Calibration sheet for full-automatic focusing and focusing method thereof

Abstract

The invention discloses a calibration sheet for full-automatic focusing, which comprises a light shielding layer, a glass layer and a fluorescent layer, the light shielding layer, the glass layer and the fluorescent layer are sequentially arranged up and down, calibration patterns are engraved on the light shielding layer, the calibration patterns are line diagrams formed by removing part of the light shielding layer, and the calibration patterns comprise a position calibration diagram, a malformation measurement diagram and a resolution measurement diagram; the invention further discloses a focusing method of the calibration piece for full-automatic focusing, which comprises the following steps: 1, position calibration: preliminarily positioning the position of the center point of the platform, re-positioning the position of the center point of the platform, and finally calibrating the position of the center point of the platform; 2, correcting distortion; and 3, measuring the resolution ratio. The calibration piece has the advantages that the calibration piece is simple in structure, easy to manufacture and low in production cost, a position calibration graph, a malformation measurement graph and a resolution measurement graph are integrated, rapid focusing of a camera of a measurement imaging system can be achieved, the focusing speed is high, and the focusing precision is high; the focusing method is simple in operation mode and process.

Description

Technical Field

[0001] The present invention relates to the field of imaging technology, and particularly to a calibration sheet for full-automatic focusing and a focusing method thereof. Background Art

[0002] A measurement imaging system is an analytical instrument used in the field of physics for imaging analysis of products. By taking pictures of samples with a camera, high-definition imaging analysis can be achieved. Before using the measurement imaging system, it is necessary to focus the camera on its calibration platform to ensure imaging quality and measurement effect. For example, in the fields of biology and medicine, sometimes it is necessary to perform imaging detection on some sample cells to achieve detection and analysis of the cells.

[0003] Before detecting the sample, it is necessary to first focus the measurement imaging system, that is, focus the camera on its calibration platform, to ensure clear imaging and high imaging quality when the measurement imaging system takes pictures of the sample. The existing focusing methods for measurement imaging systems are generally phase detection focusing, contrast detection focusing, or a hybrid focusing mode that combines the two. However, phase detection focusing has poor effects in a dark environment and cannot evaluate the accuracy and precision of focusing; contrast detection focusing has a relatively slow focusing speed and a long focusing time, which is not conducive to rapid imaging detection of samples. At the same time, the costs of both phase detection focusing and contrast detection focusing are relatively high.

[0004] Although calibration sheets are commonly used tools for calibrating the camera lenses of measurement imaging systems, in the prior art, most calibration sheets have a single function. When calibrating different parameters, calibration sheets with different functions often need to be used, so it may be necessary to frequently replace the calibration sheets, which is complicated to operate and has low calibration efficiency. Summary of the Invention

[0005] The purpose of the present invention is to provide a calibration sheet for full-automatic focusing and a focusing method thereof to make up for the deficiencies in the prior art and solve the problems raised in the background art.

[0006] To achieve the above purpose, the present invention provides the following technical solution: A calibration sheet for full-automatic focusing includes a light-shielding layer, a glass layer, and a fluorescent layer. The light-shielding layer is disposed above the glass layer, and the fluorescent layer is disposed below the glass layer. A calibration pattern is engraved on the light-shielding layer. The calibration pattern is a line pattern formed by removing a part of the light-shielding layer, and the calibration pattern includes a position calibration pattern, a distortion measurement pattern, and a resolution measurement pattern.

[0007] Further preferably, the position calibration pattern is a circular pattern with a cross-shaped line in the middle and countless straight lines arranged at equal angles around 360°. The cross point can be accurately found through the cross-shaped line in the middle, and thus the calibration of the camera focus position can be achieved.

[0008] Further preferably, the deformity measurement diagram is a pattern composed of three 田-shaped cross-line diagrams of different sizes, and the three 田-shaped cross-line diagrams are arranged in order from small to large along the same straight line. The 田-shaped cross-line diagrams of different sizes can be used to detect whether there is bending deformation in the captured image, thereby achieving distortion correction.

[0009] Further preferably, the resolution measurement diagram is a rectangular pattern composed of a plurality of lines arranged horizontally and vertically and shrinking inwards, and a plurality of numbers are provided on the sides of each line group, so as to measure the minimum resolvable size of lines or patterns in the image and evaluate the resolution.

