TOF module calibration method and device, computer equipment and storage medium

Abstract

The invention relates to a TOF module calibration method and device, computer equipment and a storage medium, and the method comprises the steps: obtaining a related image corresponding to a preset target plate based on the preset target plate and a to-be-calibrated module which are disposed in a combined manner, and enabling the related image to comprise a light spot gray image and a chip image in a gray mode; determining an imaging center coordinate of each feature point in the target plate in the chip image; determining an emission angle corresponding to each target pixel point in the chip image based on a fitting relational expression between the emission angle of each feature point and the imaging center coordinate; the optical center position of the to-be-calibrated module is determined based on the related image, and the point cloud data of the target pixel point is generated according to the emission angle corresponding to the target pixel point and the optical center position, so that the problem that the corresponding relation between the pixel coordinate of the module and the emission angle cannot be obtained under the condition that the internal reference data of the module is not calibrated is solved, and the calibration accuracy is improved. The corresponding relation between the pixel coordinate and the emission angle of the module can be obtained without calibrating the internal reference of the module.

Description

Technical Field

[0001] The present application relates to the field of machine vision technology, and in particular to a calibration method, device, computer equipment and storage medium for a TOF module. Background Art

[0002] At present, 3D visual imaging technology is constantly developing, and imaging technology based on time of flight is also developing rapidly. TOF modules are widely used in many fields, such as 3D modeling, obstacle detection, posture tracking, and environmental perception. Among them, the TOF module calculates the distance between it and the object by measuring the time required from transmission to reception. Therefore, in order to improve the accuracy and reliability of the TOF module measurement results, it is usually necessary to calibrate the TOF module.

[0003] The current calibration method realizes the corresponding calculation of chip pixels and emission angles by calibrating the module's focal length, distortion coefficient and other internal parameter data. When using the above method to calibrate a TOF module with a large field of view, it is necessary to set up large equipment for the TOF module to complete the correction of the module's internal parameters. However, in actual application, the above large equipment cannot be provided. Therefore, without calibrating the module's internal parameter data, it is impossible to obtain the corresponding relationship between the module's pixel coordinates and the emission angle to output the final point cloud data.

[0004] With regard to the problem in the related art that the correspondence between the module pixel coordinates and the emission angle cannot be obtained when the module internal parameter data is not calibrated, no effective solution has been proposed so far. Summary of the invention

[0005] In this embodiment, a TOF module calibration method, apparatus, computer device and storage medium are provided to solve the problem in the related art that the correspondence between the module pixel coordinates and the emission angle cannot be obtained without calibrating the module internal parameter data.

[0006] In a first aspect, a calibration method for a TOF module is provided in this embodiment, and the method includes:

[0007] Based on the preset target plate and the module to be calibrated placed in combination, a related image corresponding to the preset target plate is obtained; the related image includes a light spot grayscale image and a chip image in grayscale mode;

[0008] Determine the imaging center coordinates of each feature point in the preset target plate in the chip image;

[0009] Determine the emission angle corresponding to each target pixel point in the chip image based on the fitting relationship between the emission angle of each feature point and the corresponding imaging center coordinate;

[0010] The optical center position of the module to be calibrated is determined based on the relevant image, and point cloud data of the target pixel point is generated according to the emission angle corresponding to the target pixel point and the optical center position.

[0011] In some of the embodiments, before acquiring the relevant image corresponding to the preset target plate based on the combined placement of the preset target plate and the module to be calibrated, the method further includes:

[0012] Determine whether the receiving end field of view of the module to be calibrated is greater than a field of view angle threshold;

[0013] When the field of view angle of the receiving end of the module to be calibrated is greater than the field of view angle threshold, the preset mark plate is fixed to the side of the module to be calibrated; wherein the center row of each of the feature points in the preset mark plate is parallel to the 180-degree field of view angle of the module to be calibrated.

[0014] In some of the embodiments, after determining whether the receiving end field of view angle of the module to be calibrated is greater than the field of view angle threshold, the method further includes:

[0015] When the receiving end field of view angle of the module to be calibrated is less than or equal to the field of view angle threshold, the preset mark plate is fixed directly above the module to be calibrated; wherein the central feature point of the preset mark plate coincides with the 0 degree field of view angle of the module to be calibrated.

[0016] In some embodiments, determining the optical center position of the module to be calibrated based on the relevant image includes:

[0017] Determining whether the light spot grayscale image includes a ring-shaped light spot;

[0018] When the light spot grayscale image includes the annular light spot, converting the light spot grayscale image into a corresponding binary contour image;

[0019] Determine the inner contour and the outer contour of the annular light spot in the binary contour image;

[0020] The inner contour and the outer contour of the annular light spot are processed respectively by a circle fitting algorithm to obtain a first optical center position corresponding to the inner contour and a second optical center position corresponding to the outer contour;

[0021] The optical center position of the module to be calibrated is determined according to the first optical center position and the second optical center position.

[0022] In some of the embodiments, after determining whether the light spot grayscale image includes a ring-shaped light spot, the method further includes:

[0023] When the light spot grayscale image does not include the annular light spot, determining the imaging center position of the central feature point of the preset target plate in the chip image;

[0024] The imaging center position of the central feature point in the chip image is used as the optical center position of the module to be calibrated.

[0025] In some embodiments, determining the imaging center position of the central feature point of the preset target plate in the chip image includes:

[0026] Selecting pixel points in the chip image whose pixel brightness value is greater than a brightness threshold;

[0027] A weighted operation is performed on the coordinates of the pixel point and the corresponding pixel brightness value, and the imaging center position of the central feature point in the chip image is determined according to the operation result.

[0028] In some of the embodiments, determining the emission angle corresponding to each target pixel point in the chip image based on the fitting relationship between the emission angle of each feature point and the corresponding imaging center coordinates includes:

[0029] Determining the emission angle of each of the feature points in the preset target plate according to the field of view angle of the receiving end of the module to be calibrated;

[0030] The emission angle of each feature point and the corresponding imaging center coordinates are processed by a surface fitting algorithm to obtain the fitting relationship;

[0031] The coordinates of each target pixel point in the chip image are input into the fitting relationship to obtain the emission angle corresponding to each target pixel point.

