+ for(i=1; i<num_infiles; i++) {
+ if(load_image(&tmpimg, infiles[i]) == -1) {
+ fprintf(stderr, "failed to load PNG file: %s\n", infiles[i]);
+ return 1;
+ }
+ if(tmpimg.width != img.width || tmpimg.height != img.height) {
+ fprintf(stderr, "size mismatch: first image (%s) is %dx%d, %s is %dx%d\n",
+ infiles[0], img.width, img.height, infiles[i], tmpimg.width, tmpimg.height);
+ return 1;
+ }
+ if(tmpimg.bpp != img.bpp) {
+ fprintf(stderr, "bpp mismatch: first image (%s) is %d bpp, %s is %d bpp\n",
+ infiles[0], img.bpp, infiles[i], img.bpp);
+ return 1;
+ }
+
+ overlay_key(&tmpimg, 0, &img);
+ }
+
+ if(img.bpp == 4 && renibble) {
+ unsigned char *ptr = img.pixels;
+ for(i=0; i<img.width * img.height; i++) {
+ unsigned char p = *ptr;
+ *ptr++ = (p << 4) | (p >> 4);
+ }
+ }
+