causing a sudden change in the reference envelope shape, so that the reference envelope is not affected by the sudden change.

[0023] 3. During the extrapolation search process, the reference envelope weight gradually increases, and the current searched envelope weight gradually decreases; avoiding the influence of the spot shape change caused by the distortion of the camera field of view edge on the reference envelope, so that the reference envelope is also applicable to the camera field of view edge.

[0024] 4. Multiple envelopes are obtained based on the average brightness of the camera pixels in the middle spot and the nearby 3 to 5 horizontal or vertical spot areas. The average value of the peak point column coordinates of the multiple envelopes is taken as the peak point column coordinates of the initial reference envelope. This can avoid accidental deviations in the envelope peak point position corresponding to the middle spot, thereby making the reference envelope more accurate.

[0025] 5. The searched peak point column coordinates meet the peak point column coordinates of the envelope of an integer multiple of the standard spot spacing, eliminating the influence of stray light with high similarity to the envelope, so that the searched screen four corners coordinates are accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the light spot, stray optical image and its corresponding envelope on the display screen image taken by the camera.

[0027] Figure 2 It is a flow chart of the present invention.

[0028] Figure 3a to Figure 3d is a schematic diagram of the sequence of images S1 to S4, in which white circles represent lit single-primary-color sub-pixels, and black circles represent extinguished single-primary-color sub-pixels.

[0029] Figure 4 It is a schematic diagram of dividing the horizontal strip area and the three intermediate light spot areas distributed vertically.

[0030] Figure 5 It is a schematic diagram of the envelope series corresponding to the light spot in the transverse strip area.

[0031] Figure 6 This is a schematic diagram of the calculation method of the peak point column coordinate x0 of the reference envelope.

[0032] Figure 7 is a schematic diagram of the display screen. DETAILED DESCRIPTION

[0033] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0034] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood in specific circumstances.

[0035] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" or "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0036] In the description of this embodiment, the terms "upper", "lower", "left", "right" and other directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplified operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0037] When the LED display screen is displaying the test image, no matter how complex the on-site environment is, it will inevitably block the stray light behind it, so that the screen area image contains normal display pixel matrix information, of course, also includes the gap information of the module, module and cabinet splicing, and those complex stray optical images appear in the peripheral area around the entire screen, such as Figure 1 As shown in the figure, the brightness of the stray optical image corresponding to a single ultra-bright lighting source is saturated and clustered; the brightness peak of the stray optical image corresponding to the strip-shaped support frame of the screen background is within the normal range of the light spot and is strip-shaped; the brightness peak of the stray optical image corresponding to the bright area of ​​the window is within the normal range of the light spot and is rectangular; the stray light spot is similar to the normal light spot, but is isolated or non-uniformly distributed.

[0038] According to the above characteristics, the on-site seam repair method of the LED display screen of the present invention pushes outward from the central area of ​​the display screen to determine the similarity between the displayed image and the normal light spot image at a specific spacing and a specific position, thereby obtaining the column coordinates of the left and right ends of the display screen and the row coordinates of the upper and lower ends, thereby calculating the location of the gap between the module, the module, and the box according to the number of columns and rows of pixels displayed on the display screen; finally, the seam repair ratio is obtained according to the standard spacing of the light spots and the non-standard spacing of the light spots, thereby completing the on-site seam repair of the LED display screen.

[0039] The on-site seam repair method of the LED display screen of the present invention is specifically as follows:

[0040] Assume that the camera resolution is M×N (number of camera pixel columns×number of camera pixel rows), and the display resolution is m×n (number of display pixel columns×number of display pixel rows); the display screen displays the sequence images S1 to S4 in a Gh-column-by-Gh-row display mode, and each sequence image lights up the single-primary color sub-pixels (red, green or blue, and the light spots in the pictures taken by the camera are typical standard normal distribution spots) in every Gh column and every Gh row. Each sequence image lights up the single-primary color sub-pixels in different rows and columns, Gh=2~8; taking Gh=2 as an example, the sequence images S1 to S4 are as follows: Figure 3a-3dAs shown. Take 80% of the camera field of view as the effective area to shoot 4 display screen pictures, and adjust the camera before shooting so that the brightness peak of the light spot in the camera field of view is greater than 93% of the maximum grayscale. For example, the brightness peak of the light spot should be around 240 when the grayscale is 8bit; the brightness peak of the light spot should be around 3800 when the grayscale is 12bit; the brightness peak of the light spot should be around 62000 when the grayscale is 16bit.

