Non-uniform inclination angle correction method and device, equipment and storage medium

Abstract

The invention discloses a non-uniform tilt angle correction method and device, equipment and a storage medium, and relates to the technical field of display panel automatic optical detection, a region of interest (ROI) of a target image is intercepted, and coordinates of each column of maximum gray value pixels of the ROI are determined; taking the coordinates of the maximum gray value pixel in each column of the ROI for filtering, and deleting the ROI column of which the offset exceeds a threshold value; calculating the mass center of each ROI fragment formed after filtering; and fitting a straight line according to the centroid of each ROI segment to calculate an inclination angle, and performing angle correction on the target image according to the inclination angle. According to the method, the edge points can be quickly screened for linear fitting and angle correction, and the stability and the precision are relatively high.

Description

Technical Field

[0001] The present application relates to the technical field of automatic optical detection of display panels, and in particular to a method, device, equipment and storage medium for correcting an angle of non-uniform tilt. Background Art

[0002] AOI (Automated Optical Inspection) of display panels is a process that uses high-tech imaging technology to automatically detect defects in display panels. This process is crucial to ensuring the quality of display panels.

[0003] In the process of automatic optical inspection of LCD / OLED display panels, angle correction is usually involved. The commonly used angle correction method is the linear fitting method of edge profile, which has high requirements on the uniformity of edge profile. The smaller the fluctuation of profile, the higher the accuracy. However, it has limitations on small fluctuations and is not suitable for high-precision small angle measurement. Summary of the invention

[0004] The present application provides a method, device, equipment and storage medium for non-uniform tilt angle correction, which can quickly screen edge points for linear fitting and angle correction with high stability and accuracy.

[0005] In a first aspect, an embodiment of the present application provides a method for correcting an angle of non-uniform tilt, the method comprising:

[0006] Intercept the region of interest ROI of the target image and determine the coordinates of the pixel with the maximum gray value in each column of the ROI;

[0007] Take the coordinates of the pixel with the maximum gray value in each column of ROI for filtering, and delete the ROI columns whose offset exceeds the threshold;

[0008] Calculate the centroid of each ROI segment formed after filtering;

[0009] A straight line is fitted according to the centroid of each ROI segment to calculate the tilt angle, and the target image is angle corrected according to the tilt angle.

[0010] In combination with the first aspect, in one implementation, after intercepting the region of interest ROI of the target image and before determining the coordinates of the pixel with the maximum gray value in each column of the ROI, the method further includes:

[0011] The morphological method is used to remove the interference near the ROI.

[0012] In combination with the first aspect, in one implementation, an area threshold is set, and regions with an area smaller than the area threshold are deleted to remove interference near the ROI.

[0013] In combination with the first aspect, in one implementation, taking the coordinates of the pixel with the maximum gray value in each column of the ROI for filtering and deleting the ROI column with an offset exceeding a threshold value includes:

[0014] Take the row coordinates of the pixel with the maximum gray value in each column of ROI and perform sliding median filtering;

[0015] Filter the ROI column where the pixels whose offset is greater than the set pixel are located.

[0016] In combination with the first aspect, in one implementation, the calculating the centroid of each ROI segment formed after filtering includes:

[0017] Divide the filtered ROI into multiple ROI segments;

[0018] According to the formula: and Calculate the centroid (x) of each ROI segment c ,y c ), where (x i ,y i ) is the coordinate of the i-th pixel in the ROI segment, and I(i) is the grayscale value of the i-th pixel.

[0019] In combination with the first aspect, in one implementation, dividing the filtered ROI into a plurality of ROI segments includes:

[0020] Based on the deleted ROI columns and the set maximum number of ROI columns included in a single ROI segment, the filtered ROI is divided into multiple ROI segments.

[0021] In combination with the first aspect, in one implementation, the step of fitting a straight line according to the centroid of each ROI segment to calculate the tilt angle includes:

[0022] According to the least squares method, the centroid of each ROI segment was fitted and the inclination angle of the fitted straight line relative to the horizontal line was calculated.

[0023] In a second aspect, an embodiment of the present application provides a non-uniform tilt angle correction device, the non-uniform tilt angle correction device comprising:

[0024] A capture module is used to capture the region of interest (ROI) of the target image and determine the coordinates of the pixel with the maximum gray value in each column of the ROI;

[0025] A filtering module is used to obtain the coordinates of the pixel with the maximum gray value in each column of the ROI for filtering, and delete the ROI columns whose offset exceeds the threshold;

[0026] A calculation module, which is used to calculate the centroid of each ROI segment formed after filtering;

[0027] The correction module is used to fit a straight line according to the centroid of each ROI segment to calculate the tilt angle, and perform angle correction on the target image according to the tilt angle.

