diff --git a/Lib/Makefile b/Lib/Makefile
index 9f4d8b5..67503a6 100644
--- a/Lib/Makefile
+++ b/Lib/Makefile
@@ -125,7 +125,6 @@ text1.o:	text1.c		$(DEPS)
 text16x24.o:	text16x24.c	$(DEPS)
 tga.o:		tga.c		$(DEPS)
 tools.o:	tools.c		$(DEPS)
-trigo.o:	trigo.c		$(DEPS)
 turtle.o:	turtle.c	$(DEPS)
 
 vignetize.o:	vignetize.c	$(DEPS)
@@ -174,7 +173,7 @@ OBJECTS =	7seg.o							\
 		scale.o	sobel4.o stereo.o				\
 		tamppool.o tele_2.o television.o			\
 		text0.o text1.o text16x24.o				\
-		tga.o tools.o trigo.o turtle.o				\
+		tga.o tools.o turtle.o					\
 		vignetize.o						\
 		warp0.o warp1.o warp2.o warp3.o				\
 		zoom.o
@@ -186,7 +185,7 @@ OBJECTS =	7seg.o							\
 #-----------------------------------------------------------------
 
 foo:		foo.c $(DEPS) ../libtthimage.a
-	gcc $(CFLAGS) $< ../libtthimage.a -o $@
+	gcc $(CFLAGS) $< ../libtthimage.a -lm -o $@
 
 t_png:	t_png.c $(DEPS)  ../libtthimage.a
 	gcc $(CFLAGS) $< ../libtthimage.a -lpng -lz -o $@
diff --git a/Lib/contrast.c b/Lib/contrast.c
index 41dff67..77d903e 100644
--- a/Lib/contrast.c
+++ b/Lib/contrast.c
@@ -6,6 +6,48 @@
 #include  <math.h>
 #include  "../tthimage.h"
 
+
+/*::------------------------------------------------------------------::*/
+/*
+ *	new: Fri Sep 15 20:18:35 UTC 2023
+ *	inspired by the sam func in FloatImg
+ */
+int Image_egalise_cos01(Image_Desc *source, Image_Desc *but, int k)
+{
+unsigned char	lut[256], uc;
+int		idx, x, y, pix, foo;
+float		fidx;
+
+fprintf(stderr, ">>> %s ( %p  %p  %d )\n", __func__,
+		source, but, k);
+
+if ( (foo=Image_compare_desc(source, but)) ) {
+	fprintf(stderr, "%s: images not compatible, %d\n", __func__, foo);
+	return foo;
+	}
+
+for (idx=0; idx<256; idx++) {
+	fidx = (float)idx / 255.0;
+	uc = (unsigned char)(255.0*(0.5 - 0.5 * cos(3.141592654*fidx)));
+	lut[idx] = uc;
+	/* printf("%7d    %7d\n", idx, uc); */
+	}
+
+for (y=0; y<source->height; y++) {
+	for (x=0; x<source->width; x++) {
+
+		pix = source->Rpix[y][x];
+		but->Rpix[y][x] = lut[pix];
+		pix = source->Gpix[y][x];
+		but->Gpix[y][x] = lut[pix];
+		pix = source->Bpix[y][x];
+		but->Bpix[y][x] = lut[pix];
+
+		}
+	}
+
+return FULL_NUCKED;
+}
 /*::------------------------------------------------------------------::*/
 /*
  *	cette fonction peut etre utilisee avec la meme image
@@ -20,6 +62,10 @@ float	fr, fg, fb;
 fprintf(stderr, "%s : %p -> %p\n", __func__, source, but);
 #endif
 
+if (k)	{
+	fprintf(stderr, "In %s, k must be 0, was %d\n", __func__, k);
+	}
+
 if ( (foo=Image_compare_desc(source, but)) ) {
     fprintf(stderr, "%s : images are differents %d\n", __func__, foo);
     return foo;
@@ -55,6 +101,10 @@ float	fr, fg, fb;
 fprintf(stderr, "%s : %p -> %p\n", __func__, source, but);
 #endif
 
+if (k)	{
+	fprintf(stderr, "In %s, k must be 0, was %d\n", __func__, k);
+	}
+
 if ( (foo=Image_compare_desc(source, but)) ) {
     fprintf(stderr, "%s : images are differents %d\n", __func__, foo);
     return foo;
diff --git a/Lib/foo.c b/Lib/foo.c
index 0489355..33c72d9 100644
--- a/Lib/foo.c
+++ b/Lib/foo.c
@@ -2,6 +2,7 @@
 #include  <stdlib.h>
 #include  <unistd.h>
 #include   <stdint.h>
+#include  <math.h>
 
