anchor.diff:                                   (pixel img (first f) (second f))
                                    (declare (type (unsigned-byte 8) r1 g1 b1))
                                       ;((and (eq _r 0) (eq r1 255)) (setf empty nil))
  -                                    ;((and (eq _r 255) (eq r1 255)) (setf empty nil))
  +                                    (if (and (eq _r 255) (eq r1 255)) (setf w (+ w 1)))
                                       (if (and (eq _r 255) (eq r1 0)) (setf c (+ c 1)))
  +                                    (if (and (eq _r 0) (eq r1 255)) (setf l (+ l 1)))
  +                                    ;(if (and (eq _r 0) (eq r1 255)) (setf w (+ w 1)))
                                       ;(setf c 6)
                                    )))
                        (multiple-value-bind (r g b)
  
positive.code:                         (declare (type (unsigned-byte 8) r g b))
                             (setf v r)
                             (if (eq c 8) (setf v 0))
                             (setf (pixel img i j)
                                (values v v v))))))))))
  
  
negative.code: (defun edge-detect (img output)
     (format t "Converting to greyscale~%")
     (greyscale-image img)
     
     (format t "Bluring image~%")
     (setf img (blur-image img))
  
     (format t "Dilate the image~%")
     (setf img (dilate (discrete-convolve img *edge-kernel*)
        (make-8-bit-rgb-image 3 3 :initial-element 3)))
  
     (format t "Applying edge detect~%")
     (setf img (discrete-convolve img *edge-kernel*))
  
     (format t "Threashold the image~%")
     (threashold-image img 30)
  
     (format t "Edge thinning (long process)~%")
     (edge-thin img)
  