A hyperspectral imaging system and its calibration method and execution method

Abstract

The embodiment of the present invention provides a hyperspectral imaging system and a calibration method and an execution method thereof. The calibration method based on the hyperspectral imaging system is executed by a controller, and the method includes: controlling a time-of-flight camera to obtain the distance between the step of the calibration target and the time-of-flight camera and the intensity data of the step; calculating the height information of the step of the calibration target according to the distance between the step of the calibration target and the time-of-flight camera; adjusting the focus amount of the electric focus lens, calculating the return value of the focus evaluation function according to the focus amount, and obtaining the focus amount when the focus evaluation function obtains the best return value; obtaining the corresponding relationship between the height information and the focus value. The embodiment of the present invention provides a hyperspectral imaging system and a calibration method and an execution method thereof, so as to realize automatic focusing in the measurement phase and reduce the difficulty of using the hyperspectral imaging system.

Description

Technical Field

[0001] The present invention relates to the field of imaging technology, and in particular to a hyperspectral imaging system and a calibration method and an execution method thereof. Background Art

[0002] Hyperspectral imaging technology is a multi-band imaging technology based on spectroscopy. It combines imaging technology with spectroscopy technology to detect the two-dimensional geometric spatial information and one-dimensional spectral information of the target, and obtain continuous, narrow-band image data with high spectral resolution. At present, hyperspectral imaging technology is developing rapidly, and common ones include grating spectroscopy, acousto-optic tunable filter spectroscopy, prism spectroscopy, chip coating, etc. It can be applied in food safety, medical diagnosis, aerospace and other fields.

[0003] At present, the types of hyperspectral cameras on the market are mainly divided into push-broom type and staring type hyperspectral cameras. Push-broom type hyperspectral cameras obtain spectral data of each pixel on a line in space at one time, and the optical system is mainly composed of imaging objective lens, spectroscopic device (such as grating, gradient filter, etc.) and focal plane detector. Due to its high spectral resolution and relatively fast imaging, it is currently the most widely used. Staring type hyperspectral cameras obtain a two-dimensional image of one band at a time, and the optical system is mainly composed of imaging objective lens, adjustable filter and focal plane detector.

[0004] Considering the particularity of hyperspectral cameras that require spatial scanning or spectral scanning to obtain three-dimensional data cubes, the autofocus and autoexposure adjustment methods of traditional two-dimensional cameras are difficult to apply to hyperspectral cameras, especially push-broom hyperspectral cameras, which can only scan one line of images at a time. However, accurate focus and exposure are crucial to the imaging quality, spectral resolution, scanning time and other performance of hyperspectral cameras. In particular, when hyperspectral cameras are used in the field of industrial inspection, on-site operators usually do not have relevant expertise in hyperspectral imaging. Summary of the invention

[0005] The embodiments of the present invention provide a hyperspectral imaging system and a calibration method and an execution method thereof, so as to achieve automatic focusing in the measurement phase and reduce the difficulty of using the hyperspectral imaging system.

[0006] In a first aspect, an embodiment of the present invention provides a calibration method based on a hyperspectral imaging system, which is executed by a controller, and the method includes:

[0007] Controlling the time-of-flight camera to obtain the distance between the step of the calibration target object and the time-of-flight camera and the intensity data of the step;

[0008] Calculating height information of the step of the calibration target object according to the distance between the step of the calibration target object and the time-of-flight camera;

[0009] Adjusting the focus amount of the electric focus lens, calculating the return value of the focus evaluation function according to the focus amount, and obtaining the focus amount when the focus evaluation function obtains the best return value;

[0010] Obtain a correspondence between the height information and the focus value.

[0011] Optionally, the step includes a high reflectivity region and a low reflectivity region;

[0012] After controlling the time-of-flight camera to acquire the distance between the step of the calibration target object and the time-of-flight camera and the intensity data of the step, the method further includes:

[0013] Establishing a relationship between the intensity data and reflectivity for each step;

[0014] Adjusting the exposure time of the hyperspectral camera, when the gray level of the high reflectivity area is a preset gray level, obtaining the gray level of the high reflectivity area and the gray level of the low reflectivity area, and obtaining the relationship between the reflectivity and the exposure time;

[0015] A relationship between the intensity information and the exposure time is obtained.

