anchor.diff:  (defun create-image (size depth channels)
     "Create an image with dimensions given by SIZE, DEPTH bits per
   channel, and CHANNELS number of channels."
  -  (let ((nsize (cv-size-to-int64 size)))
  +  (let ((nsize (cv-size->int64 size)))
       (%create-image nsize depth channels)))
   
   ;; CvSize cvGetSize(const CvArr* arr)
  
positive.code: 
  (defun set-image-roi (image rect)
    "Set the ROI of IMAGE to the rectangle RECT."
    (let ((irect (cv-rect-to-int64s rect)))
      (%set-image-roi image (first irect) (second irect))))
  
  ;; void cvSub(const CvArr* src1, const CvArr* src2, CvArr* dst, 
  
negative.code: ;; double. We provide a helper function to create a Lisp version of a
  ;; scalar. The helper ensures that there are only four values in the
  ;; scalar.
  (defun make-cv-scalar (&rest args)
    (mapcar #'(lambda (v) (coerce v 'double-float))
  	  (cond ((> (length args) 4) (subseq args 0 4))
  		((< (length args) 4) 
  