One-stop testing method for tof camera module and calibration board for one-stop testing

Abstract

Disclosed are a one-stop test method for a TOF camera module and a test board for one-stop test, wherein the test method can integrally test multiple performances of the TOF camera module in a one-stop manner, so as to improve efficiency and reduce cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of testing of TOF camera modules, and more particularly, to a one-stop testing method of TOF camera modules and a target plate for one-stop testing. BACKGROUND

[0002] In recent years, TOF camera modules have been widely applied in fields such as somatosensory control, behavior analysis, monitoring, automatic driving, artificial intelligence, machine vision, and 3D modeling. Before a TOF camera module is put into use, multiple performances of the TOF camera module need to be tested, such as absolute accuracy of depth measurement, absolute accuracy of depth measurement, relative accuracy of depth measurement, relative accuracy of depth vector, XY resolution, etc.

[0003] However, the existing testing scheme for TOF camera modules adopts a sub-station mode to detect each performance of the TOF camera module one by one. For example, first, the absolute accuracy and absolute accuracy of the TOF camera module are measured by using Box3 to control the depth value of the center area after reduction; then, the relative accuracy and XY resolution are measured on another two devices respectively. This sub-station testing scheme increases the investment of equipment, personnel and time.

[0004] Therefore, an optimized performance testing scheme for TOF camera modules is expected. SUMMARY

[0005] One advantage of the present application is to provide a one-stop testing method of TOF camera modules and a target plate for one-stop testing, wherein the testing method can integrally test multiple performances of the TOF camera module in a one-stop manner to improve efficiency and reduce cost.

[0006] Another advantage of the present application is to provide a one-stop testing method of TOF camera modules and a target plate for one-stop testing, wherein the testing method realizes one-stop testing by using a target plate with a specific pattern.

[0007] In order to achieve at least one of the above advantages or other advantages and purposes, according to one aspect of the present application, a target plate for one-stop testing of a TOF camera module is provided, comprising:

[0008] a target plate body, the target plate body having a first side surface and a second side surface opposite to the first side surface, wherein the first side surface forms a test surface; and

[0009] a test pattern group penetrating the test surface;

[0010] wherein the test pattern group comprises:

[0011] a first test pattern formed through the middle region and the edge region of the test surface respectively;

[0012] a second test pattern formed through the middle region and the edge region of the test surface respectively, wherein the second test pattern extends along the X axis or the Y axis of the test surface;

[0013] a positioning reference point for positioning the first test pattern and the second test pattern of the test surface;

[0014] In the test process, the middle region of the test surface corresponds to the TOF camera module to be tested, the first test pattern in the middle region of the test surface is used to test the relative accuracy and relative precision of the TOF camera module to be tested in the middle region, the first test pattern in the edge region of the test surface is used to test the relative accuracy and relative precision of the TOF camera module to be tested in the edge region, the second test pattern in the middle region of the test surface is used to test the XY resolution of the TOF camera module to be tested in the middle region, and the second test pattern in the edge region of the test surface is used to test the XY resolution of the TOF camera module to be tested in the edge region.

[0015] In the test process, the blank part of the test pattern group in the test surface is used to test the absolute accuracy and absolute precision of the TOF camera module to be tested.

[0016] In the test process, the first test pattern includes a plurality of squares arranged in an array.

[0017] In the test process, the plurality of squares arranged in an array are connected to each other.

[0018] In the test process, the second test pattern is a triangular pattern.

[0019] In the test process, the second test pattern includes a first isosceles triangle pattern and a second isosceles triangle pattern, wherein the top angle of the first isosceles triangle pattern is smaller than the top angle of the second isosceles triangle pattern.

[0020] In the test process, the positioning reference point is four in number and is located in the four edge regions of the test surface.

[0021] According to another aspect of the present application, a one-stop testing method for testing a TOF camera module is also provided, the TOF camera module comprising a projection unit and a light receiving unit, which comprises:

[0022] projecting laser light by the projection unit of the TOF camera module to the target plate as described above, wherein the TOF camera module corresponds to the middle region of the test surface of the target plate;

[0023] receiving laser light from the target plate by the light receiving unit of the TOF camera module and generating a target plate depth image of the target plate;

[0024] determining the relative accuracy and the relative precision of the TOF camera module in the middle region based on the depth values of the first test pattern in the middle region of the test surface in the target plate depth image;

[0025] determining the relative accuracy and the relative precision of the TOF camera module in the edge region based on the depth values of the first test pattern in the edge region of the test surface in the target plate depth image;

[0026] determining the XY resolution of the TOF camera module in the middle region based on the pixel information of the second test pattern in the middle region of the test surface in the target plate depth image; and

[0027] determining the XY resolution of the TOF camera module in the edge region based on the pixel information of the second test pattern in the edge region of the test surface in the target plate depth image.

[0028] In the one-stop testing method according to the present application, the test scheme further comprises: determining the absolute accuracy and the absolute precision of the TOF camera module based on the depth values of the blank part of the test surface in the target plate depth image except the test pattern group.

