Color correction method and system for wide-width line scanning camera

Abstract

The invention provides a color correction method, system and device for a wide-width line scanning camera, and a medium. The method comprises the following steps: S1, obtaining a to-be-corrected color card picture; s2, extracting the central position of each standard color block in the to-be-corrected color card picture through an image processing edge segmentation method; s3, correcting the central position of each standard color block in the to-be-corrected color card picture; and S4, color correction is carried out on the to-be-corrected color card pushing piece. The lookup table obtained by processing the color correction problem can be reused, and the effects of higher pertinence and higher speed for solving similar conditions are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of color correction, and in particular to a color correction method and system for a wide-format line scan camera. Background Art

[0002] Since line scan wide-format cameras are easily affected by environmental factors and pixel differences during shooting, the quality of the obtained images will be affected; in the prior art, color correction is completed by using a lookup table method, but due to complex calculations, color correction cannot be achieved quickly.

[0003] Patent document CN113923429A (application number: 202111535771.7) discloses a color correction method based on a color card, including the steps of extracting linearized color card color values ​​from an image to be corrected that includes a color card, matching the brightness of the extracted linearized color card color values ​​to the brightness of the standard color card through brightness matching, obtaining color values ​​after brightness matching, and then calculating a color correction matrix using the color values ​​after brightness matching, and calculating a corrected image using the color correction matrix. By calculating the brightness matching coefficient, the brightness of the extracted linearized color card color values ​​is matched to the brightness of the standard color card; calculating the color correction matrix using the color values ​​after brightness matching includes the sub-steps of: using the color values ​​after brightness matching and the standard color matrix to calculate the initial CCM matrix through the matrix calculation formula of the least squares method, but due to the complexity of the CCM matrix calculation, the generation speed is slow under the same configuration. Summary of the invention

[0004] In view of the defects in the prior art, an object of the present invention is to provide a color correction method and system for a wide-format line scan camera.

[0005] A color correction method for a wide-format line scan camera provided by the present invention comprises:

[0006] Step S1: Obtain a color card image to be calibrated;

[0007] Step S2: extracting the center position of each standard color block in the color card image to be corrected by using an image processing edge segmentation method;

[0008] Step S3: calibrating the center position of each standard color block in the color card image to be calibrated;

[0009] Step S4: Perform color correction on the color card to be corrected.

[0010] Preferably, the step S1 comprises: using a wide-width line scan camera to photograph a color card to be calibrated having complete color information of color blocks, to obtain a picture of the color card to be calibrated.

[0011] Preferably, the step S3 comprises:

[0012]

[0013] Among them, [V R V G V B ] indicates the center position of the color block, V R V G V B Represents R, G, and B component values ​​respectively; represents the CCM matrix; [V′ R V′ G V′ B ] indicates the center position of the color block after correction.

[0014] Preferably, the step S4 comprises:

[0015]

[0016] Wherein, I0 represents the color card image to be calibrated; represents the CCM matrix; I′ represents the corrected color card image.

[0017] A color correction system for a wide-format line scan camera provided by the present invention comprises:

[0018] Module M1: Get the color card image to be calibrated;

[0019] Module M2: extract the center position of each standard color block in the color card image to be corrected by using the image processing edge segmentation method;

[0020] Module M3: calibrate the center position of each standard color block in the color card image to be calibrated;

[0021] Module M4: Perform color correction on the color card to be corrected.

[0022] Preferably, the module M1 comprises: using a wide-width line scan camera to photograph a color card to be calibrated having complete color information of color blocks, to obtain a picture of the color card to be calibrated.

[0023] Preferably, the module M3 comprises:

[0024]

[0025] Among them, [V R V G V B ] indicates the center position of the color block, V R V G V B Represents R, G, and B component values ​​respectively; represents the CCM matrix; [0′ R V′ G V′B ] indicates the center position of the color block after correction.