[0032] In a second aspect, a calibration device for a TOF module is provided in this embodiment, the device comprising: an acquisition module, an analysis module, a fitting module and a generation module;

[0033] The acquisition module is used to acquire the relevant image corresponding to the preset target plate based on the preset target plate and the module to be calibrated placed in combination; the relevant image includes the spot grayscale image and the chip image;

[0034] The analysis module is used to determine the imaging center coordinates of each feature point in the preset target plate in the chip image;

[0035] The fitting module is used to determine the emission angle corresponding to each target pixel point in the chip image based on the fitting relationship between the emission angle of each feature point and the corresponding imaging center coordinate;

[0036] The generating module is used to determine the optical center position of the module to be calibrated based on the relevant image, and to generate point cloud data of the target pixel point according to the emission angle corresponding to the target pixel point and the optical center position.

[0037] In a third aspect, a computer device is provided in this embodiment, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the TOF module calibration method described in the first aspect when executing the computer program.

[0038] In a fourth aspect, a storage medium is provided in this embodiment, on which a computer program is stored, and when the program is executed by a processor, the calibration method of the TOF module described in the first aspect is implemented.

[0039] Compared with the related art, the calibration method, device, computer equipment and storage medium of the TOF module provided in this embodiment obtain the relevant image corresponding to the preset target plate based on the combined placement of the preset target plate and the module to be calibrated, and the relevant image includes the spot grayscale image and the chip image in the grayscale mode; determine the imaging center coordinates of each feature point in the preset target plate in the chip image; further, based on the fitting relationship between the emission angle of each feature point and the corresponding imaging center coordinate, determine the emission angle corresponding to each target pixel point in the chip image, and determine the optical center position of the module to be calibrated based on the relevant image, so that the point cloud data of the target pixel point can be generated according to the emission angle and optical center position corresponding to the target pixel point, which solves the problem that the correspondence between the module pixel coordinates and the emission angle cannot be obtained without calibrating the module internal parameter data, and realizes that the correspondence between the module pixel coordinates and the emission angle can be obtained without calibrating the module internal parameter, so as to output the final point cloud data, while reducing the equipment cost.

[0040] Details of one or more embodiments of the present application are set forth in the following drawings and description to make other features, objects, and advantages of the present application more readily apparent. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0042] Figure 1 It is a hardware structure block diagram of a terminal device of a TOF module calibration method provided in an embodiment of the present application;

[0043] Figure 2 is a flow chart of a TOF module calibration method provided in one embodiment of the present application;

[0044] Figure 3 is a schematic diagram of a TOF module calibration environment provided in an embodiment of the present application;

[0045] Figure 4 is a schematic diagram of a TOF module calibration environment provided in an embodiment of the present application;

[0046] Figure 5 is a schematic diagram of a method for calculating the optical center position provided in an embodiment of the present application;

[0047] Figure 6 is a schematic diagram of a method for calculating an emission angle provided in an embodiment of the present application;

[0048] Figure 7 is a schematic diagram of a method for calculating an emission angle provided in an embodiment of the present application;

[0049] Figure 8 It is a flow chart of a calibration method of a TOF module provided in a preferred embodiment of the present application;

[0050] Fig. 9 It is a structural block diagram of a calibration device for a TOF module provided in one embodiment of the present application.

[0051] In the figure: 102, processor; 104, memory; 106, transmission device; 108, input and output device; 10, acquisition module; 20, analysis module; 30, fitting module; 40, generation module. DETAILED DESCRIPTION

[0052] In order to more clearly understand the purpose, technical solutions and advantages of the present application, the present application is described and illustrated below in conjunction with the accompanying drawings and embodiments.

[0053] Unless otherwise defined, the technical terms or scientific terms involved in this application shall have the general meaning understood by people with ordinary skills in the technical field to which this application belongs. The words "one", "a", "a", "the", "these" and the like in this application do not represent quantitative restrictions, and they can be singular or plural. The terms "include", "comprise", "have" and any variants thereof involved in this application are intended to cover non-exclusive inclusions; for example, a process, method and system, product or device comprising a series of steps or modules (units) is not limited to the listed steps or modules (units), but may include unlisted steps or modules (units), or may include other steps or modules (units) inherent to these processes, methods, products or devices. The words "connect", "connected", "coupled" and the like involved in this application are not limited to physical or mechanical connections, but may include electrical connections, whether directly or indirectly. The "multiple" involved in this application refers to two or more. "And / or" describes the association relationship of associated objects, indicating that there can be three relationships. For example, "A and / or B" can mean: A exists alone, A and B exist at the same time, and B exists alone. Usually, the character " / " indicates that the objects associated with each other are in an "or" relationship. The terms "first", "second", "third", etc. involved in this application are only used to distinguish similar objects and do not represent a specific ordering of the objects.

[0054] The method embodiment provided in this embodiment can be executed in a terminal, a computer or a similar computing device. For example, running on a terminal, Figure 1 FIG. 1 is a hardware structure diagram of a terminal of the TOF module calibration method of this embodiment. Figure 1 As shown, the terminal may include one or more ( Figure 1 Only one is shown in the figure) processor 102 and memory 104 for storing data, wherein processor 102 may include but is not limited to a processing device such as a microprocessor MCU or a programmable logic device FPGA. The above terminal may also include a transmission device 106 and an input and output device 108 for communication functions. It can be understood by those skilled in the art that Figure 1 The structure shown is only for illustration and does not limit the structure of the above terminal. Figure 1 More or fewer components as shown, or with Figure 1 Different configurations shown.

[0055] The memory 104 can be used to store computer programs, for example, software programs and modules of application software, such as the computer program corresponding to the calibration method of the TOF module in the present embodiment. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, that is, to implement the above method. The memory 104 may include a high-speed random access memory, and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include a memory remotely arranged relative to the processor 102, and these remote memories may be connected to the terminal via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and a combination thereof.

[0056] The transmission device 106 is used to receive or send data via a network. The above network includes a wireless network provided by the communication provider of the terminal. In one example, the transmission device 106 includes a network adapter (Network Interface Controller, referred to as NIC), which can be connected to other network devices through a base station so as to communicate with the Internet. In one example, the transmission device 106 can be a radio frequency (Radio Frequency, referred to as RF) module, which is used to communicate with the Internet wirelessly.

