diff --git a/floatimg.h b/floatimg.h
index 826ae7db..0a697375 100644
--- a/floatimg.h
+++ b/floatimg.h
@@ -3,7 +3,7 @@
  *			ugly code from tTh
  */
 
-#define		FIMG_VERSION	119
+#define		FIMG_VERSION	120
 
 /*
  *	in memory descriptor
@@ -128,7 +128,10 @@ int fimg_power_2(FloatImg *s, FloatImg *d, double maxval);
 int fimg_cos_01(FloatImg *s, FloatImg *d, double maxval);
 int fimg_cos_010(FloatImg *s, FloatImg *d, double maxval);
 int fimg_mix_rgb_gray(FloatImg *img, float mix);
+
+/*	funcs/saturation.c		*/
 int     fimg_shift_to_zero(FloatImg *s, FloatImg *d, float coefs[6]);
+int     fimg_auto_shift_to_zero(FloatImg *s, FloatImg *d);
 
 /*	--> funcs/plasmas.c		*/
 int fimg_prototype_plasma(FloatImg *img, double time, int type);
diff --git a/funcs/saturation.c b/funcs/saturation.c
index 8c53b16c..5254463b 100644
--- a/funcs/saturation.c
+++ b/funcs/saturation.c
@@ -70,5 +70,30 @@ for (idx=0; idx<sz; idx++) {
 return 0;
 }
 
-
 /* -------------------------------------------------------------- */
+int  fimg_auto_shift_to_zero(FloatImg *src, FloatImg *dst)
+{
+float		coefs[6];
+int		foo;
+
+if (FIMG_TYPE_RGB != src->type) {
+	fprintf(stderr, "%s: bad image type %d\n", __func__, src->type);
+	return -6;
+	}
+
+foo = fimg_get_minmax_rgb(src, coefs);
+if (foo) {
+	fprintf(stderr, "%s: err %d get minmax\n", __func__, foo);
+	return foo;
+	}
+
+foo = fimg_shift_to_zero(src, dst, coefs);
+if (foo) {
+	fprintf(stderr, "%s WTF?\n", __func__);
+	return foo;
+	}
+
+return 0;
+}
+/* -------------------------------------------------------------- */
+