CCD camera calibration system, method, computing device and storage medium

1 . A CCD camera calibration system, comprising:

a transport mechanism;

a calibration component, wherein the calibration component is disposed on the transport mechanism, a plurality of calibration pattern units are arranged in a length direction on the calibration component, each calibration pattern unit comprises a first calibration block, and the first calibration block comprises a positioning identifier and multiple first calibration patterns that are arranged uniformly;

a CCD camera for photographing the calibration component to obtain a first image while the calibration component is travelling;

a processing module, wherein the processing module is in communication connection with the CCD camera, and is adapted to calculate a transformation matrix of internal and external parameters of the CCD camera according to the first image; and

a verification strip adapted for replacing the calibration component after the transformation matrix of the internal and external parameters of the CCD camera is obtained, wherein multiple stripes distributed at equal intervals are provided on the verification strip.

2 . The CCD camera calibration system according to claim 1 , wherein the verification strip is a film with a white substrate, and the stripes are black stripes.

3 . The CCD camera calibration system according to claim 1 , wherein the calibration component comprises a calibration strip, the calibration strip comprises a white substrate, and the first calibration patterns is black in color.

4 . The CCD camera calibration system according to claim 3 , wherein the first calibration patterns are formed into circles.

5 . The CCD camera calibration system according to claim 1 , wherein the calibration pattern unit further comprises a second calibration block, which is disposed on one side of the first calibration block in a width direction of the calibration component.

6 . The CCD camera calibration system according to claim 1 , wherein the calibration pattern unit comprises multiple first calibration blocks arranged in a width direction of the calibration component; and

the calibration component is adapted for being separated into multiple sub calibration components after being split in the transport mechanism, and each sub calibration component comprises at least one first calibration block.

7 . A CCD camera calibration method, comprising:

obtaining a first image, wherein the first image is an image obtained by photographing a calibration component with a CCD camera when the calibration component is travelling at a first travelling rate on a transport mechanism, wherein the calibration component comprises a plurality of calibration pattern units arranged in a length direction, each calibration pattern unit comprising a first calibration block having a positioning identifier and multiple uniformly arranged first calibration patterns;

identifying feature points in respective first calibration patterns belonging to the same first calibration block from the first image;

determining coordinate positions of the feature points in the respective first calibration patterns belonging to the same first calibration block in a calibration coordinate system, wherein the calibration coordinate system is determined according to a position of a positioning identifier in the first image;

determining distances between respective adjacent two feature points according to positions of the feature points in the respective first calibration patterns belonging to the same first calibration block; and

obtaining a transformation matrix of internal and external parameters of the CCD camera according the distances and the coordinate positions of the respective feature points in the first image in the calibration coordinate system, replacing the calibration component with a verification strip having multiple stripes distributed at equal intervals;

obtaining a second image by photographing the verification strip with the CCD camera while the verification strip travels on the transport mechanism;

determining measurement distances between respective adjacent stripes according to positions of the stripes in the second image and the transformation matrix; and

verifying the transformation matrix of the CCD camera according to the measurement distances and a standard distance between adjacent stripes.

8 . The CCD camera calibration method according to claim 7 , wherein before obtaining the second image, the method further comprises:

calculating a distortion parameter fitting curve of the CCD camera according to the coordinate positions of the respective feature points in the first image in the calibration coordinate system; and

determining a fitting accuracy of the distortion parameter fitting curve according to the coordinate positions of the respective feature points in the first image in the calibration coordinate system and the distortion parameter fitting curve;

the obtaining the second image comprises:

obtaining the second image when the fitting accuracy reaches a preset accuracy threshold.

9 . The CCD camera calibration method according to claim 7 , wherein the determining the measurement distances between respective adjacent stripes according to the positions of the stripes in the second image and the transformation matrix comprises:

determining coordinate positions of pixels of the respective stripes in the calibration coordinate system according to the positions of the stripes in the second image; and

calculating the measurement distances between respective adjacent stripes according to the coordinate positions of the pixels of the respective stripes in the calibration coordinate system and the transformation matrix.

10 . The CCD camera calibration method according to claim 7 , wherein the verifying the transformation matrix of the CCD camera according to the measurement distances and the standard distance between adjacent stripes comprises:

calculating calibration errors according to the standard distance and respective measurement distances between adjacent stripes;

comparing respective calibration errors with a preset error threshold; and

determining that the transformation matrix has not passed the verification, when a number of calibration errors greater than the preset error threshold among the respective calibration errors reaches a preset verification threshold.

11 . The CCD camera calibration method according to claim 7 , wherein the calibration pattern unit further comprises a second calibration block, which is disposed on one side of the first calibration block in a width direction of the calibration component; and

before identifying the feature points in the respective first calibration patterns belonging to the same first calibration block from the first image, the method further comprises:

positioning the first calibration block belonging to the same calibration pattern unit according to information of the second calibration block in the first image.

12 . The CCD camera calibration method according to claim 11 , wherein the second calibration block is rectangular.

13 . The CCD camera calibration method according to claim 7 , wherein the first calibration patterns are formed into circles, and the feature points are at centers of the circles.

14 . A CCD calibration device, comprising:

a photographing module for obtaining a first image, wherein the first image is an image obtained by photographing a calibration component with a CCD camera when the calibration component is travelling at a first travelling rate on a transport mechanism, wherein the calibration component comprises a plurality of calibration pattern units arranged in a length direction, each calibration pattern unit comprising a first calibration block having a positioning identifier and multiple uniformly arranged first calibration patterns;

an identifying module for identifying feature points in respective first calibration patterns belonging to the same first calibration block from the first image;

a positioning module for determining coordinate positions of the feature points in the respective first calibration patterns belonging to the same first calibration block in a calibration coordinate system, wherein the calibration coordinate system is determined according to a position of a positioning identifier in the first image;

a calculating module for determining distances between respective adjacent two feature points according to positions of the feature points in the respective first calibration patterns belonging to the same first calibration block; and

a calibration module for obtaining a transformation matrix of internal and external parameters of the CCD camera according to the distances and the coordinate positions of respective feature points in the first image in the calibration coordinate system,

a verification module configured to control replacement of the calibration component with a verification strip having multiple stripes distributed at equal intervals, obtain a second image of the verification strip, determine measurement distances between adjacent stripes using the transformation matrix, and verify the transformation matrix according to the measurement distances and a standard distance between adjacent stripes.

15 . A computing device, comprising a processor and a memory for storing computer program instructions;

the processor implements the CCD camera calibration method according to claim 7 when executing the computer program instructions.

16 . A non-transitory computer storage medium storing computer program instructions, wherein the computer program instructions when executed on a processor causes the processor to perform the CCD camera calibration method according to claim 7 .

17 . A CCD camera calibration system, comprising:

a transport mechanism;

a calibration component, wherein the calibration component is disposed on the transport mechanism, a plurality of calibration pattern units are arranged in a length direction on the calibration component, each calibration pattern unit comprises multiple first calibration blocks arranged in a width direction of the calibration component, and the first calibration block comprises a positioning identifier and multiple first calibration patterns that are arranged uniformly, the calibration component is adapted for being separated into multiple sub calibration components after being split in the transport mechanism, and each sub calibration component comprises at least one first calibration block;

a CCD camera for photographing the calibration component to obtain a first image while the calibration component is travelling; and

a processing module, wherein the processing module is in communication connection with the CCD camera, and is adapted to calculate a transformation matrix of internal and external parameters of the CCD camera according to the first image.