[0057] In this embodiment, a TOF module calibration method is provided. Figure 2 FIG. 1 is a flow chart of the calibration method of the TOF module of this embodiment. Figure 2 As shown, the process includes the following steps:

[0058] Step S220, based on the combined placed preset target plate and the module to be calibrated, obtaining a related image corresponding to the preset target plate; the related image includes a light spot grayscale image and a chip image.

[0059] In this embodiment, the number of rows and columns of each feature point in the preset target plate is designed according to the use area of ​​the module lens to be calibrated to cover its area range. The distance between the above feature points is fixed, and the distance design is closely related to factors such as the calibration distance and the emission angle of the receiving end lens.

[0060] When the calibration distance is fixed, if the distance between feature points is too large or too small, the imaging spacing of feature points will be too far or too close respectively. Among them, under a fixed calibration distance, the imaging spacing of feature points decreases as the emission angle of the receiving end lens increases; under a fixed receiving end lens emission angle, the imaging spacing of feature points decreases as the calibration distance increases.

[0061] Therefore, in the actual calibration process, it is necessary to reasonably set the distance between each feature point in the preset target plate according to the calibration distance and the emission angle of the receiving end lens to ensure that the imaging spacing of the feature points is appropriate.

[0062] Specifically, according to the viewing angle of the receiving end of the module to be calibrated, the preset standard plate is combined and placed with the module to be calibrated in different ways to build a calibration environment for the module. When the viewing angle of the receiving end of the module to be calibrated is greater than the viewing angle threshold, the preset standard plate is fixed to the side of the module to be calibrated; when the viewing angle of the receiving end of the module to be calibrated is less than or equal to the viewing angle threshold, the preset standard plate is fixed directly above the module to be calibrated.

[0063] It is important to know that for a module whose receiving end field of view angle is greater than the field of view angle threshold, if it is necessary to calibrate all its field of view angles, that is, the calibration range includes not only the receiving end field of view angles greater than the field of view angle threshold, but also the receiving end field of view angles less than or equal to the field of view angle threshold, then preset reference plates are fixed on the side and top of the module to be calibrated.

[0064] In addition, the spot grayscale image refers to the image collected by the module when only the vertical-cavity surface emitting laser (VCSEL) is turned on, while the chip image refers to the image collected by the module when the VCSEL is turned off and the feature point emits light with the same wavelength as the module chip receives, or when the feature point is supplemented with external light.

[0065] Step S240, determining the imaging center coordinates of each feature point in the preset target plate in the chip image.

[0066] Specifically, the module collects the chip image in grayscale mode by emitting light of the same wavelength as the module chip receives from the feature point or by supplementing the feature point with external light. At this time, each feature point in the target plate has its corresponding imaging center coordinates in the chip image. For example, the number of rows and columns of feature points in the preset target plate is 9 rows and 37 columns respectively, and the chip image collected by the module contains 9*37 imaging center coordinates.

[0067] Step S260, determining the emission angle corresponding to each target pixel point in the chip image based on the fitting relationship between the emission angle of each feature point and the corresponding imaging center coordinates.

[0068] Specifically, according to the field of view angle of the receiving end of the module to be calibrated, the emission angle of each feature point in the preset target plate is calculated, and the emission angle of each feature point and the corresponding imaging center coordinates are processed by a surface fitting algorithm to obtain a fitting relationship.

[0069] Based on this, the coordinates of each target pixel in the chip image are input into the fitting equation to calculate the emission angle corresponding to each target pixel.

[0070] Step S280, determining the optical center position of the module to be calibrated based on the relevant image, and generating point cloud data of the target pixel point according to the emission angle and the optical center position corresponding to the target pixel point.

[0071] Specifically, for modules with a receiving end field of view angle greater than the field of view angle threshold, that is, when the preset mark is fixed on the side of the module to be calibrated, VCSEL can be used to generate a spot grayscale image, and the optical center position of the module to be calibrated can be calculated based on the annular spot in the spot grayscale image to simplify the optical center calculation process and effectively reduce the calculation cost. For modules with a receiving end field of view angle less than or equal to the field of view angle threshold, or when the module with a receiving end field of view angle greater than the field of view angle threshold needs to use the full field of view, a preset mark needs to be set directly above the module to be calibrated. At this time, the imaging center position of the central feature point of the preset mark in the chip image can be used as the optical center position.

[0072] Furthermore, relevant calculations are performed according to the emission angle and the optical center position corresponding to the target pixel point to obtain the point cloud data of the target pixel point.

[0073] In order to improve the accuracy and reliability of the TOF module measurement results, it is usually necessary to calibrate the TOF module. In the existing calibration method, the correspondence between the chip pixel and the emission angle is calculated by calibrating the module's focal length, distortion coefficient and other internal parameter data. When using the above method to calibrate a TOF module with a larger field of view angle, it is necessary to set up a large device for the TOF module to complete the correction of the module's internal parameters. However, in actual application, the above large device cannot be provided, and then without calibrating the module's internal parameter data, it is impossible to obtain the correspondence between the module pixel coordinates and the emission angle to output the final point cloud data.

[0074] Compared with the prior art, the present application combines and places the preset target plate and the module to be calibrated in a preset manner, and collects the relevant images corresponding to the preset target plate, which include the light spot grayscale image and the chip image. Furthermore, the imaging center coordinates of each feature point in the preset target plate in the chip image are calculated, and the fitting relationship between the emission angle of each feature point and the corresponding imaging center coordinates is obtained, so that the emission angle corresponding to each target pixel point in the chip image can be determined according to the fitting relationship, avoiding the need to calculate the correspondence between chip pixels and emission angles through the internal reference data such as the focal length and distortion coefficient of the calibration module.

[0075] On this basis, the optical center position of the module to be calibrated is determined according to the relevant images, and the point cloud data of the target pixel point can be obtained by calculating the emission angle and optical center position corresponding to the target pixel point. This solves the problem of being unable to obtain the correspondence between the module pixel coordinates and the emission angle without calibrating the module internal parameter data. It realizes the correspondence between the module pixel coordinates and the emission angle without calibrating the module internal parameters, so as to output the final point cloud data, while reducing the equipment cost.

