memcpy(buf, output_dir, output_path_len);
buf[output_path_len] = '/';
for (image = 1; image <= w->hdr.image_count; image++) {
memcpy(buf, output_dir, output_path_len);
buf[output_path_len] = '/';
for (image = 1; image <= w->hdr.image_count; image++) {