Color correction using a device-dependent display profile

Abstract

A method includes obtaining a chromatic correction for a display device based on a device-dependent display profile. The method may ensure that images that appear on a display device in a soft proofing environment will be visually equivalent to images that appear on print media.

1 . A method comprising applying selective chromaticity corrections to device-independent coordinates using at least one piecewise linear correction function.  
   
   
       2 . The method of  claim 1  wherein the piecewise linear correction function operates on linear device-dependent coordinates associated with an output device.  
   
   
       3 . The method of  claim 1  further comprising: 
 providing a group of piecewise linear correction functions, each group corresponding to a different region of color in a device-dependent coordinate space associated with an output device; and    applying each group of piecewise linear correction functions to the device-independent coordinates in the corresponding regions of color to perform chromaticity corrections to the device-independent coordinates.    
   
   
       4 . A method comprising applying selective chromaticity corrections to device-independent coordinates that define colors in a visually non-uniform color space, wherein the chromaticity corrections are based on linear correction functions of linear device-dependent coordinates, and wherein the chromaticity corrections are applied to device-independent coordinates in a piecewise fashion between color boundaries to produce chromatically corrected device-independent coordinates.  
   
   
       5 . A method, comprising: 
 determining a correction level based on desired changes in saturation, hue and brightness for chromatic colors of a device-dependent color space associated with a display device;    calculating a correction factor based on a linear correction function associated with the display device; and    applying the correction factor and the correction level to device-independent coordinates that define chromatic colors of a printing device to produce chromatically corrected device-independent coordinates.    
   
   
       6 . The method of  claim 5  further comprising displaying the chromatic colors using the chromatically corrected device-independent coordinates on the display device.  
   
   
       7 . The method of  claim 5  wherein calculating the correction factor further comprises calculating a piecewise linear correction function of linear device-dependent coordinates.  
   
   
       8 . The method of  claim 7  wherein the linear device-dependent coordinates are linear RGB coordinates.  
   
   
       9 . The method of  claim 7  further comprising: 
 calculating a group of piecewise linear correction functions, each group corresponding to a different region of color; and    applying each group of piecewise linear correction functions to the device-independent coordinates in the corresponding regions of color.    
   
   
       10 . A method comprising: 
 converting device-dependent coordinates that define a color in a printing device to device-independent coordinates;    applying chromaticity corrections to the device-independent coordinates based on a linear correction function of device-dependent coordinates associated with the printing device to produce corrected device-independent coordinates; and    converting the corrected device-independent coordinates to device-dependent coordinates that define a color in a display device associated with the device-dependent display profile.    
   
   
       11 . The method of  claim 10 , further comprising displaying the color using the corrected device-dependent coordinates on the display device.  
   
   
       12 . The method of  claim 11 , wherein the displayed color is visually equivalent to the color on a hard copy printed by the printing device.  
   
   
       13 . The method of  claim 10 , further comprising correcting the white point for the display device.  
   
   
       14 . The method of  claim 10 , wherein applying chromaticity corrections to the device-independent coordinates comprises: 
 calculating primary correction factors corresponding to each primary region of color of the display device based on the linear correction function of device-dependent coordinates;    calculating secondary correction factors corresponding to each secondary region of color of the display device based on the linear correction function of device-dependent coordinates;    applying each primary correction factor to the device-independent coordinates in the corresponding primary regions of color; and    applying each secondary correction factor to the device-independent coordinates in the corresponding secondary regions of color of the device-independent coordinates.    
   
   
       15 . The method of  claim 14 , further comprising: 
 determining primary correction levels corresponding to each primary region of color;    determining secondary correction levels corresponding to each secondary region of color;    applying each primary correction level to the device-independent coordinates in the corresponding primary regions of color; and    applying each secondary correction level to the device-independent coordinates in corresponding secondary regions of color.    
   
   
       16 . The method of  claim 15  wherein the primary correction levels and the secondary correction levels each comprise adjustments to the hue, saturation, and brightness for corresponding primary and secondary regions of color of the device-independent coordinates.  
   