[0076] In some of the embodiments, before obtaining the relevant image corresponding to the preset target plate based on the combined placement of the preset target plate and the module to be calibrated, the following steps are also included:

[0077] Step S211, determining whether the receiving end viewing angle of the module to be calibrated is greater than the viewing angle threshold;

[0078] Step S212, when the receiving end field of view of the module to be calibrated is greater than the field of view threshold, fix the preset mark plate to the side of the module to be calibrated; wherein the center row of each feature point in the preset mark plate is parallel to the 180 degree field of view of the module to be calibrated.

[0079] In this embodiment, it is first determined whether the receiving end viewing angle of the module to be calibrated is greater than the viewing angle threshold. If the receiving end viewing angle of the module to be calibrated is greater than the viewing angle threshold, the preset mark plate is fixed to the side of the module to be calibrated.

[0080] When placing the preset target plate, it is necessary to satisfy that the center row of each feature point in the preset target plate is parallel to the 180-degree field of view of the module to be calibrated, the center row is parallel to the wider edge of the preset target plate, and contains the center feature point of the preset target plate. The center feature point refers to the feature point located at the center of the preset target plate, and the distance D1 between the center feature point and the module to be calibrated is recorded at the same time, that is, the horizontal distance between the center feature point and the center of the lens of the module to be calibrated.

[0081] See also Figure 3 , taking the preset standard plate having 9 rows and 37 columns and a field of view angle threshold of 150 degrees as an example, when the field of view of the receiving end of the module to be calibrated is greater than 150 degrees, the preset standard plate is fixed to the side of the module to be calibrated. Figure 3 (a) is the front view of the preset target plate, and the 5th row is the center row of each feature point in the preset target plate. Figure 3 (b) indicates that the preset mark plate is placed on the side of the module to be calibrated. Figure 3 When the position is as shown in (b), the fifth row of the preset target plate is parallel to the 180-degree field of view of the module to be calibrated, and the horizontal distance between the central feature point and the center of the lens of the module to be calibrated is recorded.

[0082] Through this embodiment, it is determined whether the field of view angle of the receiving end of the module to be calibrated is greater than the field of view angle threshold. When the field of view angle of the receiving end of the module to be calibrated is greater than the field of view angle threshold, the preset mark plate is fixed to the side of the module to be calibrated, and the center row of each feature point in the preset mark plate is parallel to the 180-degree field of view angle of the module to be calibrated. The calibration environment of the module whose receiving end field of view angle is greater than the field of view angle threshold is set up in a correct manner to facilitate subsequent module analysis.

[0083] In some of the embodiments, after determining whether the receiving end viewing angle of the module to be calibrated is greater than the viewing angle threshold, the following steps are also included:

[0084] When the receiving end field of view angle of the module to be calibrated is less than or equal to the field of view angle threshold, the preset mark plate is fixed directly above the module to be calibrated; wherein the central feature point of the preset mark plate coincides with the 0 degree field of view angle of the module to be calibrated.

[0085] Specifically, the receiving end field of view angle of the module to be calibrated is compared with the field of view angle threshold. If the receiving end field of view angle of the module to be calibrated is less than or equal to the field of view angle threshold, the preset mark plate is fixed directly above the module to be calibrated.

[0086] When placing the preset mark plate, it is necessary to satisfy that the central feature point of the preset mark plate coincides with the 0 degree field of view of the module to be calibrated, and the preset mark plate is parallel to the horizontal plane. The central feature point refers to the feature point located at the center of the preset mark plate, and the distance D2 between the central feature point and the module to be calibrated is recorded at the same time, that is, the closest distance between the central feature point and the end face of the lens of the module to be calibrated.

[0087] See also Figure 4 , taking the preset standard plate with 9 rows and 37 columns and a field of view angle threshold of 150 degrees as an example, when the field of view of the receiving end of the module to be calibrated is less than or equal to 150 degrees, the preset standard plate is fixed directly above the module to be calibrated. Figure 4 (a) is the front view of the preset target plate, and the 5th row is the center row of each feature point in the preset target plate. Figure 4 (b) indicates that the preset standard plate is placed directly above the module to be calibrated. Figure 4 When the preset target plate is in the position shown in (b), the preset target plate is parallel to the horizontal plane, the central feature point thereof coincides with the 0 degree field of view of the module to be calibrated, and the distance between the central feature point and the module to be calibrated is recorded.

[0088] Through this embodiment, when the field of view angle of the receiving end of the module to be calibrated is less than or equal to the field of view angle threshold, the preset mark plate is fixed directly above the module to be calibrated, and the central feature point of the preset mark plate coincides with the 0 degree field of view angle of the module to be calibrated, so that the calibration environment of the module with the field of view angle of the receiving end less than or equal to the field of view angle threshold is set up in a correct manner, which facilitates subsequent module analysis.

[0089] In some of the embodiments, determining the optical center position of the module to be calibrated based on the relevant image includes the following steps:

[0090] Step S281, determining whether the light spot grayscale image contains a ring light spot;

[0091] Step S282, when the light spot grayscale image includes a ring-shaped light spot, converting the light spot grayscale image into a corresponding binary contour image;

[0092] Step S283, determining the inner contour and outer contour of the annular light spot in the binary contour image;

[0093] Step S284, processing the inner contour and the outer contour of the annular light spot respectively by a circle fitting algorithm to obtain a first optical center position corresponding to the inner contour and a second optical center position corresponding to the outer contour;

[0094] Step S285, determining the optical center position of the module to be calibrated according to the first optical center position and the second optical center position.

[0095] It should be noted that when the receiving end field of view angle of the module to be calibrated is greater than the field of view angle threshold, when setting up its calibration environment, the preset standard plate will be fixed to the side of the module to be calibrated, based on which a spot grayscale image containing a ring-shaped spot will be collected.

[0096] Specifically, see Figure 5 , the light spot grayscale image is binarized and divided into foreground and background, where the annular light spot is used as the foreground and other image areas are used as the background, and the corresponding binary contour image is obtained, so that the inner contour and outer contour of the annular light spot in the image can be determined.