[0029] In the one-stop testing method according to the present application, the first test pattern comprises a plurality of squares arranged in an array; wherein determining the relative accuracy and the relative precision of the TOF camera module in the middle region based on the depth values of the first test pattern in the middle region of the test surface in the target plate depth image comprises:

[0030] determining the relative precision of the TOF camera module in the middle region based on the difference between the depth values of the squares arranged in an array and spaced apart in the first test pattern; and

[0031] The relative accuracy of the TOF camera module in the middle area is determined based on the mean square error of the depth values ​​of all squares in the plurality of squares arranged in an array of the first test pattern.

[0032] In the one-stop testing method according to the present application, determining the relative accuracy and relative precision of the TOF camera module in the edge area based on the depth value of the first test pattern located in the edge area of ​​the test surface in the target depth image includes:

[0033] determining a relative accuracy of the TOF camera module in the edge area based on a difference in depth values ​​between spaced-apart squares in the plurality of squares arranged in an array of the first test pattern; and

[0034] The relative accuracy of the TOF camera module in the edge area is determined based on the mean square error of the depth values ​​of all squares in the plurality of squares arranged in an array of the first test pattern.

[0035] In the one-stop testing method according to the present application, determining the absolute accuracy and absolute precision of the TOF camera module based on the depth value of the blank portion of the test surface excluding the test pattern group in the target depth image includes:

[0036] Calculating an average value of depth values ​​of pixels in a specific area adjacent to the middle area in the blank portion as the absolute accuracy of the TOF camera module; and

[0037] The mean square error of pixels in a specific area adjacent to the edge area in the blank portion is calculated as the absolute accuracy of the TOF camera module.

[0038] Further objectives and advantages of the present application will be fully reflected through understanding of the following description and drawings.

[0039] These and other objects, features and advantages of the present application are fully reflected in the following detailed description, drawings and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 The figure shows a three-dimensional schematic diagram of a target plate for one-stop testing of a TOF camera module according to an embodiment of the present application.

[0041] Figure 2 The figure shows a front view of a target plate for one-stop testing of a TOF camera module according to an embodiment of the present application.

[0042] Figure 3 The figure illustrates a flow chart of a one-stop testing method for a TOF camera module according to an embodiment of the present application.

[0043] Figure 4 The figure illustrates a flowchart of determining the relative accuracy and relative precision of the TOF camera module in the middle area based on the depth value of the first test pattern located in the middle area of ​​the test surface in the target plate depth image in the one-stop testing method of the TOF camera module according to an embodiment of the present application.

[0044] Figure 5 The figure illustrates a flowchart of determining the relative accuracy and relative precision of the TOF camera module in the edge area based on the depth value of the first test pattern located in the edge area of ​​the test surface in the target plate depth image in the one-stop testing method of the TOF camera module according to an embodiment of the present application.

[0045] Figure 6 The figure illustrates a flowchart of determining the XY resolution of the TOF camera module in the middle area based on the pixel information of the second test pattern located in the middle area of ​​the test surface in the target depth image in the one-stop testing method of the TOF camera module according to an embodiment of the present application.

[0046] Figure 7 The figure illustrates a flowchart of determining the XY resolution of the TOF camera module in the edge area based on the pixel information of the second test pattern located in the edge area of ​​the test surface in the target plate depth image in the one-stop testing method of the TOF camera module according to an embodiment of the present application.

[0047] Figure 8 The figure illustrates a flowchart of determining the absolute precision and absolute accuracy of the TOF camera module based on the depth value of the blank portion of the test surface excluding the test pattern group in the target plate depth image in the one-stop testing method of the TOF camera module according to an embodiment of the present application. DETAILED DESCRIPTION

[0048] The following description is intended to disclose the present application so that those skilled in the art can implement the present application. The embodiments described below are for illustrative purposes only, and those skilled in the art may conceive of other obvious variations. The basic principles of the present application defined in the following description may be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the present application.

[0049] Application Overview

[0050] As mentioned above, the test scheme for TOF camera module according to the present application is committed to integrally test multiple performance parameters of the TOF camera module in a one-stop manner to improve efficiency and reduce cost. In the process of implementing the technical concept of one-stop testing, the present inventors realize that there are two technical keys: test board and test algorithm.

[0051] For the test board, it should meet the requirements of testing multiple performance parameters of the TOF camera module, that is, the test board has test patterns for testing multiple performance parameters of the TOF camera module.

[0052] A feasible method is to provide multiple test boards, and replace different test boards to respectively test different performance parameters of the TOF camera module during the test process. However, in specific implementation, this test scheme needs to configure a complex mechanical structure, and in the process of replacing the test board, new measurement errors are introduced.

[0053] Another feasible method is to integrate multiple test patterns on the same test board. In this technical concept, the difficulty lies in how to integrate different test patterns on the same test board so that it can meet the one-stop test of multiple performance parameters of the TOF camera module. And when integrating multiple test patterns on the same test board, the design difficulty of the subsequent test algorithm also needs to be considered. If multiple test patterns are simply arranged on the test board, it may not be conducive to the design of the subsequent test algorithm.

[0054] Considering the above factors, the present inventors comprehensively consider how to arrange multiple test patterns on the same test board and how to arrange the test patterns to facilitate the design of the back-end test algorithm in the process of designing the test board to propose a test board with a specific pattern and a matching test algorithm to achieve one-stop test of multiple performances of the TOF camera module.