[0010] Further preferably, each of the line groups includes six groups of horizontal lines and six groups of vertical lines, each group of the horizontal lines corresponds to a group of vertical lines, each group of the horizontal lines and the corresponding vertical lines have a corresponding number on their sides, and the number corresponding to each group of the horizontal lines increases as the horizontal lines decrease. The resolution is determined by the change in the size of the horizontal lines.

[0011] Further preferably, the resolution measurement diagram has six line groups, and the six line groups are arranged in a rectangular structure pattern, representing six groups of different resolution ranges.

[0012] More preferably, the thickness of the light shielding layer is 0.1 mm, the thickness of the glass layer is 2 mm, and the thickness of the fluorescent layer is 0.1 mm.

[0013] Further preferably, the position calibration map, the resolution measurement map and the deformity measurement map are arranged sequentially along the same straight line.

[0014] The present invention also provides a focusing method for a calibration sheet for full-automatic focusing, based on the calibration sheet for full-automatic focusing, comprising the following steps:

[0015] Step 1: Place the calibration sheet on the measuring platform of the measuring imaging system;

[0016] Step 2: Calibrate the center point of the calibration platform. The calibration platform of the measuring imaging system uses a camera to capture the position calibration diagram of the calibration piece, analyze the captured image, calculate the center point position, and then move the calibration platform X-axis and Y-axis to the calculated center point position to achieve center point position calibration of the calibration platform.

[0017] Step 3: Distortion correction: After the system completes position calibration, the camera automatically moves to the top of the deformity measurement diagram of the calibration piece and shoots the deformity measurement diagram until the image is clear. The system automatically identifies whether the lines in the image are deformed. If they are bent or deformed, the system automatically calculates the pixels that need to be offset and saves the recognition results.

[0018] Step 4: Resolution measurement. After saving the results of distortion correction, the camera automatically moves above the resolution measurement chart of the calibration sheet and takes pictures of the resolution measurement chart until the captured image is clear. The system automatically calculates the resolution and saves the resolution results.

[0019] Further preferably, the calibration of the platform center point position in step 2 includes preliminary positioning of the platform center point position, repositioning of the platform center point position, and final calibration of the platform center point position. The specific steps are as follows:

[0020] 1. Preliminary positioning of the platform center point position: Calibrate the position of the camera lens through the calibration sheet. The camera takes pictures of the calibration chart for preliminary positioning, analyzes the captured image, calculates the center point position, and then moves the calibration platform along the X-axis and Y-axis to the calculated center point position.

[0021] 2. Repositioning of the platform center point position: The camera takes pictures of the calibration chart again, analyzes the captured image, further calculates the center point position, and then moves the calibration platform along the X-axis and Y-axis to the calculated new center point position.

[0022] 3. Final calibration of the platform center point position: The camera takes pictures of the calibration chart and checks whether the center point of the calibration platform is located at the center point of the calibration sheet. If it is, the system automatically saves and completes the calibration of the platform center point position; if not, repeat steps 1-3.

[0023] Beneficial effects: The calibration sheet for full-automatic focusing of the present invention has a simple structure, is easy to manufacture, and has a low production cost. It integrates a position calibration chart, a distortion measurement chart, and a resolution measurement chart. By using position calibration, focus point calibration, image distortion correction, and image resolution measurement, it can achieve rapid focusing of the camera on the calibration platform of the measurement imaging system, with a fast focusing speed and high focusing accuracy; the calibration function of the calibration sheet is comprehensive. When calibrating the measurement imaging system, there is no need to frequently replace the calibration sheet, the operation is simple, and the calibration efficiency is high.

[0024] The focusing method of the calibration sheet for full-automatic focusing has a simple operation method and process. It can be used for automatic focusing of the measurement imaging system or for manual operation of the measurement imaging system by humans, and can achieve rapid focusing of the camera. It can optimize and adjust the measurement imaging system, improve the resolution and imaging quality of the measurement imaging system, and ensure the clarity of subsequent imaging.

