using autoshift to zero

Fonderie/crapulator.c

@@ -126,11 +126,21 @@ if (retval) {
 	fprintf(stderr, "%s error %d on filter\n", __func__, retval);
 	exit(1);
 	}
+
+foo = fimg_auto_shift_to_zero(&img, &img);
+if (foo) {
+	fprintf(stderr, "%s: err %d zero shift\n", __func__, foo);
+	exit(1);
+	}
+
 /**	may be, we can check for negative values ? */
+/**	or is this useless because whe have shifted to zero ? */
 if (verbosity > 1) {
 	foo = fimg_count_negativ(&img);
-	fprintf(stderr, "%s -> %d / %d negative pixels\n", __func__,
-				foo, img.width*img.height);
+	if (foo) {
+		fprintf(stderr, "%s -> %d / %d negative pixels\n", __func__,
+					foo, img.width*img.height);
+		}
 	}
 
 fimg_killborders(&img);