[0055] Based on this, the present application provides a target plate for one-stop testing of a TOF camera module, comprising: a target plate body, a first side surface of the calibration body and a second side surface opposite to the first side surface, wherein the first side surface forms a test surface; and a test pattern group running through the test surface; wherein the test pattern group comprises: a first test pattern respectively formed through the middle area and the edge area of ​​the test surface; a second test pattern respectively formed through the middle area and the edge area of ​​the test surface, wherein the second test pattern extends on the test surface along the X-axis set by the test surface or along the Y-axis set by the test surface; and the first test pattern and the test pattern for positioning the test surface A positioning reference point of the second test pattern; wherein, during the test process, the middle area of ​​the test surface corresponds to the TOF camera module to be tested, wherein the first test pattern located in the middle area of ​​the test surface is used to test the relative accuracy and relative precision of the TOF camera module to be tested in the middle area; the first test pattern located in the edge area of ​​the test surface is used to test the relative accuracy and relative precision of the TOF camera module to be tested in the edge area; the second test pattern located in the middle area of ​​the test surface is used to test the XY resolution of the TOF camera module to be tested in the middle area; the second test pattern located in the edge area of ​​the test surface is used to test the XY resolution of the TOF camera module to be tested in the edge area.

[0056] Based on this, the present application also provides a one-stop testing method for a TOF camera module, which is used to test the TOF camera module, wherein the TOF camera module includes a projection unit and a photosensitive receiving unit, wherein the testing method includes: projecting a laser onto the target plate as described above through the projection unit of the TOF camera module, wherein the TOF camera module corresponds to the middle area of ​​the test surface of the target plate; receiving the laser from the target plate through the photosensitive receiving unit of the TOF camera module and generating a target plate depth image of the target plate; based on the depth value of the first test pattern located in the middle area of ​​the test surface in the target plate depth image, Determine the relative accuracy and relative precision of the TOF camera module in the middle area; determine the relative accuracy and relative precision of the TOF camera module in the edge area based on the depth value of the first test pattern located in the edge area of ​​the test surface in the target depth image; determine the XY resolution of the TOF camera module in the middle area based on the pixel information of the second test pattern located in the middle area of ​​the test surface in the target depth image; and determine the XY resolution of the TOF camera module in the edge area based on the pixel information of the second test pattern located in the edge area of ​​the test surface in the target depth image.

[0057] After introducing the basic principles of the present application, various non-limiting embodiments of the present application will be described in detail with reference to the accompanying drawings.

[0058] Example target

[0059] like Figure 1 and Figure 2 As shown, a target plate based on an embodiment of the present application is illustrated, wherein the target plate is used to perform a one-stop test of multiple performance characteristics of a TOF camera module. In particular, in the embodiment of the present application, the target plate is described by taking the one-stop test of the absolute accuracy, absolute accuracy, relative accuracy, relative accuracy, and XY resolution of the TOF camera module as an example.

[0060] like Figure 1 and 2 As shown, the target according to an embodiment of the present application includes a target body 10 and a test pattern group 20, wherein the target body has a first side surface 11 and a second side surface 12 opposite to the first side surface 11. During the test process, the first side surface 11 of the target body 10 faces the TOF camera module under test. For ease of understanding, in the embodiment of the present application, the first side surface 11 of the target body 10 facing the TOF camera module under test is defined as the test surface, that is, the first side surface 11 forms the test surface.

[0061] like Figure 1 As shown, in the embodiment of the present application, the test pattern group 20 runs through the test surface, that is, the test pattern group 20 runs through the first side surface 11 of the calibration body. More specifically, in the embodiment of the present application, the test pattern group 20 is formed through the first side surface 11 but does not pass through the second side surface 12. Therefore, during the test process, the laser projected by the TOF camera module can be reflected by the second side surface 12.

[0062] like Figure 1 In the embodiment of the present application, the test pattern group 20 includes: a first test pattern 21 formed through the middle area 30 and the edge area 40 of the test surface respectively; a second test pattern 22 formed through the middle area 30 and the edge area 40 of the test surface respectively, wherein the second test pattern 22 extends along the X-axis set by the test surface or along the Y-axis set by the test surface on the test surface; and a positioning reference point 23 for positioning the first test pattern 21 and the second test pattern 22 on the test surface.

[0063] During the testing process, the middle area 30 of the test surface corresponds to the TOF camera module to be tested, wherein the first test pattern 21 located in the middle area 30 of the test surface is used to test the relative accuracy and relative precision of the TOF camera module to be tested in the middle area 30; the first test pattern 21 located in the edge area 40 of the test surface is used to test the relative accuracy and relative precision of the TOF camera module to be tested in the edge area 40; the second test pattern 22 located in the middle area 30 of the test surface is used to test the XY resolution of the TOF camera module to be tested in the middle area 30; the second test pattern 22 located in the edge area 40 of the test surface is used to test the XY resolution of the TOF camera module to be tested in the edge area 40; the blank part of the test surface except the test pattern group 20 is used to test the absolute accuracy and absolute accuracy of the TOF camera module to be tested.