[0025] The calibration sheet for full-automatic focusing and its focusing method can be applied to a medical imaging system. Through this calibration sheet and its focusing method, the imaging quality of the sample on the glass slide can be guaranteed, and the sample detection result can be improved. Description of the Drawings

[0026] Figure 1Schematic diagram of the structural lines of the calibration sheet for full-automatic focusing disclosed in the embodiments of the present invention;

[0027] Figure 2 Schematic diagram of the structure of the position calibration map disclosed in the embodiments of the present invention;

[0028] Figure 3 Schematic diagram of the structure of the deformity measurement map disclosed in the embodiments of the present invention;

[0029] Figure 4 Schematic diagram of the structure of the resolution measurement map disclosed in the embodiments of the present invention;

[0030] Figure 5 Schematic diagram of the image screen taken when initially positioning the center point of the platform in step two of the focusing method of the calibration sheet for full-automatic focusing disclosed in the embodiments of the present invention;

[0031] Figure 6 Schematic diagram of the image screen taken when re-positioning the center point of the platform in step two of the focusing method of the calibration sheet for full-automatic focusing disclosed in the embodiments of the present invention;

[0032] Figure 7 Schematic diagram of the image screen taken when finally calibrating the center point position of the platform in step two of the focusing method of the calibration sheet for full-automatic focusing disclosed in the embodiments of the present invention;

[0033] Figure 8 Schematic diagram of the image screen taken when performing distortion correction in step three of the focusing method of the calibration sheet for full-automatic focusing disclosed in the embodiments of the present invention;

[0034] Figure 9 Schematic diagram of the image screen taken when measuring the resolution in step four of the focusing method of the calibration sheet for full-automatic focusing disclosed in the embodiments of the present invention;

[0035] Figure 10 Schematic diagram of the size structure of the calibration sheet and the corresponding glass slide in actual application disclosed in the embodiments of the present invention.

[0036] Reference numerals: 1 - light-shielding layer, 11 - position calibration map, 12 - deformity measurement map, 13 - resolution measurement map, 2 - glass layer, 3 - fluorescent layer. Detailed implementation manners

[0037] The following are specific embodiments of the present invention and, in conjunction with the accompanying drawings, further describe the technical solutions of the present invention, but the present invention is not limited to these embodiments.

[0038] Such as Figure 1-4As shown in the figure, a calibration film for full-automatic focusing is used to calibrate the position of the camera's focus point, correct distortion, and measure the resolution of the calibration platform of the imaging system, ensuring the accurate position of the center points of the X-axis and Y-axis of the calibration platform - that is, the accurate focus point of the camera, no distortion in the camera's shooting image, and clear imaging of the camera, so as to optimize and adjust the measurement imaging system and improve its forming quality. The calibration film includes a light-shielding layer 1, a glass layer 2, and a fluorescent layer 3. The light-shielding layer 1 is arranged above the glass layer 2, and the fluorescent layer 3 is arranged below the glass layer 2. A calibration pattern is engraved on the light-shielding layer 1, and the calibration pattern is a line pattern formed by removing part of the light-shielding layer 1. Among them, the fluorescent layer 3 is used to emit fluorescence, which can be captured by the camera through the calibration pattern of the light-shielding layer 1, and then the calibration of the calibration platform of the measurement imaging system is realized through the captured image; the light-shielding layer 1 is used to block part of the fluorescence emitted by the fluorescent layer 3, and only allows part of the fluorescence to be emitted through the calibration pattern; the calibration pattern is used for automatic focusing of the camera on the calibration platform, realizing camera position calibration, focus point position calibration, image distortion correction, and image resolution measurement, and improving the resolution and imaging quality of the measurement imaging system. The calibration pattern includes a position calibration diagram 11, a distortion measurement diagram 12, and a resolution measurement diagram 13. Among them, the position calibration diagram 11 is used for position calibration to ensure the accurate position of the camera and the focus point; the distortion measurement diagram 12 can detect whether there is distortion in the image captured by the camera. If so, it can automatically offset the corresponding pixel positions during shooting to ensure that the captured image is distortion-free; the resolution of the camera can be automatically adjusted through the resolution measurement diagram 13 to ensure that the camera is in the best resolution state.

[0039] Through this calibration film, rapid focusing of the camera on the calibration platform of the measurement imaging system can be achieved. Moreover, the focusing of this calibration film is not affected by the environment, can achieve focusing in a dark environment, and has high focusing accuracy. Through this calibration film, the calibration accuracy can be effectively improved. At the same time, the structure of the calibration film is simple, easy to manufacture, and has low production costs.

