Hybrid color correction model construction method, and anti-off-color image processing method and device

Abstract

The application belongs to the technical field of image processing, and provides a mixed color correction model construction method, a color deviation prevention image processing method and device. The mixed color correction model construction method comprises the following steps: obtaining a first spectral reflectance characteristic curve according to the color information and corresponding reflection spectrum data of a printing material; obtaining a second spectral reflectance characteristic curve according to the color gamut range and corresponding reflection spectrum data of a target ink on an unengraved printing material; obtaining a third spectral reflectance characteristic curve through the color value and corresponding reflection spectrum data of a multi-level gray background produced by a laser engraving machine; superimposing the target color ink and the multi-level gray background to obtain mixed color values and mixed spectrum data, and then constructing a mixed color correction model. The method and device realize accurate reverse mapping from the target color to the laser parameters and ink parameters, and avoid the occurrence of significant and nonlinear color deviation of the superimposed color ink.

Description

Technical Field

[0001] This invention relates to the field of image processing technology, and in particular to a method for constructing a hybrid color correction model, a method and apparatus for preventing color cast in image processing. Background Technology

[0002] In the manufacture of high-value documents (such as passports and ID cards), a composite process combining "laser engraving" and "color ink printing" is used to balance image encryption and color performance. Laser engraving is used to form a solid black background, outline, or grayscale portrait, while three-color (CMY) inks are used to overlay color information to restore photo-realistic visual effects. However, this composite process has serious color reproduction distortion problems.

[0003] In related technologies, traditional color printing relies on a mature color management process, which works by establishing a property file between device-dependent color spaces (such as the CMYK color model of a printer) and device-independent color spaces (such as the CIELab color system). Since the entire color conversion process is based on the assumption that "the substrate is a constant white", the laser engraving process creates a continuous grayscale image from "pure white" (unengraved) to "deep black" (strongly engraved) on the material surface by changing the power. This results in the "substrate" color and reflectivity of each pixel being different, which leads to significant, non-linear color shifts in the subsequent overprinted color inks. Summary of the Invention

[0004] This invention provides a method for constructing a hybrid color correction model, a method and apparatus for anti-color deviation image processing, to solve the problem that in the prior art, when performing color printing through a color management process, the laser engraving process causes each pixel to have different base color and reflective characteristics, resulting in significant and non-linear color deviation in the subsequent overprinted color inks.

[0005] This invention provides a method for constructing a hybrid color correction model, comprising:

[0006] Based on the colorimetric information of the printing substrate and the corresponding reflectance spectral data, the first spectral reflectance characteristic curve is obtained;

[0007] Based on the color gamut range and corresponding reflectance spectrum data of the target ink on the unengraved substrate, a second spectral reflectance characteristic curve of the target ink is obtained; the target ink includes pure monochromatic ink and mixed ink.

[0008] By using a laser engraving machine to engrave multi-level grayscale background colors on materials with different power parameters, and obtaining the chromaticity values ​​and corresponding reflectance spectral data, the third spectral reflectance characteristic curves of the laser grayscale background color and the substrate material are obtained.

[0009] The target color ink is overprinted with the multi-level grayscale background to obtain mixed chromaticity values ​​and mixed spectral data;

[0010] A hybrid color correction model is constructed based on at least one of the first modeling parameters and the second modeling parameters; wherein, the first modeling parameter includes the chromaticity information of the printing material, the color gamut range, the chromaticity value of the multi-level grayscale background color, and the hybrid chromaticity value; the second modeling parameter includes the first spectral reflectance characteristic curve, the second spectral reflectance characteristic curve, the third spectral reflectance characteristic curve, and the hybrid spectral data; each spectral reflectance characteristic curve is used to represent the trend of reflectance variation corresponding to different wavelengths.

[0011] According to a method for constructing a hybrid color correction model provided by the present invention, the step of constructing a hybrid color correction model based on at least one of a first modeling parameter and a second modeling parameter includes:

[0012] The first chromaticity coordinates are obtained by calculating the chromaticity coordinates of the target ink when it is printed on an unengraved substrate based on the color gamut range.

[0013] The second chromaticity coordinates are obtained by calculating the chromaticity values ​​of the multi-level grayscale background color on the laser engraving machine at the corresponding multi-level grayscale background color.

[0014] The chromaticity coordinates of the target color ink and the multi-level grayscale background after overprinting are calculated based on the mixed chromaticity value to obtain the third chromaticity coordinates;

[0015] Calculate the normalized grayscale value for laser engraving based on the chromaticity information of the substrate;

[0016] The mixed color correction model is constructed based on the first chromaticity coordinates, the second chromaticity coordinates, the third chromaticity coordinates, the normalized grayscale value, and the ink offset attenuation coefficient; wherein, the ink offset attenuation coefficient is used to represent the relationship between ink type and concentration.

[0017] According to the present invention, a method for constructing a hybrid color correction model, wherein constructing the hybrid color correction model based on the first chromaticity coordinates, the second chromaticity coordinates, the third chromaticity coordinates, the normalized grayscale value, and the ink offset attenuation coefficient includes:

[0018] The hybrid color correction model is expressed by the following formula:

[0019] ;

[0020] in, The third chromaticity coordinates, Let the first chromaticity coordinates be... The second chromaticity coordinates, The normalized gray value, The ink offset attenuation coefficient is denoted as .

[0021] According to a method for constructing a hybrid color correction model provided by the present invention, the step of constructing a hybrid color correction model based on at least one of a first modeling parameter and a second modeling parameter includes:

[0022] Calculate the reference reflectance based on the first spectral reflectance characteristic curve;

[0023] Calculate the reflectance of the target ink based on the second spectral reflectance characteristic curve;

[0024] Calculate the reflectivity of the laser engraving machine based on the third spectral reflectance characteristic curve.

[0025] The mixed reflectance corresponding to the overprinting of the target color ink and the multi-level grayscale background color is calculated based on the mixed spectral data.

