diff --git a/tools/fimg2pnm.c b/tools/fimg2pnm.c
index 9b589e21..3296fe2e 100644
--- a/tools/fimg2pnm.c
+++ b/tools/fimg2pnm.c
@@ -11,13 +11,14 @@
 int		verbosity;
 
 /* --------------------------------------------------------------------- */
-int convertir_fimg_en_pnm(char *srcname, char *dstname, int notused)
+int convertir_fimg_en_pnm(char *srcname, char *dstname, int to_gray)
 {
 int		foo, infos[3];
-FloatImg	fimg;
+FloatImg	fimg, gris, *outptr;
 
 #if DEBUG_LEVEL
-fprintf(stderr, ">>> %25s ( '%s' '%s' )\n", __func__, srcname, dstname);
+fprintf(stderr, ">>> %25s ( '%s' '%s' %d )\n", __func__,
+			srcname, dstname, to_gray);
 #endif
 
 foo = fimg_fileinfos(srcname, infos);
@@ -35,13 +36,36 @@ if (foo) {
 	return -1;
 	}
 
+outptr = &fimg;		/* safe default value */
+
+if (to_gray) {
+	puts("converting to gray...");
+	foo = fimg_create(&gris, fimg.width, fimg.height, FIMG_TYPE_GRAY);
+	if (foo) {
+		fprintf(stderr, "err create gray %d\n", foo);
+		return -2;
+		}
+	foo = fimg_mk_gray_from(&fimg, &gris, 0);
+	if (foo) {
+		fprintf(stderr, "err mk gray %d\n", foo);
+		return -4;
+		}
+	outptr = &gris;
+	}
+
 #if DEBUG_LEVEL > 1
-print_floatimg(&fimg, "created fimg");
+print_floatimg(outptr, "created fimg");
 #endif
 
-foo = fimg_save_as_pnm(&fimg, dstname, 0);
+foo = fimg_save_as_pnm(outptr, dstname, 0);
 if(foo) { fprintf(stderr, "%p to '%s' -> %d\n", &fimg, dstname, foo); }
 
+if (to_gray) {
+	fimg_destroy(&gris);
+	outptr = NULL;
+	/* please run valgrind every hour */
+	}
+
 return 0;
 }
 /* --------------------------------------------------------------------- */
@@ -58,14 +82,16 @@ puts("\tfimg2pnm [flags] infile.fimg outfile.pnm");
 int main(int argc, char *argv[])
 {
 int		foo, opt;
+int		to_gray = 0;
 
 if (argc == 1) {
 	help(0);
 	exit(0);
 	}
 
-while ((opt = getopt(argc, argv, "v")) != -1) {
+while ((opt = getopt(argc, argv, "ghv")) != -1) {
 	switch(opt) {
+		case 'g':	to_gray = 1;
 		case 'v':	verbosity++;		break;
 		case 'h':	help(1);		exit(1);
 		}
@@ -89,7 +115,7 @@ if ( 0 != access(argv[optind], R_OK) ) {	/* fimg is NOT readable */
 	exit(2);
 	}
 
-foo = convertir_fimg_en_pnm(argv[optind], argv[optind+1], 0);
+foo = convertir_fimg_en_pnm(argv[optind], argv[optind+1], to_gray);
 if (foo) fprintf(stderr, "conversion -> %d\n", foo);
 
 return 0;