[0064] More specifically, in an embodiment of the present application, the first test pattern 21 includes a plurality of squares arranged in an array. Accordingly, when measuring the relative accuracy of the TOF camera module using the first test pattern 21, the calculation can be performed based on the depth values ​​of the spaced-apart squares among the plurality of squares, or based on the depth values ​​of the adjacent squares among the plurality of squares. Preferably, in order to improve the calculation accuracy, the relative accuracy of the TOF camera module is calculated based on the depth values ​​of the spaced-apart squares among the plurality of squares.

[0065] In a specific example of the application, the plurality of grids arranged in an array are connected to each other, such as Figure 1 and 2 Of course, in other examples of the present application, the plurality of grids arranged in an array may also be spaced apart from each other, which is not limited to the present application.

[0066] Furthermore, in the embodiment of the application, the second test pattern 22 is a triangular pattern, that is, the second test pattern 22 is an isosceles triangle extending along the X-axis set by the test surface or extending along the Y-axis set by the test surface. In particular, in the embodiment of the present application, Figure 1 and 2 As shown, the second test pattern 22 includes a first isosceles triangle pattern and a second isosceles triangle pattern, wherein the vertex angle of the first isosceles triangle pattern is smaller than the vertex angle of the second isosceles triangle pattern. Here, the triangle pattern with a relatively small vertex angle can be used for more precise measurement, while the triangle pattern with a relatively large vertex angle can be used for relatively fuzzy measurement.

[0067] Furthermore, in this embodiment of the present application, there are four positioning reference points 23, each located in one of four edge regions 40 of the test surface. It should be understood that the positioning reference points 23 are used to determine the positions of the first test pattern 21 and the second test pattern 22 of the test surface within the target depth image using machine vision technology. Accordingly, by using the four positioning reference points 23 to locate each of the four edge regions 40, positioning difficulty can be reduced and positioning accuracy can be improved.

[0068] In summary, the target plate according to the embodiment of the present application is explained, which integrates multiple different test patterns for measuring multiple performances of the TOF camera module into the same target plate, so that multiple performances of the TOF camera module can be tested in one stop by using the target plate and the test algorithm.

[0069] Those skilled in the art should understand that although the above example uses a one-stop test of the absolute accuracy, absolute precision, relative accuracy, relative precision, and XY resolution of the TOF camera module, in other examples of the present application, when other performance of the TOF camera module needs to be tested, other test patterns can also be integrated into the target plate, which is not limited to the present application.

[0070] Exemplary One-Stop Testing Approach

[0071] According to another aspect of the present application, a one-stop testing method for a TOF camera module is also provided.

[0072] Figure 3 FIG is a flowchart of a one-stop testing method for a TOF camera module according to an embodiment of the present application. Figure 3As shown, the one-stop test method of the TOF camera module according to the embodiment of the present application includes the following steps: S110, projecting a laser onto the target plate as described above through the projection unit of the TOF camera module, wherein the TOF camera module corresponds to the middle area of ​​the test surface of the target plate; S120, receiving the laser from the target plate through the light-receiving unit of the TOF camera module and generating a target plate depth image of the target plate; S130, determining the relative accuracy and relative precision of the TOF camera module in the middle area based on the depth value of the first test pattern located in the middle area of ​​the test surface in the target plate depth image; S140, determining the relative accuracy and relative precision of the TOF camera module in the middle area based on the depth value of the first test pattern located in the middle area of ​​the test surface in the target plate depth image; The TOF camera module is configured to determine the relative accuracy and relative precision of the TOF camera module in the edge area based on the depth value of the first test pattern in the edge area; S150, based on the pixel information of the second test pattern located in the middle area of ​​the test surface in the target depth image, determine the XY resolution of the TOF camera module in the middle area; S160, based on the pixel information of the second test pattern located in the edge area of ​​the test surface in the target depth image, determine the XY resolution of the TOF camera module in the edge area; S170, based on the depth value of the blank part of the test surface excluding the test pattern group in the target depth image.

[0073] That is, in the embodiment of the present application, the absolute accuracy, relative accuracy and XY resolution of the TOF camera module are tested in one stop using the target plate as described above.

[0074] In step S110 and step S120, a laser is projected onto the target plate as described above by the projection unit of the TOF camera module, and the laser from the target plate is received by the light-receiving unit of the TOF camera module and a target plate depth image of the target plate is generated. That is, the TOF camera module is started to collect the target plate depth image of the target plate by the TOF camera module. In particular, in the one-stop test method according to the present application, during the test process, the TOF camera module corresponds to the middle area of ​​the test surface of the target plate. Accordingly, when the laser projected by the TOF camera module is projected onto the blank part of the test surface, the laser is reflected on the test surface, and when the laser projected by the TOF camera module is projected onto the first test pattern or the second test pattern, the laser is reflected on the second side of the target plate body.

[0075] In step S130, based on the depth value of the first test pattern located in the middle area of ​​the test surface in the target depth image, the relative accuracy and relative precision of the TOF camera module in the middle area are determined. As previously mentioned, the first test pattern of the target includes a plurality of squares arranged in an array.