[0028] In the third aspect, an embodiment of the present application provides an angle correction device for non-uniform tilt, wherein the angle correction device for non-uniform tilt comprises a processor, a memory, and a non-uniform tilt angle correction program stored in the memory and executable by the processor, wherein when the non-uniform tilt angle correction program is executed by the processor, the steps of the above-mentioned non-uniform tilt angle correction method are implemented.

[0029] In a fourth aspect, a computer-readable storage medium stores a non-uniform tilt angle correction program, wherein when the non-uniform tilt angle correction program is executed by a processor, the steps of the above-mentioned non-uniform tilt angle correction method are implemented.

[0030] The beneficial effects brought by the technical solution provided by the embodiment of the present application include at least:

[0031] The non-uniform tilt angle correction method in the present application intercepts the region of interest ROI of the target image, determines the coordinates of the maximum grayscale value pixel in each column of the ROI; takes the coordinates of the maximum grayscale value pixel in each column of the ROI for filtering, and deletes the ROI column whose offset exceeds a threshold; calculates the centroid of each ROI segment formed after filtering; fits a straight line according to the centroid of each ROI segment to calculate the tilt angle, and performs angle correction on the target image according to the tilt angle.

[0032] That is, the angle correction method for non-uniform tilt in the present application can quickly screen and filter the non-uniformly changing tilt edges. For non-uniformly changing edges and non-linear fluctuations in edge contours, edge points can be quickly screened for linear fitting and angle correction, which has the advantages of being fast, stable and highly accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A schematic diagram showing the relative position of the display panel and the ink-coated area when the display panel is tilted;

[0034] Figure 2 A schematic diagram showing the relative position of the display panel and the ink coating area after angle correction;

[0035] Figure 3 A schematic diagram of a flow chart of an embodiment of a method for correcting a non-uniform tilt angle of the present application;

[0036] Figure 4 Schematic diagram of the process of intercepting the region of interest and removing interference for this application;

[0037] Figure 5This is a schematic diagram of the results of sliding median filtering and fitting straight line in this application;

[0038] Figure 6 This is a structural block diagram of an embodiment of a non-uniform tilt angle correction device of the present application;

[0039] Figure 7 This is a schematic diagram of the hardware structure of the non-uniform tilt angle correction device involved in the embodiment of the present application. DETAILED DESCRIPTION

[0040] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0041] It is worth noting that the inner side of the display panel needs to be coated with ink to block light to prevent light from leaking out when the screen is turned on. Figure 1 As shown, the position of the green wireframe is the area that needs to be inked. After inking, you need to take a picture to determine the inking situation by locating the green wireframe.

[0042] However, since the display panel is usually fixed on the carrier by vacuum adsorption, the dust on the carrier and the adsorption force will cause the display panel to tilt, making it difficult to locate the green wireframe. Figure 1 In the figure, the protective film of the display panel has bulged downward. There is a gap between the lower right corner of the first green frame and the white area below (the side of the display panel, that is, the image in the thickness direction of the display panel). Therefore, the display panel needs to be angle-corrected. The final effect can be seen in Figure 2 As shown, Figure 2 It can be seen that the green wireframe and the white area are basically aligned.

[0043] In addition, due to the limitations of the display panel material, its surface cannot be absolutely smooth, and there will be particles or burrs, that is, the display panel has non-uniformly changing inclined edges. The purpose of this application is to screen and filter the non-uniformly changing inclined edges to improve the accuracy of angle correction and prepare for subsequent judgment of the ink coating condition.

[0044] It should be noted that the above is an introduction to the relevant usage scenarios, but the solution in the present application is not limited to the above scenarios. As long as non-uniformly changing inclined edges are processed, the solution in the present application is also applicable.

[0045] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.

[0046] In a first aspect, an embodiment of the present application provides a method for correcting an angle of non-uniform tilt.

[0047] In one embodiment, referring to Figure 3 , Figure 3 This is a flow chart of an embodiment of a method for correcting the non-uniform tilt angle of the present application. Figure 3 As shown, the method for correcting the angle of non-uniform tilt includes:

[0048] S1, intercept the region of interest ROI of the target image, and determine the coordinates of the pixel with the maximum gray value in each column of the ROI;

[0049] See also Figure 4 As shown in FIG. 1 , the image captured is the side of the display panel, that is, the image in the thickness direction of the display panel. The ROI captured in this embodiment is the area selected in the red dotted box. If there is interference in the selected area, it is necessary to use a morphological method to remove the interference near the ROI. Specifically, an area threshold can be set to delete areas with an area smaller than the area threshold to remove the interference near the ROI (corresponding to Figure 4 The process is described by the downward red arrow in the figure).

