diff --git a/floatimg.h b/floatimg.h
index d9a05b7..5083630 100644
--- a/floatimg.h
+++ b/floatimg.h
@@ -2,7 +2,7 @@
  *	floatimg.h
  */
 
-#define		FIMG_VERSION	90
+#define		FIMG_VERSION	91
 
 /*
  *	in memory descriptor
diff --git a/funcs/geometry.c b/funcs/geometry.c
index 26065d3..dab2ee3 100644
--- a/funcs/geometry.c
+++ b/funcs/geometry.c
@@ -4,6 +4,7 @@
  */
 
 #include  <stdio.h>
+#include  <stdlib.h>
 
 #include  "../floatimg.h"
 
@@ -40,12 +41,12 @@ for (y=0; y<hd; y++) {
 	for (x=0; x<wd; x++) {
 		foo = fimg_get_rgb(src, x*2, y*2, pixel);
 		if (foo) {
-			fprintf(stderr, "%s: err get %d\n", foo);
+			fprintf(stderr, "%s: err get %d\n", __func__, foo);
 			abort();
 			}
 		foo = fimg_plot_rgb(dst, x, y, pixel[0], pixel[1], pixel[2]);
 		if (foo) {
-			fprintf(stderr, "%s: err plot %d\n", foo);
+			fprintf(stderr, "%s: err plot %d\n", __func__, foo);
 			abort();
 			}
 		}
diff --git a/funcs/t.c b/funcs/t.c
index 615ad45..07fcb61 100644
--- a/funcs/t.c
+++ b/funcs/t.c
@@ -10,6 +10,8 @@
 
 int		verbosity;
 
+float		global_fvalue;
+
 /* --------------------------------------------------------------------- */
 int essai_geometrie(char *infile)
 {
@@ -35,7 +37,7 @@ if (foo) {
 	return -2;
 	}
 
-fimg_describe(&result, "result after halfsize");
+if (verbosity) fimg_describe(&result, "result after halfsize");
 
 foo = fimg_save_as_pnm(&result, "something.pnm", 0);
 
@@ -57,12 +59,23 @@ else	{
 	}
 
 foo = fimg_save_as_pnm(&fimg, "something.pnm", 0);
-
+if (foo) {
+	fprintf(stderr, "%s: err save %d\n", __func__, foo);
+	return -6;
+	}
 foo = fimg_killcolors_a(&fimg, 0.0);
 foo = fimg_save_as_pnm(&fimg, "colorskilled-a.pnm", 0);
+if (foo) {
+	fprintf(stderr, "%s: err save %d\n", __func__, foo);
+	return -6;
+	}
 
 foo = fimg_killcolors_b(&fimg, 0.0);
 foo = fimg_save_as_pnm(&fimg, "colorskilled-b.pnm", 0);
+if (foo) {
+	fprintf(stderr, "%s: err save %d\n", __func__, foo);
+	return -6;
+	}
 
 
 return 0;
@@ -159,11 +172,24 @@ return 0;
 /* --------------------------------------------------------------------- */
 int main(int argc, char *argv[])
 {
-int		foo;
+int		foo, opt;
 
 puts("++++++++++++++++++++++++++++++++");
 
+global_fvalue = 1.0;
+
+while ((opt = getopt(argc, argv, "hk:v")) != -1) {
+	switch(opt) {
+		// case 'h':	help(0);			break;
+		case 'k':	global_fvalue = atof(optarg);	break;
+		case 'v':	verbosity++;			break;
+		}
+	}
+
 foo = essai_geometrie("foo.fimg");
+if (foo) {
+	fprintf(stderr, "************ %d\n", foo);
+	}
 
 return 0;
 }
diff --git a/tools/fimgfx.c b/tools/fimgfx.c
index 9a8f378..08d2902 100644
--- a/tools/fimgfx.c
+++ b/tools/fimgfx.c
@@ -19,7 +19,7 @@ typedef struct {
 	int		nbarg;
 	} Fx;
 
-enum fxid { Fx_cos01, Fx_cos010, Fx_pow2, Fx_sqrt, Fx_gray0 };
+enum fxid { Fx_cos01, Fx_cos010, Fx_pow2, Fx_sqrt, Fx_gray0, Fx_halfsz0 };
 
 Fx fx_list[] = {
 	{ "cos01",		Fx_cos01,	0 },
@@ -27,6 +27,7 @@ Fx fx_list[] = {
 	{ "pow2",		Fx_pow2,	0 },
 	{ "sqrt",		Fx_sqrt,	0 },
 	{ "gray0",		Fx_gray0,	0 },
+	{ "halfsz0",		Fx_halfsz0,	0 },
 	{ NULL,			0,	0 }
 	};
 
@@ -112,6 +113,10 @@ switch (act) {
 		fimg_to_gray(&src); fimg_copy_data(&src, &dest);
 								break;
 
+	case Fx_halfsz0:
+		fprintf(stderr, "not implemented\n");
+		return -3;
+
 	default:
 		fprintf(stderr, "*** %s : %d is bad action\n", __func__, act);
 		break;