anchor.diff:      (declare #.*optimize*
                (type fixnum dx dy h w height width xend yend)
                (type (simple-vector *) YUV Y U V)
  -             (type (array uint8 *) RGB))
  +             (type (simple-array uint8 (*)) RGB))
       (setf xend (min xend (1- w)))
       (setf yend (min yend (1- h)))
       (loop for yd fixnum from dy to yend
  
positive.code:   (let* ((buffer (descriptor-buffer image))
           (nw (mul (descriptor-width image) 3)))
      (declare #.*optimize*
               (type (array uint8 *) buffer)
               (type fixnum nw))
      (loop for y fixnum from 0 below (descriptor-height image)
            for yp fixnum from 0 by nw do
  
negative.code:                             &key (q-tabs +q-tables+) (sampling '((2 2)(1 1)(1 1))) (q-factor 64))
    (declare #.*optimize*
             (type fixnum ncomp h w q-factor)
             (type (simple-array uint8 (*)) image))
    (when (= ncomp 1)
      (setq sampling '((1 1))))
    (let* ((wd (loop for entry in sampling maximize (first entry)))
  