Setting the white balance of a video frame

Abstract

Disclosed is a method for setting the white balance of a video frame. The frame is first divided into sub-regions. Those sub-regions determined to be possibly dominantly monochromatic are eliminated from consideration, and the white balance is set by adjusting the color gain of the frame, the adjusting based on the other sub-regions in the frame. A sub-region is determined to be possibly dominantly monochromatic if the difference between its averaged color and each of a set of neutral reference colors is greater than a threshold. If the difference between the averaged color and at least one of the neutral reference colors is less than or equal to the threshold, then the sub-region is still determined to be possibly dominantly monochromatic if that neutral reference color, along with an illuminant type of a previous frame in the video, match closely enough to an element in an ambiguous reference color list.

1 - 14 . (canceled) 
     
     
         15 . A method for creating an ambiguous color reference list, the method comprising:
 comparing a neutral reference color with a plurality of reference colors under a plurality of illuminants; and   based, at least in part, on the comparing, creating a list of ambiguous color points, wherein each element of the list indicates a reference color under a first illuminant that has a color value whose difference from a color value of the neutral reference color under a second illuminant is less than a threshold.   
     
     
         16 . The method of  claim 15  wherein the reference colors comprise Macbeth colors. 
     
     
         17 . The method of  claim 15  wherein illuminants comprise lighting conditions selected from the group consisting of: day lighting, cloudy lighting, fluorescent lighting, and tungsten lighting. 
     
     
         18 . A computing server comprising:
 a memory configured for storing an ambiguous color reference list; and   a processor operatively coupled to the memory and configured for creating the ambiguous color reference list, the creating comprising:   comparing a neutral reference color with a plurality of reference colors under a plurality of illuminants; and   based, at least in part, on the comparing, creating a list of ambiguous color points, wherein each element of the list indicates a reference color under a first illuminant that has a color value whose difference from a color value of the neutral reference color under a second illuminant is less than a threshold.   
     
     
         19 . The computing server of  claim 18  wherein the reference colors comprise Macbeth colors. 
     
     
         20 . The computing server of  claim 18  wherein illuminants comprise lighting conditions selected from the group consisting of: day lighting, cloudy lighting, fluorescent lighting, and tungsten lighting. 
     
     
         21 . The computing server of  claim 18  further comprising:
 a transceiver operatively coupled to the memory and to the processor and configured for transmitting the ambiguous color reference list.