[0076] Accordingly, in a specific example of the present application, based on the depth value of the first test pattern located in the middle area of ​​the test surface in the target depth image, the process of determining the relative accuracy and relative precision of the TOF camera module in the middle area includes: first, based on the difference in depth values ​​of the spaced-apart squares in the plurality of array-arranged squares of the first test pattern, determining the relative precision of the TOF camera module in the middle area. More specifically, first, the first test pattern located in the middle area in the target depth image is positioned by positioning a reference point; then, the difference in depth values ​​of the spaced-apart squares in the plurality of array-arranged squares of the first test pattern is calculated, for example, the difference in depth values ​​of the odd-numbered squares (for example, the first and third) in the plurality of array-arranged squares is calculated as the relative precision of the TOF camera module in the middle area.

[0077] Furthermore, the process of determining the relative accuracy and relative precision of the TOF camera module in the middle area based on the depth value of the first test pattern located in the middle area of ​​the test surface in the target depth image also includes: determining the relative accuracy of the TOF camera module in the middle area based on the mean square error of the depth values ​​of all squares in the plurality of squares arranged in an array of the first test pattern. More specifically, the first test pattern located in the middle area in the target depth image is first located by positioning a reference point; then, the mean square error of the depth values ​​of all squares in the plurality of squares arranged in an array of the first test pattern is calculated as the relative accuracy of the TOF camera module in the middle area.

[0078] Figure 4 The figure shows a flow chart of determining the relative accuracy and relative precision of the TOF camera module in the middle area based on the depth value of the first test pattern in the middle area of ​​the test surface in the target depth image in the one-stop test method of the TOF camera module according to an embodiment of the present application. Figure 4As shown, in an embodiment of the present application, based on the depth value of the first test pattern located in the middle area of ​​the test surface in the target plate depth image, the relative accuracy and relative precision of the TOF camera module in the middle area are determined, including: S210, based on the difference in depth values ​​of the spaced-apart squares in the plurality of squares arranged in an array of the first test pattern, determining the relative precision and relative precision of the TOF camera module in the middle area; and, S220, based on the mean square deviation of the depth values ​​of all squares in the plurality of squares arranged in an array of the first test pattern, determining the relative precision of the TOF camera module in the middle area.

[0079] In step S140 , based on the depth value of the first test pattern located in the edge area of ​​the test surface in the target depth image, the relative accuracy and relative precision of the TOF camera module in the edge area are determined.

[0080] Specifically, in a specific example of the present application, based on the depth value of the first test pattern located in the edge area of ​​the test surface in the target depth image, the process of determining the relative accuracy and relative precision of the TOF camera module in the edge area includes: first, based on the difference in depth values ​​of the spaced-apart squares in the plurality of array-arranged squares of the first test pattern, determining the relative precision of the TOF camera module in the edge area. More specifically, first, the first test pattern located in the edge area in the target depth image is positioned by positioning a reference point; then, the difference in depth values ​​of the spaced-apart squares in the plurality of array-arranged squares of the first test pattern is calculated, for example, the difference in depth values ​​of the odd-numbered squares (for example, the first and third) in the plurality of array-arranged squares is calculated as the relative precision of the TOF camera module in the edge area.

[0081] Furthermore, the process of determining the relative accuracy and relative precision of the TOF camera module in the edge area based on the depth value of the first test pattern located in the edge area of ​​the test surface in the target depth image also includes: determining the relative accuracy of the TOF camera module in the edge area based on the mean square deviation of the depth values ​​of all squares in the plurality of squares arranged in an array of the first test pattern. More specifically, the first test pattern located in the edge area in the target depth image is first located by positioning a reference point; then, the mean square deviation of the depth values ​​of all squares in the plurality of squares arranged in an array of the first test pattern is calculated as the relative accuracy of the TOF camera module in the edge area.

[0082] It is worth mentioning that in the calculation process, the relative accuracy and the relative accuracy of each edge region can be calculated respectively, and the average of the relative accuracy and the relative accuracy of multiple edge regions is taken as the final relative accuracy and relative accuracy of the TOF camera module in the edge region.

[0083] Figure 5 Fig. 1 illustrates a flowchart of determining the relative accuracy and the relative accuracy of the TOF camera module in the edge region based on the depth values of the first test pattern in the edge region of the test surface in the test method of the TOF camera module according to the embodiments of the present application. As shown in the figure, Figure 6 In the embodiments of the present application, the relative accuracy and the relative accuracy of the TOF camera module in the edge region are determined based on the depth values of the first test pattern in the edge region of the test surface in the test plate depth image, which includes: S310, determining the relative accuracy of the TOF camera module in the edge region based on the difference between the depth values of the adjacent squares in the plurality of array-arranged squares of the first test pattern; and S320, determining the relative accuracy of the TOF camera module in the edge region based on the mean square error of the depth values of all squares in the plurality of array-arranged squares of the first test pattern.

[0084] In step S150, the XY resolution of the TOF camera module in the middle region is determined based on the pixel information of the second test pattern in the middle region of the test surface in the test plate depth image.

[0085] Specifically, in the embodiments of the present application, the process of determining the XY resolution of the TOF camera module in the middle region based on the pixel information of the second test pattern in the middle region of the test surface in the test plate depth image includes: first, calculating the proportional relationship a between the pixel size and the physical size of the test plate depth image based on the positioning reference points in the test plate depth image. That is, based on the captured positioning reference points, the proportional relationship a between the pixel size and the physical size is calculated, for example, the quotient of the pixel distance between the two positioning reference points and the physical size between the two positioning reference points is taken as the proportional relationship a.