[0026] The hybrid color correction model is constructed based on the reference reflectance, the reflectance corresponding to the target ink, the reflectance corresponding to the laser engraving machine, the mixed reflectance, the normalized grayscale value during laser engraving, and the ink offset attenuation characteristic curve; wherein, the ink offset attenuation characteristic curve is used to represent the variation trend of the ink offset attenuation coefficient at different wavelengths.

[0027] According to the present invention, a method for constructing a hybrid color correction model, wherein constructing the hybrid color correction model based on the reference reflectance, the reflectance corresponding to the target ink, the reflectance corresponding to the laser engraving machine, the hybrid reflectance, the normalized grayscale value during laser engraving, and the ink offset attenuation characteristic curve includes:

[0028] The hybrid color correction model is expressed by the following formula:

[0029] ;

[0030] in, For wavelength, The mixed reflectivity, The reflectivity corresponding to the laser engraving machine. The reflectivity corresponding to the target ink. The normalized gray value, The ink offset attenuation characteristic curve is given, and the reference reflectivity is 1.

[0031] The present invention also provides a method for anti-color cast image processing, comprising:

[0032] The grayscale image of the image to be processed is divided using a brightness threshold, and the division boundary is smoothed to obtain the divided grayscale image.

[0033] The grayscale image after division is color-corrected using a hybrid color correction model to obtain a color-corrected grayscale image; wherein, the hybrid color correction model is constructed using the hybrid color correction model construction method.

[0034] The present invention also provides a hybrid color correction model building device, comprising:

[0035] The first curve acquisition module is used to obtain the first spectral reflectance characteristic curve based on the colorimetric information of the substrate and the corresponding reflectance spectral data.

[0036] The second curve acquisition module is used to obtain the second spectral reflectance characteristic curve of the target ink based on the color gamut range and corresponding reflectance spectrum data of the target ink on the unengraved substrate; the target ink includes pure monochromatic ink and mixed ink;

[0037] The third curve acquisition module is used to obtain the chromaticity values ​​and corresponding reflectance spectral data of the multi-level grayscale background color generated by laser engraving machine with different power parameters on the material, and to obtain the third spectral reflectance characteristic curve of the laser grayscale background color and the substrate material.

[0038] The mixed data acquisition module is used to overprint the target color ink with the multi-level grayscale background to obtain mixed chromaticity values ​​and mixed spectral data;

[0039] The model building module is used to construct a hybrid color correction model based on at least one of the first modeling parameters and the second modeling parameters; wherein, the first modeling parameters include the chromaticity information of the printing material, the color gamut range, the chromaticity value of the multi-level grayscale background color, and the hybrid chromaticity value; the second modeling parameters include the first spectral reflectance characteristic curve, the second spectral reflectance characteristic curve, the third spectral reflectance characteristic curve, and the hybrid spectral data; each spectral reflectance characteristic curve is used to represent the trend of reflectance variation corresponding to different wavelengths.

[0040] The present invention also provides an anti-color cast image processing device, comprising:

[0041] The image segmentation module is used to segment the grayscale image of the image to be processed using a brightness threshold and to smooth the segmentation boundaries to obtain the segmented grayscale image.

[0042] The color correction module is used to perform color correction on the divided grayscale image using a hybrid color correction model to obtain a color-corrected grayscale image; wherein, the hybrid color correction model is constructed by the hybrid color correction model construction method.

[0043] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the hybrid color correction model construction method or the anti-color cast image processing method described above.

[0044] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the hybrid color correction model construction method or the anti-color cast image processing method as described above.

[0045] The hybrid color correction model construction method, anti-color deviation image processing method, and apparatus provided by this invention obtain a first spectral reflectance characteristic curve by using the chromaticity information and corresponding reflectance spectral data of the printing material; obtain a second spectral reflectance characteristic curve of the target ink based on the color gamut range and corresponding reflectance spectral data of the target ink on the unengraved printing material; obtain a third spectral reflectance characteristic curve by using the chromaticity value and corresponding reflectance spectral data of the multi-level grayscale background color generated by the laser engraving machine; obtain mixed chromaticity value and mixed spectral data by overprinting the target color ink with the multi-level grayscale background color; and finally, perform mathematical modeling based on the obtained data to obtain a hybrid color correction model, realizing an accurate inverse mapping from the target color to laser parameters and ink parameters, and avoiding significant, non-linear color deviation in the overprinted colored ink. Attached Figure Description

[0046] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0047] Figure 1 This is a flowchart illustrating the hybrid color correction model construction method provided by the present invention.

[0048] Figure 2 This is one of the flowcharts illustrating the anti-color distortion image processing method provided by the present invention.

[0049] Figure 3 This is the second flowchart of the anti-color distortion image processing method provided by the present invention.

[0050] Figure 4 This is the third flowchart of the anti-color distortion image processing method provided by the present invention.

[0051] Figure 5 This is a schematic diagram of the hybrid color correction model construction device provided by the present invention.

[0052] Figure 6 This is a schematic diagram of the anti-color distortion image processing device provided by the present invention.

[0053] Figure 7 This is a schematic diagram of the structure of the electronic device provided by the present invention. Detailed Implementation

[0054] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0055] The following is combined with Figures 1-6 The present invention describes a method for constructing a hybrid color correction model, a method for processing images to prevent color cast, and an apparatus for such processing.

[0056] Figure 1 This is a flowchart illustrating the hybrid color correction model construction method provided by the present invention, as shown below. Figure 1 As shown, the method includes the following steps:

[0057] Step 110: Obtain the first spectral reflectance characteristic curve based on the chromaticity information of the substrate and the corresponding reflectance spectral data.

[0058] In this step, the first spectral reflectance characteristic curve is the ability of the raw printing substrate (such as white cardboard for ID cards, polycarbonate layer, etc.) to reflect light of different wavelengths under standard lighting conditions without any processing.

[0059] In this step, the chromaticity information of the printing substrate establishes the "physical white point" or reference zero point of the color space, thereby obtaining the reference background for the color calibration model. All subsequent ink absorption and laser blackening effects are subtractive or superimposed operations based on this reference background. The chromaticity information of the printing substrate can be CIE (…). x , y )coordinate.

