diff --git a/lib/operators.c b/lib/operators.c
index 8961c2ed..00bc49fa 100644
--- a/lib/operators.c
+++ b/lib/operators.c
@@ -63,12 +63,13 @@ if (FIMG_TYPE_RGB != a->type || FIMG_TYPE_RGB != b->type) {
 
 nbpixels = a->width * a->height;
 
+	/*   are we cache-friendly here ? 
+	 *   we need an accurate benchmarking... */
+
 for (idx=0; idx<nbpixels; idx++) {
 	b->R[idx] += a->R[idx];
 	b->G[idx] += a->G[idx];
 	b->B[idx] += a->B[idx];
-	/*   are we cache-friendly here ? 
-	 *   we need an accurate benchmarking... */
 	}
 
 return 0;
@@ -85,8 +86,8 @@ int		idx, nbpixels;
 fprintf(stderr, ">>> %s ( %p %p %p )\n", __func__, a, b, d);
 #endif
 
-if (FIMG_TYPE_RGB != a->type ||
-	FIMG_TYPE_RGB != b->type ||
+if (	FIMG_TYPE_RGB != a->type  ||
+	FIMG_TYPE_RGB != b->type  ||
 	FIMG_TYPE_RGB != d->type) {
 	fprintf(stderr, "%s : got a bad type fimg\n", __func__);
 	return -8;
@@ -175,13 +176,15 @@ if (FIMG_TYPE_RGB != a->type || FIMG_TYPE_RGB != b->type ||
 	return -8;
 	}
 
-nbiter = a->width * a->height * 3;
+nbiter = a->width * a->height;
 
 for (idx=0; idx<nbiter; idx++) {
-	if (a->R[idx] > b->R[idx])
-			d->R[idx] = a->R[idx];
-	else
-			d->R[idx] = b->R[idx];
+	if (a->R[idx] > b->R[idx])	d->R[idx] = a->R[idx];
+	else				d->R[idx] = b->R[idx];
+	if (a->G[idx] > b->G[idx])	d->G[idx] = a->G[idx];
+	else				d->G[idx] = b->G[idx];
+	if (a->B[idx] > b->B[idx])	d->B[idx] = a->B[idx];
+	else				d->B[idx] = b->B[idx];
 	}
 
 return 0;
@@ -201,13 +204,15 @@ if (FIMG_TYPE_RGB != a->type || FIMG_TYPE_RGB != b->type ||
 	return -8;
 	}
 
-nbiter = a->width * a->height * 3;
+nbiter = a->width * a->height ;
 
 for (idx=0; idx<nbiter; idx++) {
-	if (a->R[idx] < b->R[idx])
-			d->R[idx] = a->R[idx];
-	else
-			d->R[idx] = b->R[idx];
+	if (a->R[idx] < b->R[idx])	d->R[idx] = a->R[idx];
+	else				d->R[idx] = b->R[idx];
+	if (a->G[idx] < b->G[idx])	d->G[idx] = a->G[idx];
+	else				d->G[idx] = b->G[idx];
+	if (a->B[idx] < b->B[idx])	d->B[idx] = a->B[idx];
+	else				d->B[idx] = b->B[idx];
 	}
 
 return 0;