--- a/ccdemos/image.h	Fri Apr 04 13:54:47 2008 +0200
+++ b/ccdemos/image.h	Tue Apr 08 01:05:12 2008 +0200
@@ -9,11 +9,11 @@
 	int pixel_size;  /* should be 1 for grayscale and 3 for RGB*/
 	int width;
 	int height;
-	char *data;
+	unsigned char *data;
 };
 
 int new_image(struct image **img, int width, int height, int pixelsize);
-int destroy_image(struct image **img);
+void destroy_image(struct image **img);
 
 int save_png(const char *fname, struct image *img);