[0040] In the solution of this application, the position calibration diagram 11 is a circular pattern with a cross-shaped line in the middle and countless equally angled lines arranged 360° around it. Through countless circular patterns intersecting at one point, it can be judged whether the focus point of the camera is at the same position as the intersection of the X-axis and Y-axis of the calibration platform of the measurement imaging system. By shooting the position calibration diagram 11 several times, calculating according to the lines on the position calibration diagram 11 and finding the center point of the position calibration diagram 11, and moving the intersection of the X-axis and Y-axis of the calibration platform to this position, the calibration of the camera position and focus point can be achieved.

[0041] In the solution of this application, the deformation measurement diagram 12 is a pattern composed of three cross-shaped diagrams of different sizes in the shape of a Chinese character 'tian' (field), and the three cross-shaped diagrams in the shape of a Chinese character 'tian' are arranged in ascending order along the same straight line. Each cross-shaped diagram in the shape of a Chinese character 'tian' contains multiple horizontal and vertical lines that intersect perpendicularly. By taking pictures of the three cross-shaped diagrams in the shape of a Chinese character 'tian' in the deformation measurement diagram 12 with a camera, and identifying whether the horizontal and vertical lines in the three cross-shaped diagrams in the shape of a Chinese character 'tian' are bent or deformed to determine whether the captured image is distorted. If there is bending or deformation, the measurement imaging system will automatically calculate the number of pixel points that need to be offset; then, in the subsequent actual imaging process, the system will automatically offset the corresponding pixel positions for the captured image to ensure that the captured image is not distorted, and complete the automatic distortion correction.

[0042] In the solution of this application, the resolution measurement diagram 13 is a rectangular pattern composed of several horizontal and vertical lines that continuously shrink inward. The resolution of the camera on the calibration platform of the measurement imaging system is judged by line groups of different sizes arranged horizontally and vertically. According to the clarity of the corresponding line groups in the resolution measurement diagram 13 captured by the camera, its resolution is determined, and then the system saves the resolution result, so that the subsequent actual imaging can use the determined resolution as the resolution of the captured image to ensure imaging clarity and the imaging quality of the measurement imaging system. By viewing the image of the resolution measurement diagram 13 obtained by shooting, observing the clarity of the lines or patterns, if the edges of the lines or patterns are clear and the details are distinct, it indicates that the resolution of the imaging system is high; on the contrary, if the edges of the lines or images are blurred and the details are lost, it indicates that the resolution of the imaging system is low. A number of digits are correspondingly provided on the side of each line group for distinguishing the resolutions corresponding to the horizontal and vertical lines of different sizes within the line group. The larger the digit, the higher the resolution.

[0043] Based on the above solution, each line group contains six groups of horizontal lines and six groups of vertical lines, and each group of horizontal lines corresponds to a group of vertical lines. Through the structural setting of the horizontal and vertical lines, the pseudo-resolution can be effectively reduced, and the resolution of the measurement imaging system is determined by the largest indistinguishable horizontal and vertical lines. A digit is correspondingly provided on the side of each group of horizontal lines and the corresponding vertical lines. The digit corresponding to each group of horizontal lines increases as the horizontal lines shrink, that is, the resolutions corresponding to the group of horizontal lines and vertical lines are indicated by the horizontal and vertical lines of different sizes and the corresponding digits, and the resolution represented by the group of horizontal lines and vertical lines can be directly found through the resolution comparison table. By taking pictures of the image of the resolution measurement diagram 13 with a camera to find the resolution limit of the system to locate the highest-frequency elements, where the horizontal or vertical lines are not blurred.

[0044] Based on the above solution, the resolution measurement chart 13 has six line groups, and the six line groups are arranged in a rectangular structure pattern. That is, the resolution of the resolution measurement chart 13 can represent six different resolution ranges. Through the six line groups, the resolution of the measurement imaging system can be better confirmed. The camera of the calibration platform of the measurement imaging system is adjusted to the highest resolution. And high resolution means that the system can capture more details and provide a clearer image, which is crucial for the performance and application of the imaging system.

[0045] In the solution of this application, the thickness of the light-shielding layer 1 is 0.1 mm, the thickness of the glass layer 2 is 2 mm, and the thickness of the fluorescent layer 3 is 0.1 mm. Using the glass layer 2 as the intermediate layer not only has good light transmittance but also has a small thermal expansion coefficient, and the influence of temperature change is almost zero. The 0.1 mm thick light-shielding layer 1 can effectively ensure its light-shielding effect, and the 0.1 mm thick fluorescent layer 3 can ensure its fluorescence effect. That is, the light-shielding layer 1 and the fluorescent layer 3 are coated on the upper and lower surfaces of the glass layer 2 by means of coating, which is convenient for the production of this calibration film.

