CGI Programming by Collin Forbes
  Postcard 2.5 Software Requirements   Updated: Thur, 20 Apr 2000  

You must compile additional software to use Postcards 2.5
These utilities may already be installed on your system, contact your system administrator. You may also be able to find and download precompiled versions of the utilities which can be installed in your own disk area.

The NetPBM Utilities

Collection of many utilities able to convert images back and forth between almost any bitmapped image format. Selected utilities are used to write text as bitmapped graphics (pbmtext, pnminvert, and pnmcrop), merge graphics files together (pnmarith), and convert images to and from portable bitmaps (giftopnm and ppmtogif).

ftp://metalab.unc.edu/pub/Linux/apps/graphics/convert/netpbm-8.4.tgz
ftp://ftp.x.org/contrib/utilities/netpbm-1mar1994.p1.tar.gz

Independent JPEG Group JPEG software

Libraries and software to read and write JPEGS.

ftp://ftp.uu.net/graphics/jpeg/jpegsrc.v6b.tar.gz
ftp://ftp.cdrom.com/pub/FreeBSD/distfiles/jpegsrc.v6b.tar.gz

Code from the PNG Development Group

The netpbm PNG converters to convert PNG images to portable anymaps. Requires the netpbm libraries, libpng and zlib.

ftp://swrinde.nde.swri.edu/pub/png/applications/pnmtopng-2.37.4.tar.gz
ftp://swrinde.nde.swri.edu/pub/png/src/libpng-1.0.6.tar.gz
ftp://ftp.uu.net/pub/archiving/zip/zlib/zlib-1.1.3.tar.gz

If you can't or won't install the additional software, you will lose the corresponding functions.