[0086] Then, the pixel height h1 of the triangular pattern in the middle region of the test plate depth image is determined. Specifically, corner point detection is performed on the test plate depth image to determine the three positions of the triangular pattern, and the pixel distance h1 from the vertex to the bottom side of the triangular pattern is calculated.

[0087] Then, based on the pixel height h1 and the proportional relationship α, the physical size H1 corresponding to the pixel height h1 in the target depth image is determined. That is, the physical size H1 of the recognizable height of the triangular pattern in the depth target image is obtained by performing a transformation based on the proportional relationship between the pixel size and the physical size.

[0088] Next, the XY resolution of the TOF camera module in the middle area is determined based on the physical dimension H1, the actual physical height dimension H of the triangular pattern, and the actual physical base dimension R of the triangular pattern. That is, based on the physical dimension H of the height of the triangle design and the physical dimension R of the base length, the recognizable width r = R*(H-α*h1) / H is obtained through a similarity relationship. Here, r represents the XY resolution of the TOF camera module in the middle area.

[0089] Figure 6 The figure shows a flow chart of determining the XY resolution of the TOF camera module in the middle area based on the pixel information of the second test pattern in the target depth image in the middle area of ​​the test surface in the one-stop test method of the TOF camera module according to an embodiment of the present application. Figure 6 As shown, in an embodiment of the present application, based on the pixel information of the second test pattern located in the middle area of ​​the test surface in the target depth image, the XY resolution of the TOF camera module in the middle area is determined, including: S410, based on the positioning reference point in the target depth image, calculating the proportional relationship α between the pixel size of the target depth image and the physical size; S420, determining the pixel height h1 of the triangular pattern located in the middle area of ​​the target depth image; S430, based on the pixel height h1 and the proportional relationship α, determining the physical size H1 corresponding to the pixel height h1 in the target depth image; and, S440, based on the physical size H1, the real physical height size H of the triangular pattern, and the real physical base size R of the triangular pattern, determining the XY resolution of the TOF camera module in the middle area.

[0090] In step S160 , the XY resolution of the TOF camera module in the edge area is determined based on the pixel information of the second test pattern located in the edge area of ​​the test surface in the target depth image.

[0091] Specifically, in the embodiments of the present application, based on the pixel information of the second test pattern located in the edge region of the test surface in the calibration target depth image, the process of determining the XY resolution of the TOF camera module in the edge region comprises: first, based on the positioning reference points in the calibration target depth image, calculating the proportional relationship a between the pixel size and the physical size of the calibration target depth image. That is, based on the captured positioning reference points, the proportional relationship a between the pixel size and the physical size is calculated, for example, the quotient of the pixel distance between the two positioning reference points and the physical size between the two positioning reference points is taken as the proportional relationship a.

[0092] Then, the pixel height h1 of the triangular pattern located in the edge region in the calibration target depth image is determined. Specifically, corner point detection is performed on the calibration target depth image to determine the three positions of the triangular pattern, and the pixel distance h1 from the vertex to the bottom of the triangular pattern is calculated.

[0093] Then, based on the pixel height h1 and the proportional relationship a, the physical size H1 corresponding to the pixel height h1 in the calibration target depth image is determined. That is, according to the proportional relationship between the pixel size and the physical size, the physical size H1 of the identifiable height of the triangular pattern in the calibration target depth image is obtained.

[0094] Then, based on the physical size H1, the real physical height size H of the triangular pattern, and the real physical bottom size R of the triangular pattern, the XY resolution of the TOF camera module in the edge region is determined. That is, according to the physical size H of the design height of the triangular pattern and the physical size R of the bottom length, the similarity relationship is obtained: identifiable width r = R*(H-a*h1) / H, where r represents the XY resolution of the TOF camera module in the edge region.

[0095] Figure 7Fig. 6 illustrates a flow chart of determining the XY resolution of the TOF camera module in the edge region based on the pixel information of the second test pattern in the edge region of the test surface in the one-stop test method of the TOF camera module according to the embodiments of the present application. In the embodiments of the present application, the process of determining the XY resolution of the TOF camera module in the edge region based on the pixel information of the second test pattern in the edge region of the test surface in the test plate depth image comprises: S510, calculating the proportional relationship a between the pixel size and the physical size of the test plate depth image based on the positioning reference point in the test plate depth image; S520, determining the pixel height h1 of the triangular pattern in the edge region of the test plate depth image; S530, determining the physical size H1 corresponding to the pixel height h1 in the test plate depth image based on the pixel height h1 and the proportional relationship a; and S540, determining the XY resolution of the TOF camera module in the middle region based on the physical size H1, the real physical height size H of the triangular pattern, and the real physical base size R of the triangular pattern.

[0096] In step S170, the absolute accuracy and absolute precision of the TOF camera module are determined based on the depth values of the blank part of the test surface except the test pattern group in the test plate depth image. It should be understood that in the test method according to the present application, the distance between the TOF camera module and the blank part of the test surface is the distance between the TOF camera module and the test plate, and therefore, the absolute accuracy and absolute precision of the TOF camera module can be calculated based on the depth values of the blank part of the test surface except the test pattern group in the test plate depth image.