[0016] Optionally, the preset gray level is 85% to 95% of the maximum gray level.

[0017] Optionally, before controlling the time-of-flight camera to acquire the distance between the step of the calibration target object and the time-of-flight camera and the intensity data of the step, the method further includes:

[0018] The motion mechanism is controlled to move along a first direction, so as to drive the calibration target to pass through an imaging area of ​​the time-of-flight camera.

[0019] Optionally, before adjusting the exposure time of the hyperspectral camera, when the gray level in the high reflectivity area is a preset gray level, obtaining the gray level of the high reflectivity area and the gray level of the low reflectivity area, and obtaining the relationship between the reflectivity and the exposure time, the method further includes:

[0020] The motion mechanism is controlled to move along a first direction, so as to drive the calibration target object to pass through an imaging area of ​​the hyperspectral camera.

[0021] Optionally, the calibration target object is controlled to stay in the imaging area of ​​the hyperspectral camera for a time greater than a preset time.

[0022] In a second aspect, an embodiment of the present invention provides an execution method based on a hyperspectral imaging system, which is executed by a controller, and the method includes:

[0023] Controlling the time-of-flight camera to obtain the distance between the measured sample and the time-of-flight camera and the intensity data of the measured sample;

[0024] Calculating the height information of the sample under test according to the distance between the sample under test and the time-of-flight camera;

[0025] The current focus value of the electric focus lens is acquired according to the height information and the corresponding relationship between the height information and the focus value.

[0026] Optionally, after controlling the time-of-flight camera to acquire the distance between the sample under test and the time-of-flight camera and the intensity data of the sample under test, the method further includes:

[0027] The current exposure time of the hyperspectral camera is obtained according to the intensity information and the relationship between the intensity information and the exposure time.

[0028] In a third aspect, an embodiment of the present invention provides a hyperspectral imaging system, including a hyperspectral camera, an electric focus lens, a time-of-flight camera, and a controller;

[0029] The electric focus lens is mounted on the hyperspectral camera and is used as an imaging objective lens; the hyperspectral camera and the time-of-flight camera are arranged along a first direction;

[0030] The controller is used to execute the method according to any one of claims 1 to 8.

[0031] Optionally, a motion mechanism is further included, and the motion mechanism is used to carry the calibration target or the sample to be measured, and drive the calibration target or the sample to be measured to pass through the imaging areas of the time-of-flight camera and the hyperspectral camera in sequence along the first direction.

[0032] The embodiment of the present invention provides a calibration method for a hyperspectral imaging system, which controls a time-of-flight camera to obtain the distance between the step of the calibration target and the time-of-flight camera and the intensity data of the step. According to the distance between the step of the calibration target and the time-of-flight camera, the height information of the step of the calibration target is calculated. The focus amount of the electric focus lens is adjusted, and the return value of the focus evaluation function is calculated according to the focus amount. When the focus evaluation function obtains the best return value, the focus amount is obtained. The correspondence between the height information and the focus value is obtained. The focus value calibration of the hyperspectral imaging system is completed in the calibration stage, so that automatic focusing is completed in the measurement stage, and the difficulty of using the hyperspectral imaging system is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A schematic diagram of a hyperspectral imaging system provided by an embodiment of the present invention;

[0034] Figure 2 for Figure 1 A top view of the calibration target shown in ;

[0035] Figure 3 A flow chart of a calibration method for a hyperspectral imaging system provided by an embodiment of the present invention;

[0036] Figure 4 A flow chart of another calibration method for a hyperspectral imaging system provided by an embodiment of the present invention;

[0037] Figure 5 A flow chart of another calibration method for a hyperspectral imaging system provided by an embodiment of the present invention;

[0038] Figure 6 for Figure 1 Another schematic diagram of the hyperspectral imaging system shown in FIG.