   
       17 . A system comprising: 
 a display device; and    a processor coupled to the display, wherein the processor applies selective chromaticity corrections to device-independent coordinates using at least one piecewise linear correction function.    
   
   
       18 . The method of  claim 17  wherein the piecewise linear correction function operates on linear device-dependent coordinates associated with an output device.  
   
   
       19 . The method of  claim 17  further comprising: 
 providing a group of piecewise linear correction functions, each group corresponding to a different region of color in a device-dependent coordinate space associated with an output device; and    applying each group of piecewise linear correction functions to the device-independent coordinates in the corresponding regions of color to perform chromaticity corrections to the device-independent coordinates.    
   
   
       20 . A system comprising: 
 a printing device;    a display device; and    a processor coupled to the printing device and the display device, wherein the processor: 
 converts device-dependent coordinates that define a color in the printing device to device-independent coordinates;  
 applies chromaticity corrections to the device-independent coordinates based on a linear correction function of device-dependent coordinates associated with the printing device to produce corrected device-independent coordinates; and  
 converts the corrected device-independent coordinates to device-dependent coordinates that define a color in a display device associated with the device-dependent display profile.  
   
   
   
       21 . A system comprising: 
 a display device;    a memory device; and    a processor coupled to the display device and the memory device, wherein the processor: 
 receives a first set of image data from the memory device defining a first visual representation of an image on a hard copy;  
 creates a second set of image data defining a second visual representation of the image for display on the display device based on a linear correction function; and  
 displays the image on the display.  
   
   
   
       22 . A computer-readable medium containing instructions for causing a processor to: 
 receive a white point correction for a display device;    determine chromaticity corrections to device-independent coordinates corresponding to each region of color in a device-dependent coordinate space based on linear device-dependent coordinates;    apply the white point correction to the device-independent coordinates; and    apply the chromaticity corrections to the device-independent coordinates in the corresponding regions of color to obtain corrected device-independent coordinates.    
   
   
       23 . A computer-readable medium containing instructions for causing a processor to: 
 convert device-dependent coordinates that define a color in a printing device to device-independent coordinates;    applying chromaticity corrections to the device-independent coordinates based on a linear correction function of device-dependent coordinates associated with the printing device to produce corrected device-independent coordinates; and    convert the corrected device-independent coordinates to device-dependent coordinates that define a color in a display device associated with the device-dependent display profile.    
   
   
       24 . The computer-readable medium of  claim 23  further containing instructions for causing a processor to calculate correction factors corresponding to each region of color that are piecewise linear correction functions within the corresponding regions of color.  
   
   
       25 . The computer-readable medium of  claim 24  wherein the each piecewise linear correction function operates on the linear device-dependent coordinates within the corresponding region of color.  
   
   
       26 . The computer-readable medium of  claim 25  wherein the linear device-dependent coordinates comprise linear RGB coordinates.  
   
   
       27 . The computer-readable medium of  claim 23  wherein the device-independent coordinates comprise linear device-independent coordinates.  
   
   
       28 . The computer-readable medium of  claim 27  wherein the device-independent coordinates comprise coordinates in tristimulus space.  
   
   
       29 . The computer-readable medium of  claim 27  wherein the device-independent coordinates comprise coordinates in chromaticity space.  
   
   
       30 . The computer-readable medium of  claim 23  wherein the regions of color in the device-dependent coordinate space comprise red, green, blue, cyan, magenta and yellow.  
   
   
       31 . A method comprising: 
 obtaining a white point correction for a display device;    obtaining a first chromatic correction for the display device by determining a chromatic correction matrix;    generating first corrected device-independent coordinates based on the white point correction and the first chromatic correction;    determining a second chromatic correction to the first set of corrected device-independent coordinates based on a linear correction function; and    applying the second chromatic correction to the first corrected device-independent coordinates to produce second corrected device-independent coordinates.