[0060] In this embodiment, a fixed observation environment is set (e.g., using a D65 standard light source), and all subsequent test lighting conditions are kept constant. A high-precision spectroradiometer is used to scan and measure a blank document substrate that has not been laser-engraved or coated with ink. The instrument collects spectral reflectance data within a certain wavelength range (unit: nanometers nm), which is then normalized and recorded as follows. That is, the first spectral reflectance characteristic curve.

[0061] Step 120: Based on the color gamut range and corresponding reflectance spectrum data of the target ink on the unengraved substrate, obtain the second spectral reflectance characteristic curve of the target ink; the target ink includes pure monochromatic ink and mixed ink.

[0062] In this step, the target ink can be the three primary color inks of cyan (C), magenta (M), and yellow (Y) used in the process, as well as the secondary colors produced by their superposition, such as red (R), green (G), blue (B), and black (K).

[0063] In this step, the second spectral reflectance characteristic curve is used to characterize the spectral absorption characteristics of the ink material itself; it should be noted that the physical superposition of inks is nonlinear and cannot be simply derived by monochromatic addition.

[0064] In this embodiment, the inkjet device is controlled to print a series of color blocks on the unengraved original substrate. These color blocks include: (1) pure monochrome color blocks: 100% concentration of C, M, Y; (2) proportionally mixed color blocks: C+M=blue (B), C+Y=green (G), M+Y=red (R), C+M+Y=black (K0), where Y represents yellow.

[0065] In this embodiment, a spectrophotometer can be used to measure the spectral reflectance of these color patches individually. The color gamut range coordinates were determined, and the second spectral reflectance curve was plotted based on these data.

[0066] Step 130: Using a laser engraving machine with different power parameters, engrave the chromaticity values ​​and corresponding reflectance spectral data of the multi-level grayscale background color on the material to obtain the third spectral reflectance characteristic curve of the laser grayscale background color and the substrate material.

[0067] In this step, the multi-level grayscale background color is a gradient sequence from light gray to dark black formed when the material carbonizes and turns black after the laser beam acts on the material surface with different powers or pulse densities.

[0068] In this step, the dynamic effect of laser ablation on light reflectivity is described by the third spectral reflectance characteristic curve, which is then used to establish the functional relationship between laser control parameters and the actual physical background color.

[0069] For example, controlling a laser engraving machine to output a grayscale step map, covering from... =0 (no carving) to =1 (maximum power engraving) with multiple levels (e.g., 10%, 20%...100%). As the laser power increases, the material not only darkens (overall reflectivity decreases), but the color coordinates also shift. These changes occur with... K The set of curves showing the changes in values ​​constitutes the third spectral reflectance characteristic curve.

[0070] Step 140: Overprint the target color ink with a multi-level grayscale background to obtain mixed color values ​​and mixed spectral data.

[0071] In this step, the mixed chromaticity values ​​after overprinting on different laser grayscale backgrounds form a large number of corresponding datasets of "laser-ink-chromaticity-spectrum".

[0072] Specifically, through physical experiments, the actual color of the ink when it is applied to a rough, blackened laser-ablated surface is measured, thereby collecting the corresponding mixed chromaticity values ​​and mixed spectral data to reflect the complex physical coupling effects (such as penetration, scattering, and occlusion) between the ink layer and the laser base color layer.

[0073] In this embodiment, a key color (such as blue ink mixed from C and M, where C is cyan and M is magenta) is selected and sprayed onto a laser background of different gray levels (such as 20% gray level and 50% gray level) generated in step 130. The mixed chromaticity coordinates of the final superimposed area are then recorded using a measuring device. and mixed reflectivity In addition, with As the value increases, the coordinates of the mixed color will shift approximately linearly towards the coordinates of the laser background color.

[0074] Step 150: Construct a hybrid color correction model based on at least one of the first modeling parameters and the second modeling parameters; wherein, the first modeling parameters include the chromaticity information of the substrate, the color gamut range, the chromaticity values ​​of the multi-level grayscale background, and the mixed chromaticity values; the second modeling parameters include the first spectral reflectance characteristic curve, the second spectral reflectance characteristic curve, the third spectral reflectance characteristic curve, and the mixed spectral data; each spectral reflectance characteristic curve is used to represent the trend of reflectance variation corresponding to different wavelengths.

[0075] In this step, the changing trends of each spectral reflectance characteristic curve intuitively reflect the energy distribution of light after absorption by the ink layer and scattering by the laser base color layer. Compared with a single chromaticity value, it contains richer physical light and color mixing information.

[0076] In this embodiment, a computable color correction formula is generated by mathematically fitting the collected data.

[0077] This embodiment can provide two modeling paths:

[0078] (1) Based on the first modeling parameter, a chromaticity coordinate model is constructed, and the geometric relationship of chromaticity values ​​is utilized, which is suitable for fast calculation.

[0079] (2) Based on the second modeling parameters, a spectral reflectance model is constructed, and the color reproduction accuracy is higher by utilizing the physical laws of the spectrum.

[0080] Furthermore, in step 150 above, the first modeling parameter can be achieved through the following steps:

[0081] Constructing a hybrid color correction model based on at least one of the first and second modeling parameters includes:

[0082] Step 151: Calculate the chromaticity coordinates of the target ink when it is printed on the unengraved substrate based on the color gamut range, and obtain the first chromaticity coordinates.

[0083] In this step, the first chromaticity coordinate represents the color position of the ink on the unengraved substrate, which can be calculated by interpolation from gamut boundary data or integration from spectral data.

[0084] For example, for a magenta ink, first, measure the reflectance spectral data or chromaticity data of the ink on an unengraved substrate in step 120. If the data source is the spectrum, the precise coordinates on the CIE chromaticity diagram can be obtained by integrating the CIE 1931 standard chromaticity observer function and illuminant data, denoted as the first chromaticity coordinate, and then as the second chromaticity coordinate. .