[0026] Preferably, the module M4 comprises:

[0027]

[0028] Wherein, I0 represents the color card image to be calibrated; represents the CCM matrix; I′ represents the corrected color card image.

[0029] According to an electronic device provided by the present invention, the electronic device includes a memory and at least one processor, and instructions are stored in the memory;

[0030] The at least one processor calls the instructions in the memory to enable the electronic device to execute the various steps of the color correction method for a wide-format line scan camera as described above.

[0031] According to a computer-readable storage medium provided by the present invention, instructions are stored on the computer-readable storage medium, and when the instructions are executed by a processor, each step of the color correction method for a wide-format line scan camera as described above is implemented.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] 1. The present invention solves the problem of a large color gap between the pictures taken by a wide-format line scan camera and the actual objects by combining the color card standard value with the obtained color card value to generate a lookup table;

[0034] 2. The lookup table obtained by the present invention for processing the color correction problem can be reused, so as to obtain a more targeted and faster effect for solving similar situations;

[0035] 3. The present invention envisions the process of taking pictures with a line scan wide-format camera as a process of correcting the original pixel sensitivity value with a correction matrix. By constructing an overdetermined equation with the center values ​​of multiple color blocks of a given color block image, the revised matrix CCM of the original image is obtained analytically to quickly achieve color correction. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0037] Figure 1 Flowchart of the color correction method for wide-format line scan cameras.

[0038] Figure 2 This is a schematic diagram of the color card image to be calibrated.

[0039] Figure 3This is a schematic diagram of the center position of each color block of the color card to be calibrated. DETAILED DESCRIPTION

[0040] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0041] Example 1

[0042] Since color digital imaging devices are affected by many factors during the imaging process, it is difficult for the output image to be consistent with the image actually observed by the human eye, and the color difference of the imaging will directly affect the image quality.

[0043] According to a color correction method, system, device and medium for a wide-format line scan camera provided by the present invention, a color correction algorithm is proposed for a wide-format line scan camera based on multiple iterations and polynomial fitting ideas. The algorithm can greatly reduce environmental interference factors during the imaging process and improve the fidelity of the output image color.

[0044] The color correction method of the wide-format line scan camera is as follows: Figure 1 As shown, including:

[0045] Step S1: Get the color card image to be calibrated, such as Figure 2 As shown;

[0046] In this embodiment, a wide-width line scan camera is used to capture a color card image to be calibrated with complete color information of color blocks, which is represented as a matrix I0 in the algorithm.

[0047] Step S2: Extract the center position of each standard color block in the color card image to be corrected by using the image processing edge segmentation method, such as Figure 3 As shown;

[0048] In this embodiment, the color card image includes 243 standard color blocks, and the R, G, and B component values ​​at the center of each color block are extracted.

[0049] Step S3: calibrating the center position of each standard color block in the color card image to be calibrated;

[0050] In this embodiment, it is assumed that the center position data V of each color block in the color card image I0 to be corrected needs to be calculated with the CCM correction matrix to obtain the corrected image I′. This process can be expressed as algorithm formula (1):

[0051]

[0052] Among them, the CCM matrix is Color block center position data V = [V R V G V B ], the corrected image I′, each pixel value V′=[V′ R V′ G V′ B ]. The purpose of this step is to solve each parameter in the CCM matrix.

[0053] In formula (1), V is the actual color card image. There are 243 data on the center position of each color block. In order to solve the matrix, V′ in the formula can be set to the color card standard color data corresponding to the center position of each color block. In this way, an overdetermined linear equation system with more known quantities than unknown quantities is constructed, and each element in the CCM matrix is ​​inversely solved.

[0054] Step S4: Perform color correction on the color card to be corrected.

[0055] In this embodiment, the CCM matrix is ​​used as a transformation coefficient for the operation of each pixel value of the original image to be corrected color card picture I0, that is, the application of formula (1) can obtain the corrected image I′.