[0039] Figure 7 for Figure 1 Another schematic diagram of the hyperspectral imaging system shown in FIG.

[0040] Figure 8 A flow chart of an execution method of a hyperspectral imaging system provided by an embodiment of the present invention;

[0041] Fig. 9 A schematic diagram of another hyperspectral imaging system provided by an embodiment of the present invention;

[0042] Fig.10 A flow chart of another execution method of a hyperspectral imaging system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0043] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0044] Figure 1 A schematic diagram of a hyperspectral imaging system provided by an embodiment of the present invention, Figure 2 for Figure 1 A top view of the calibration target shown in , Figure 3 A flow chart of a calibration method for a hyperspectral imaging system provided by an embodiment of the present invention, referring to Figure 1-Figure 3 , the calibration method based on the hyperspectral imaging system consists of a controller ( Figure 1 ), the method comprising:

[0045] S101 , controlling the time-of-flight camera 11 to acquire the distance between the step of the calibration target 16 and the time-of-flight camera 11 and the intensity data of the step.

[0046] A time-of-flight camera is a range imaging camera system that uses time-of-flight technology to resolve the distance between the camera and the object for each point in the image by measuring the round-trip time of artificial light.

[0047] For example, Figure 1 and Figure 2 As shown, the calibration target 16 includes a plurality of steps, at least two of which have different heights. In this step, the distance between each step of the calibration target 16 and the time-of-flight camera 11 is obtained through the time-of-flight camera 11, and the intensity data of each step is obtained.

[0048] Here, the intensity data is a function of reflectivity.

[0049] S102 , calculating height information of the step of the calibration target 16 according to the distance between the step of the calibration target 16 and the time-of-flight camera 11 .

[0050] In this step, based on the above step S101, the height information of each step in the calibration target 16 is obtained by calculation. That is, the distance between the step of the calibration target 16 and the time-of-flight camera 11 is converted into the distance between each step and the working surface (the surface of the step away from the time-of-flight camera 11 is located on the working surface).

[0051] The height of the step refers to the distance between the surface of the step away from the time-of-flight camera 11 and the surface of the step close to the time-of-flight camera 11 .

[0052] S103, adjusting the focus amount of the electric focus lens 13, calculating the return value of the focus evaluation function according to the focus amount, and obtaining the focus amount when the focus evaluation function obtains the best return value.

[0053] In this step, when the scanning line of the hyperspectral camera 12 is aligned with a certain step of the calibration target 16, the focusing amount of the electric focus lens 13 is adjusted, the return value of the focus evaluation function is calculated, and the focusing amount of the electric focus lens 13 is continuously adjusted by feedback until the focus evaluation function obtains the best return value, and the focusing amount of the electric focus lens 13 at this time is recorded.

[0054] S104: Obtain the corresponding relationship between the height information and the focus value.

[0055] The embodiment of the present invention provides a calibration method for a hyperspectral imaging system, which controls a time-of-flight camera 11 to obtain the distance between the step of the calibration target 16 and the time-of-flight camera 11 and the intensity data of the step. According to the distance between the step of the calibration target 16 and the time-of-flight camera 11, the height information of the step of the calibration target 16 is calculated. The focus amount of the electric focus lens 13 is adjusted, and the return value of the focus evaluation function is calculated according to the focus amount. When the focus evaluation function obtains the best return value, the focus amount is obtained. The correspondence between the height information and the focus value is obtained. In this way, the focus value calibration of the hyperspectral imaging system is completed in the calibration stage, so that automatic focusing is completed in the measurement stage, and the difficulty of using the hyperspectral imaging system is reduced.

[0056] Figure 4 Another method for calibrating a hyperspectral imaging system provided by the present invention is shown in FIG. Figure 1 , Figure 2 and Figure 4 , the method comprising:

[0057] S201 , controlling the time-of-flight camera 11 to obtain the distance between the step of the calibration target 16 and the time-of-flight camera 11 and the intensity data of the step.

