Difference        457 magick/composite.c     composite->red=gamma*Difference(p->red,Sa,q->red,Da);
Difference        458 magick/composite.c     composite->green=gamma*Difference(p->green,Sa,q->green,Da);
Difference        459 magick/composite.c     composite->blue=gamma*Difference(p->blue,Sa,q->blue,Da);
Difference        461 magick/composite.c       composite->index=gamma*Difference(p->index,Sa,q->index,Da);