Photoelectric detection equipment precision evaluation method and system and storage medium

Abstract

The invention discloses a photoelectric detection equipment precision evaluation method and system and a storage medium, and the method comprises the steps: lightening each pixel point of a calibration screen pixel by pixel, and obtaining a current measurement value of a standard photoelectric detection equipment alignment reference region pixel by pixel; calculating a difference result between the current measurement value and the previous measurement value for positioning a boundary pixel point so as to obtain a position relation between an effective sampling area and a reference area of the standard photoelectric detection equipment in the boundary pixel point; acquiring a reference screen image acquired by the photoelectric detection equipment to be detected, and positioning a measurement area corresponding to the effective sampling area on the reference screen image through the reference area; according to the invention, the submillimeter-level alignment precision is realized in an easy-to-operate manner, and the measurement position of the reference instrument is positioned in the image obtained by the imaging colorimeter in cooperation with an algorithm, so that the time interval between the measurement of the reference instrument and the measurement of the to-be-measured instrument is greatly shortened, and the measurement precision is obviously improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of optical instruments, and particularly relates to a precision evaluation method and system for photoelectric detection equipment and a storage medium. BACKGROUND

[0002] A surface brightness and chroma measuring device (or photoelectric detection equipment) is a device that can measure the brightness and chroma of different positions on the surface of an object. It has a wide range of applications in screen detection, lighting device detection, vehicle-mounted display, etc. It can greatly improve the measurement speed of brightness and chroma. The process of evaluating the absolute measurement precision of the surface brightness and chroma measuring device can determine whether the device can meet the precision requirements. This process usually has two implementation methods: I. Using a reference instrument to measure the object to be measured and comparing the measurement results with those of the tested instrument (reference method); II. Using an object with known chroma and brightness to measure the object with the tested instrument (absolute measurement method); Method II corresponds to a standard light source / absolute brightness reference, which usually requires complex maintenance and high cost. In comparison, method I is more commonly used, i.e., using a reference instrument as a reference to compare the precision of the instrument to be tested. The reference instrument is usually a point-type brightness and chroma measuring device, which can only measure the average brightness and chroma of a fixed-size field of view at a time.

[0003] In order to compare the results of the reference instrument and the instrument to be tested, it is necessary to accurately know the position in the field of view of the instrument to be tested that is measured by the reference instrument. For a point-type chroma meter, this process can usually only be achieved by manual estimation, making auxiliary marks, or using a complex motion mechanism.

[0004] Patent CN108876842A discloses a method, system, device and storage medium for measuring sub-pixel edge angle. It collects the original image of a standard part, establishes a measurement model and adds the distribution parameters of the measurement region of the edge of the standard part in the original image; collects the target image of the part to be measured, obtains the measurement region of the edge of the part to be measured in the target image; aligns the measurement region with the measurement region, extracts the edge points of the measurement region; uses the random sample consensus algorithm to fit the edge of the measurement region, and obtains the sub-pixel edge angle of the part to be measured. In this patent, the alignment of the measurement region and the measurement region is disclosed, but the specific alignment method is not disclosed.

[0005] The patent CN119984512A discloses a calibration device and method for a standard colorimeter, which determines the aperture diameter of the diaphragm according to the size of the light spot required for testing at the current time, adjusts the aperture diameter of the diaphragm to be the same as the size of the test aperture, and enables the standard colorimeter and the colorimeter to be tested to measure the same light spot (same position and same size) so that the measurement points of the standard colorimeter and the colorimeter to be tested correspond one by one. However, the actual detection area of the standard colorimeter cannot be obtained in the patent, resulting in a large alignment error.

[0006] In the actual production process of the prior art, the registration of the field of view of the reference instrument and the measurement range of the instrument to be tested is usually realized by manual marking, making auxiliary markers, and using motion mechanisms to assist positioning. These methods have obvious precision defects (for example, the manual marking method cannot accurately mark the measurement range, and even cannot guarantee that the reference instrument is perpendicular to the surface of the object to be measured). Some methods are too high in cost and lack convenience (for example, using an auxiliary three-dimensional displacement mechanism to help positioning).

[0007] Therefore, the present application provides a photoelectric detection device precision evaluation method, which can achieve sub-millimeter alignment accuracy through an easy-to-operate method, and can help locate the measurement position of the reference instrument in the image obtained by the imaging colorimeter, greatly shorten the time interval between the measurement of the reference instrument and the measurement of the instrument to be tested, and significantly improve the measurement precision. SUMMARY

[0008] The present application aims to overcome the above problems existing in the prior art and provides a photoelectric detection device precision evaluation method, system and storage medium.

