diff --git a/Makefile b/Makefile
index e16f5c5..3d629b1 100644
--- a/Makefile
+++ b/Makefile
@@ -3,7 +3,7 @@
 #          a look to the 'build.sh' script !       #
 ####################################################
 
-COPT = -Wall -fpic -g -pg -DDEBUG_LEVEL=0
+COPT = -Wall -fpic -g -pg  -no-pie -DDEBUG_LEVEL=0
 LDOPT = libfloatimg.a -pg -lm 
 
 all:	essai
diff --git a/lib/fimg-file.c b/lib/fimg-file.c
index 8446270..14b6e11 100644
--- a/lib/fimg-file.c
+++ b/lib/fimg-file.c
@@ -136,7 +136,8 @@ if (foo) {
 	return foo;
 	}
 
-foo = fread(head->R, sizeof(float), filehead.w*filehead.h*3, fp);
+foo = fread(head->R, sizeof(float),
+		filehead.w*filehead.h*filehead.t, fp);
 
 fclose(fp);
 
diff --git a/lib/fimg-math.c b/lib/fimg-math.c
index d73c2bc..2f4be78 100644
--- a/lib/fimg-math.c
+++ b/lib/fimg-math.c
@@ -7,7 +7,8 @@
 #include  <stdio.h>
 #include  <stdlib.h>
 #include  <unistd.h>
-#include  "string.h"
+#include  <string.h>
+#include  <math.h>
 
 #include  "../floatimg.h"
 
@@ -19,6 +20,12 @@ float fimg_get_maxvalue(FloatImg *head)
 float		maxval;
 int		foo;
 
+if (head->type != FIMG_TYPE_RGB) {
+	fprintf(stderr, "%s : type %d invalide\n",
+				__func__, head->type);
+	return nanf("wtf ?");
+	}
+
 maxval = 0.0;		/* no negative values allowed */
 
 for (foo=0; foo<(head->width*head->height); foo++) {
@@ -57,6 +64,12 @@ int fimg_to_gray(FloatImg *head)
 float		add;
 int		foo;
 
+if (head->type != FIMG_TYPE_RGB) {
+	fprintf(stderr, "%s : type %d invalide\n",
+				__func__, head->type);
+	return -3;
+	}
+
 for (foo=0; foo<(head->width*head->height); foo++) {
 	add  = head->R[foo];
 	add += head->G[foo];
@@ -70,6 +83,12 @@ void fimg_add_cste(FloatImg *fi, float value)
 {
 int		nbre, idx;
 
+if (fi->type != FIMG_TYPE_RGB) {
+	fprintf(stderr, "%s : type %d invalide\n",
+				__func__, fi->type);
+	return;
+	}
+
 nbre = fi->width * fi->height * fi->type;
 #if DEBUG_LEVEL
 fprintf(stderr, "%s, nbre is %d\n", __func__, nbre);
diff --git a/lib/t.c b/lib/t.c
index 1a4a8ce..ebb7040 100644
--- a/lib/t.c
+++ b/lib/t.c
@@ -13,7 +13,7 @@ int main(int argc, char *argv[])
 int		foo;
 FloatImg 	fimg;
 int		datas[3];
-
+char		*fname = "foo.fimg";
 verbosity = 1;
 
 fimg_print_version(0);
@@ -25,9 +25,12 @@ fimg_printhead(&fimg);
 fimg_describe(&fimg, "vroum");
 
 // fimg_save_as_pnm(&fimg, "foo.pnm",  0);
-foo = fimg_dump_to_file(&fimg, "foo.fimg", 0);
+foo = fimg_dump_to_file(&fimg, fname, 0);
 
 foo = fimg_fileinfos("foo.fimg", datas);
 
+printf("%s : largeur %d hauteur %d type %d\n",
+		fname, datas[0], datas[1], datas[2]);
+
 return 0;
 }