diff --git a/funcs/sfx4.c b/funcs/sfx4.c
index 5b14e3b1..1e4da9b8 100644
--- a/funcs/sfx4.c
+++ b/funcs/sfx4.c
@@ -83,4 +83,38 @@ for(idx=0; idx<surface; idx++) {
 return 0;
 }
 /* -------------------------------------------------------------- */
+int fimg_make_triptyq(FloatImg *src, FloatImg *dst, int notused)
+{
+int		x, y, sh, foo, ow;
+float		r, g, b, in[3];
+
+#if DEBUG_LEVEL
+fprintf(stderr, ">>> %s ( %p %p 0x%04x )\n", __func__, src, dst, notused);
+#endif
+
+if (fimg_images_not_compatible(src, dst)) {
+	fprintf(stderr, "%s : compatibility error\n", __func__);
+	return -8;
+	}
+
+fimg_clear(dst);
+
+ow = src->width / 3;
+for (y=0; y<src->height; y++) {
+	for (x=0; x<src->width/3; x++) {
+		r = g = b = 0.0;
+		for (sh=0; sh<3; sh++) {
+			foo =  fimg_get_rgb(src, (x*3)+sh, y, in);
+			r+=in[0], g+=in[1], b+=in[2];
+			}
+		for (sh=0; sh<3; sh++) {
+			fimg_plot_rgb(dst, x,        y,   r, 0, 0);
+			fimg_plot_rgb(dst, x+ow,     y,   0, g, 0);
+			fimg_plot_rgb(dst, x+(2*ow), y,   0, 0, b);
+			}
+		}
+	}
+
+return 0;
+}
 /* -------------------------------------------------------------- */
diff --git a/funcs/t.c b/funcs/t.c
index 025f52bb..d0d21257 100644
--- a/funcs/t.c
+++ b/funcs/t.c
@@ -26,7 +26,7 @@ enum nCmd { Equalize=1, Rotate, Sfx0, F3x3, MIRE, Wfits, Wpng, Wtiff,
 			Geometrie, FileType, Mirror, KillRGB,
 			Pixelize,SplitLevel, DecompRgbz, DecompRgbg,
 			Rectangle, Dicom, Fakolor0, Fakolor3,
-			Fmorpho0, Fluffy, ThermoCol  };
+			Fmorpho0, Fluffy, ThermoCol, TriPtyq  };
 typedef struct {
 	char	*name;
 	int	Cmd;
@@ -66,6 +66,7 @@ Command commands[] = {
 	{ "fmorpho0",	Fmorpho0	},
 	{ "fluffy",	Fluffy		},
 	{ "thermocol",	ThermoCol	},
+	{ "triptyq",    TriPtyq		},
 	{ NULL,		0		}
 	} ;
 
@@ -271,6 +272,10 @@ switch(opt) {
 		foo = essai_thermocol(filename, outfile);
 		fprintf(stderr, "retour thermocolor = %d\n", foo);
 		break;
+	case TriPtyq:
+		foo = essai_triptyq(filename, outfile);
+		fprintf(stderr, "retour triptyq = %d\n", foo);
+		break;
 
 	default:
 		fprintf(stderr, "'%s' is a bad command\n", command);
diff --git a/funcs/tests.c b/funcs/tests.c
index 2797abd7..5b279fed 100644
--- a/funcs/tests.c
+++ b/funcs/tests.c
@@ -23,6 +23,39 @@ extern int		verbosity;
 #define W 1024
 #define H 768
 
+/* --------------------------------------------------------------------- */
+/* new Mon Apr  1 15:35:57 UTC 2024     -> sfx4.c			 */
+int essai_triptyq(char *infile, char *outfile)
+{
+FloatImg	src, dst;
+int		idx, foo;
+
+fprintf(stderr, ">>> %s ( %s %s )\n", __func__, infile, outfile);
+
+foo = fimg_create_from_dump(infile, &src);
+if (0 != foo) {
+	fprintf(stderr, "%s: err %d loading image '%s'\n", __func__,
+				foo, 		infile);
+	return foo;
+	}
+fimg_clone(&src, &dst, 1);
+
+foo = fimg_make_triptyq(&src, &dst, 0);
+if (0 != foo) {
+	fprintf(stderr, "%s: make_triptyq -> %d\n", __func__, foo);
+	return foo;
+	}
+
+foo = fimg_export_picture(&dst, outfile, 0);
+if (0 != foo) {
+	fprintf(stderr, "%s: err %d exporting to '%s'\n", __func__,
+				foo, 		outfile);
+	return foo;
+	}
+
+return 0;
+}
+
 /* --------------------------------------------------------------------- */
 /*
  *	nouveau 30 octobre 2022     --> fmorpho.c
diff --git a/funcs/tests.h b/funcs/tests.h
index 9349d895..e270d2fb 100644
--- a/funcs/tests.h
+++ b/funcs/tests.h
@@ -31,6 +31,7 @@ int fimg_essai_histo(FloatImg *src, char *outpic, int k); /* histogram.c */
 int essai_histogramme(char *fname, int k);
 int essai_0_fausses_couleurs(char *dstfile, int type);
 int essai_thermocol(char *infile, char *outfile);
+int essai_triptyq(char *infile, char *outfile);
 
 int essai_lecture_png(char *fname, char *outfile, int notused);