[0009] To achieve the above technical purposes and effects, the present application realizes the following technical solutions: A photoelectric detection device precision evaluation method, comprising: Lighting each pixel point of a calibration screen pixel by pixel to obtain the current measurement value of the alignment reference area of the standard photoelectric detection device, wherein the lighting is to adjust the gray scale of the pixel point from the minimum value to the maximum value, and the size of the pixel point of the calibration screen is smaller than the effective sampling area of the standard photoelectric detection device; Calculating the difference between the current measurement value and the previous measurement value to locate the boundary pixel point and obtain the positional relationship between the effective sampling area and the reference area of the standard photoelectric detection device inside the boundary pixel point; Obtaining a reference screen image collected by the photoelectric detection device to be tested to locate the measurement area corresponding to the effective sampling area on the reference screen image through the reference area; Comparing the measurement area with the measurement value of the reference area of the standard photoelectric detection device on the reference screen to obtain the precision evaluation result of the to-be-tested photoelectric detection device; The boundary pixel point is a current lighted pixel point corresponding to a differential result absolute value greater than the average of all differential results. The standard photoelectric detection device is a point detection device, and the to-be-tested photoelectric detection device is a surface detection device.

[0010] Further, the reference area is a target, including a plurality of distinguishably directional marker points, for distinguishing the image direction.

[0011] Further, the calibration screen is an OLED screen or a Mini-LED screen, to realize pixel-by-pixel lighting.

[0012] Further, before the step of positioning the measurement area corresponding to the effective sampling area on the reference screen image through the reference area, the method further comprises: Adjusting the image size of the reference area in the reference screen image to be consistent with the size of the reference area in the matrix calibration image formed by the measurement value obtained by the pixel-by-pixel point through an interpolation algorithm; The interpolation algorithm is bilinear interpolation or bicubic interpolation.

[0013] Further, the step of positioning the measurement area corresponding to the effective sampling area on the reference screen image through the reference area comprises: Obtaining the relative position relationship between the effective sampling area and the reference area, and obtaining the position of the reference area in the reference screen image through the Harris corner detection and K-Means clustering algorithm, to position the measurement area corresponding to the effective sampling area through the same reference area in the reference screen image.

[0014] Further, before the step of obtaining the relative position relationship between the effective sampling area and the reference area, the method further comprises: Aligning the reference area by positioning the standard photoelectric detection device through a positioning member, so that the relative position relationship between the effective sampling area and the reference area is unique.

[0015] Further, the positioning member is a jig or a clamp.

[0016] Further, the photoelectric detection device is used for detecting one or more of luminance or chrominance.

[0017] A photoelectric detection device precision evaluation system, comprising: The calibration module calibrates each pixel point of the calibration screen pixel by pixel to obtain the current measurement value of the standard photoelectric detection device on the reference area pixel by pixel, wherein the calibration is adjusting the gray scale of the pixel point from the minimum value to the maximum value, and the size of the pixel point of the calibration screen is smaller than the effective sampling area of the standard photoelectric detection device; The calculation module calculates the difference between the current measurement value and the previous measurement value to locate the boundary pixel point, so as to obtain the positional relationship between the effective sampling area of the standard photoelectric detection device inside the boundary pixel point and the reference area; The acquisition module acquires the reference screen image collected by the to-be-tested photoelectric detection device to locate the measurement area corresponding to the effective sampling area on the reference screen image through the reference area; The comparison module compares the measurement area with the measurement value of the reference area of the standard photoelectric detection device on the reference screen to obtain the precision evaluation result of the to-be-tested photoelectric detection device; The boundary pixel point is the current calibration pixel point corresponding to the absolute value of the difference result being greater than the average value of all difference results. The standard photoelectric detection device is a point detection device, and the to-be-tested photoelectric detection device is a surface detection device.

[0018] A storage medium having a computer program stored thereon, wherein the computer program is executed by a processor to implement the photoelectric detection device precision evaluation method.