[0085] Step 152: Calculate the chromaticity coordinates of the laser engraving machine on the corresponding multi-level grayscale background based on the chromaticity values ​​of the multi-level grayscale background, and obtain the second chromaticity coordinates.

[0086] In this step, the second chromaticity coordinate represents the position of the black / gray background color produced by laser engraving on the chromaticity map. Since the laser power is variable, the second chromaticity coordinate is essentially about the normalized grayscale value. K The function.

[0087] For example, for each grayscale level output by the laser engraving machine (such as...) K =0.5), and the second chromaticity coordinates of the background color at this grayscale are calculated using the data measured in step 130, denoted as . It should be noted that as the laser power changes, the second chromaticity coordinates will form a trajectory on the chromaticity diagram.

[0088] Step 153: Calculate the chromaticity coordinates of the target color ink and the multi-level grayscale background after overprinting based on the mixed chromaticity value, and obtain the third chromaticity coordinates.

[0089] In this step, the inks of the key colors and corresponding mixed colors are overprinted with the multi-level grayscale background colors. The chromaticity coordinates of the actual chromaticity after mixing are calculated by instrument measurement or spectral data integration. These are the third chromaticity coordinates, which are the same as the mixed chromaticity coordinates mentioned above.

[0090] For example, spray the aforementioned magenta ink onto... KOn a laser background with a value of 0.5, the third chromaticity coordinates of the mixture are obtained by instrument measurement or spectral data integration calculation, denoted as... .

[0091] Step 154: Calculate the normalized grayscale value for laser engraving based on the chromaticity information of the substrate; construct a mixed color correction model based on the first chromaticity coordinate, the second chromaticity coordinate, the third chromaticity coordinate, the normalized grayscale value, and the ink offset attenuation coefficient; wherein, the ink offset attenuation coefficient is used to represent the relationship between ink type and concentration.

[0092] In this step, the ink offset attenuation coefficient can be obtained as follows:

[0093] exist K For different values ​​(e.g.) K The values ​​are 0.1, 0.3, 0.5, and 0.7 respectively (while keeping the ink type and concentration constant), which can measure different... K The values ​​correspond to the mixed target chromaticity, laser chromaticity, and ink chromaticity, which can then be calculated separately. K A(ink), because of this K The actual change of each A(ink) is very small. In this embodiment, the least squares method is used again to... K We fit data to each A(ink) and finally obtain an A(ink) that minimizes the error.

[0094] Furthermore, in step 154 ​​above, constructing the hybrid color correction model based on the first chromaticity coordinates, the second chromaticity coordinates, the third chromaticity coordinates, the normalized grayscale value, and the ink offset attenuation coefficient includes:

[0095] The mixed color correction model is represented by the following formula:

[0096] ;

[0097] in, The third chromaticity coordinates, The first chromaticity coordinate is... The second chromaticity coordinates, For normalized grayscale values, This is the ink offset attenuation coefficient.

[0098] This embodiment extracts key physical parameters describing the interaction between ink and laser, and simplifies complex physical phenomena into efficient linear algebraic equations. In subsequent applications, only the target color needs to be input, and the required laser grayscale and ink amount can be quickly calculated using this model. This mixed color correction model is suitable for scenarios where the requirements for mixed color accuracy are not high (e.g., only visual inspection is required).

[0099] Furthermore, in step 150 above, the second modeling parameter can be achieved through the following steps:

[0100] Constructing a hybrid color correction model based on at least one of the first and second modeling parameters includes:

[0101] Step 155: Calculate the reference reflectance based on the first spectral reflectance characteristic curve.

[0102] In this embodiment, the reference reflectance corresponds to the constant term in the physical model formula (usually normalized to 1), representing the reflectivity of the background color, and also indicating the state in which light is not absorbed.

[0103] For example, using the first spectral reflectance curve measured in step 110, in order to simplify the calculation when building the model, this curve can be used as the denominator to normalize all other measurement data. At this time, the reflectance of the uncarved substrate in the model is the reference reflectance, and its value is 1 at each wavelength, representing the state in which light is not absorbed.

[0104] Step 156: Calculate the reflectance of the target ink based on the second spectral reflectance characteristic curve.

[0105] In this step, the reflectivity of the target ink reflects the transmission or reflection efficiency of the ink layer for different wavelengths of light, denoted as . Different wavelengths Each corresponds to a reflectivity.

[0106] For example, for cyan ink, the corresponding spectral data is first obtained through step 120, and then normalized relative to the reference reflectance to obtain the spectral distribution of the ink in the 380nm-780nm band. For example, the reflectance of cyan ink is extremely low in the 600nm-700nm (red light band) (because it absorbs red light), while the reflectance is relatively high in the 450nm-500nm (blue-green band).

[0107] Step 157: Calculate the reflectivity of the laser engraving machine based on the third spectral reflectance characteristic curve.

[0108] In this step, the reflectivity of the laser engraving machine is the normalized grayscale value of the laser emitted by the laser engraving machine. K When applied to materials, the resulting black background color reflects the spectrum.

[0109] For example, targeting K When the grayscale value is 0.5, the background color spectral curve at that grayscale is calculated using the data obtained in step 130, and the reflectance corresponding to different wavelengths is obtained, denoted as . .

[0110] It should be noted that, unlike the selective absorption of inks, the carbon black produced by laser ablation usually exhibits low reflectivity across the entire wavelength range (i.e., overall darkening), but may also exhibit specific material properties in certain wavelength ranges (such as near-infrared or ultraviolet).

[0111] Step 158: Calculate the mixed reflectance corresponding to the overprinting of the target color ink and the multi-level grayscale background color based on the mixed spectral data.

[0112] In this step, the mixed reflectivity reflects the true optical performance after the ink and laser base color are physically coupled, including complex physical information such as scattering and penetration.

[0113] For example, measuring the area covered by cyan ink K The region on the 0.5 laser background was used to obtain the mixed spectral data. Then, the actual mixed reflectance curve under this state was calculated and denoted as... .