[0097] Furthermore, the inner and outer contours of the annular spot are fitted by a circle fitting algorithm, and the center of the fitting circle corresponding to the inner contour is taken as the first optical center position (OC_insidex, OC_insidey), and the center of the fitting circle corresponding to the outer contour is taken as the second optical center position (OC_outx, OC_outy). On this basis, the optical center position of the module to be calibrated is calculated according to the first optical center position and the second optical center position. The specific calculation formula is as follows:

[0098] OC X =(OC_insidex+OC_outx) / 2;

[0099] OC Y =(OC_insidey+OC_outy) / 2;

[0100] Among them, OC X Indicates the X coordinate of the optical center position, OCY OC_insidex represents the X coordinate of the first optical center position, OC_insidey represents the Y coordinate of the first optical center position; OC_outx represents the X coordinate of the second optical center position, OC_outy represents the Y coordinate of the second optical center position. In addition, the circle fitting algorithm in this embodiment includes but is not limited to the least squares fitting algorithm and the global optimal circle fitting algorithm.

[0101] Through this embodiment, when the light spot grayscale image contains a ring-shaped light spot, the light spot grayscale image is converted into a corresponding binary contour image, and the ring-shaped light spot in the binary contour image is divided into a left contour and a right contour; the inner contour and the outer contour of the ring-shaped light spot in the binary contour image are determined, and the inner contour and the outer contour of the ring-shaped light spot are processed respectively through a circle fitting algorithm to obtain a first optical center position corresponding to the inner contour and a second optical center position corresponding to the outer contour, so that the optical center position of the module to be calibrated can be accurately calculated according to the first optical center position and the second optical center position.

[0102] In some of the embodiments, after determining whether the light spot grayscale image includes a ring-shaped light spot, the following steps are further included:

[0103] When the light spot grayscale image does not contain a ring-shaped light spot, determine the imaging center position of the central feature point of the preset target plate in the chip image;

[0104] The imaging center position of the central feature point in the chip image is taken as the optical center position of the module to be calibrated.

[0105] It should be noted that when the field of view angle of the receiving end of the module to be calibrated is less than or equal to the field of view angle threshold, when setting up its calibration environment, the preset standard plate will be fixed directly above the module to be calibrated. Based on this, the grayscale image of the light spot collected does not contain a ring-shaped light spot.

[0106] In addition, if the module with a receiving end field of view angle greater than the field of view angle threshold needs to use the full field of view angle, a preset target plate is set directly above the module to be calibrated. At this time, the spot grayscale image collected based on the target plate directly above does not contain a ring-shaped spot.

[0107] In this embodiment, since the center feature point has been aligned with the module to be calibrated when building the module calibration environment, the imaging center position of the center feature point of the preset target plate in the chip image is calculated, and the imaging center position is the optical center position of the module to be calibrated.

[0108] Through this embodiment, when the light spot grayscale image does not contain a ring-shaped light spot, the imaging center position of the central feature point of the preset target plate in the chip image is determined, and the imaging center position of the central feature point in the chip image is used as the optical center position of the module to be calibrated, so as to accurately obtain the optical center position of the module to be calibrated.

[0109] In some of the embodiments, determining the imaging center position of the central feature point of the preset target plate in the chip image includes the following steps:

[0110] Select the pixel points in the chip image whose pixel brightness value is greater than the brightness threshold;

[0111] The coordinates of the pixel points and the corresponding pixel brightness values ​​are weighted, and the imaging center position of the central feature point in the chip image is determined based on the calculation result.

[0112] Specifically, select pixel points whose pixel brightness value is greater than the brightness threshold from the chip image, perform weighted operation on the coordinates of the pixel points and the corresponding pixel brightness value, and the calculated imaging center coordinates are the coordinates of the optical center position. The specific calculation formula is as follows:

[0113]

[0114]

[0115] Among them, OC X Indicates the X coordinate of the optical center position, OC Y represents the Y coordinate of the optical center; (x, y) represents the coordinates of the pixel; GL (x, y) represents the brightness of the pixel; N x and N y is the number of pixels greater than the brightness threshold, which means there are N x and N y Substitute the coordinates into the above formula for calculation, and N x With N y equal.

[0116] Through this embodiment, pixel points in the chip image whose pixel brightness values ​​are greater than the brightness threshold are selected, the coordinates of the pixel points and the corresponding pixel brightness values ​​are weightedly calculated, and based on the calculation results, the imaging center position of the central feature point in the chip image is determined, so as to accurately obtain the imaging center position of the central feature point.

[0117] In some of the embodiments, determining the emission angle corresponding to each target pixel point in the chip image based on the fitting relationship between the emission angle of each feature point and the corresponding imaging center coordinates includes the following steps:

[0118] Step S261, determining the emission angle of each feature point in the preset target plate according to the field of view angle of the receiving end of the module to be calibrated;

[0119] Step S262, processing the emission angle of each feature point and the corresponding imaging center coordinates through a surface fitting algorithm to obtain a fitting relationship;

[0120] Step S263, inputting the coordinates of each target pixel in the chip image into the fitting equation to obtain the emission angle corresponding to each target pixel.

[0121] Specifically, according to the viewing angle of the receiving end of the module to be calibrated, the emission angle of each feature point in the preset target plate is calculated, where a 90-degree emission angle corresponds to a 180-degree viewing angle. Figure 6 As shown, taking the preset standard plate with 9 rows and 37 columns as an example, the case where the field of view angle of the receiving end of the calibrated module is greater than the field of view angle threshold is explained. Since the horizontal distance between the central feature point and the center of the lens of the module to be calibrated is D1, the spatial coordinates of the central feature point relative to the module are (0, 0, D1).

[0122] For the feature points in each row between the center row of feature points in the preset target plate and the upper edge of the target plate, that is, the first feature points included in the first row to the fourth row from top to bottom, the corresponding emission angle is less than 90 degrees. At this time, the calculation formula of the emission angle θ is as follows:

[0123] θ=90-arctan(Ydis / sqrt(Xdis*Xdis+D1*D1));

[0124] Among them, Xdis represents the physical distance between the above-mentioned first feature point and the central feature point in the X direction; Ydis represents the physical distance between the above-mentioned first feature point and the central feature point in the Y direction.