[0019] The present application has the following advantages: In the present application, each pixel point of the calibration screen is calibrated pixel by pixel to obtain the current measurement value of the standard photoelectric detection device on the reference area, wherein the calibration is adjusting the gray scale of the pixel point from the minimum value to the maximum value, the size of the pixel point of the calibration screen is smaller than the effective sampling area of the standard photoelectric detection device, and whether each calibration pixel point of the calibration screen affects the measurement result of the standard photoelectric detection device is accurately detected, thereby improving the positioning precision of the actual detection range of the standard photoelectric detection device. The difference between the current measurement value and the previous measurement value is calculated to locate the boundary pixel point, so as to obtain the positional relationship between the effective sampling area of the standard photoelectric detection device inside the boundary pixel point and the reference area, the change amount of the measurement result is highlighted by using the difference method, and the influence of the fluctuation of the basic brightness or chroma of the pixel point of the calibration screen is avoided, so as to reduce the calculation error of the relative positional relationship between the effective sampling area and the reference area. The reference screen image collected by the to-be-tested photoelectric detection device is acquired to locate the measurement area corresponding to the effective sampling area on the reference screen image through the reference area, so that the measurement area corresponding to the effective sampling area can be accurately obtained in the image based on the standard reference system of the reference area, and the detection areas of the standard photoelectric detection device and the to-be-tested photoelectric detection device are aligned. The precision evaluation result of the to-be-tested photoelectric detection device is obtained by comparing the measurement area with the measurement value of the reference area on the reference screen by the standard photoelectric detection device, so as to realize the precision evaluation of the area-type detection device by the point-type detection device. BRIEF DESCRIPTION OF DRAWINGS

[0020] The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and serve to explain the principles of the application. In the drawings: Figure 1 is a flow chart of the photoelectric detection device precision evaluation method in the application; Figure 2 is a flow chart of the photoelectric detection device precision evaluation system in the application; Figure 3 is a structural schematic diagram of the calibration screen in embodiment 1 of the application; Figure 4 is a structural schematic diagram of the target area in the calibration screen in embodiment 1 of the application; Figure 5 is a schematic diagram of the target. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application.

[0022] As shown in Figure 1 , the application first provides a photoelectric detection device precision evaluation method, comprising: lighting each pixel point of the calibration screen pixel by pixel to obtain the current measurement value of the alignment reference area by the standard photoelectric detection device pixel by pixel, wherein the lighting is to adjust the pixel point gray scale from the minimum value to the maximum value, and the size of the calibration screen pixel is smaller than the effective sampling area of the standard photoelectric detection device; calculating the difference between the current measurement value and the previous measurement value to locate the boundary pixel point, so as to obtain the position relationship between the effective sampling area and the reference area inside the boundary pixel point by the standard photoelectric detection device; obtaining the reference screen image collected by the to-be-tested photoelectric detection device to locate the measurement area corresponding to the effective sampling area on the reference screen image by the reference area; comparing the measurement area with the measurement value of the reference area on the reference screen by the standard photoelectric detection device to obtain the precision evaluation result of the to-be-tested photoelectric detection device; The boundary pixel point is a current lighted pixel point corresponding to a difference result absolute value greater than a mean value of all difference results. The standard photoelectric detection device is a point detection device, and the photoelectric detection device to be measured is a surface detection device.

[0023] In this embodiment, in order to improve the comparison accuracy of the measurement values of the standard photoelectric detection device and the photoelectric detection device to be measured, the actual detection range of the standard photoelectric detection device, that is, the effective sampling area, needs to be determined, and then the measurement area corresponding to the effective sampling area in the image collected by the photoelectric detection device to be measured is determined, so that the actual collection areas of the photoelectric detection device to be measured and the standard photoelectric detection device are aligned, and the precision of the photoelectric detection device to be measured is accurately evaluated.

[0024] In this embodiment, the engineering principle for determining the effective sampling area of the standard photoelectric detection device includes: When the scanning light point passes through the boundary of the detection field of view of the standard photoelectric detection device, that is, the point detection device, the total light flux received by the standard photoelectric detection device will change abruptly, and the measurement value of the standard photoelectric detection device will also change abruptly based on the change. The scanning light point causing the change in the measurement value can be used to accurately locate the boundary of the detection field of view of the standard photoelectric detection device.

[0025] In this embodiment, based on the above principle, the standard photoelectric detection device is directed to the calibration screen, and each pixel point of the calibration screen is lighted pixel by pixel, and a measurement is performed after each time of lighting to obtain the current measurement value of the standard photoelectric detection device. The adjacent measurement values are compared by difference to obtain a mutation difference result greater than a threshold value in the comparison result, and the pixel point currently lighted is marked as the boundary of the detection range of the standard photoelectric detection device, so that the effective sampling area is determined.

[0026] In this embodiment, the difference result has two cases of positive number and negative number, which respectively represent that the scanning light point enters or leaves the effective sampling area, and therefore the lighted pixel point corresponding to the absolute value of the difference result greater than the threshold value is defined as the boundary of the effective sampling area.