[0114] Step 159: Construct a mixed color correction model based on the reference reflectance, the reflectance corresponding to the target ink, the reflectance corresponding to the laser engraving machine, the mixed reflectance, the normalized gray value during laser engraving, and the ink offset attenuation characteristic curve; wherein, the ink offset attenuation characteristic curve is used to represent the changing trend of the ink offset attenuation coefficient at different wavelengths.

[0115] In this step, since the linear change in chromaticity is essentially a linear change in each band of the spectrum, this embodiment can also be implemented in... K To measure different values K The values ​​correspond to the mixed target chromaticity, laser chromaticity, and ink chromaticity, which can then be calculated separately. K indivual Using the least squares method K indivual Perform data fitting to obtain a In the ink offset attenuation characteristic curve, different wavelengths correspond to a The curve is denoted as ; for The corresponding ink offset attenuation coefficient.

[0116] Further, in step 159 above, the hybrid color correction model is constructed based on the reference reflectance, the reflectance corresponding to the target ink, the reflectance corresponding to the laser engraving machine, the mixed reflectance, the normalized grayscale value during laser engraving, and the ink offset attenuation characteristic curve, including:

[0117] The mixed color correction model is represented by the following formula:

[0118] ;

[0119] in, For wavelength, This refers to the mixed reflectance, which is the spectral reflectance at wavelength λ after mixing. This refers to the reflectivity corresponding to the laser engraving machine, which is also the spectral reflectivity of the laser-engraved substrate at wavelength λ. This represents the reflectance of the target ink, which is also the spectral reflectance of the ink on a standard white printing substrate at wavelength λ. Normalized grayscale values ​​(0 for no engraving, 1 for maximum power engraving). The curve shows the ink offset attenuation characteristics, with a reference reflectance of 1.

[0120] In this embodiment, the aforementioned hybrid color correction model can accurately predict the final spectral reflectance curve based on any input ink and laser parameters, and then convert it into a color value with extremely high precision.

[0121] The hybrid color correction model construction method provided in this invention obtains a first spectral reflectance characteristic curve by using the chromaticity information and corresponding reflectance spectral data of the printing material; obtains a second spectral reflectance characteristic curve of the target ink by using the color gamut range and corresponding reflectance spectral data of the target ink on the unengraved printing material; obtains a third spectral reflectance characteristic curve by using the chromaticity value and corresponding reflectance spectral data of the multi-level grayscale background color generated by the laser engraving machine; obtains mixed chromaticity value and mixed spectral data by overprinting the target color ink with the multi-level grayscale background color; and finally, performs mathematical modeling based on the obtained data to obtain a hybrid color correction model, realizing an accurate inverse mapping from the target color to the laser parameters and ink parameters, and avoiding significant and nonlinear color shift in the overprinted colored ink.

[0122] The anti-color cast image processing method provided by the present invention is described below. The anti-color cast image processing method described below can be referred to in correspondence with the hybrid color correction model construction method described above.

[0123] Figure 2 This is one of the flowcharts illustrating the anti-color distortion image processing method provided by the present invention, such as... Figure 2 As shown, this anti-color cast image processing method includes the following steps:

[0124] Step 210: Divide the grayscale image of the image to be processed using a brightness threshold, and smooth the division boundary to obtain the divided grayscale image.

[0125] In this step, the image to be processed can be a color image, such as an RGB color ID photo.

[0126] In this embodiment, the image to be processed is first converted into a grayscale image, and then the image pixels are divided into two categories based on the brightness threshold (set according to actual needs), such as including "dark areas" suitable for depth and "bright areas" that need to protect the background color.

[0127] In this embodiment, a smoothing function based on brightness characteristics can be used to determine the intensity of laser engraving, which can prevent harsh jagged edges or breaks at the junction of the two types of areas and ensure a natural visual transition.

[0128] Specifically, (1) first convert the three channels RGB (primary colors) of the input RGB (color portrait photo) into luminance y, such as using the following formula:

[0129] y=R×0.299+G×0.587+B×0.114;

[0130] (2) Then set a brightness threshold based on the image (it needs to be adjusted according to the image to get a suitable effect, for example, brightness threshold T=90), and use this threshold to decompose the input digital image (such as ID photo) into different regions.

[0131] For example, (2.1) Dark area segmentation and processing: For areas with low gray levels in the image (such as black hair and dark clothing), the target color itself has very low brightness and is "dark". These areas will be allocated relatively high laser power for engraving.

[0132] (2.2) Light-colored area segmentation and processing: For areas with high gray levels in the image (such as skin color of human face, light-colored clothing), which are "bright colors", relatively low laser power will be allocated to these areas for engraving.

[0133] Meanwhile, to avoid abrupt changes near the brightness of 90, a sigmoid function or a linear interpolation function can be used to calculate the laser intensity coefficient of each pixel in the transition zone near the threshold T (e.g., y∈[80,100]). α For the above two types of areas α After smoothing the gradient, the final result is a grayscale image with smooth transition information after region weighting.

[0134] Step 220: Use the hybrid color correction model to perform color correction on the divided grayscale image to obtain the corrected grayscale image; wherein, the hybrid color correction model is constructed by the hybrid color correction model construction method.

[0135] In this embodiment, the hybrid color correction model is constructed through the following steps:

[0136] (1) Based on the chromaticity information of the substrate and the corresponding reflectance spectral data, the first spectral reflectance characteristic curve is obtained;

[0137] (2) Based on the color gamut range and corresponding reflectance spectrum data of the target ink on the unengraved substrate, the second spectral reflectance characteristic curve of the target ink is obtained; the target ink includes pure monochromatic ink and mixed ink;

[0138] (3) By using a laser engraving machine to engrave the multi-level grayscale background color on the material with different power parameters, the chromaticity value and corresponding reflectance spectrum data of the laser grayscale background color are obtained, and the third spectral reflectance characteristic curve of the laser grayscale background color and the substrate material is obtained.