[0125] For the characteristic points in each row between the center row of characteristic points in the preset target plate and the lower edge of the target plate, that is, the second characteristic points included in the sixth row to the ninth row from top to bottom, the corresponding emission angle is greater than 90 degrees. At this time, the calculation formula of the emission angle θ is as follows:

[0126] θ=90+arctan(Ydis / sqrt(Xdis*Xdis+D1*D1));

[0127] Among them, Xdis represents the physical distance between the above-mentioned first feature point and the central feature point in the X direction; Ydis represents the physical distance between the above-mentioned first feature point and the central feature point in the Y direction; D1 represents the horizontal distance between the central feature point and the center of the lens of the module to be calibrated.

[0128] like Figure 7 As shown, taking the preset target plate with 9 rows and 37 columns as an example, the case where the receiving end field of view of the module to be calibrated is less than or equal to the field of view threshold is explained. Since the closest distance between the central feature point and the end face of the lens of the module to be calibrated is D2, the spatial coordinates of the central feature point relative to the module are (0, 0, D2). At this time, the calculation formula for the emission angle θ of any feature point on the preset target plate that is different from the central feature point is as follows:

[0129] θ=arctan(sqrt(Xdis*Xdis+Ydis*Ydis) / D2);

[0130] Among them, Xdis represents the physical distance between the above-mentioned first feature point and the central feature point in the X direction; Ydis represents the physical distance between the above-mentioned first feature point and the central feature point in the Y direction; D2 represents the shortest distance between the central feature point and the end face of the lens of the module to be calibrated.

[0131] After that, the fitting method between the emission angle of the feature point and its imaging center coordinates is the same in the conventional module and the ultra-wide-angle module. Through the second-order or multi-order surface fitting algorithm, the emission angle of each feature point and the corresponding imaging center coordinates are processed to obtain the fitting relationship. Taking the second-order surface fitting algorithm as an example, the preliminary fitting relationship is θ(x,y)=ax 2 +bxy+cy 2 +dx+ey+f, through nonlinear optimization, the known emission angle θ and its imaging center coordinates (x, y) are iterated and converged, and the coefficients a, b, c, d, e and f are calculated and substituted into the above preliminary fitting relationship to obtain the final fitting relationship between the emission angle and its imaging center coordinates. On this basis, the coordinates of each target pixel in the chip image are input into the fitting relationship to obtain the emission angle corresponding to each target pixel.

[0132] Furthermore, the relevant calculation is performed according to the emission angle and the optical center position corresponding to the target pixel point to obtain the point cloud data of the target pixel point. When the field of view angle of the receiving end of the module to be calibrated is greater than the field of view angle threshold, the calculation formula of the point cloud data of the target pixel point is as follows:

[0133] Pclound Z =tan(θ(x,y))*Radial;

[0134] Ratio=arctan((y-OC Y ),(x-OC X ));

[0135] Pclound Y =sqrt(Radial*Radial-Pclound Z *Pclound Z )*(sin(Ratio));

[0136] Pclound X =sqrt(Radial*Radial-Pclound Z *Pclound Z)*(cos(Ratio));

[0137] Among them, Pclound X 、Pclound Y and Pclound Z Respectively represent the point cloud data of the target pixel in the X-axis, Y-axis and Z-axis directions; (x, y) represents the coordinates of the target pixel; θ(x, y) represents the emission angle corresponding to the target pixel; (OC X ,OC Y ) represents the coordinates of the optical center position; Radial represents the ray distance, that is, the physical distance measured by the module chip; Ratio is a floating point value, which represents the angle between the point cloud direction and the X-axis.

[0138] In addition, when the field of view angle of the receiving end of the module to be calibrated is less than or equal to the field of view angle threshold, the calculation formula of the point cloud data of the target pixel is as follows:

[0139] Pclound Z =cot(θ(x,y))*Radial;

[0140] Ratio=arctan((y-OC Y ),(x-OC X ));

[0141] Pclound Y =sqrt(Radial*Radial-Pclound Z *Pclound Z )*(sin(Ratio));

[0142] Pclound X =sqrt(Radial*Radial-Pclound Z *Pclound Z )*(cos(Ratio));

[0143] Among them, Pclound X 、Pclound Y and Pclound Z Respectively represent the point cloud data of the target pixel in the X-axis, Y-axis and Z-axis directions; (x, y) represents the coordinates of the target pixel; θ(x, y) represents the emission angle corresponding to the target pixel; (OC X ,OC Y ) represents the coordinates of the optical center position; Radial represents the ray distance, that is, the physical distance measured by the module chip; Ratio is a floating point value, which represents the angle between the point cloud direction and the X-axis.

[0144] Through this embodiment, according to the field of view angle of the receiving end of the module to be calibrated, the emission angle of each feature point in the preset target plate is calculated, and the emission angle of each feature point and the corresponding imaging center coordinates are processed by a surface fitting algorithm to obtain a fitting relationship. Then, the coordinates of each target pixel point in the chip image are input into the fitting relationship to obtain the emission angle corresponding to each target pixel point, so as to avoid the internal parameter data such as the focal length and distortion coefficient of the calibration module to realize the corresponding calculation of chip pixels and emission angles.

[0145] The present embodiment is described and illustrated below through preferred embodiments.

[0146] Figure 8 : is a flow chart of the calibration method of the TOF module of the preferred embodiment. Figure 8 As shown, the calibration method of the TOF module includes the following steps:

[0147] Step S810, based on the preset target plate and the module to be calibrated placed in combination, obtaining a related image corresponding to the preset target plate; the related image includes a light spot grayscale image and a chip image in grayscale mode;

[0148] Step S820, determining the imaging center coordinates of each feature point in the preset target plate in the chip image;

[0149] Step S830, determining the emission angle of each feature point in the preset target plate according to the field of view angle of the receiving end of the module to be calibrated;

[0150] Step S840, processing the emission angle of each feature point and the corresponding imaging center coordinates through a surface fitting algorithm to obtain a fitting relationship;

[0151] Step S850, inputting the coordinates of each target pixel in the chip image into the fitting equation to obtain the emission angle corresponding to each target pixel;

[0152] Step S860, determining the optical center position of the module to be calibrated based on the relevant image, and generating point cloud data of the target pixel point according to the emission angle and the optical center position corresponding to the target pixel point.

