Color enhancement method and system
AssigneeEastman Kodak Company
InventorsYee Seung Ng, Hwai-Tzuu Tai, Chung-Hui Kuo, Dmitri Anatolyevich Gusev
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Abstract
An apparatus and method for calibrating a multi-color imaging system are provided. Color values are measured for each of the different color patches, and compared to target process-sensitive colors color values, representing a weight-adjusted memory color. An error value is calculated. The error value represents a deviation of the measured color values from the target color values. The input values for each colorant then are independently adjusted to reduce the error value to a predetermined degree.
Claims20
A method for recalibrating a multi-color imaging system wherein the imaging system is capable of outputting corrections by including weight-adjusted coefficients on process-sensitive memory color colors based on selected input target color values, the method comprising:
- a. forming selected input target process-sensitive color combinations, wherein one or more of the process-sensitive color combinations includes at least two different colors including a human sensitive memory color;
- measuring color values for each of the different color combinations of process-sensitive colors;
- b. comparing each of the measured color values to values corresponding to the input target color values that represent a desired condition of the imaging system;
- c. calculating an error value that represents a deviation of the measured color values from the input target color values;
- d. assigning weight-adjusting coefficients on one or more of the input target color values to reduce the error value to a predetermined degree, wherein the adjustment of the input target color values for one of the colors is performed independently of the adjustment of the input target color values for others of the colors and continued as needed to make all the corrections needed to match the input target process-sensitive color combinations;
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- e. further assigning weight-adjusting coefficients on one or more of the input target color values comprising the human sensitive memory color to reduce the error value to a predetermined degree, wherein the weight adjustment of the input target color values for one of the colors is performed independently of the weight adjustment of the input target color values for others of the colors such that error values for the human sensitive memory color are less than the other error values and continued as needed to make all the corrections needed to match the target color sensitive color combinations weight coefficients.
A method for recalibrating a multi-color imaging system wherein the imaging system is capable of outputting corrections by including weight-adjusted coefficients on both process-sensitive and memory-sensitive colors without intervention based on selected input target color values, method comprising:
- a. Selecting an original process-sensitive color set of process-sensitive colors in LAB color space;
- b. Generating a first process-sensitive target colorant set of target process-sensitive colors in CMYK space and a second memory-sensitive target colorant set of memory-sensitive colors [colorant set] in CMYK space;
- c. Printing the target process-sensitive and memory-sensitive colorant set in CMYK space for a specific substrate using an applicable post finishing system;
- d. Measuring a printed process-sensitive and a print memory-sensitive colorant set with a measurement device to obtain L′A′B′ data set;
- e. Generating a new target process-sensitive and memory-sensitive colorant set in C′M′Y′K′ space though a color transform using the measured L′A′B′ data set;
- f. Minimizing the color differences between the original color set of colors (CMYK) and the new target colorant set (C′M′Y′K′) by applying a regression on each of the two sets using assigned weighted coefficients for both the different process-sensitive and memory-sensitive colors such that the error values for the memory-sensitive colors are less than the other error values;
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- g. Loading the corrections resulted from minimization process into the printer.
A method for recalibrating a multi-color imaging system wherein the imaging system is capable of outputting corrections by including weight-adjusted coefficients on color sensitive colon, with suitable operator interactive controls, based on selected input target color values, the method comprising:
- a. Selecting an original color set of color sensitive colors in LAB color space;
- b. Generating a target color sensitive colorant set in CMYK space;
- c. Printing the target color sensitive colorant set in CMYK space for a specific substrate using an applicable post finishing system;
- d. Measuring the printed color -sensitive colorant set with a measurement device to obtain L′A′B′ data set;
- e. Generating a new target color -sensitive colorant set in C′M′Y′K′ space though a color transform using the measured L′A′B′ data set;
- f. Minimizing the color differences between the original color set of color sensitive colors (CMYK) and the new target color sensitive colorant set (C′M′Y′K′) by applying a regression on the two sets using assigning weighted coefficients the different color sensitive colors such that error values for the memory-sensitive colors are less than the other error values;
- g. Loading the corrections resulted from minimizing process into the printer.
A computer readable medium encoded with a computer program arranged such that, upon execution of the computer program, a processor performs a method for recalibrating a multi-color imaging system, the imaging system configured to correct output colors based on corresponding input target color values, the method comprising:
- forming target color sensitive color combinations, wherein one or more of the color sensitive color combinations includes at least two different colors, including a human sensitive memory color;
- measuring color values for each of the different color combinations of color sensitive colors;
- comparing each of the measured color values to corresponding to the input target color values that represent a desired condition of the imaging system;
- calculating an error value that represents a deviation of the measured color values from the input target color values comprising an error value for each measured color including an error value for the human sensitive memory color;
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- assigning weight-adjusting coefficients on one or more of the input target color values to reduce the error value to a predetermined degree, wherein the weight adjustment of the input target color values for one of the colors is performed independently of the weight adjustment of the input target color values for others of the colors such that error values for the human sensitive memory color are less than the other error values and continued as needed to make all the corrections needed to match the target color sensitive color combinations.
Dependencies are inferred from the claim text.