[0027] In this embodiment, for the calibration screen, a pixel point represents the smallest light emitting or light control unit. Specifically, for an LCD screen, a pixel point represents the smallest liquid crystal light control unit, and for a Mini-LED screen or an OLED screen, a pixel point represents the smallest independent light emitting unit.

[0028] In this embodiment, in order to realize the effective sampling area calibration acquisition of the standard detection device, each pixel point of the calibration screen needs to be lit up pixel by pixel. For Mini-LED screens or OLED screens, lighting up means controlling the smallest independent light-emitting unit to switch from not emitting light to emitting the brightest light. For LCD screens and the like with backlight light-emitting, the minimum liquid crystal light control unit is controlled to switch from the lowest light transmission to the highest light transmission to complete the adjustment of the corresponding pixel point gray scale from the minimum value to the maximum value. Generally speaking, the lighting operation can be realized by adjusting the pixel gray scale display from 0 gray scale to 255 gray scale.

[0029] In this embodiment, in order to realize that the effective sampling area of the standard photoelectric detection device can be drawn in the calibration screen, the pixel point size of the calibration screen needs to be smaller than the standard photoelectric detection device, so as to avoid that the standard photoelectric detection device cannot capture the complete calibration screen pixel point inside the effective sampling area.

[0030] In this embodiment, the reference area is used to determine the specific position of the effective sampling area, so as to set the same coordinate system in the reference screen image, thereby uniquely determining the measurement area corresponding to the effective sampling area.

[0031] In this embodiment, by aligning the standard photoelectric detection device with the reference area and acquiring the effective sampling area, the position relationship of the effective sampling area in the reference area can be determined, thereby establishing the calibration system of the reference area and the standard photoelectric detection device. In this calibration system, the effective sampling area of the standard photoelectric detection device is uniquely determined. Therefore, when the same reference screen is measured by the standard photoelectric detection device and the to-be-measured photoelectric detection device respectively, the same reference area can be used to locate the measurement area in the reference screen image which corresponds to the effective sampling area uniquely.

[0032] In this embodiment, the coordinates of the reference area in the standard screen coordinate system can be determined by visual comparison or using a camera to take pictures and the like, thereby obtaining the position relationship between the effective sampling area and the reference area of the standard photoelectric detection device.

[0033] In this embodiment, after the establishment of the calibration system is completed, the reference screen image with the reference area is collected by the to-be-measured photoelectric detection device, and the same reference area on the same reference screen is measured by the standard photoelectric detection device. Therefore, according to the known relative position relationship between the effective sampling area and the reference area of the standard photoelectric detection device on the reference screen, the measurement area in the reference screen image corresponding to the effective sampling area acquired by the to-be-measured photoelectric detection device can be accurately recognized, so as to perform precision evaluation according to the measurement values of the same area by the to-be-measured photoelectric detection device and the standard photoelectric detection device, thereby improving the precision of the precision evaluation.

[0034] In this embodiment, in order to set a relatively accurate threshold value for the mutation of the measurement value to accurately locate the boundary of the effective sampling area, the threshold value is the average of all difference results.

[0035] In this embodiment, the average of all difference results is taken as the threshold value for judging the boundary of the effective sampling area, so as to evaluate the degree or level of the measurement value in the current test environment, and the robustness and universality of the effective sampling area boundary identification in different measurement environments can be ensured.

[0036] In this embodiment, the standard photoelectric detection device is a point detection device with high measurement accuracy, and the to-be-detected photoelectric detection device is an imaging area detection device, and the imaging area detection device is evaluated by the point detection device with high accuracy, so as to improve the evaluation accuracy. Specifically, the standard photoelectric detection device can be a colorimeter or a spectroradiometer, and the to-be-detected photoelectric detection device can be an imaging colorimeter.

[0037] In the present application, the pixels of the calibration screen are calibrated by lighting each pixel, so as to obtain the current measurement value of the standard photoelectric detection device to the reference area by pixel. The lighting is to adjust the gray scale of the pixel from the minimum value to the maximum value. The size of the pixel of the calibration screen is smaller than the effective sampling area of the standard photoelectric detection device. Whether each lighted pixel of the calibration screen affects the measurement result of the standard photoelectric detection device is accurately detected, so as to improve the positioning accuracy of the actual detection range of the standard photoelectric detection device. The difference between the current measurement value and the previous measurement value is calculated to locate the boundary pixel, so as to obtain the position relationship between the effective sampling area and the reference area of the standard photoelectric detection device inside the boundary pixel. The change amount of the measurement result is highlighted by using the difference method, and the influence of the basic brightness or chroma fluctuation of the pixel of the calibration screen is avoided, so as to reduce the calculation error of the relative position relationship between the effective sampling area and the reference area. The reference screen image collected by the to-be-detected photoelectric detection device is obtained, so as to locate the measurement area corresponding to the effective sampling area in the reference screen image based on the reference area. Based on the standard reference system of the reference area, the measurement area corresponding to the effective sampling area can be accurately obtained in the image, so that the detection areas of the standard photoelectric detection device and the to-be-detected photoelectric detection device are aligned. The measurement value of the measurement area in the reference screen of the standard photoelectric detection device is compared with the measurement value of the reference area, so as to obtain the precision evaluation result of the to-be-detected photoelectric detection device, and the precision evaluation of the point detection device to the area detection device is realized.