[0058] S202 , calculating height information of the step of the calibration target object 16 according to the distance between the step of the calibration target object 16 and the time-of-flight camera 11 .

[0059] S203: Establish a relationship between intensity data and reflectivity for each step.

[0060] refer to Figure 2 , wherein the step includes a high reflectivity region 21 and a low reflectivity region 22. The reflectivity of the high reflectivity region 21 is greater than the reflectivity of the low reflectivity region 22.

[0061] S204, adjusting the focus amount of the electric focus lens 13, calculating the return value of the focus evaluation function according to the focus amount, and obtaining the focus amount when the focus evaluation function obtains the best return value.

[0062] S205, adjusting the exposure time of the hyperspectral camera 12, and when the gray level of the high reflectivity region 21 is a preset gray level, obtaining the gray level of the high reflectivity region 21 and the gray level of the low reflectivity region 22, and obtaining the relationship between the reflectivity and the exposure time.

[0063] In this step, the exposure time of the hyperspectral camera 12 is adjusted so that when the grayscale of the high reflectivity area 21 of the current step is the preset grayscale, the grayscale of the high reflectivity area 21 and the grayscale of the low reflectivity area 22 are recorded, and the relationship between the reflectivity and the exposure time of the hyperspectral camera is calculated and recorded.

[0064] Optionally, the preset gray level is 85% to 95% of the maximum gray level. For example, the preset gray level is 90% of the maximum gray level.

[0065] S206: Obtain the correspondence between the height information and the focus value.

[0066] S207: Obtain the relationship between intensity information and exposure time.

[0067] In an embodiment of the present invention, on the basis of the above embodiment, a relationship between intensity data and reflectivity is established for each step. The exposure time of the hyperspectral camera 12 is adjusted, and when the grayscale of the high reflectivity region 21 is a preset grayscale, the grayscale of the high reflectivity region 21 and the grayscale of the low reflectivity region 22 are obtained, and the relationship between the reflectivity and the exposure time is obtained. The relationship between the intensity information and the exposure time is obtained. In order to realize the focus value calibration and exposure time calibration of the hyperspectral imaging system in the calibration stage, to realize the adjustment of autofocus and autoexposure in the measurement stage, and to reduce the difficulty of using the hyperspectral imaging system. It should be noted that the above steps S203, S205 and S207 only need to be located after step S201. The embodiment of the present invention does not limit the specific position of the above steps S203, S205 and S207 after step S201. For example, in one embodiment, the above step S207 can also be located before the above step S206.

[0068] In one embodiment, auto focus and auto exposure can also be adjusted simultaneously, that is, at least one of the following three conditions is satisfied: the above steps S206 and S207 can be executed simultaneously in the same step, the above steps S204 and S205 can be executed simultaneously in the same step, and the above steps S202 and S203 can be executed simultaneously in the same step.

[0069] In one embodiment, the hyperspectral camera 12 is a staring hyperspectral camera, which measures the intensity data of each step according to different wavelengths without calibrating the movement of the target object 16 .

[0070] In another embodiment, the hyperspectral camera 12 is a line scan hyperspectral camera. In this case, the calibration target 16 needs to move to measure the intensity data of each step.

[0071] Figure 5 A flow chart of another calibration method for a hyperspectral imaging system provided by an embodiment of the present invention, Figure 6 for Figure 1 Another state diagram of the hyperspectral imaging system shown in FIG. Figure 7 for Figure 1 Another schematic diagram of the hyperspectral imaging system shown in , refer to Figure 1 , Figure 2 ,as well as Figure 5-Figure 7 , the method comprising:

[0072] S301 , controlling the motion mechanism 15 to move along a first direction, so as to drive the calibration target 16 to pass through the imaging area of ​​the time-of-flight camera 11 .

[0073] refer to Figure 1 , control the motion mechanism 15 to move along the first direction, driving the calibration target 16 to move along the first direction until Figure 6 As shown, the calibration target 16 is located in the imaging area of ​​the time-of-flight camera 11 , and the time-of-flight camera 11 can image one or more steps in the calibration target 16 .

