The only things you have to do to create pnmtoltp, is copying the file pnmnoraw.c to pnmtoltp.c and editing the line: pnm_writepnminit( stdout, cols, rows, maxval, format, 1 ); to become pnm_writepnminit( stderr, cols, rows, maxval, format, 1 ); To compile, add the pnmtoltp program in the Makefile. Ronald Wiemer ARCHIS, Amersfoort The Netherlands