[0050] Then, the coordinates of the pixel with the maximum gray value in each column of the ROI can be determined. It is worth noting that in image processing, the position of pixels in an image is mainly located by row coordinates (usually expressed as y coordinates) and column coordinates (usually expressed as x coordinates).

[0051] S2, taking the coordinates of the pixel with the maximum gray value in each column of the ROI for filtering, and deleting the ROI columns whose offset exceeds the threshold;

[0052] After processing in step S1, we can get Figure 4 In the picture on the lower right, as mentioned above, because the material cannot be absolutely smooth, burrs will appear and further processing is required.

[0053] Specifically, this embodiment takes the row coordinates of the pixel with the maximum gray value in each column of the ROI to perform sliding median filtering; and filters the ROI column where the pixel point with a deviation greater than the set pixel is located.

[0054] Sliding median filtering is a nonlinear digital filtering technique that is often used to remove salt-and-pepper noise or other random noise in images while keeping the edges of the image clear. The sliding median filter replaces the value of the pixel by defining a neighborhood (usually a square or circular window) around a pixel and calculating the median value within this neighborhood.

[0055] See also Figure 5 As shown, the green points are the filtered values.

[0056] S3, calculating the centroid of each ROI segment formed after filtering;

[0057] Specifically, step S3 includes:

[0058] S31, dividing the filtered ROI into multiple ROI segments;

[0059] In this embodiment, the division of the ROI segments is mainly determined based on two principles. One is that the column deleted in step S2 will become the boundary between two ROI segments. The other is that a maximum number of ROI columns will be set for one ROI segment. The ROI segment exceeding this maximum number of columns will become the next ROI segment. For example, if the maximum number of ROI columns is set to 64, then a continuous area of ​​65 columns will be divided into two ROI segments, one ROI segment including 64 columns and the other ROI segment including 1 column.

[0060] S32, according to the formula: and Calculate the centroid (x) of each ROI segment c ,y c ), where (x i ,y i ) is the coordinate of the i-th pixel in the ROI segment, I(i) is the grayscale value of the i-th pixel, and N is the total number of pixels in the ROI segment.

[0061] S4. Fit a straight line according to the centroid of each ROI segment to calculate the tilt angle, and perform angle correction on the target image according to the tilt angle.

[0062] In this embodiment, the centroid of each ROI segment is fitted according to the least square method, and the inclination angle of the fitting line relative to the horizontal line is calculated. Figure 5 As shown, the red cross is the centroid and the red oblique line is the fitting line.

[0063] At this point, the angle correction of the non-uniform tilt of the display panel is completed.

[0064] In summary, the non-uniform tilt angle correction method in the present application intercepts the region of interest ROI of the target image to determine the coordinates of the pixel with the maximum grayscale value in each column of the ROI; takes the coordinates of the pixel with the maximum grayscale value in each column of the ROI for filtering, and deletes the ROI column whose offset exceeds the threshold; calculates the center of mass of each ROI segment formed after filtering; fits a straight line according to the center of mass of each ROI segment to calculate the tilt angle, and performs angle correction on the target image according to the tilt angle.

[0065] That is, the angle correction method for non-uniform tilt in the present application can quickly screen and filter the non-uniformly changing tilt edges. For non-uniformly changing edges and non-linear fluctuations in edge contours, edge points can be quickly screened for linear fitting and angle correction, which has the advantages of being fast, stable and highly accurate.

[0066] In a second aspect, an embodiment of the present application also provides a device for correcting an angle of non-uniform tilt.

[0067] In one embodiment, referring to Figure 6 , Figure 6 This is a functional module diagram of an embodiment of the non-uniform tilt angle correction device of the present application. Figure 6 As shown, the non-uniform tilt angle correction device includes an interception module, a filtering module, a calculation module and a correction module.

[0068] The interception module is used to intercept the region of interest ROI of the target image and determine the coordinates of the maximum gray value pixel in each column of the ROI;

[0069] A filtering module is used to obtain the coordinates of the pixel with the maximum gray value in each column of the ROI for filtering, and delete the ROI columns whose offset exceeds the threshold;

[0070] A calculation module, which is used to calculate the centroid of each ROI segment formed after filtering;

[0071] The correction module is used to fit a straight line according to the centroid of each ROI segment to calculate the tilt angle, and perform angle correction on the target image according to the tilt angle.