[0038] In some embodiments, in order to further determine the directional position relationship of the effective sampling area in the reference area, the reference area is a target, such as Figure 5 As shown, a plurality of mark points in distinguishable directions are used to distinguish the image direction.

[0039] In the embodiment, the target is set as the reference area on the reference screen or the calibration screen surface, which facilitates the identification of the target position in the subsequent reference screen image, and the target is a plurality of distinguishable mark points, so that the image direction can be determined by the direction of the target in the reference screen image, thereby ensuring that the direction relationship of the effective sampling area in the reference area is unique.

[0040] In the embodiment, the number of mark points is usually four and is arranged at the corner points of the rectangular area, which is used to better locate the reference area through the four corner points.

[0041] In some embodiments, in order to improve the accuracy of the determination of the boundary of the effective sampling area, the calibration screen is an OLED screen, a Mini-LED screen or an LCD screen to realize pixel-by-pixel lighting.

[0042] In the embodiment, the rules for pixel-by-pixel lighting of the calibration screen include but are not limited to the following methods: 1. Taking the upper left corner of the calibration screen as the starting point, sequentially lighting each pixel point on the calibration screen in the order from left to right and from top to bottom.

[0043] 2. Taking the upper left corner of the calibration screen as the starting point, sequentially lighting each pixel point on the calibration screen in the order from top to bottom and from left to right.

[0044] 3. Sequentially lighting each pixel point on the calibration screen in any order.

[0045] In some embodiments, in order to further ensure the uniformity of the test conditions before the comparison between the to-be-tested photoelectric detection device and the standard photoelectric detection device, before the step of positioning the measurement area corresponding to the effective sampling area in the reference screen image through the reference area, the method further comprises: adjusting the image size of the reference area in the reference screen image to be consistent with the size of the reference area in the matrix calibration image formed by the measurement values obtained by the standard photoelectric detection device pixel by pixel through an interpolation algorithm; The interpolation algorithm includes but is not limited to bilinear interpolation or bicubic interpolation.

[0046] In the embodiment, the adjustment of the image size of the reference area is realized through two-dimensional interpolation operation, so that the size of the reference area in the reference screen image obtained by the to-be-tested photoelectric detection device is consistent with the size of the reference area in the matrix calibration image formed by the measurement values obtained by the standard photoelectric detection device pixel by pixel in the calibration process, and the measurement area obtained by the effective sampling area has higher reliability.

[0047] In some embodiments, in order to improve the accuracy of using the reference area as a bridge between the to-be-tested photoelectric detection device and the standard photoelectric detection device, the step of locating the measurement area corresponding to the effective sampling area in the reference screen image through the reference area includes: obtaining the relative position relationship between the effective sampling area and the reference area, and obtaining the position of the reference area in the reference screen image to locate the measurement area corresponding to the effective sampling area in the reference screen image through the same reference area.

[0048] In this embodiment, the position of the reference area in the reference screen image is obtained through target detection, which includes but is not limited to: The position of the reference area in the reference screen image is obtained through Harris corner detection and search algorithm, so as to locate the measurement area corresponding to the effective sampling area in the reference screen image through the same reference area.

[0049] In this embodiment, the coordinates of the reference area in the standard screen coordinate system are determined through visual comparison or using a camera to take pictures, so as to obtain the position relationship between the effective sampling area and the reference area of the standard photoelectric detection device, and a plurality of mark points in the reference area in the reference screen image are used, and one mark point different from the other mark points in direction is set, the position of the mark point different in direction is obtained through corner matching algorithm to determine the target position, and the positions of the other mark points are obtained through search algorithm to determine the target coverage range, and finally the position information of the reference area, that is, the target, is obtained, so as to locate the measurement area corresponding to the effective sampling area in the reference screen image through the same reference area in the reference screen as the standard coordinate system, wherein the effective sampling area is located by the standard photoelectric detection device in the same reference screen and the same reference area.