[0074] S302 , controlling the time-of-flight camera 11 to obtain the distance between the step of the calibration target 16 and the time-of-flight camera 11 and the intensity data of the step.

[0075] S303 , calculating height information of the step of the calibration target object 16 according to the distance between the step of the calibration target object 16 and the time-of-flight camera 11 .

[0076] S304: Establish a relationship between intensity data and reflectivity for each step.

[0077] S305 , controlling the motion mechanism 15 to move along the first direction, so as to drive the calibration target 16 to pass through the imaging area of ​​the hyperspectral camera 12 .

[0078] refer to Figure 6 , control the motion mechanism 15 to move along the first direction, driving the calibration target 16 to move along the first direction until Figure 7 As shown, the calibration target 16 is located in the imaging area of ​​the hyperspectral camera 12 , and the hyperspectral camera 12 can image one or more steps in the calibration target 16 .

[0079] Exemplarily, the motion mechanism 15 drives the calibration target 16 to pass through the scanning line of the hyperspectral camera 12, and uses the data of the time-of-flight camera 11 to make each step of the calibration target 16 stay on the scanning line of the hyperspectral camera 12 for more than a preset time, so as to perform subsequent focus calibration and exposure calibration.

[0080] S306 , adjusting the focus amount of the electric focus lens 13 , calculating the return value of the focus evaluation function according to the focus amount, and obtaining the focus amount when the focus evaluation function obtains the best return value.

[0081] S307, adjusting the exposure time of the hyperspectral camera 12, and when the grayscale of the high reflectivity region 21 is the preset grayscale, obtaining the grayscale of the high reflectivity region 21 and the grayscale of the low reflectivity region 22, and obtaining the relationship between the reflectivity and the exposure time.

[0082] S308: Obtain the correspondence between the height information and the focus value.

[0083] S309: Obtain the relationship between intensity information and exposure time.

[0084] In this step, the relationship between the intensity information returned by the time-of-flight camera 11 and the exposure time of the hyperspectral camera 12 at each altitude is calculated.

[0085] In the embodiment of the present invention, the motion mechanism 15 is controlled to move along the first direction, driving the calibration target 16 to sequentially pass through the imaging area of ​​the time-of-flight camera 11 and the imaging area of ​​the hyperspectral camera 12. This allows the hyperspectral imaging system to be calibrated for focus value and exposure time during the calibration phase, and to be adjusted for autofocus and autoexposure during the measurement phase, thereby reducing the difficulty of using the hyperspectral imaging system.

[0086] Based on the concept of simultaneously using the time-of-flight camera 11 and the hyperspectral camera 12 , an embodiment of the present invention further provides an execution method of a hyperspectral imaging system. Figure 8 A flowchart of an execution method of a hyperspectral imaging system provided by an embodiment of the present invention is provided. Fig. 9 A schematic diagram of another hyperspectral imaging system provided by an embodiment of the present invention, referring to Figure 8 and Fig. 9 , the execution method based on the hyperspectral imaging system is composed of a controller ( Fig. 9 ), the method comprising:

[0087] S401 , controlling the time-of-flight camera 11 to obtain the distance between the measured sample 17 and the time-of-flight camera and the intensity data of the measured sample 17 .

[0088] In this step, the distance between the measured sample 17 and the time-of-flight camera 11 and the intensity data of the measured sample 17 are obtained through the time-of-flight camera 11 .

[0089] S402 , calculating height information of the sample 17 to be tested according to the distance between the sample 17 to be tested and the time-of-flight camera 11 .

[0090] In this step, based on the above step S401, the height information of the sample 17 is obtained by calculation. That is, the distance between the step of the sample 17 and the time-of-flight camera 11 is converted into the distance from the sample 17 to the working surface (the surface of the sample 17 away from the time-of-flight camera 11 is located on the working surface).

[0091] S403 , acquiring the current focus value of the electric focus lens 13 according to the height information and the corresponding relationship between the height information and the focus value.

[0092] In this step, the focus value that needs to be set for the electric focus lens 13 is calculated through the result of the calibration stage.