[0139] (4) Overprint the target color ink with a multi-level grayscale background to obtain mixed color values ​​and mixed spectral data;

[0140] (5) Construct a mixed color correction model based on at least one of the first modeling parameter and the second modeling parameter; wherein, the first modeling parameter includes the chromaticity information of the substrate, the color gamut range, the chromaticity value of the multi-level grayscale background color and the mixed chromaticity value; the second modeling parameter includes the first spectral reflectance characteristic curve, the second spectral reflectance characteristic curve, the third spectral reflectance characteristic curve and the mixed spectral data; each spectral reflectance characteristic curve is used to represent the trend of reflectance change corresponding to different wavelengths.

[0141] It should be noted that the implementation methods corresponding to steps (1)-(5) correspond one-to-one with steps 110-150, and will not be repeated in this embodiment.

[0142] In this embodiment, the mixed color calibration model calculated in step 154 ​​is suitable for scenarios where the requirements for mixed color accuracy are not high, while the mixed color calibration model calculated in step 159 is suitable for scenarios where the requirements for color accuracy are high (e.g., when a colorimeter is used for measurement).

[0143] In this embodiment, the two hybrid color correction models can be used individually or in combination. For example, in an image, some colors have high color accuracy requirements while others have low requirements. In this case, the two schemes can be used for mixed processing.

[0144] The following explanation uses the hybrid color correction model calculated in step 159 as an example to illustrate color correction of a color image.

[0145] In this embodiment, for all colors, an excessively high grayscale laser background will cause severe color shift, especially for "bright colors". Therefore, both areas need to adjust the grayscale of the final output. This embodiment uses the aforementioned mixed color correction model and the expected color performance (for example, using four-color CMYK as a reference) to adjust and print to obtain a mixed image with the expected colors.

[0146] In this embodiment, the hybrid color correction model outputs a color-corrected grayscale image and a color-corrected ink image. The grayscale values ​​in the color-corrected grayscale image are corrected by the model. For example, a face shadow with a grayscale of 10% in the original image may be corrected to 0% or 2% to prevent the laser from "burning" the face. The ink data in the color-corrected ink image includes compensation for the background color. For example, in order to display pure yellow on a slightly gray background, the model may instruct to spray more yellow ink to offset the absorption of the background color.

[0147] Figure 3 This is the second flowchart of the anti-color distortion image processing method provided by the present invention. Figure 3 In the embodiment shown, a color image is first input, and then the color of the color image is separated to generate an initial laser grayscale image, i.e., the divided grayscale image. The initial laser grayscale image is input into a mixed color correction model for color correction, and the final laser grayscale image is output for laser engraving. The corrected three-color ink image is also output for ink spraying, and finally, a finished product with accurate color is obtained.

[0148] The anti-color distortion image processing method provided in this invention divides the grayscale image of the image to be processed by using a brightness threshold, and smooths the division boundary to obtain the divided grayscale image. Then, a hybrid color correction model is used to perform color correction on the divided grayscale image to obtain the corrected grayscale image. This results in a final product that has both the anti-counterfeiting depth of laser and the photo-quality color of ink, improving the color correction quality and efficiency of color sample images.

[0149] Figure 4 This is the third flowchart of the anti-color cast image processing method provided by the present invention. Figure 4 In the illustrated embodiment, the method includes the following steps:

[0150] Step 1: Machine colorimetric measurement and data acquisition;

[0151] Step 2: Construct a laser-ink hybrid mapping model;

[0152] Step 3: Color separation based on image content;

[0153] Step four: perform color correction and output the laser grayscale image and the three-color ink image.

[0154] The hybrid color correction model construction apparatus provided by the present invention is described below. The hybrid color correction model construction apparatus described below and the hybrid color correction model construction method described above can be referred to in correspondence.

[0155] Figure 5 This is a schematic diagram of the hybrid color correction model construction device provided by the present invention, as shown below. Figure 5 As shown, the hybrid color correction model building device includes:

[0156] The first curve acquisition module 510 is used to obtain the first spectral reflectance characteristic curve based on the colorimetric information of the substrate and the corresponding reflectance spectral data.

[0157] The second curve acquisition module 520 is used to obtain the second spectral reflectance characteristic curve of the target ink based on the color gamut range and corresponding reflectance spectrum data of the target ink on the unengraved substrate; the target ink includes pure monochromatic ink and mixed ink;

[0158] The third curve acquisition module 530 is used to obtain the chromaticity values ​​and corresponding reflectance spectral data of the multi-level grayscale background color generated by laser engraving machine with different power parameters on the material, and to obtain the third spectral reflectance characteristic curve of the laser grayscale background color and the substrate material.

[0159] The mixed data acquisition module 540 is used to overprint the target color ink with a multi-level grayscale background to obtain mixed color values ​​and mixed spectral data.

[0160] The model building module 550 is used to build a mixed color correction model based on at least one of the first modeling parameters and the second modeling parameters; wherein, the first modeling parameters include the chromaticity information of the substrate, the color gamut range, the chromaticity values ​​of the multi-level grayscale background color and the mixed chromaticity values; the second modeling parameters include the first spectral reflectance characteristic curve, the second spectral reflectance characteristic curve, the third spectral reflectance characteristic curve and the mixed spectral data.

[0161] The hybrid color correction model construction device provided in this invention obtains a first spectral reflectance characteristic curve by using the chromaticity information and corresponding reflectance spectral data of the printing material. It then obtains a second spectral reflectance characteristic curve of the target ink based on the color gamut range and corresponding reflectance spectral data of the target ink on the unengraved printing material. Finally, it obtains a third spectral reflectance characteristic curve by using the chromaticity value and corresponding reflectance spectral data of the multi-level grayscale background color generated by the laser engraving machine. By overprinting the target color ink with the multi-level grayscale background color, it obtains mixed chromaticity values ​​and mixed spectral data. Finally, it performs mathematical modeling based on the acquired data to obtain a hybrid color correction model, achieving accurate inverse mapping from the target color to laser parameters and ink parameters, thus avoiding significant, non-linear color shifts in the overprinted colored inks.

[0162] The anti-color distortion image processing apparatus provided by the present invention is described below. The anti-color distortion image processing apparatus described below can be referred to in correspondence with the anti-color distortion image processing method described above.