[0041] For any picture, the spot row spacing D0 and column spacing D are determined according to the image data. c ; usually D0≈D c ;like Figure 4 As shown, a horizontal strip area A is taken in the middle of the vertical position of the image, and its width D = (1.3-1.7) × D0, and its length is the horizontal length of the image, that is, the length is equal to N; the brightness mean of each column of camera pixels in the horizontal strip area A is calculated, and the brightness mean of the camera pixels in the horizontal strip area column forms a series of envelopes, such as Figure 5 As shown; the actual column spacing D of the normal light spot is determined according to the column coordinates of the peak points of the two envelopes at the lateral middle position of the lateral strip area. c '; Take the envelope corresponding to the spot in the middle of the horizontal strip area as the reference envelope; take the spot and 3 to 5 spot areas in the longitudinal direction nearby (taking 3 spot areas B1, B2, and B3 as an example), calculate the average brightness of the camera pixels for each spot area, and obtain 3 envelopes, such as Figure 6 As shown, taking the average of the peak point column coordinates of the three envelopes as the peak point column coordinate x0 of the reference envelope can avoid accidental deviation in the envelope peak point position corresponding to the middle position spot in the horizontal strip area.

[0042] Since the shape of the envelope will gradually stretch and distort toward the sides or up and down of the display screen, and the coordinate position may also change slightly, the reference envelope shape and position should be gradually adjusted; at the same time, in order to avoid mutations, when calculating the column (or) row coordinates of the new reference envelope peak point, the current extrapolated searched envelope should account for a small proportion, so as to avoid the abnormal shape of the new reference envelope causing a mutation in the shape of the reference light spot.

[0043] Take the reference envelope at this time as the center and search for the next complete envelope with the envelope peak point column coordinates as the center; for any currently searched envelope, calculate its correlation coefficient r with the reference envelope; if r>0.7, take the envelope as the new reference envelope and adjust its peak point column coordinates to x1′;

[0044]

[0045] I is the number of camera pixel columns occupied by the currently searched envelope, X i is the camera pixel brightness value of the i-th column in the currently searched envelope, is the average brightness of all camera pixels in the currently searched envelope; J is the number of camera pixel columns occupied by the reference envelope, Y j is the brightness value of the camera pixel in the jth column in the reference envelope, is the average brightness of all camera pixels in the reference envelope;

[0046] x′1=x0×w0+x1×w1

[0047] Wherein, x0 is the reference envelope peak point column coordinate, x1 is the currently searched envelope peak point column coordinate; w0 is the reference envelope weight, w0=75%~85%, w1 is the currently searched envelope weight, w1=15%~25%, w0+w1=1.

[0048] Taking the new reference envelope as the base point, continue to search for the next complete envelope centered on the envelope peak point column coordinates along the transverse strip area, and calculate its correlation coefficient r with the reference envelope according to the above method; if r>0.7, use the envelope as the new reference envelope and adjust its envelope peak point column coordinates to x2′; similarly, continue to search for the next complete envelope centered on the envelope peak point column coordinates along the transverse strip area until the first and last envelopes are searched, record the first and last envelope peak point column coordinates whose correlation coefficients with the reference envelope are greater than 0.7 and whose adjusted envelope peak point column coordinates meet the integer multiple of the standard spot spacing, and use them as the leftmost envelope peak point column coordinates and the rightmost envelope peak point column coordinates of the image; during the extrapolation search process, w0 gradually increases and w1 gradually decreases; when the new reference envelope peak point column coordinates are extrapolated and adjusted for the last time, w0=95%, w1=5%.

[0049] Similarly, take a longitudinal strip area in the middle of the image, and continuously extrapolate the search to update the reference envelope upward and downward until the top and bottom envelopes are found. Record the row coordinates of the top and bottom envelope peak points whose correlation coefficients with the reference envelope are greater than 0.7 and whose column coordinates of the adjusted envelope peak points meet the integer multiple of the standard spot spacing, and use them as the row coordinates of the top envelope peak point and the bottom envelope peak point of the image.