[0153] Through this embodiment, the preset target plate and the module to be calibrated are combined and placed in a preset manner, and the relevant image corresponding to the preset target plate is obtained, the relevant image includes the spot grayscale image and the chip image, and the imaging center coordinates of each feature point in the preset target plate in the chip image are calculated. The emission angle of each feature point and the corresponding imaging center coordinates are processed by the surface fitting algorithm to obtain a fitting relationship, and the emission angle corresponding to each target pixel point in the chip image is determined according to the fitting relationship, thereby avoiding the calculation of the corresponding relationship between the chip pixel and the emission angle through the internal reference data such as the focal length and distortion coefficient of the calibration module.

[0154] Furthermore, the optical center position of the module to be calibrated is determined according to relevant images, and the point cloud data of the target pixel point can be obtained by calculating the emission angle and the optical center position corresponding to the target pixel point, which solves the problem of being unable to obtain the correspondence between the module pixel coordinates and the emission angle without calibrating the module internal parameter data. It is possible to obtain the correspondence between the module pixel coordinates and the emission angle without calibrating the module internal parameters, so as to output the final point cloud data.

[0155] It should be noted that the steps shown in the above process or the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0156] In this embodiment, a calibration device for a TOF module is also provided, which is used to implement the above-mentioned embodiments and preferred implementation modes, and will not be repeated hereafter. The terms "module", "unit", "subunit", etc. used below can implement a combination of software and / or hardware for a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceivable.

[0157] Fig. 9 : is a structural block diagram of the calibration device of the TOF module of this embodiment, such as Fig. 9 As shown, the device includes: an acquisition module 10, an analysis module 20, a fitting module 30 and a generation module 40;

[0158] The acquisition module 10 is used to acquire the relevant image corresponding to the preset target plate based on the preset target plate and the module to be calibrated placed in combination; the relevant image includes the spot grayscale image and the chip image in the grayscale mode;

[0159] An analysis module 20, used to determine the imaging center coordinates of each feature point in the preset target plate in the chip image;

[0160] A fitting module 30, for determining the emission angle corresponding to each target pixel point in the chip image based on a fitting relationship between the emission angle of each feature point and the corresponding imaging center coordinate;

[0161] The generating module 40 is used to determine the optical center position of the module to be calibrated based on the relevant image, and to generate point cloud data of the target pixel point according to the emission angle and the optical center position corresponding to the target pixel point.

[0162] Through the device provided in this embodiment, based on the preset target plate and the module to be calibrated placed in combination, a related image corresponding to the preset target plate is obtained, and the related image includes a light spot grayscale image and a chip image; the imaging center coordinates of each feature point in the preset target plate in the chip image are determined; further, based on the fitting relationship between the emission angle of each feature point and the corresponding imaging center coordinate, the emission angle corresponding to each target pixel point in the chip image is determined, and the optical center position of the module to be calibrated is determined based on the related image, so that the point cloud data of the target pixel point can be generated according to the emission angle and optical center position corresponding to the target pixel point, which solves the problem that the correspondence between the module pixel coordinates and the emission angle cannot be obtained without calibrating the module internal parameter data, and realizes that the correspondence between the module pixel coordinates and the emission angle can be obtained without calibrating the module internal parameter, so as to output the final point cloud data, while reducing the equipment cost.

[0163] In some of these embodiments, Fig. 9 On the basis of, the device also includes a first judgment module, which is used to judge whether the field of view angle of the receiving end of the module to be calibrated is greater than the field of view angle threshold; when the field of view angle of the receiving end of the module to be calibrated is greater than the field of view angle threshold, the preset mark plate is fixed to the side of the module to be calibrated; wherein the center row of each feature point in the preset mark plate is parallel to the 180-degree field of view angle of the module to be calibrated.

[0164] In some of these embodiments, Fig. 9 On the basis of this, the device also includes a second judgment module, which is used to fix the preset mark plate directly above the module to be calibrated when the field of view angle of the receiving end of the module to be calibrated is less than or equal to the field of view angle threshold; wherein the central feature point of the preset mark plate coincides with the 0 degree field of view angle of the module to be calibrated.

[0165] In some of these embodiments, Fig. 9On the basis of, the device also includes a third judgment module, which is used to judge whether the light spot grayscale image contains a ring-shaped light spot; when the light spot grayscale image contains a ring-shaped light spot, the light spot grayscale image is converted into a corresponding binary contour image; the inner contour and outer contour of the ring-shaped light spot in the binary contour image are determined; through a circle fitting algorithm, the inner contour and outer contour of the ring-shaped light spot are processed respectively to obtain a first optical center position corresponding to the inner contour and a second optical center position corresponding to the outer contour; according to the first optical center position and the second optical center position, the optical center position of the module to be calibrated is determined.

[0166] In some of these embodiments, Fig. 9 On the basis of this, the device also includes a fourth judgment module, which is used to determine the imaging center position of the central feature point of the preset target plate in the chip image when the light spot grayscale image does not contain a ring-shaped light spot; and the imaging center position of the central feature point in the chip image is used as the optical center position of the module to be calibrated.

[0167] In some of these embodiments, Fig. 9 On the basis of, the device also includes a weighted operation module, which is used to select pixel points in the chip image whose pixel brightness values ​​are greater than a brightness threshold; perform weighted operation on the coordinates of the pixel points and the corresponding pixel brightness values, and determine the imaging center position of the central feature point in the chip image based on the operation result.

[0168] In some of these embodiments, Fig. 9 On the basis of this, the device also includes a surface fitting module, which is used to determine the emission angle of each feature point in the preset standard plate according to the field of view angle of the receiving end of the module to be calibrated; through the surface fitting algorithm, the emission angle of each feature point and the corresponding imaging center coordinates are processed to obtain a fitting relationship; the coordinates of each target pixel point in the chip image are input into the fitting relationship to obtain the emission angle corresponding to each target pixel point.

[0169] It should be noted that the above modules can be functional modules or program modules, and can be implemented by software or hardware. For modules implemented by hardware, the above modules can be located in the same processor; or the above modules can be located in different processors in any combination.

[0170] In this embodiment, a computer device is further provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor is configured to run the computer program to execute the steps in any one of the above method embodiments.