[0163] Figure 6 This is a schematic diagram of the anti-color distortion image processing device provided by the present invention, as shown below. Figure 6 As shown, the anti-color distortion image processing device includes:

[0164] The image segmentation module 610 is used to segment the grayscale image of the image to be processed using a brightness threshold and to smooth the segmentation boundary to obtain the segmented grayscale image.

[0165] The color correction module 620 is used to perform color correction on the divided grayscale image using a hybrid color correction model to obtain the corrected grayscale image; wherein, the hybrid color correction model is constructed by a hybrid color correction model construction method.

[0166] The anti-color distortion image processing device provided in this embodiment of the invention divides the grayscale image of the image to be processed by using a brightness threshold and smooths the division boundary to obtain the divided grayscale image. Then, a hybrid color correction model is used to perform color correction on the divided grayscale image to obtain the corrected grayscale image. This makes the final product have both the anti-counterfeiting depth of laser and the photo-quality color of ink, improving the color correction quality and efficiency of color sample images.

[0167] Figure 7 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 7 As shown, the electronic device may include: a processor 710, a communications interface 720, a memory 730, and a communications bus 740, wherein the processor 710, the communications interface 720, and the memory 730 communicate with each other through the communications bus 740. The processor 710 can call logic instructions in the memory 730 to execute a hybrid color correction model construction method. This method includes: obtaining a first spectral reflectance characteristic curve based on the chromaticity information and corresponding reflectance spectral data of the printing material; obtaining a second spectral reflectance characteristic curve of the target ink based on the color gamut range and corresponding reflectance spectral data of the target ink on the unengraved printing material; the target ink includes pure monochrome ink and mixed ink; obtaining a third spectral reflectance characteristic curve corresponding to the laser grayscale background color and the printing material by engraving a multi-level grayscale background color with different power parameters using a laser engraving machine and obtaining the chromaticity values ​​and corresponding reflectance spectral data of the multi-level grayscale background color; overprinting the target color ink with the multi-level grayscale background color to obtain mixed chromaticity values ​​and mixed spectral data; constructing a hybrid color correction model based on at least one of a first modeling parameter and a second modeling parameter; wherein the first modeling parameter includes the chromaticity information of the printing material, the color gamut range, the chromaticity values ​​of the multi-level grayscale background color, and the mixed chromaticity values; the second modeling parameter includes the first spectral reflectance characteristic curve, the second spectral reflectance characteristic curve, the third spectral reflectance characteristic curve, and the mixed spectral data; each spectral reflectance characteristic curve is used to represent the changing trend of reflectance corresponding to different wavelengths.

[0168] Alternatively, an anti-color cast image processing method can be implemented, which includes: dividing the grayscale image of the image to be processed using a brightness threshold and smoothing the division boundary to obtain the divided grayscale image; using a hybrid color correction model to perform color correction on the divided grayscale image to obtain the corrected grayscale image; wherein, the hybrid color correction model is constructed using a hybrid color correction model construction method.

[0169] Furthermore, the logical instructions in the aforementioned memory 730 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, essentially, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0170] On the other hand, the present invention also provides a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements a method for constructing a mixed color correction model provided by the above methods. This method includes: obtaining a first spectral reflectance characteristic curve based on the chromaticity information of the printing material and corresponding reflectance spectral data; obtaining a second spectral reflectance characteristic curve of the target ink based on the color gamut range of the target ink on an unengraved printing material and corresponding reflectance spectral data; the target ink includes pure monochrome ink and mixed ink; and the chromaticity values ​​and corresponding values ​​of a multi-level grayscale background color generated by laser engraving on the material at different power parameters. The reflectance spectral data is used to obtain the third spectral reflectance characteristic curves corresponding to the laser grayscale background color and the printing material; the target color ink is overprinted with the multi-level grayscale background color to obtain mixed chromaticity values ​​and mixed spectral data; a mixed color correction model is constructed based on at least one of the first modeling parameters and the second modeling parameters; wherein, the first modeling parameter includes the chromaticity information of the printing material, the color gamut range, the chromaticity values ​​of the multi-level grayscale background color, and the mixed chromaticity value; the second modeling parameter includes the first spectral reflectance characteristic curve, the second spectral reflectance characteristic curve, the third spectral reflectance characteristic curve, and the mixed spectral data; each spectral reflectance characteristic curve is used to represent the trend of reflectance variation corresponding to different wavelengths.

[0171] Alternatively, an anti-color cast image processing method can be implemented, which includes: dividing the grayscale image of the image to be processed using a brightness threshold and smoothing the division boundary to obtain the divided grayscale image; using a hybrid color correction model to perform color correction on the divided grayscale image to obtain the corrected grayscale image; wherein, the hybrid color correction model is constructed using a hybrid color correction model construction method.

[0172] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0173] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0174] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for constructing a hybrid color correction model, characterized in that, include: Based on the colorimetric information of the printing substrate and the corresponding reflectance spectral data, the first spectral reflectance characteristic curve is obtained; Based on the color gamut range and corresponding reflectance spectrum data of the target ink on the unengraved substrate, a second spectral reflectance characteristic curve of the target ink is obtained; the target ink includes pure monochromatic ink and mixed ink. By using a laser engraving machine to engrave multi-level grayscale background colors on a material with different power parameters, and obtaining the chromaticity values ​​and corresponding reflectance spectral data, the third spectral reflectance characteristic curves of the laser grayscale background color and the substrate material are obtained. The target color ink is overprinted with the multi-level grayscale background to obtain mixed chromaticity values ​​and mixed spectral data; A hybrid color correction model is constructed based on at least one of the first modeling parameters and the second modeling parameters; wherein, the first modeling parameters include the chromaticity information of the printing material, the color gamut range, the chromaticity value of the multi-level grayscale background color, and the hybrid chromaticity value; the second modeling parameters include the first spectral reflectance characteristic curve, the second spectral reflectance characteristic curve, the third spectral reflectance characteristic curve, and the hybrid spectral data; each spectral reflectance characteristic curve is used to represent the trend of reflectance variation corresponding to different wavelengths; The step of constructing a hybrid color correction model based on at least one of the first modeling parameters and the second modeling parameters includes: Based on the first modeling parameters, construct a chromaticity coordinate model; A spectral reflectance model is constructed based on the second modeling parameter.