[0046] In the solution of this application, the position calibration chart 11, the resolution measurement chart 13, and the distortion measurement chart 12 are arranged in sequence along the same straight line, which is convenient for the continuous operation of camera position calibration, focus position calibration, image distortion correction, and image resolution measurement, realizing rapid calibration and effectively improving the calibration efficiency of the measurement imaging system.

[0047] This application also provides a focusing method for a calibration film for automatic focusing. Based on the calibration film for automatic focusing, by placing the calibration film on the measurement platform of the measurement imaging system, rapid focusing of the camera on the calibration platform of the measurement imaging system can be achieved, ensuring the imaging quality of the measurement imaging system. The focusing method includes the following steps:

[0048] Step 1: Place the calibration film on the measurement platform of the measurement imaging system;

[0049] Step 2: Center point position calibration of the calibration platform. The calibration platform of the measurement imaging system takes a picture of the position calibration chart 11 of the calibration film through the camera, analyzes the captured picture, calculates the center point position, and then moves the calibration platform along the X-axis and Y-axis to the calculated center point position to achieve the center point position calibration of the calibration platform. This center point position calibration includes preliminary positioning of the center point position of the platform, repositioning of the center point position of the platform, and final center point position calibration of the platform. The specific step content is as follows:

[0050] 1. Preliminary positioning of the center point position of the platform. The camera takes a picture of the position calibration chart 11 for preliminary positioning. For example, Figure 5As shown, 4 straight lines are displayed. The position calibration algorithm is used to analyze the captured image, calculate the central directions of the 4 straight lines, further calculate the center point position of the calibration film in the image, and then move the X-axis and Y-axis of the calibration platform to the calculated center point position;

[0051] 2. Locate the center point position of the platform again. The camera captures the calibration image again at the calculated center point position and analyzes the captured image. If the center point position is incorrect, more straight lines will be displayed, as Figure 6 shown. The position calibration algorithm is used to calculate the central directions of these straight lines, further calculate the center point position of the calibration film, and then move the X-axis and Y-axis of the calibration platform to the calculated new center point position;

[0052] 3. Finally, calibrate the center point position of the platform. The camera captures the calibration image and analyzes the captured image to detect whether the center point of the calibration platform is located at the center point of the calibration film. If so, the system automatically saves it and completes the calibration of the center point position of the platform, as Figure 7 shown; if not, repeat steps 1 - 3;

[0053] Step 3: Distortion correction. After the system completes the position calibration, the camera automatically moves above the distortion measurement chart 12 of the calibration film and captures the distortion measurement chart 12. The measurement imaging system automatically adjusts the objective lens of the camera until the captured image is clear, as Figure 8 shown. The system automatically identifies whether there is deformation in the lines of the captured image. If there is bending deformation, the system automatically calculates the number of pixel points to be offset, saves the recognition result, and during the subsequent imaging process, the system will automatically offset the corresponding pixel positions for the captured image to ensure that the captured image has no distortion;

[0054] Step 4: Resolution measurement. After saving the distortion correction result, the camera automatically moves above the resolution measurement chart 13 of the calibration film and captures the resolution measurement chart 13, as Figure 9 shown. The measurement imaging system automatically adjusts the objective lens of the camera until the captured image is clear, and the system automatically calculates the resolution and saves the resolution result.

[0055] In this solution, as Figure 10 shown, the size of the calibration film of this application is 74x22 mm, corresponding to a glass slide of 74x22 mm, which is used for sample detection of blood and cells in the medical field. By putting blood or cells into the glass slide and then capturing the blood or cells on the glass slide through the measurement imaging system, the detection and analysis of them are realized. Before the measurement imaging system captures and detects the sample on the glass slide, first calibrate the focus of the camera on the calibration platform of the measurement imaging system through the calibration film, and then capture and image the sample on the glass slide, which can effectively ensure clear imaging and accurate position, and ensure the imaging quality of the sample on the glass slide.

[0056] In this solution, the position calibration algorithm calculates the intersection position of two intersecting straight lines. The intersection position of the two straight lines can be obtained by methods such as solving equations or the vector cross product method. The method of solving equations obtains the coordinates of the intersection point by solving the system of equations by combining the equations. The vector cross product method calculates the cross product of vectors and uses the properties of the cross product to obtain the coordinates of the intersection point.