[0050] In some embodiments, in order to ensure that the position relationship between the standard photoelectric detection device and the reference area is consistent and fixed, before the step of obtaining the relative position relationship between the effective sampling area and the reference area, the method further includes: aligning the standard photoelectric detection device with the reference area through the positioning member to make the relative position relationship between the effective sampling area and the reference area unique.

[0051] In this embodiment, the positioning member is used to install the standard photoelectric detection device, so that the relative position between the standard photoelectric detection device and the reference area is determined, and the positioning member is provided with an installation point position accurately corresponding to the reference area, so as to quickly locate the relative position relationship between the standard photoelectric detection device and the reference area.

[0052] Specifically, when the reference region is a target having a plurality of mark points, the positioning member is provided with positioning points corresponding to the mark points one by one, so as to position the standard photoelectric detection device and the reference region by one-to-one correspondence between the positioning points and the mark points.

[0053] In some embodiments, in order to position the standard photoelectric detection device, the positioning member is a jig or a clamp.

[0054] In this embodiment, the positioning member is used to clamp or fix the standard photoelectric detection device, so as to keep the whole calibration system stable during the calibration process and ensure the reliability of the measurement value of the standard photoelectric detection device during testing.

[0055] In some embodiments, in order to ensure the reliability of the precision evaluation method, the photoelectric detection device is used to detect one or more of luminance or chrominance.

[0056] In this embodiment, the standard photoelectric detection device and the to-be-tested photoelectric detection device can be used to detect luminance, chrominance or both luminance and chrominance, but the detection ranges of the two devices need to be consistent, that is, when the to-be-tested photoelectric detection device is a luminance detection device, the selected standard photoelectric detection device must also be a luminance detection device, so as to ensure the reliability of the precision evaluation.

[0057] In some embodiments, in order to further improve the precision of the precision evaluation, the reference screen can be divided into not less than 1 test region, and the precision evaluation method is performed on each test region respectively.

[0058] In this embodiment, the reference screen is divided into a plurality of partitions as test regions, and the above evaluation method is performed respectively, so as to further improve the precision of the evaluation result by multiple evaluations. Embodiment 1

[0059] In this embodiment, the reference region is a target, the positioning member is a jig, the standard photoelectric detection device is a point-type colorimeter, and the to-be-tested photoelectric detection device is an imaging colorimeter. In order to accurately use the device described in this embodiment, the target-jig system needs to be calibrated accurately first, and the calibration process is as follows: S101, placing the target on a calibration screen S; S102, fixing the point-type colorimeter on the jig, aligning the jig positioning points with the target mark points, and fixing the system to be stable; S103, assuming that the calibration screen contains WxH pixels, starting from the first pixel, lighting each pixel in turn from left to right and from top to bottom; each time a pixel is lit, a measurement is performed using the point-type colorimeter, and the a-th measurement result is recorded as M a ; Note that a measurement is performed when all pixels are black, and the result is recorded as M0.

[0060] S104, calculate M a Difference of the sequence ΔM a The calculation formula is: ΔM a = M a -M a-1 , a∈[0,W×H]; Wherein, W×H represents the number of pixels.

[0061] It can be found that for the pixel located in the nth row and the mth column, ΔM n*W+m Can describe the influence of the light emission of this pixel on the measurement result of the point colorimeter, and then can be used to evaluate whether the pixel is located within the field of view of the point colorimeter.

[0062] S105, define the error ε as the mean of ΔM a All points greater than ε in ΔM a are considered to be inside the measurement field of view of the point colorimeter; all the serial numbers of the points constituting the measurement field of view of the colorimeter are recorded as set S filed .

[0063] As Figure 3 illustrated, the following is illustrated as an example, wherein the calibration screen is a 9×9 pixel point set, and the shaded area is the effective sampling area of the point colorimeter, and the pixel point serial number and coordinates are as follows:

[0064] S106, determine the coordinates of the target marker in the calibration screen coordinate system by visual comparison / using a camera to take pictures, etc., so as to obtain the positional relationship between the measurement range of the point colorimeter and the target marker. As Figure 4 illustrated, here taking four targets respectively aligned with (1, 1), (7, 1), (6, 1), and (6, 7) as examples, the black frame is the corresponding area of the target on the calibration screen, and taking the upper left target as the starting point, the effective sampling area S filed is remapped as:

[0065] S104, construct a corresponding measurement range mapping image IMG Calib , wherein the point value in the range is 1, and the rest is 0:

[0066] Wherein, the range of i and j is limited by the target coordinates, and i and j need to correspond to within the rectangle surrounded by the four targets.

