if(dest_width != width || dest_height != height) {
/* TODO: size conversion */
fprintf(stderr, "size mismatch: %dx%d != %dx%d\n", width, height, dest_width, dest_height);
if(dest_width != width || dest_height != height) {
/* TODO: size conversion */
fprintf(stderr, "size mismatch: %dx%d != %dx%d\n", width, height, dest_width, dest_height);