-int image_init_matrix(struct image_thread *it, struct image *img, byte *pixels, uns cols, uns rows, uns row_size, uns flags);
-int image_init_subimage(struct image_thread *it, struct image *img, struct image *src, uns left, uns top, uns cols, uns rows);
+struct image *image_init_matrix(struct image_thread *it, struct image *img, byte *pixels, uns cols, uns rows, uns row_size, uns flags);
+struct image *image_init_subimage(struct image_thread *it, struct image *img, struct image *src, uns left, uns top, uns cols, uns rows);