[0097] Specifically, in one specific example of the present application, the process of determining the absolute accuracy and absolute precision of the TOF camera module based on the depth values of the blank part of the test surface except the test pattern group in the test plate depth image comprises: first, calculating the average of the depth values of the pixels in a specific region adjacent to the middle region in the blank part as the absolute precision of the TOF camera module. That is, the average of the depth values of the pixels in the specific region adjacent to the middle region in the blank part is taken as the absolute precision of the TOF camera module, and the specific region can be a matrix region, and of course, other shapes of regions are also possible, which are not limited in the present application.

[0098] Furthermore, the process of determining the absolute accuracy and absolute precision of the TOF camera module based on the depth value of the blank portion of the test surface excluding the test pattern group in the target depth image further includes: calculating the mean square error of pixels in a specific area adjacent to the edge area in the blank portion as the absolute accuracy of the TOF camera module. Here, the specific area adjacent to the edge area can also be set to a rectangular area of ​​a specific size. Of course, it can also be an area of ​​other shapes and sizes, which is not limited by this application.

[0099] Figure 8 The figure shows a flow chart of determining the absolute accuracy and precision of the TOF camera module based on the depth value of the blank portion of the test surface excluding the test pattern group in the target depth image in the one-stop test method of the TOF camera module according to an embodiment of the present application. Figure 8 As shown, in an embodiment of the present application, the absolute precision and absolute accuracy of the TOF camera module are determined based on the depth value of the blank portion of the test surface excluding the test pattern group in the target plate depth image, including: S610, calculating the average value of the depth values ​​of pixels in a specific area adjacent to the middle area in the blank portion as the absolute accuracy of the TOF camera module; and, S620, calculating the mean square error of the pixels in a specific area adjacent to the edge area in the blank portion as the absolute precision of the TOF camera module.

[0100] In summary, a one-stop testing method for the TOF camera module based on an embodiment of the present application is explained, wherein the testing method uses the target plate as described above and a matching testing algorithm to perform a one-stop test on multiple performances of the TOF camera module.

[0101] Those skilled in the art should understand that although the above example uses a one-stop test of the five performance items of the TOF camera module, namely, absolute accuracy, absolute precision, relative accuracy, relative accuracy and XY resolution, in other examples of the present application, the one-stop testing method can also be extended to the one-stop test of other performance items, which is not limited to the present application.

[0102] The basic principles of the present application have been described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, and effects mentioned in this application are merely illustrative and not restrictive, and it should not be assumed that these advantages, strengths, and effects are required of each embodiment of this application. In addition, the specific details disclosed above are merely illustrative and facilitating understanding, and are not restrictive. The above details do not limit this application to necessarily being implemented using the above specific details.

[0103] The block diagrams of the devices, devices, equipment, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As will be appreciated by those skilled in the art, these devices, devices, equipment, and systems can be connected, arranged, or configured in any manner. Words such as "include," "comprise," "have," and the like are open-ended words, meaning "including but not limited to," and can be used interchangeably therewith. The words "or" and "and" used herein refer to the words "and / or" and can be used interchangeably therewith, unless the context clearly indicates otherwise. The word "such as" used herein refers to the phrase "such as but not limited to," and can be used interchangeably therewith.

[0104] It should also be noted that in the apparatus, device, and method of the present application, each component or each step can be decomposed and / or recombined, and such decomposition and / or recombination should be regarded as equivalent solutions of the present application.

[0105] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of the present application. Therefore, the present application is not intended to be limited to the aspects shown herein, but rather to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0106] The above description has been given for the purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although a number of example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A target plate for one-stop testing of TOF camera modules, characterized in that: include: a target body having a first side surface and a second side surface opposite to the first side surface, wherein the first side surface forms a test surface; and a test pattern group running through the test surface; The test pattern group includes: a first test pattern formed penetratingly in a middle area and an edge area of ​​the test surface; a second test pattern formed through a middle region and an edge region of the test surface, respectively, wherein the second test pattern extends along an X-axis or a Y-axis set for the test surface on the test surface; and positioning reference points for positioning the first test pattern and the second test pattern on the test surface; In which, during the test process, the middle area of ​​the test surface corresponds to the TOF camera module to be tested, wherein the first test pattern located in the middle area of ​​the test surface is used to test the relative accuracy and relative precision of the TOF camera module to be tested in the middle area; the first test pattern located in the edge area of ​​the test surface is used to test the relative accuracy and relative precision of the TOF camera module to be tested in the edge area; the second test pattern located in the middle area of ​​the test surface is used to test the XY resolution of the TOF camera module to be tested in the middle area; the second test pattern located in the edge area of ​​the test surface is used to test the XY resolution of the TOF camera module to be tested in the edge area.

2. The one-stop test target for TOF camera modules according to claim 1, wherein: During the test process, the blank portion of the test surface except the test pattern group is used to test the absolute precision and absolute accuracy of the TOF camera module to be tested.