[0057] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A calibration sheet for full-automatic focusing, characterized in that: The device comprises a shading layer, a glass layer and a fluorescent layer, wherein the shading layer is arranged above the glass layer, the fluorescent layer is arranged below the glass layer, a calibration pattern is engraved on the shading layer, and the calibration pattern is a line pattern formed by removing part of the shading layer, and the calibration pattern comprises a position calibration pattern, a deformity measurement pattern and a resolution measurement pattern.

2. The calibration sheet for full-automatic focusing according to claim 1, characterized in that: The position calibration diagram is a circular pattern with a cross-shaped line in the middle and countless straight lines arranged at equal angles around 360 degrees.

3. The calibration sheet for full-automatic focusing according to claim 1, characterized in that: The deformity measurement diagram is a pattern composed of three field-shaped cross-line diagrams of different sizes, and the three field-shaped cross-line diagrams are arranged in order from small to large along the same straight line.

4. The calibration sheet for full-automatic focusing according to claim 1, characterized in that: The resolution measurement diagram is a rectangular pattern composed of a plurality of lines arranged horizontally and vertically and shrinking inwards, and a plurality of numbers are correspondingly arranged on the side of each line group.

5. The calibration sheet for full-automatic focusing according to claim 4, characterized in that: Each of the line groups includes six groups of horizontal lines and six groups of vertical lines, each group of horizontal lines corresponds to a group of vertical lines, each group of horizontal lines and the corresponding vertical line sides correspond to a number, and the number corresponding to each group of horizontal lines increases as the horizontal lines decrease.

6. The calibration sheet for full-automatic focusing according to claim 5, characterized in that: The resolution measurement diagram has six line groups, and the six line groups are arranged in a rectangular structure pattern.

7. The calibration sheet for full-automatic focusing according to claim 1, characterized in that: The thickness of the light shielding layer is 0.1 mm, the thickness of the glass layer is 2 mm, and the thickness of the fluorescent layer is 0.1 mm.

8. The calibration sheet for full-automatic focusing according to claim 1, characterized in that: The position calibration map, the resolution measurement map and the deformity measurement map are arranged sequentially along the same straight line.

9. A focusing method for a calibration sheet for full-automatic focusing, characterized in that: The calibration sheet for full-automatic focusing according to any one of claims 1 to 8 comprises the following steps: Step 1: Place the calibration sheet on the measuring platform of the measuring imaging system; Step 2: Calibrate the center point of the calibration platform. The calibration platform of the measuring imaging system uses a camera to capture the position calibration diagram of the calibration piece, analyze the captured image, calculate the center point position, and then move the calibration platform X-axis and Y-axis to the calculated center point position to achieve center point position calibration of the calibration platform. Step 3: Distortion correction: After the system completes position calibration, the camera automatically moves to the top of the deformity measurement diagram of the calibration piece and shoots the deformity measurement diagram until the image is clear. The system automatically identifies whether the lines in the image are deformed. If they are bent or deformed, the system automatically calculates the pixels that need to be offset and saves the recognition results. Step 4: Resolution measurement. After the distortion correction result is saved, the camera automatically moves to the top of the resolution measurement chart of the calibration piece and shoots the resolution measurement chart until the picture is clear. The system automatically calculates the resolution and saves the resolution result.

10. The focusing method of a calibration sheet for full-automatic focusing according to claim 9, characterized in that: The platform center point position calibration in step 2 includes preliminary positioning of the platform center point position, re-positioning of the platform center point position and final platform center point position calibration, and the specific steps are as follows:

1. Preliminarily locate the center point of the platform, calibrate the camera lens position through the calibration sheet, and use the camera shooting position calibration chart for initial positioning. Analyze the shooting picture, calculate the center point position, and then move the calibration platform X-axis and Y-axis to the calculated center point position; 2. Locate the center point of the platform again, take a picture of the calibration image again, analyze the picture, further calculate the center point, and then move the X-axis and Y-axis of the calibration platform to the calculated new center point position; 3. Finally, the platform center point position is calibrated. The camera takes a calibration picture to detect whether the center point of the calibration platform is located at the center point of the calibration piece. If so, the system automatically saves the information and completes the platform center point position calibration. If not, repeat steps 1-3.

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