My bad, stupidity in reading colour mapped images.

Reference: /n/sources/patch/applied/bmp-read
Date: Tue Jan 11 15:54:45 CET 2005

--- /sys/src/cmd/jpg/readbmp.c	Tue Jan 11 15:54:45 2005
+++ /sys/src/cmd/jpg/readbmp.c	Tue Jan 11 15:54:45 2005
@@ -489,7 +489,7 @@
 
 	if(num_coltab) {
 		int i; 
-		Bseek(b, bmih.size + sizeof(Infohdr), 0);
+		Bseek(b, bmih.size + Filehdrsz, 0);
 
 		for(i = 0; i < num_coltab; i++) {
 			clut[i].blue  = (uchar)Bgetc(b);
--- /sys/src/cmd/jpg/bmp.h	Tue Jan 11 15:54:45 2005
+++ /sys/src/cmd/jpg/bmp.h	Tue Jan 11 15:54:44 2005
@@ -11,9 +11,11 @@
 	uchar alpha;
 } Rgb;
 
+#define Filehdrsz	14
+
 typedef struct {
         short	type;
-        long	size;
+        long	size;		/* file size, not structure size */
         short	reserved1;
         short	reserved2;
         long	offbits;