If `convert' is not required, it is not invoked.

(twittering-retrieve-image): Do not invoke `convert' if Emacs supports
the image type and resize is not required.

ChangeLog

@@ -60,6 +60,8 @@
 
 	* twittering-mode.el (twittering-image-type): Try to detect image
 	type with `image-type-from-data' at first.
+	(twittering-retrieve-image): Do not invoke `convert' if Emacs
+	supports the image type and resize is not required.
 
 2010-01-08  Yuto Hayamizu  <y.hayamizu@gmail.com>
 

twittering-mode.el

@@ -1965,7 +1965,10 @@ following symbols;
   (let ((image-data (gethash `(,image-url . ,twittering-convert-fix-size)
 			     twittering-image-data-table)))
     (when (not image-data)
-      (let ((image-type nil))
+      (let ((image-type nil)
+	    (image-spec nil)
+	    (converted-image-size
+	     `(,twittering-convert-fix-size . ,twittering-convert-fix-size)))
 	(with-temp-buffer
 	  (set-buffer-multibyte nil)
 	  (let ((coding-system-for-read 'binary)
@@ -1974,7 +1977,13 @@ following symbols;
 	    (url-insert-file-contents image-url)
 	    (setq image-type (twittering-image-type image-url
 						    (current-buffer)))
-	    (when (and twittering-convert-fix-size twittering-use-convert)
+	    (setq image-spec `(image :type ,image-type
+				     :data ,(buffer-string)))
+	    (when (and twittering-convert-fix-size twittering-use-convert
+		       (not
+			(and (image-type-available-p image-type)
+			     (equal (image-size image-spec t)
+				    converted-image-size))))
 	      (call-process-region 
 	       (point-min) (point-max)
 	       twittering-convert-program