 #include  "../tthimage.h"
 
@@ -14,6 +15,20 @@ else
 	Image_t16x24_essai("16x24gruik", "0123456789abcdef", "16x24.tga");
 return 0;
 }
+
+/*		==============================				*/
+void mk_lut(unsigned char lut[])
+{
+int		idx, uc;
+float		fidx;
+
+for (idx=0; idx<256; idx++) {
+	fidx = (float)idx / 255.0;
+	uc = (unsigned char)(255.0*(0.5 - 0.5 * cos(3.141592654*fidx)));
+	lut[idx] = uc;
+	printf("%7d    %7d\n", idx, uc); 
+	}
+}
 /*		==============================				*/
 int essai_draw_paint_rect(char *outga)
 {
@@ -62,7 +77,11 @@ return OLL_KORRECT;
 int main(int argc, char *argv[])
 {
 int		foo;
+unsigned char	Lut[256];
 
+mk_lut(Lut);
+
+#if 0
 Image_print_version(2);
 Image_print_sizeof_structs("foo");
 
@@ -72,5 +91,8 @@ fprintf(stderr, "essai show t16x24 --> %d\n", foo);
 foo = essai_draw_paint_rect("foo.tga");
 fprintf(stderr, "essai draw rect --> %d\n", foo);
 
+Image_egalise_cos01(NULL, NULL, 0);
+#endif
+
 return 0;
 }
diff --git a/Tools/tga_equalize.c b/Tools/tga_equalize.c
index b102671..041476e 100644
--- a/Tools/tga_equalize.c
+++ b/Tools/tga_equalize.c
@@ -14,6 +14,7 @@
 /*::------------------------------------------------------------------::*/
 #define		EQ_STD		4
 #define		EQ_GRAY		8
+#define		EQ_COS01	9
 #define		EQ_2X2		12
 #define		EQ_LUMIN	14
 #define		EQ_SQUARE	16
@@ -26,6 +27,7 @@ mot_clef mots_clef[] =
 { "std",	EQ_STD,		"", 	"standard method"	},
 { "rgb",	EQ_STD,		"", 	"same as 'std'"		},
 { "gray",	EQ_GRAY,	"",	"gray based"		},
+{ "cos01",	EQ_COS01,	"",	"cosinus 0->1"		},
 { "2x2",	EQ_2X2,		"",	"2x2 matrix"		},
 { "lumin",	EQ_LUMIN,	"i",	"param: ident is 256"	},
 /* { "gamma",	EQ_GAMMA,	"d",	"not implemented"	},*/
@@ -38,7 +40,7 @@ mot_clef mots_clef[] =
 /*::------------------------------------------------------------------::*/
 void usage()
 {
-fprintf(stderr, "* tga_equalize v 0.0.21 [%s]  (dwtfywl) tonton Th\n",
+fprintf(stderr, "* tga_equalize v 0.0.23 [%s]  (dwtfywl) tonton Th\n",
 					TGA_OUTILS_VERSION);
 fprintf(stderr, "  compiled %s at %s\n", __DATE__, __TIME__);
 fprintf(stderr, "usage:\n\ttga_equalize avant.tga mode apres.tga [params]\n");
@@ -106,6 +108,10 @@ switch (commande)
 		foo = Image_pix_sqroot(src, dst, 0);
 		break;
 
+	case EQ_COS01:
+		foo = Image_egalise_cos01(src, dst, 0);
+		break;
+
 	case EQ_GAMMA:
 		fprintf(stderr, "no gamma func in %d\n", getpid());
 		foo = FULL_NUCKED;
diff --git a/tthimage.h b/tthimage.h
index 46bee1c..91fd80d 100644
--- a/tthimage.h
+++ b/tthimage.h
@@ -4,7 +4,7 @@
 	http://la.buvette.org/devel/libimage/
 */
 #ifndef IMAGE_VERSION_STRING
-	#define IMAGE_VERSION_STRING "0.4.51 pl 46"
+	#define IMAGE_VERSION_STRING "0.4.51 pl 49"
 
 /*::------------------------------------------------------------------::*/
 /*
@@ -1192,6 +1192,8 @@ int	Image_insert_with_alpha(Image_Desc *img, Image_Desc *ins, int foo);
 int Image_pix_square(Image_Desc *source, Image_Desc *but, int k);
 int Image_pix_sqroot(Image_Desc *source, Image_Desc *but, int k);
 
+int Image_egalise_cos01(Image_Desc *source, Image_Desc *but, int k);
+
 /*::------------------------------------------------------------------::*/
 /*
 	module levels.c			new: Jan 2001