[0056]

[0057] The present invention also provides a color correction system for a wide-format line scan camera. The color correction system for a wide-format line scan camera can be implemented by executing the process steps of the color correction method for a wide-format line scan camera, that is, those skilled in the art can understand the color correction method for a wide-format line scan camera as a preferred implementation of the color correction system for a wide-format line scan camera.

[0058] According to an electronic device provided by the present invention, the electronic device includes a memory and at least one processor, and instructions are stored in the memory;

[0059] The at least one processor calls the instructions in the memory to enable the electronic device to execute the various steps of the color correction method for a wide-format line scan camera as described above.

[0060] According to a computer-readable storage medium provided by the present invention, instructions are stored on the computer-readable storage medium, and when the instructions are executed by a processor, each step of the color correction method for a wide-format line scan camera as described above is implemented.

[0061] Those skilled in the art know that, in addition to realizing the system and its various devices, modules, and units provided by the present invention in a purely computer-readable program code, it is entirely possible to realize the same functions in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers by logically programming the method steps. Therefore, the system and its various devices, modules, and units provided by the present invention can be considered as a hardware component, and the devices, modules, and units included therein for realizing various functions can also be regarded as structures within the hardware component; the devices, modules, and units for realizing various functions can also be regarded as both software modules for realizing the method and structures within the hardware component.

[0062] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A color correction method for a wide-format line scan camera, characterized in that: include: Step S1: Obtain a color card image to be calibrated; Step S2: extracting the center position of each standard color block in the color card image to be corrected by using an image processing edge segmentation method; Step S3: calibrating the center position of each standard color block in the color card image to be calibrated; Step S4: Perform color correction on the color card to be corrected.

2. The color correction method for a wide-format line scan camera according to claim 1, characterized in that: The step S1 includes: using a wide-width line scan camera to photograph a color card to be calibrated having complete color information of color blocks, to obtain a picture of the color card to be calibrated.

3. The color correction method for a wide-format line scan camera according to claim 1, characterized in that: The step S3 comprises: Among them, [V R V G V B ] indicates the center position of the color block, V R V G V B Represents R, G, and B component values ​​respectively; represents the CCM matrix; [V′ R V′ G V′ B ] indicates the center position of the color block after correction.

4. The color correction method for a wide-format line scan camera according to claim 1, characterized in that: The step S4 comprises: Wherein, I0 represents the color card image to be calibrated; represents the CCM matrix; I′ represents the corrected color card image.

5. A color correction system for a wide-format line scan camera, characterized in that: include: Module M1: Get the color card image to be calibrated; Module M2: extract the center position of each standard color block in the color card image to be corrected by using the image processing edge segmentation method; Module M3: calibrate the center position of each standard color block in the color card image to be calibrated; Module M4: Perform color correction on the color card to be corrected.

6. The color correction system for a wide-format line scan camera according to claim 5, characterized in that: The module M1 includes: using a wide-width line scan camera to shoot a color card to be calibrated with complete color information of color blocks to obtain a picture of the color card to be calibrated.

7. The color correction system for a wide-format line scan camera according to claim 5, characterized in that: The module M3 comprises: Among them, [V R V G V B ] indicates the center position of the color block, V R V G V B Represents R, G, and B component values ​​respectively; represents the CCM matrix; [V′ R V′ G V′ B ] indicates the center position of the color block after correction.

8. The color correction system for a wide-format line scan camera according to claim 5, characterized in that: The module M4 comprises: Wherein, I0 represents the color card image to be calibrated; represents the CCM matrix; I′ represents the corrected color card image.

9. An electronic device, comprising a memory and at least one processor, wherein instructions are stored in the memory; The at least one processor calls the instructions in the memory so that the electronic device executes each step of the color correction method for a wide-format line scan camera as described in any one of claims 1 to 4.

10. A computer-readable storage medium having instructions stored thereon, characterized in that: When the instructions are executed by the processor, the steps of the color correction method for a wide-format line scan camera as described in any one of claims 1 to 4 are implemented.

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