==============================================
IMPORTANT: Tested only with
           libpng ver. 1.0.{5,6,8,9,10,12}, 1.2.{0,1,2,3}
           jpeg ver. 6b
==============================================

1) You need libpng and jpeg sources (available, e.g., from
   www.libpng.org, ftp.uu.net/graphics/[png,jpeg].

2) Their sources must be unpacked in sub-directories of this dir.
   The libpng sources must be in sub-dir named 'libpng' (as required 
   by the libpng documentation).
   Example:
   > mv libpng-1.2.3 libpng
   > tar xzvf jpegsrc.v6b.tar.gz
   If jpeg version is different from 6b, edit 'Makefile' and change 
   the definition of JPEGDIR.

3) Then,
   > make
   should build  Rbitmap.dll and install it in R_HOME/bin.