[0050] Take the column coordinates of the leftmost envelope peak point with the smallest column coordinates in the four pictures as the column coordinates L0 of the left end of the display screen, the column coordinates of the rightmost envelope peak point with the largest column coordinates as the column coordinates L1 of the right end of the display screen, the column coordinates of the uppermost envelope peak point with the smallest row coordinates as the row coordinates C0 of the upper end of the display screen, and the row coordinates of the lowermost envelope peak point with the largest row coordinates as the row coordinates C1 of the lower end of the display screen; determine the column coordinates of each vertical seam and the row coordinates of the horizontal seam according to L0, L1, C0, C1 and the number of module columns and rows on the display screen;

[0051] All the single-primary color sub-pixels of the LED display screen are lit up at the same time, or one column on the left side and two columns on the right side of the vertical seam, and one row on the upper side and two rows on the lower side of the horizontal seam are lit up at the same time, and a picture of the display screen is taken with a camera; for the vertical seam between any two adjacent modules, 90% of the middle vertical seam height is taken, and the brightness of the three columns of light spots on both sides is vertically integrated to obtain three envelopes, and the spacing between the first and second envelope peak points is used as the non-standard spacing of the horizontal light spots; the spacing between the second and third envelope peak points is used as the standard spacing of the horizontal light spots; the non-standard spacing of the horizontal light spots is divided by the standard spacing of the horizontal light spots to obtain the seam repair ratio of the vertical seam; the original correction coefficient of the display pixels of one or two columns on both sides of the vertical seam of the display screen is multiplied by the seam repair ratio to obtain the corrected correction coefficient; similarly, the corrected correction coefficient of the LED pixels of one or two rows on both sides of the horizontal seam between each two adjacent modules of the display screen is obtained.

[0052] The present invention is not limited to the above embodiments. When the display screen adopts the display mode of every Gh columns and every Gh rows, the red, green and blue tube cores of the display pixels can also be lit at the same time, and the contrast can be increased at the same time, which is more conducive to combating the complex environment of daytime collection. The light spot in the picture is a white special-shaped light spot with an atypical standard normal distribution (a triangle, vertical line or L-shaped light spot that matches the display pixel process structure). For virtual pixels, only single-primary color sub-pixels are lit, and the light spot in the picture is a special-shaped light spot with a certain arrangement pattern (a diamond-shaped or diamond-shaped light spot that matches the display pixel process structure); for virtual pixels, the red, green and blue tube cores can also be lit at the same time, and the light spot is a white special-shaped light spot with a certain arrangement pattern (a diamond-shaped or diamond-shaped light spot that matches the display pixel process structure).

[0053] The image of the spot in the display area meets the judgment criteria in terms of similarity with the standard spot or the spot spacing, while the complex images outside the display are excluded because they do not meet the similarity with the standard spot or because the spot spacing does not meet the criteria. The installation frame, lighting source, window, doorway and other complex interfering optical images in the environment cannot pass the above double judgment, thus excluding all interfering images (spots).

[0054] The present invention has several major characteristics, such as searching from the inside to the outside in the middle of the screen, judging the similarity between the spot image and the standard spot image, judging whether the spot spacing meets the standard spacing, displaying the three primary color components of the pixel at the same time, and gradually changing the reference spot shape.