[0067] In the above example, the target area measurement value is written in matrix form to obtain the calibration image as:

[0068] At this point, the target-tool system is calibrated.

[0069] After calibration, the embodiment is applied to the test of the actual system, and the specific steps are as follows: S201, a plurality of test areas are determined on the reference screen (for example, 9 test areas are set according to the IDMS standard), and targets are placed on the test areas, and attention should be paid to making the orientations of the targets consistent; S202, the calibrated tool-point colorimeter system is placed on each target in turn, the positioning point of the tool is aligned with the mark point of the target, the results of each point are measured, and are recorded as M b ; S203, the reference screen is photographed by using the measured imaging colorimeter, and the focusing is clear and the exposure is moderate during the photographing process. The specific operation mode is determined by the manual of the measured instrument. The photographed result is recorded as I i,j . The following description assumes that the distortion in I i,j has been fully corrected, so that each matrix target still presents as a rectangle in the image; this constraint can be achieved by various distortion correction algorithms.

[0070] S204, an angle point extraction algorithm is executed in I i,j , the direction of the angle point is controlled, and the upper left target positioning point of each target is found. Here, the coordinates of the Nth target found are recorded as:

[0071] S205, an angle point extraction algorithm is executed in I i,j : the direction of the angle point is controlled, and the upper right, lower right, and lower left target positioning points of each target are found. Through a search algorithm, these mark points and the upper left target positioning point are managed into a group. Here, the algorithms that can be used include but are not limited to the K-Means clustering algorithm, the nearest neighbor search, and the breadth-first search. There are many related technologies, and details are not described here. After the search is completed, the range of each target in the I image is obtained.

[0072] S206, the image of the field of view corresponding to each target in I is intercepted. For example, for the Nth target, the coordinates of the upper left, upper right, lower left, and lower right target points are recorded as:

[0073] S207, a two-dimensional matrix IMG target is constructed, and an interpolation algorithm is used to make the size equal to that of the calibration image. The filling rule of the i, jth pixel is as follows: S208, the x coordinate and y coordinate corresponding to the i, j pixel in the I image are calculated:

[0074] S209, using an interpolation algorithm, the value of the point is calculated according to the value in the image I, here the interpolation algorithm is bilinear interpolation, the calculation method is as follows: Let: ,

[0075] The meaning is to take the integer part downward.

[0076] S210, then the measurement value of the part corresponding to the target in the to-be-measured imaging colorimeter image can be given by the following formula:

[0077] S211, the above operation is performed on each target, that is, the measurement result M of the to-be-measured colorimeter corresponding to the measurement result of the standard colorimeter at each target is obtained, and subsequent operations including absolute accuracy verification and color calibration are completed.

[0078] Based on the same inventive concept, as shown in Figure 2 The application further provides a photoelectric detection equipment precision evaluation system, which comprises: A calibration module, which calibrates each pixel point of a calibration screen in a pixel-by-pixel manner to obtain a current measurement value of an alignment reference area of a standard photoelectric detection equipment in a pixel-by-pixel manner, wherein the calibration is adjusting the gray scale of the pixel point from a minimum value to a maximum value, and the pixel point size of the calibration screen is smaller than the effective sampling area of the standard photoelectric detection equipment; A calculation module, which calculates a difference result of the current measurement value and the previous measurement value to locate a boundary pixel point, so as to obtain the positional relationship between the effective sampling area and the reference area of the standard photoelectric detection equipment inside the boundary pixel point; A collection module, which collects a reference screen image collected by a to-be-measured photoelectric detection equipment to locate a measurement area corresponding to the effective sampling area on the reference screen image through the reference area; A comparison module, which compares the measurement area and the measurement value of the reference screen in the reference area of the standard photoelectric detection equipment to obtain a precision evaluation result of the to-be-measured photoelectric detection equipment; Wherein, the boundary pixel point is a current calibration pixel point corresponding to a difference result whose absolute value is greater than the average value of all difference results; The standard photoelectric detection equipment is a point type detection equipment, and the to-be-measured photoelectric detection equipment is a surface type detection equipment.

[0079] Based on the same inventive concept, the application further provides a storage medium having a computer program stored thereon, wherein the computer program is executed by a processor to implement the photoelectric detection equipment precision evaluation method.

[0080] In the description of the present specification, the description referring to the terms "one embodiment", "an example", "a specific example" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Also, the specific features, structures, materials or characteristics described can be combined in any suitable manner in one or more embodiments or examples.

