diff --git a/lib/fimg-2gray.c b/lib/fimg-2gray.c
index cf7ab5f2..70723bbf 100644
--- a/lib/fimg-2gray.c
+++ b/lib/fimg-2gray.c
@@ -15,7 +15,7 @@ extern int verbosity;		/* must be declared around main() */
 /*
  *	floating imgs MUST be allocated before calling this func.
  */
-int fimg_mk_gray_from(FloatImg *src, FloatImg*dst, int k)
+int fimg_mk_gray_from(FloatImg *src, FloatImg *dst, int k)
 {
 float		kr, kg, kb, kdiv;
 int		nbb, foo;
diff --git a/tools/fimgfx.c b/tools/fimgfx.c
index 03eef012..9a8f3786 100644
--- a/tools/fimgfx.c
+++ b/tools/fimgfx.c
@@ -19,13 +19,14 @@ typedef struct {
 	int		nbarg;
 	} Fx;
 
-enum fxid { Fx_cos01, Fx_cos010, Fx_pow2, Fx_sqrt };
+enum fxid { Fx_cos01, Fx_cos010, Fx_pow2, Fx_sqrt, Fx_gray0 };
 
 Fx fx_list[] = {
 	{ "cos01",		Fx_cos01,	0 },
 	{ "cos010",		Fx_cos010,	0 },
 	{ "pow2",		Fx_pow2,	0 },
 	{ "sqrt",		Fx_sqrt,	0 },
+	{ "gray0",		Fx_gray0,	0 },
 	{ NULL,			0,	0 }
 	};
 
@@ -59,6 +60,10 @@ puts("------ fimg special effects ------");
 puts("usage:");
 puts("\tfimgfix [options] <effect> source.fimg resultat.fimg");
 
+puts("options:");
+puts("\t-k N.N\tset the floating value");
+puts("\t-v\tincrease verbosity");
+
 puts("effects:"); 
 printf("\t");
 for (fx=fx_list; fx->name; fx++) {
@@ -103,6 +108,10 @@ switch (act) {
 	case Fx_sqrt:
 		fimg_square_root(&src, &dest, maxval);		break;
 
+	case Fx_gray0:		/* new 2020 01 10 */
+		fimg_to_gray(&src); fimg_copy_data(&src, &dest);
+								break;
+
 	default:
 		fprintf(stderr, "*** %s : %d is bad action\n", __func__, act);
 		break;