3. The one-stop test target for TOF camera module according to claim 2, wherein: The first test pattern includes a plurality of squares arranged in an array.

4. The one-stop test target for TOF camera modules according to claim 3, wherein: The plurality of grids arranged in an array are connected to each other.

5. The one-stop test target for TOF camera module according to claim 2, wherein: The second test pattern is a triangular pattern, wherein a height of the triangular pattern extends along an X-axis set on the test surface or along a Y-axis set on the test surface.

6. The one-stop test target for TOF camera modules according to claim 5, wherein: The second test pattern includes a first isosceles triangle pattern and a second isosceles triangle pattern, wherein a vertex angle of the first isosceles triangle pattern is smaller than a vertex angle of the second isosceles triangle pattern.

7. The target plate for one-stop testing of TOF camera modules according to claim 2, wherein: The number of the positioning reference points is 4, which are respectively located at the four edge areas of the test surface.

8. A one-stop testing method for a TOF camera module, for testing the TOF camera module, wherein the TOF camera module includes a projection unit and a light receiving unit, characterized in that: include: Projecting a laser onto the target plate according to any one of claims 1 to 7 through a projection unit of the TOF camera module, wherein the TOF camera module corresponds to a middle area of ​​a test surface of the target plate; receiving the laser from the target plate through the light-receiving unit of the TOF camera module and generating a target plate depth image of the target plate; Determining the relative accuracy and relative precision of the TOF camera module in the middle area based on the depth value of the first test pattern located in the middle area of ​​the test surface in the target depth image; Determining the relative accuracy and relative precision of the TOF camera module in the edge area based on the depth value of the first test pattern located in the edge area of ​​the test surface in the target depth image; Determining an XY resolution of the TOF camera module in the middle area based on pixel information of the second test pattern located in the middle area of ​​the test surface in the target depth image; and Based on the pixel information of the second test pattern located in the edge area of ​​the test surface in the target depth image, the XY resolution of the TOF camera module in the edge area is determined.

9. The one-stop testing method according to claim 8, further comprising: Based on the depth value of the blank portion of the test surface excluding the test pattern group in the target depth image, the absolute precision and absolute accuracy of the TOF camera module are determined.

10. The one-stop testing method according to claim 8, wherein: The first test pattern includes a plurality of squares arranged in an array; Wherein, determining the relative accuracy and relative precision of the TOF camera module in the middle area based on the depth value of the first test pattern located in the middle area of ​​the test surface in the target depth image includes: determining a relative accuracy of the TOF camera module in the middle area based on a difference in depth values ​​between spaced-apart squares in the plurality of squares arranged in an array of the first test pattern; and The relative accuracy of the TOF camera module in the middle area is determined based on the mean square error of the depth values ​​of all squares in the plurality of squares arranged in an array of the first test pattern.

11. The one-stop testing method according to claim 10, wherein: Determining the relative accuracy and relative precision of the TOF camera module in the edge area based on the depth value of the first test pattern in the target depth image, including: determining a relative accuracy of the TOF camera module in the edge area based on a difference in depth values ​​between spaced-apart squares in the plurality of squares arranged in an array of the first test pattern; and The relative accuracy of the TOF camera module in the edge area is determined based on the mean square error of the depth values ​​of all squares in the plurality of squares arranged in an array of the first test pattern.

12. The one-stop testing method according to claim 9, wherein: Determining the absolute accuracy and absolute precision of the TOF camera module based on a depth value of a blank portion of the test surface excluding the test pattern group in the target depth image, including: Calculating an average value of depth values ​​of pixels in a specific area adjacent to the middle area in the blank portion as the absolute accuracy of the TOF camera module; and The mean square error of pixels in a specific area adjacent to the edge area in the blank portion is calculated as the absolute accuracy of the TOF camera module.

13. The one-stop testing method according to claim 8, wherein: The second test pattern is a triangle pattern; Wherein, determining the XY resolution of the TOF camera module in the middle area based on pixel information of the second test pattern located in the middle area of ​​the test surface in the target depth image includes: Calculating a proportional relationship α between a pixel size of the target depth image and a physical size based on the positioning reference point in the target depth image; Determine a pixel height h1 of the triangular pattern located in a middle area of ​​the target depth image; Determining a physical size H1 corresponding to the pixel height h1 in the target depth image based on the pixel height h1 and the proportional relationship α; and Based on the physical size H1, the real physical height size H of the triangular pattern, and the real physical base size R of the triangular pattern, the XY resolution of the TOF camera module in the middle area is determined.

14. The one-stop testing method according to claim 8, wherein: The second test pattern is a triangular pattern, wherein determining the XY resolution of the TOF camera module in the edge area based on pixel information of the second test pattern located in the edge area of ​​the test surface in the target depth image includes: Calculating a proportional relationship α between a pixel size of the target depth image and a physical size based on the positioning reference point in the target depth image; Determine a pixel height h1 of the triangular pattern located in an edge area in the target depth image; Determining a physical size H1 corresponding to the pixel height h1 in the target depth image based on the pixel height h1 and the proportional relationship α; and Based on the physical size H1, the real physical height size H of the triangular pattern, and the real physical base size R of the triangular pattern, the XY resolution of the TOF camera module in the middle area is determined.

Images