diff --git a/Fonderie/sfx.c b/Fonderie/sfx.c
index 6cb0867..48025c7 100644
--- a/Fonderie/sfx.c
+++ b/Fonderie/sfx.c
@@ -21,6 +21,38 @@
  */
 extern	int		verbosity;
 
+/* -------------------------------------------------------------- */
+/*
+ * nouveau Sun Jul 16 07:37:22 UTC 2023
+ */
+int poke_sup_rb_g(FloatImg *src, FloatImg *dst)
+{
+int		idx, nbpix, foo;
+
+#if DEBUG_LEVEL
+fprintf(stderr, ">>> %s ( %p %p )\n", __func__, src, dst);
+#endif
+
+if ( (foo=fimg_images_not_compatible(src, dst)) )
+	{
+	fprintf(stderr, "%s: no compat %d\n", __func__, foo);
+	return foo;
+	}
+
+nbpix = src->width * src->height;
+fprintf(stderr, "%s work on %d pixels\n", __func__, nbpix);
+
+for (idx=0; idx<nbpix; idx++) {
+	dst->R[idx] = src->R[idx];
+	dst->B[idx] = src->B[idx];
+	if (dst->R[idx] > dst->B[idx])
+		dst->G[idx] = dst->R[idx];
+	else
+		dst->G[idx] = dst->B[idx];
+	}
+
+return 0;
+}
 /* -------------------------------------------------------------- */
 /* nouveau 14 mai 2022 rue Ernest Renan */
 
diff --git a/Fonderie/sfx.h b/Fonderie/sfx.h
index 51d13f2..5378376 100644
--- a/Fonderie/sfx.h
+++ b/Fonderie/sfx.h
@@ -7,6 +7,7 @@ int graylevel2popcolors(FloatImg *src, FloatImg *dst, int k);
 
 int incrustation_vignette(FloatImg *src, FloatImg *dst, int k);
 
+int poke_sup_rb_g(FloatImg *src, FloatImg *dst);
 
 int trinitron(FloatImg *pimg, int notused);
 
diff --git a/Fonderie/t.c b/Fonderie/t.c
index 275ca89..b845adb 100644
--- a/Fonderie/t.c
+++ b/Fonderie/t.c
@@ -40,7 +40,7 @@ double		debut, fin;
 
 foo = fimg_create_from_dump(fIname, &image);
 if (foo) {
-	fprintf(stderr, "err %d create image\n", foo);
+	fprintf(stderr, "%s: err %d create from dump\n", __func__, foo);
 	exit(1);
 	}
 
@@ -73,8 +73,6 @@ return 0;
 
 foo = essayer_single("capture/???42.fimg", "/tmp/x8/", STK);
 fprintf(stderr, "essayer single -> %d\n", foo);
-
-
  */
 int essayer_single(char *globpattern, char *destdir, int chain)
 {
@@ -161,14 +159,14 @@ puts("\t-s\tdo single test");
 exit(0);
 }
 /* ----------------------------------------------------------- */
-int experiment(void)
+int experiment(char *fname)
 {
 int		foo;
 FloatImg	image, dest;
 
-fprintf(stderr, "--------- EXPERIMENT ------------\n");
+fprintf(stderr, "----- EXPERIMENT on '%s' -----\n", fname);
 
-foo = fimg_create_from_dump("mire.fimg", &image);
+foo = fimg_create_from_dump(fname, &image);
 if (foo) {
 	fprintf(stderr, "%s: err %d on create_from_dump\n",
 			__func__, foo);
@@ -177,8 +175,8 @@ if (foo) {
 
 foo = fimg_clone(&image, &dest, 0);
 
-foo = graylevel2popcolors(&image, &dest, 0);
-fprintf(stderr, "POP COLOR- -> %d\n", foo);
+foo = poke_sup_rb_g(&image, &dest);
+fprintf(stderr, "poke sup rb g --> %d\n", foo);
 
 fimg_export_picture(&dest, "foo.png", 0);
 
@@ -230,7 +228,7 @@ if (foo) {
 	}
 
 if (do_xper) {
-	experiment();
+	experiment(infile);
 	return 0;
 	}
 if (do_single) {