[0081] The basic principles, main features and advantages of the present application are shown and described above. It should be understood by those skilled in the art that the present application is not limited by the above embodiments, and the above embodiments and descriptions in the specification are only illustrative of the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application.

Claims

1. A method for evaluating the accuracy of photoelectric detection equipment, characterized in that, include: Each pixel on the calibration screen is illuminated pixel by pixel to obtain the current measurement value of the reference area aligned with the standard photoelectric detection device pixel by pixel. The illumination is achieved by adjusting the grayscale of the pixel from the minimum value to the maximum value. The pixel size of the calibration screen is smaller than the effective sampling area of ​​the standard photoelectric detection device. The difference between the current measurement value and the previous measurement value is calculated to locate the boundary pixel, so as to obtain the positional relationship between the effective sampling area of ​​the standard photoelectric detection device and the reference area inside the boundary pixel; Acquire a reference screen image collected by the photoelectric detection device under test, and locate the measurement area corresponding to the effective sampling area on the reference screen image through a reference area; The measurement area is compared with the measurement value of the standard photoelectric detection device in the reference area on the reference screen to obtain the accuracy evaluation result of the photoelectric detection device under test; Wherein, the boundary pixel is the currently lit pixel when the absolute value of the difference result is greater than the mean of all difference results; The standard photoelectric detection equipment is a point-type detection equipment, while the photoelectric detection equipment under test is a surface-type detection equipment.

2. The method for evaluating the accuracy of photoelectric detection equipment according to claim 1, characterized in that, The reference area is a target, which includes several directional markers used to distinguish the image orientation.

3. The method for evaluating the accuracy of photoelectric detection equipment according to claim 2, characterized in that, The calibration screen is an OLED screen, a Mini-LED screen, or an LCD screen, to achieve pixel-by-pixel illumination.

4. The method for evaluating the accuracy of photoelectric detection equipment according to claim 3, characterized in that, Before the step of locating the measurement region corresponding to the effective sampling region on the reference screen image through the reference region, the method further includes: The size of the reference region in the reference screen image is adjusted using an interpolation algorithm to be consistent with the size of the reference region in the matrix calibration image formed by the measurement values ​​obtained pixel by pixel by a standard photoelectric detection device. The interpolation algorithm is either bilinear interpolation or bicubic interpolation.

5. The method for evaluating the accuracy of photoelectric detection equipment according to claim 4, characterized in that, The step of locating the measurement region corresponding to the effective sampling region on the reference screen image through the reference region includes: The relative positional relationship between the effective sampling area and the reference area is obtained, and the position of the reference area is obtained in the reference screen image so as to locate the measurement area corresponding to the effective sampling area in the reference screen image through the same reference area.

6. The method for evaluating the accuracy of photoelectric detection equipment according to claim 5, characterized in that, Before the step of obtaining the relative positional relationship between the effective sampling area and the reference area, the method further includes: The standard photoelectric detection equipment is positioned by positioning components to align with the reference area, ensuring that the relative positional relationship between the effective sampling area and the reference area is unique.

7. The method for evaluating the accuracy of photoelectric detection equipment according to claim 6, characterized in that, The positioning element is a jig or clamp.

8. The method for evaluating the accuracy of photoelectric detection equipment according to claim 1, characterized in that, The photoelectric detection device is used to detect one or more of brightness or chromaticity.

9. A precision evaluation system for photoelectric detection equipment, characterized in that, include: The calibration module illuminates each pixel on the calibration screen pixel by pixel to obtain the current measurement value of the standard photoelectric detection device aligned with the reference area pixel by pixel. The illumination is achieved by adjusting the grayscale of the pixel from the minimum value to the maximum value. The pixel size of the calibration screen is smaller than the effective sampling area of ​​the standard photoelectric detection device. The calculation module calculates the difference between the current measurement value and the previous measurement value to locate the boundary pixel, so as to obtain the positional relationship between the effective sampling area of ​​the standard photoelectric detection device and the reference area inside the boundary pixel. The acquisition module acquires a reference screen image collected by the photoelectric detection device under test, and uses a reference area to locate the measurement area corresponding to the effective sampling area on the reference screen image; The comparison module compares the measurement area with the measurement value of the standard photoelectric detection device in the reference area on the reference screen to obtain the accuracy evaluation result of the photoelectric detection device under test; Wherein, the boundary pixel is the currently lit pixel when the absolute value of the difference result is greater than the mean of all difference results; The standard photoelectric detection equipment is a point-type detection equipment, while the photoelectric detection equipment under test is a surface-type detection equipment.

10. A storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements a method for evaluating the accuracy of an optoelectronic detection device as described in any one of claims 1-8.

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