Color gamut scalability techniques

Abstract

Techniques are described that can be used to either compress or expand video. Color compression techniques are described that can be used to compress the wide color gamut content into lower color gamut for inclusion in a baseline layer. Color expansion techniques are described that convert lower color gamut data into wider color gamut format for inclusion in an enhancement layer. Both of the baseline video stream and enhancement layer video streams may be transmitted through a channel or stored in a memory device to be viewed later. Accordingly, both baseline and enhancement video layers are available so that either lower or higher quality displays can be used to display video.

What is claimed is: 
     
         1 . A method comprising:
 transforming video from a first color gamut to a second color gamut, wherein the first color gamut comprises a wide color gamut and the second color gamut is lower color gamut than the first color gamut, wherein the transforming video comprises:
 applying color compression comprising:
 performing color space conversion from YCbCr to RGB, 
 performing inverse opto-electronic transfer, 
 performing color space conversion from RGB to XYZ, and 
 performing color triangle transformation via translation, 
 
 rotation, and scaling, and 
   applying baseline layer video encoding to form baseline video based at least in part on the color compressed video; and   providing an enhancement layer version of video based at least in part on the wide color gamut video.   
     
     
         2 . The method of  claim 1 , wherein the enhancement layer includes video of higher bit depth and the baseline layer includes video of lower bit depth. 
     
     
         3 . The method of  claim 1 , wherein the applying color compression further comprises:
 performing color space conversion based on RGB, hue, saturation, lightness, brightness, and intensity.   
     
     
         4 . The method of  claim 1 , further comprising:
 applying color expansion to convert the video of lower color gamut into wide color gamut and   using an enhancement layer video encoding to form the enhancement layer version of video based at least in part on the converted wide color gamut video and based at least in part on the wide color gamut video.   
     
     
         5 . The method of  claim 4 , wherein the applying color expansion comprises:
 performing color space conversion from YCbCr to RGB;   performing inverse opto-electronic transfer;   performing color space conversion from RGB to XYZ; and   performing color triangle transformation via translation, rotation, and scaling.   
     
     
         6 . The method of  claim 4 , wherein the applying color expansion comprises:
 performing color space conversion from YCbCr to RGB;   performing inverse opto-electronic transfer;   performing color space conversion from RGB to XYZ; and   performing color space conversion based on RGB, hue, saturation, lightness, brightness, and intensity; and   performing color triangle transformation via translation, rotation, and scaling.   
     
     
         7 . An apparatus comprising:
 color compression logic configured to translate higher gamut video to lower gamut video, wherein the color compression logic is to:
 perform color space conversion from YCbCr to RGB; 
 perform inverse opto-electronic transfer; 
 perform color space conversion from RGB to XYZ; and 
 perform color triangle transformation via translation, rotation, and scaling; 
   color expansion logic configured to translate lower gamut video to higher gamut video;   a baseline layer encoder configured to provide baseline layer video based at least in part on the translated lower gamut video;   an enhancement layer video encoder configured to form enhancement layer video based at least in part on the higher gamut video; and   a memory to store the baseline and enhancement layer video.   
     
     
         8 . The apparatus of  claim 7 , wherein the enhancement layer includes video of higher bit depth and the baseline layer includes video of lower bit depth. 
     
     
         9 . The apparatus of  claim 7 , wherein the color compression logic is also to:
 perform color space conversion based on RGB, hue, saturation, lightness, brightness, and intensity.   
     
     
         10 . The apparatus of  claim 8 , wherein the color compression logic is to:
 perform color space conversion based on RGB, hue, saturation, lightness, brightness, and intensity.   
     
     
         11 . The apparatus of  claim 7 , wherein the color expansion logic is to:
 perform color space conversion from YCbCr to RGB;   perform inverse opto-electronic transfer;   perform color space conversion from RGB to XYZ; and   perform color triangle transformation via translation, rotation, and scaling.   
     
     
         12 . The apparatus of  claim 8 , wherein the color expansion logic is to:
 perform color space conversion from YCbCr to RGB;   perform inverse opto-electronic transfer;   perform color space conversion from RGB to XYZ; and   perform color triangle transformation via translation, rotation, and scaling.   
     
     
         13 . The apparatus of  claim 7 , wherein the color expansion logic is to:
 perform color space conversion from YCbCr to RGB;   perform inverse opto-electronic transfer;   perform color space conversion from RGB to XYZ; and   perform color space conversion based on RGB, hue, saturation, lightness, brightness, and intensity; and   perform color triangle transformation via translation, rotation, and scaling.   
     
     
         14 . The apparatus of  claim 8 , wherein the color expansion logic is to:
 perform color space conversion from YCbCr to RGB;   perform inverse opto-electronic transfer;   perform color space conversion from RGB to XYZ; and   perform color space conversion based on RGB, hue, saturation, lightness, brightness, and intensity; and   perform color triangle transformation via translation, rotation, and scaling.   
     
     
         15 . An apparatus comprising:
 a memory to store video, the video including baseline layer and enhancement layer versions, wherein the memory is to store mapping parameters useful for gamut scaling from lower color gamut to a higher color gamut, wherein the mapping parameters comprise a scaling factor and an angle;   a baseline layer decoder configured to decode baseline layer video into lower color gamut video;   color expansion logic configured to convert lower color gamut video to higher color gamut video, wherein the color expansion logic is configured to convert lower color gamut video to higher color gamut video based at least in part the mapping parameters; and   an enhancement layer decoder configured to provide video based at least in part on the enhancement layer version and the converted higher color gamut video.   
     
     
         16 . The apparatus of  claim 15 , wherein the enhancement layer includes video of higher bit depth and the baseline layer includes video of lower bit depth. 
     
     
         17 . The apparatus of  claim 15 , wherein the color expansion logic is to:
 perform color space conversion from YCbCr to RGB;   perform inverse opto-electronic transfer;   perform color space conversion from RGB to XYZ; and   perform color triangle transformation via translation, rotation, and scaling.   
     
     
         18 . The apparatus of  claim 16 , wherein the color expansion logic is to:
 perform color space conversion from YCbCr to RGB;   perform inverse opto-electronic transfer;   perform color space conversion from RGB to XYZ; and   perform color triangle transformation via translation, rotation, and scaling.   
     
     
         19 . The apparatus of  claim 15 , wherein the color expansion logic is to:
 perform color space conversion from YCbCr to RGB;   perform inverse opto-electronic transfer;   perform color space conversion from RGB to XYZ; and   perform color space conversion based on RGB, hue, saturation, lightness, brightness, and intensity; and   perform color triangle transformation via translation, rotation, and scaling.   
     
     
         20 . The apparatus of  claim 16 , wherein the color expansion logic is to:
 perform color space conversion from YCbCr to RGB;   perform inverse opto-electronic transfer;   perform color space conversion from RGB to XYZ; and   perform color space conversion based on RGB, hue, saturation, lightness, brightness, and intensity; and   perform color triangle transformation via translation, rotation, and scaling.