[0072] Furthermore, in one embodiment, the interception module is further configured to, after intercepting the region of interest ROI of the target image and before determining the coordinates of the maximum grayscale value pixel in each column of the ROI, use a morphological method to remove interference near the ROI.

[0073] Furthermore, in one embodiment, the interception module sets an area threshold and deletes regions whose areas are smaller than the area threshold to remove interference near the ROI.

[0074] Furthermore, in one embodiment, the filtering module takes the coordinates of the pixel with the maximum gray value in each column of the ROI for filtering, and deletes the ROI columns whose offset exceeds a threshold, including:

[0075] Take the row coordinates of the pixel with the maximum gray value in each column of ROI and perform sliding median filtering;

[0076] Filter the ROI column where the pixels whose offset is greater than the set pixel are located.

[0077] Furthermore, in one embodiment, the calculation module calculates the centroid of each ROI segment formed after filtering, including:

[0078] Divide the filtered ROI into multiple ROI segments;

[0079] According to the formula: and Calculate the centroid (x) of each ROI segment c ,y c ), where (x i ,y i ) is the coordinate of the i-th pixel in the ROI segment, and I(i) is the grayscale value of the i-th pixel.

[0080] Furthermore, in one embodiment, the calculation module divides the filtered ROI into a plurality of ROI segments, including:

[0081] Based on the deleted ROI columns and the set maximum number of ROI columns included in a single ROI segment, the filtered ROI is divided into multiple ROI segments.

[0082] Further, in one embodiment, the correction module fits a straight line according to the centroid of each ROI segment to calculate the tilt angle, including:

[0083] According to the least squares method, the centroid of each ROI segment was fitted and the inclination angle of the fitted straight line relative to the horizontal line was calculated.

[0084] Among them, the functional implementation of each module in the above-mentioned non-uniform tilt angle correction device corresponds to each step in the above-mentioned non-uniform tilt angle correction method embodiment, and its functions and implementation processes are no longer repeated here.

[0085] In a third aspect, an embodiment of the present application provides a non-uniform tilt angle correction device, which may be a personal computer (PC), a laptop computer, a server, or other device with data processing capabilities.

[0086] Reference Figure 6 , Figure 6 Schematic diagram of the hardware structure of the non-uniform tilt angle correction device involved in the embodiment of the present application. In the embodiment of the present application, the non-uniform tilt angle correction device may include a processor, a memory, a communication interface and a communication bus.

[0087] The communication bus may be of any type and is used to interconnect the processor, the memory, and the communication interface.

[0088] The communication interface includes an input / output (I / O) interface, a physical interface, and a logical interface, etc., which are used to interconnect the devices inside the non-uniform tilt angle correction device, and an interface used to interconnect the non-uniform tilt angle correction device with other devices (such as other computing devices or user devices). The physical interface can be an Ethernet interface, an optical fiber interface, an ATM interface, etc.; the user device can be a display, a keyboard, etc.

[0089] The memory can be various types of storage media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), flash memory, optical storage, hard disk, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), etc.

[0090] The processor may be a general-purpose processor, and the general-purpose processor may call the non-uniform tilt angle correction program stored in the memory, and execute the non-uniform tilt angle correction method provided in the embodiment of the present application. For example, the general-purpose processor may be a central processing unit (CPU). The method executed when the non-uniform tilt angle correction program is called may refer to the various embodiments of the non-uniform tilt angle correction method of the present application, and will not be repeated here.

[0091] Those skilled in the art will understand that Figure 6 The hardware structure shown in the figure does not constitute a limitation on the present application, and may include more or less components than shown in the figure, or combine certain components, or arrange the components differently.

[0092] In a fourth aspect, an embodiment of the present application also provides a readable storage medium.

[0093] The readable storage medium of the present application stores a non-uniform tilt angle correction program, wherein when the non-uniform tilt angle correction program is executed by a processor, the steps of the non-uniform tilt angle correction method described above are implemented.

[0094] The method implemented when the non-uniform tilt angle correction program is executed can refer to the various embodiments of the non-uniform tilt angle correction method of the present application, and will not be described in detail here.

[0095] It should be noted that the serial numbers of the above-mentioned embodiments of the present application are only for description and do not represent the advantages or disadvantages of the embodiments.