[0171] Optionally, the computer device may further include a transmission device and an input / output device, wherein the transmission device is connected to the processor, and the input / output device is connected to the processor.

[0172] It should be noted that the specific examples in this embodiment can refer to the examples described in the above embodiments and optional implementation modes, and will not be repeated in this embodiment.

[0173] In addition, in combination with the calibration method of the TOF module provided in the above embodiments, a storage medium may also be provided in this embodiment to implement the calibration method. The storage medium stores a computer program, and when the computer program is executed by the processor, any calibration method of the TOF module in the above embodiments is implemented.

[0174] It should be understood that the specific embodiments described herein are only used to explain the application, rather than to limit it. Based on the embodiments provided in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of this application.

[0175] Obviously, the drawings are only some examples or embodiments of the present application. For ordinary technicians in the field, the present application can also be applied to other similar situations based on these drawings without creative work. In addition, it is understandable that although the work done in this development process may be complicated and lengthy, for ordinary technicians in the field, certain changes in design, manufacturing or production based on the technical content disclosed in this application are only conventional technical means and should not be regarded as insufficient content disclosed in this application.

[0176] The term "embodiment" in this application refers to a specific feature, structure or characteristic described in conjunction with the embodiment that can be included in at least one embodiment of the present application. The appearance of this phrase in various locations in the specification does not necessarily mean the same embodiment, nor does it mean that it is mutually exclusive with other embodiments and is independent or optional. It is clearly or implicitly understood by those of ordinary skill in the art that the embodiments described in this application can be combined with other embodiments without conflict.

[0177] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of patent protection. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the scope of protection of the present application. Therefore, the scope of protection of the present application shall be subject to the attached claims.

Claims

1. A TOF module calibration method, characterized in that: The method comprises: Based on the preset target plate and the module to be calibrated placed in combination, a related image corresponding to the preset target plate is obtained; the related image includes a light spot grayscale image and a chip image in grayscale mode; Determine the imaging center coordinates of each feature point in the preset target plate in the chip image; Determine the emission angle corresponding to each target pixel point in the chip image based on the fitting relationship between the emission angle of each feature point and the corresponding imaging center coordinate; The optical center position of the module to be calibrated is determined based on the relevant image, and point cloud data of the target pixel point is generated according to the emission angle corresponding to the target pixel point and the optical center position.

2. The calibration method of the TOF module according to claim 1, characterized in that: Before acquiring the relevant image corresponding to the preset target plate based on the combined placement of the preset target plate and the module to be calibrated, the method further includes: Determine whether the receiving end field of view of the module to be calibrated is greater than a field of view angle threshold; When the field of view angle of the receiving end of the module to be calibrated is greater than the field of view angle threshold, the preset mark plate is fixed to the side of the module to be calibrated; wherein the center row of each of the feature points in the preset mark plate is parallel to the 180-degree field of view angle of the module to be calibrated.

3. The calibration method of the TOF module according to claim 2, characterized in that: After determining whether the receiving end viewing angle of the module to be calibrated is greater than the viewing angle threshold, the method further includes: When the receiving end field of view angle of the module to be calibrated is less than or equal to the field of view angle threshold, the preset mark plate is fixed directly above the module to be calibrated; wherein the central feature point of the preset mark plate coincides with the 0 degree field of view angle of the module to be calibrated.

4. The TOF module calibration method according to claim 1, characterized in that: The determining the optical center position of the module to be calibrated based on the relevant image includes: Determining whether the light spot grayscale image includes a ring-shaped light spot; When the light spot grayscale image includes the annular light spot, converting the light spot grayscale image into a corresponding binary contour image; Determine the inner contour and the outer contour of the annular light spot in the binary contour image; The inner contour and the outer contour of the annular light spot are processed respectively by a circle fitting algorithm to obtain a first optical center position corresponding to the inner contour and a second optical center position corresponding to the outer contour; The optical center position of the module to be calibrated is determined according to the first optical center position and the second optical center position.

5. The TOF module calibration method according to claim 4, characterized in that: After determining whether the light spot grayscale image includes a ring-shaped light spot, the method further includes: When the light spot grayscale image does not include the annular light spot, determining the imaging center position of the central feature point of the preset target plate in the chip image; The imaging center position of the central feature point in the chip image is used as the optical center position of the module to be calibrated.

6. The TOF module calibration method according to claim 5, characterized in that: Determining the imaging center position of the central feature point of the preset target plate in the chip image includes: Selecting pixel points in the chip image whose pixel brightness value is greater than a brightness threshold; A weighted operation is performed on the coordinates of the pixel point and the corresponding pixel brightness value, and the imaging center position of the central feature point in the chip image is determined according to the operation result.

7. The TOF module calibration method according to claim 1, characterized in that: The step of determining the emission angle corresponding to each target pixel point in the chip image based on the fitting relationship between the emission angle of each feature point and the corresponding imaging center coordinates includes: Determining the emission angle of each of the feature points in the preset target plate according to the field of view angle of the receiving end of the module to be calibrated; The emission angle of each of the feature points and the corresponding imaging center coordinates are processed by a surface fitting algorithm to obtain the fitting relationship; The coordinates of each target pixel point in the chip image are input into the fitting relationship to obtain the emission angle corresponding to each target pixel point.

8. A calibration device for a TOF module, characterized in that: The device comprises: an acquisition module, an analysis module, a fitting module and a generation module; The acquisition module is used to acquire the relevant image corresponding to the preset target plate based on the preset target plate and the module to be calibrated placed in combination; the relevant image includes the spot grayscale image and the chip image in the grayscale mode; The analysis module is used to determine the imaging center coordinates of each feature point in the preset target plate in the chip image; The fitting module is used to determine the emission angle corresponding to each target pixel point in the chip image based on the fitting relationship between the emission angle of each feature point and the corresponding imaging center coordinate; The generating module is used to determine the optical center position of the module to be calibrated based on the relevant image, and to generate point cloud data of the target pixel point according to the emission angle corresponding to the target pixel point and the optical center position.

9. A computer device comprising a memory and a processor, characterized in that: A computer program is stored in the memory, and the processor is configured to run the computer program to execute the steps of the TOF module calibration method according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the TOF module calibration method described in any one of claims 1 to 7 are implemented.

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