gistfile1.lisp

(defun cocoa-get-image-bytes (image)
  (let ((bitmap (objc:invoke 
                 (objc:invoke "NSBitmapImageRep" "alloc") 
                 "initWithData:" 
                 (objc:invoke image "TIFFRepresentation"))))
    (if bitmap
        (let ((data (objc:invoke-into 
                     '(:pointer (:unsigned :char))
                     bitmap "bitmapData")))
          (values bitmap data))
        nil)))

;;; Free image data

(defun cocoa-free-image-bytes (bitmap)
  (objc:invoke bitmap "release"))