[0096] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, disk, CD) as described above, and includes a number of instructions for a terminal device to execute the methods described in each embodiment of the present application.

[0097] The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices. The terms "first", "second" and "third" are used to distinguish different objects, etc., and do not represent a sequence, nor do they limit "first", "second" and "third" to different types.

[0098] In the description of the embodiments of the present application, "exemplary", "for example" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary", "for example" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary", "for example" or "for example" is intended to present related concepts in a specific way.

[0099] In the description of the embodiments of the present application, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; the “and / or” in the text is merely a description of the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, “multiple” refers to two or more than two.

[0100] In some processes described in the embodiments of the present application, multiple operations or steps that appear in a specific order are included, but it should be understood that these operations or steps may not be executed in the order in which they appear in the embodiments of the present application or in parallel, and the sequence number of the operation is only used to distinguish the different operations, and the sequence number itself does not represent any execution order. In addition, these processes may include more or fewer operations, and these operations or steps may be executed in sequence or in parallel, and these operations or steps may be combined.

[0101] The above are only preferred embodiments of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for correcting a non-uniform tilt angle, characterized in that: The non-uniform tilt angle correction method comprises: Intercept the region of interest ROI of the target image and determine the coordinates of the pixel with the maximum gray value in each column of the ROI; Take the coordinates of the pixel with the maximum gray value in each column of ROI for filtering, and delete the ROI columns whose offset exceeds the threshold; Calculate the centroid of each ROI segment formed after filtering; A straight line is fitted according to the centroid of each ROI segment to calculate the tilt angle, and the target image is angle corrected according to the tilt angle.

2. The method for correcting the non-uniform tilt angle according to claim 1, characterized in that: After intercepting the region of interest ROI of the target image and before determining the coordinates of the pixel with the maximum gray value in each column of the ROI, the method further includes: The morphological method is used to remove the interference near the ROI.

3. The method for correcting the non-uniform tilt angle according to claim 2, wherein: Set the area threshold and delete the area smaller than the area threshold to remove interference near the ROI.

4. The method for correcting the non-uniform tilt angle according to claim 1, wherein: The filtering is performed by taking the coordinates of the pixel with the maximum gray value in each column of the ROI, and deleting the ROI column whose offset exceeds the threshold, including: Take the row coordinates of the pixel with the maximum gray value in each column of ROI and perform sliding median filtering; Filter the ROI column where the pixels whose offset is greater than the set pixel are located.

5. The method for correcting the non-uniform tilt angle according to claim 1, characterized in that: The centroid of each ROI segment formed after the calculation of filtering includes: Divide the filtered ROI into multiple ROI segments; According to the formula: and Calculate the centroid (x) of each ROI segment c ,y c ), where (x i ,y i ) is the coordinate of the i-th pixel in the ROI segment, and I(i) is the grayscale value of the i-th pixel.

6. The method for correcting the non-uniform tilt angle according to claim 5, characterized in that: The step of dividing the filtered ROI into a plurality of ROI segments comprises: Based on the deleted ROI columns and the set maximum number of ROI columns included in a single ROI segment, the filtered ROI is divided into multiple ROI segments.

7. The method for correcting the non-uniform tilt angle according to claim 1, wherein: The step of fitting a straight line according to the centroid of each ROI segment to calculate the tilt angle comprises: According to the least squares method, the centroid of each ROI segment was fitted and the inclination angle of the fitted straight line relative to the horizontal line was calculated.

8. A non-uniform tilt angle correction device, characterized in that: The non-uniform tilt angle correction device comprises: A capture module is used to capture the region of interest (ROI) of the target image and determine the coordinates of the pixel with the maximum gray value in each column of the ROI; A filtering module is used to obtain the coordinates of the pixel with the maximum gray value in each column of the ROI for filtering, and delete the ROI columns whose offset exceeds the threshold; A calculation module, which is used to calculate the centroid of each ROI segment formed after filtering; The correction module is used to fit a straight line according to the centroid of each ROI segment to calculate the tilt angle, and perform angle correction on the target image according to the tilt angle.

9. A non-uniform tilt angle correction device, characterized in that: The non-uniform tilt angle correction device includes a processor, a memory, and a non-uniform tilt angle correction program stored in the memory and executable by the processor, wherein when the non-uniform tilt angle correction program is executed by the processor, the steps of the non-uniform tilt angle correction method as described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a non-uniform tilt angle correction program, wherein when the non-uniform tilt angle correction program is executed by a processor, the steps of the non-uniform tilt angle correction method according to any one of claims 1 to 7 are implemented.

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