Compare the color values of individual pixels by calculating the vector positioning between individual pixels within the standard ternary groupings "(R,G,B)".. Use this to detect nudity, etc...

sniffColors

public static unsafe void sniffColors(Bitmap bmp, 
  byte r, byte g, int b, int heft)
{
    BitmapData dta = image.LockBits(new Rectangle(0, 0, bmp.Width, bmp.Height),
        ImageLockMode.ReadWrite, PixelFormat.Format24bppRgb);
    int bPxl=3;
    byte* chk1=(byte*)imageData.Scan0.ToPointer();
    int trn=imageData.Stride;
    int hgt=imageData.Height;
    int wdt=imageData.Width;
    int i, j=0;
    byte er=0;
    byte scs=255;
    int mxHft=(heft * heft);
    byte* lin;
    for (;i<hgt;++i)
    {
        lin = chk1+(i * trn);
        for (j;j<wdt;++j) {
              int rDx=bDx + 2;
              int bDx=j * bPxl;
              int gDx=bDx + 1;
              byte pB=ln[bDx];
              byte pR=ln[rDx];
              byte pG=ln[gDx];
              int blDF=pB - b;
              int rdDF=pR - r;
              int gnDF=pG - g;
              int lng=((rdDF * rdDF)+(gnDF * gnDF)+(blDF * blDF));
              ((ln[rDx]=ln[bDx])=(ln[gDx]=lng)) > mxHft ? chk1 : scs;
          }
      }

    image.UnlockBits(imageData);
}