[0093] The embodiment of the present invention provides an execution method of a hyperspectral imaging system. The time-of-flight camera 11 is controlled to obtain the distance between the measured sample 17 and the time-of-flight camera and the intensity data of the measured sample 17. According to the distance between the measured sample 17 and the time-of-flight camera 11, the height information of the measured sample 17 is calculated. According to the height information and the correspondence between the height information and the focus value, the current focus value of the electric focus lens 13 is obtained. When the measured sample 17 is scanned and imaged by the hyperspectral camera 12, the best focus image can be obtained. This can achieve automatic focusing in the measurement stage and reduce the difficulty of using the hyperspectral imaging system.

[0094] Fig.10 Another method flow chart of executing a hyperspectral imaging system provided by an embodiment of the present invention is shown in FIG. Fig. 9 and Fig.10 , the method comprising:

[0095] S501 , controlling the time-of-flight camera 11 to obtain the distance between the measured sample 17 and the time-of-flight camera and the intensity data of the measured sample 17 .

[0096] S502 , calculating height information of the sample 17 to be tested according to the distance between the sample 17 to be tested and the time-of-flight camera 11 .

[0097] S503 . Obtain the current focus value of the electric focus lens 13 according to the height information and the corresponding relationship between the height information and the focus value.

[0098] S504 : Acquire the current exposure time of the hyperspectral camera 12 according to the intensity information and the relationship between the intensity information and the exposure time.

[0099] In this step, the exposure time required to be set for the hyperspectral camera 12 is obtained by calculating the result of the calibration stage.

[0100] In the embodiment of the present invention, based on the above embodiment, the current exposure time of the hyperspectral camera 12 is obtained according to the intensity information and the relationship between the intensity information and the exposure time. When the sample 17 to be measured is scanned and imaged by the hyperspectral camera 12, an image with the best focus and exposure can be obtained. This enables automatic focus and automatic exposure to be completed during the measurement phase, reducing the difficulty of using the hyperspectral imaging system.

[0101] Based on the same inventive concept, the embodiment of the present invention further provides a hyperspectral imaging system, referring to Figure 1 and Fig. 9, the hyperspectral imaging system includes a hyperspectral camera 12, an electric focusing lens 13, a time-of-flight camera 11 and a controller. The electric focusing lens 13 is installed on the hyperspectral camera 12, and the electric focusing lens 13 is used as an imaging objective lens. The hyperspectral camera 12 and the time-of-flight camera 11 are arranged along a first direction. The controller is used to execute the calibration method in the above embodiment, and the execution method in the above embodiment. 2. Compared with the reflector rotating device and other mechanisms used in the existing hyperspectral camera automatic focusing scheme, the hyperspectral imaging system of the present invention does not have any motion mechanism inside, thereby improving the stability and service life of the hyperspectral imaging system.

[0102] In one embodiment, the hyperspectral camera 12 is a staring hyperspectral camera, which measures the intensity data of each step according to different wavelengths without calibrating the movement of the target object 16 .

[0103] In another embodiment, the hyperspectral camera 12 is a line scan hyperspectral camera. In this case, the hyperspectral imaging system further includes a motion mechanism 15, which is used to carry a calibration target 16 or a sample 17, and drive the calibration target 16 or the sample 17 to pass through the imaging areas of the time-of-flight camera 11 and the hyperspectral camera 12 in sequence along a first direction.

[0104] Exemplarily, the pixel resolution of the time-of-flight camera 11 is 640×480 pixels, and the distance measurement accuracy is about 1 cm.

[0105] Exemplarily, the calibration target 16 has a stepped structure, that is, the heights of the steps in the calibration target 16 increase or decrease sequentially. Figure 1 As shown, taking four steps as an example, the four steps are respectively recorded as the first step 161, the second step 162, the third step 163 and the fourth step 164, and the heights of the first step 161, the second step 162, the third step 163 and the fourth step 164 increase in sequence. In other embodiments, the height changes of each step in the calibration target 16 may not change gradually. For example, the height of the second step 162 is greater than the height of the first step 161, and the height of the second step 162 is greater than the height of the third step 163.

