//////////////////////////////////////////////////////////// 
// uchar cvBackgroundDiff( uchar *p, codeBook &c, 
// int minMod, int maxMod)
// Given a pixel and a code book, determine if the pixel is 
// covered by the codebook
//
// p Pixel pointer (YUV interleaved)
// c Codebook reference
// numChannels Number of channels we are testing
// maxMod Add this (possibly negative) number onto 
// max level when determining if new pixel is foreground
// minMod Subract this (possible negative) number from 
// min level when determining if pixel is foreground
//
// NOTES: 
// minMod and maxMod must have length numChannels, 
// e.g. 3 channels => minMod[3], maxMod[3].
//
// Return
// 0 => background, 255 => foreground
uchar cvBackgroundDiff( uchar *p, codeBook &c, int numChannels, 
 int *minMod, int *maxMod){
 int matchChannel;
 //SEE IF THIS FITS AN EXISTING CODEWORD
 for(int i=0; i<c.numEntries; i++){
 matchChannel = 0;
 for(int n=0; n<numChannels; n++){
 if((c.cb[i]->min[n] - minMod[n] <= *(p+n)) && 
 (*(p+n) <= c.cb[i]->max[n] + maxMod[n])) 
 {
 matchChannel++; //Found an entry for this channel
 }
 else
 {
 break;
 }
 }
 if(matchChannel == numChannels)
 {
 break; //Found an entry that matched all channels
 }
 }
 if(i >= c.numEntries) return(255);
 return(0);
}