diff --git a/funcs/misc-plots.c b/funcs/misc-plots.c
index 5bcfbf82..ec22d4e4 100644
--- a/funcs/misc-plots.c
+++ b/funcs/misc-plots.c
@@ -15,7 +15,7 @@ int fimg_test_pattern(FloatImg *fimg, int type, double dval)
 {
 int		nio;
 int		x, y;
-float		fr, fg, fb;
+float		fr, fg, fb, val;
 
 #if DEBUG_LEVEL
 fprintf(stderr, ">>> %s ( %p %d %g )\n", __func__, fimg, type, dval);
@@ -27,39 +27,26 @@ if (fimg->type != FIMG_TYPE_RGB) {
 	}
 
 /* rampe de primaires dans le quart du haut */
-
+val = (float)dval;
 for (x=0; x<fimg->width; x++) {
-
 	nio = x / (fimg->width / 8);
-
 	switch(nio) {
-		case 0:
-			fr = 0.0, fg = 0.0, fb = 0.0;	break;
-		case 1:
-			fr = 1.0, fg = 0.0, fb = 0.0;	break;
-		case 2:
-			fr = 0.0, fg = 1.0, fb = 0.0;	break;
-		case 3:
-			fr = 1.0, fg = 1.0, fb = 0.0;	break;
-		case 4:
-			fr = 0.0, fg = 0.0, fb = 1.0;	break;
-		case 5:
-			fr = 1.0, fg = 0.0, fb = 1.0;	break;
-		case 6:
-			fr = 0.0, fg = 1.0, fb = 1.0;	break;
-		case 7:
-			fr = 1.0, fg = 1.0, fb = 1.0;	break;
+		case 0:	fr = 0.0, fg = 0.0, fb = 0.0;	break;
+		case 1:	fr = val, fg = 0.0, fb = 0.0;	break;
+		case 2:	fr = 0.0, fg = val, fb = 0.0;	break;
+		case 3:	fr = val, fg = val, fb = 0.0;	break;
+		case 4:	fr = 0.0, fg = 0.0, fb = val;	break;
+		case 5:	fr = val, fg = 0.0, fb = val;	break;
+		case 6:	fr = 0.0, fg = val, fb = val;	break;
+		case 7:	fr = val, fg = val, fb = val;	break;
 		default:
-			// abort();
-			break;
+			abort();			break;
 		}
-
 	for (y=0; y<fimg->height/4; y++)
 			fimg_plot_rgb(fimg, x, y, fr, fg, fb);
-
 	}
 
-return -1;
+return 0;
 }
 /* --------------------------------------------------------------------- */
 int fimg_draw_something(FloatImg *fimg)
diff --git a/tools/mkfimg.c b/tools/mkfimg.c
index 98121b80..392b4e6f 100644
--- a/tools/mkfimg.c
+++ b/tools/mkfimg.c
@@ -14,6 +14,7 @@ int		verbosity;
 #define		T_GRAY		3
 #define		T_HDEG_A	4
 #define		T_VDEG_A	5
+#define		T_TPAT0		6
 
 typedef struct {
 	int		code;
@@ -27,7 +28,7 @@ Type types[] = {
 	{ T_GRAY,	"grey"			},
 	{ T_HDEG_A,	"hdeg"			},
 	{ T_VDEG_A,	"vdeg"			},
-
+	{ T_TPAT0,	"tpat0"			},
 	{ 0,		NULL			}
 	};
 
@@ -128,6 +129,7 @@ switch(type) {
 				break;
 	case T_HDEG_A:		fimg_hdeg_a(&fimg, 1.0);	break;
 	case T_VDEG_A:		fimg_vdeg_a(&fimg, 1.0);	break;
+	case T_TPAT0:		fimg_test_pattern(&fimg, 0, fvalue); break;
 	}
 
 foo = fimg_dump_to_file(&fimg, fname, 0);