[0106] Exemplarily, the hyperspectral imaging system further includes a light source 14, which is used to provide an illumination beam for a calibration target 16 or a sample 17. The light source 14 may be a halogen lamp light source or a wide-spectrum LED light source.

[0107] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, combinations and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A calibration method based on a hyperspectral imaging system, characterized in that: Executed by a controller, the method includes: Controlling the time-of-flight camera to obtain the distance between the step of the calibration target object and the time-of-flight camera and the intensity data of the step; Calculating height information of the step of the calibration target object according to the distance between the step of the calibration target object and the time-of-flight camera; Adjusting the focus amount of the electric focus lens, calculating the return value of the focus evaluation function according to the focus amount, and obtaining the focus amount when the focus evaluation function obtains the best return value; Acquire the corresponding relationship between the height information and the focusing amount; The step includes a high reflectivity region and a low reflectivity region; After controlling the time-of-flight camera to acquire the distance between the step of the calibration target object and the time-of-flight camera and the intensity data of the step, the method further includes: Establishing a relationship between the intensity data and reflectivity for each step; Adjusting the exposure time of the hyperspectral camera, when the gray level of the high reflectivity area is a preset gray level, obtaining the gray level of the high reflectivity area and the gray level of the low reflectivity area, and obtaining the relationship between the reflectivity and the exposure time; The relationship between the intensity information and the exposure time is obtained.

2. The method according to claim 1, characterized in that The preset gray level is 85% to 95% of the maximum gray level.

3. The method according to claim 1, characterized in that Before controlling the time-of-flight camera to acquire the distance between the step of the calibration target object and the time-of-flight camera and the intensity data of the step, the method further includes: The motion mechanism is controlled to move along a first direction, so as to drive the calibration target to pass through an imaging area of ​​the time-of-flight camera.

4. The method according to claim 1, characterized in that: Before adjusting the exposure time of the hyperspectral camera, when the gray level in the high reflectivity area is a preset gray level, obtaining the gray level of the high reflectivity area and the gray level of the low reflectivity area, and obtaining the relationship between the reflectivity and the exposure time, the method further includes: The motion mechanism is controlled to move along a first direction, so as to drive the calibration target object to pass through an imaging area of ​​the hyperspectral camera.

5. The method according to claim 4, characterized in that The time for which the calibration target object stays in the imaging area of ​​the hyperspectral camera is controlled to be greater than a preset time.

6. An execution method based on a hyperspectral imaging system, characterized in that: Executed by a controller, the method includes: Controlling the time-of-flight camera to obtain the distance between the measured sample and the time-of-flight camera and the intensity data of the measured sample; Calculating the height information of the sample under test according to the distance between the sample under test and the time-of-flight camera; According to the height information and the correspondence between the height information and the focusing amount obtained by the calibration method based on the hyperspectral imaging system according to claim 1, the current focusing amount of the electric focusing lens is obtained.

7. The method according to claim 6, characterized in that After controlling the time-of-flight camera to acquire the distance between the measured sample and the time-of-flight camera and the intensity data of the measured sample, the method further includes: The current exposure time of the hyperspectral camera is obtained according to the intensity information and the relationship between the intensity information and the exposure time obtained by the calibration method based on the hyperspectral imaging system according to claim 1.

8. A hyperspectral imaging system, characterized in that: Includes a hyperspectral camera, motorized focus lens, time-of-flight camera, and controller; The electric focus lens is mounted on the hyperspectral camera and is used as an imaging objective lens; the hyperspectral camera and the time-of-flight camera are arranged along a first direction; The controller is used to execute the method according to any one of claims 1 to 7.

9. The system according to claim 8, characterized in that It also includes a motion mechanism, which is used to carry the calibration target or the sample to be measured, and drive the calibration target or the sample to be measured to pass through the imaging areas of the time-of-flight camera and the hyperspectral camera in sequence along the first direction.

Images