RGB_HALF          138 ext/gd/libgd/webpimg.c     kVToR[i] = (89858 * (i - 128) + RGB_HALF) >> RGB_FRAC;
RGB_HALF          139 ext/gd/libgd/webpimg.c     kUToG[i] = -22014 * (i - 128) + RGB_HALF;
RGB_HALF          141 ext/gd/libgd/webpimg.c     kUToB[i] = (113618 * (i - 128) + RGB_HALF) >> RGB_FRAC;
RGB_HALF          144 ext/gd/libgd/webpimg.c     const int j = ((i - 16) * 76283 + RGB_HALF) >> RGB_FRAC;