Claims

1. A method for repairing seams on-site of an LED display screen, characterized in that The method is as follows: The display screen uses every Gh column every Gh row display mode to display Gh 2 sequence images and take pictures with the camera; For any picture, take a horizontal strip area A in the middle of its longitudinal direction, with a width of D = (1.3-1.7) × D0, a length of the horizontal length of the picture, and D0 is the spot row spacing; A series of envelopes formed by the average brightness of camera pixels in the horizontal strip area are calculated; the envelope corresponding to the spot in the middle of the horizontal strip area is used as the reference envelope, and the next complete envelope centered on the coordinates of the envelope peak point column is gradually extrapolated to both sides; The envelope with correlation coefficient r>0.7 with the reference envelope found by each extrapolation search is used as the new reference envelope and its peak point column coordinates are adjusted to x1′; x′1=x0×w0+x1×w1 Where x0 is the reference envelope peak point column coordinate, x1 is the currently searched envelope peak point column coordinate; w0 is the reference envelope weight, w0=75%~95%, w1 is the currently searched envelope weight, w1=5%~25%, w0+w1=1; record the first and last envelope peak point column coordinates whose correlation coefficient with the reference envelope is greater than 0.7 and whose adjusted envelope peak point column coordinates meet the integer multiple of the standard spot spacing, and use them as the leftmost and rightmost envelope peak point column coordinates of the image respectively; similarly, obtain the row coordinates of the top and bottom envelope peak points of the image; Take the column coordinates of the leftmost envelope peak point with the smallest column coordinates, the column coordinates of the rightmost envelope peak point with the largest column coordinates, the row coordinates of the top envelope peak point with the smallest row coordinates, and the row coordinates of the bottom envelope peak point with the largest row coordinates in all pictures as the left end column coordinates L0, the right end column coordinates L1, the top end row coordinates C0, and the bottom end row coordinates C1 of the display screen respectively; determine the column coordinates of each vertical seam and the row coordinates of the horizontal seam according to L0, L1, C0, C1 and the number of module columns and rows on the display screen; Calculate the repair ratio of each vertical seam and horizontal seam and multiply it by the original correction coefficient of the display pixels on both sides of the vertical seam and the horizontal seam to obtain the corrected correction coefficient, and complete the on-site repair of the LED display.

2. The on-site seam repair method for an LED display screen according to claim 1, characterized in that Gh=2~8.

3. The on-site seam repair method of the LED display screen according to claim 1, characterized in that Each sequential image lights up sub-pixels of a single primary color in every Gh columns and every Gh rows.

4. The on-site seam repair method for an LED display screen according to claim 1, characterized in that When taking sequential images, 80% of the camera's field of view is used as the effective area to take pictures of the display screen.

5. The on-site seam repair method of the LED display screen according to claim 1, characterized in that Before shooting the sequence of images, the camera is adjusted so that the brightness peak of the light spot in the camera field of view is greater than 93% of the maximum grayscale.

6. The on-site seam repair method for an LED display screen according to claim 1, characterized in that Take the light spot in the middle of the horizontal strip area and 3 to 5 light spot areas nearby in the longitudinal direction, calculate the average value of the camera pixel brightness for each light spot area, and obtain 3 to 5 envelopes; take the average value of the peak point column coordinates of these envelopes as the peak point column coordinate x0 of the initial reference envelope.

7. The on-site seam repair method for an LED display screen according to claim 1, characterized in that During the extrapolation search process, w0 gradually increases and w1 gradually decreases.

8. The on-site seam repair method for an LED display screen according to claim 1, characterized in that When the first extrapolation search adjusts the new reference envelope peak point column coordinates, w0=85%, w1=15%, and when the last extrapolation search adjusts the new reference envelope peak point column coordinates, w0=95%, w1=5%.

9. The on-site seam repair method for an LED display screen according to claim 1, characterized in that Each sequence of images simultaneously lights up the red, green and blue tube cores of the display pixels in every Gh columns and every Gh rows.

10. The on-site seam repair method of an LED display screen according to claim 1, characterized in that All the single-primary-color sub-pixels of the LED display screen are lit up at the same time, or one column on the left and two columns on the right of the vertical seam, and one row on the upper side and two rows on the lower side of the horizontal seam are lit up at the same time, and a picture of the display screen is taken with a camera; for the vertical seam between any two adjacent modules, 90% of the vertical seam height is taken in the middle, and the brightness of the three columns of light spots on both sides is vertically integrated to obtain three envelopes, and the spacing between the first and second envelope peak points is used as the non-standard spacing of the horizontal light spots; the spacing between the second and third envelope peak points is used as the standard spacing of the horizontal light spots; the non-standard spacing of the horizontal light spots is divided by the standard spacing of the horizontal light spots to obtain the vertical seam repair ratio; similarly, the horizontal seam repair ratios are obtained.

Images