2. The method for constructing a hybrid color correction model according to claim 1, characterized in that, The step of constructing a hybrid color correction model based on at least one of the first modeling parameters and the second modeling parameters further includes: The first chromaticity coordinates are obtained by calculating the chromaticity coordinates of the target ink when it is printed on an unengraved substrate based on the color gamut range. The second chromaticity coordinates are obtained by calculating the chromaticity values ​​of the multi-level grayscale background color on the laser engraving machine at the corresponding multi-level grayscale background color. The chromaticity coordinates of the target color ink and the multi-level grayscale background after overprinting are calculated based on the mixed chromaticity value to obtain the third chromaticity coordinates; Calculate the normalized grayscale value for laser engraving based on the chromaticity information of the substrate; The mixed color correction model is constructed based on the first chromaticity coordinates, the second chromaticity coordinates, the third chromaticity coordinates, the normalized grayscale value, and the ink offset attenuation coefficient; wherein, the ink offset attenuation coefficient is used to represent the relationship between ink type and concentration.

3. The method for constructing a hybrid color correction model according to claim 2, characterized in that, The step of constructing the hybrid color correction model based on the first chromaticity coordinates, the second chromaticity coordinates, the third chromaticity coordinates, the normalized grayscale value, and the ink offset attenuation coefficient includes: The hybrid color correction model is expressed by the following formula: ； in, The third chromaticity coordinates, Let the first chromaticity coordinates be... The second chromaticity coordinates, The normalized gray value, The ink offset attenuation coefficient is denoted as .

4. The method for constructing a hybrid color correction model according to claim 2, characterized in that, The step of constructing a hybrid color correction model based on at least one of the first modeling parameters and the second modeling parameters includes: Calculate the reference reflectance based on the first spectral reflectance characteristic curve; Calculate the reflectance of the target ink based on the second spectral reflectance characteristic curve; Calculate the reflectivity of the laser engraving machine based on the third spectral reflectance characteristic curve. The mixed reflectance corresponding to the overprinting of the target color ink and the multi-level grayscale background color is calculated based on the mixed spectral data. The hybrid color correction model is constructed based on the reference reflectance, the reflectance corresponding to the target ink, the reflectance corresponding to the laser engraving machine, the mixed reflectance, the normalized grayscale value during laser engraving, and the ink offset attenuation characteristic curve; wherein, the ink offset attenuation characteristic curve is used to represent the variation trend of the ink offset attenuation coefficient at different wavelengths.

5. The hybrid color correction model construction method according to claim 4, characterized in that, The construction of the hybrid color correction model based on the reference reflectance, the reflectance corresponding to the target ink, the reflectance corresponding to the laser engraving machine, the mixed reflectance, the normalized grayscale value during laser engraving, and the ink offset attenuation characteristic curve includes: The hybrid color correction model is expressed by the following formula: ； in, For wavelength, The mixed reflectivity, The reflectivity corresponding to the laser engraving machine. The reflectivity corresponding to the target ink. The normalized gray value, The ink offset attenuation characteristic curve is given, and the reference reflectivity is 1.

6. A method for preventing color cast in image processing, characterized in that, include: The grayscale image of the image to be processed is divided using a brightness threshold, and the division boundary is smoothed to obtain the divided grayscale image. The grayscale image after division is color-corrected using a hybrid color correction model to obtain a color-corrected grayscale image; wherein the hybrid color correction model is constructed by the hybrid color correction model construction method as described in any one of claims 1-5.

7. A hybrid color correction model construction device, characterized in that, include: The first curve acquisition module is used to obtain the first spectral reflectance characteristic curve based on the colorimetric information of the substrate and the corresponding reflectance spectral data. The second curve acquisition module is used to obtain the second spectral reflectance characteristic curve of the target ink based on the color gamut range and corresponding reflectance spectrum data of the target ink on the unengraved substrate; the target ink includes pure monochromatic ink and mixed ink; The third curve acquisition module is used to obtain the chromaticity values ​​and corresponding reflectance spectral data of the multi-level grayscale background color generated by laser engraving machine with different power parameters on the material, and to obtain the third spectral reflectance characteristic curve of the laser grayscale background color and the substrate material. The mixed data acquisition module is used to overprint the target color ink with the multi-level grayscale background to obtain mixed chromaticity values ​​and mixed spectral data; The model building module is used to construct a hybrid color correction model based on at least one of a first modeling parameter and a second modeling parameter; wherein, the first modeling parameter includes the chromaticity information of the printing material, the color gamut range, the chromaticity value of the multi-level grayscale background color, and the hybrid chromaticity value; the second modeling parameter includes the first spectral reflectance characteristic curve, the second spectral reflectance characteristic curve, the third spectral reflectance characteristic curve, and the hybrid spectral data; each spectral reflectance characteristic curve is used to represent the trend of reflectance variation corresponding to different wavelengths; The model building module is specifically used for: Based on the first modeling parameters, construct a chromaticity coordinate model; A spectral reflectance model is constructed based on the second modeling parameter.

8. A color cast prevention image processing device, characterized in that, include: The image segmentation module is used to segment the grayscale image of the image to be processed using a brightness threshold and to smooth the segmentation boundaries to obtain the segmented grayscale image. The color correction module is used to perform color correction on the divided grayscale image using a hybrid color correction model to obtain a color-corrected grayscale image; wherein the hybrid color correction model is constructed by the hybrid color correction model construction method as described in any one of claims 1-5.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that, When the processor executes the computer program, it implements the hybrid color correction model construction method as described in any one of claims 1 to 5 or the anti-color cast image processing method as described in claim 6.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the hybrid color correction model construction method as described in any one of claims 1 to 5 or the anti-color cast image processing method as described in claim 6.

Images