These are Linux/x86/libc5 executables for the three free demo programs
that accompany my book, "PNG: The Definitive Guide."  They were compiled
with gcc 2.7.2.3, libpng 1.0.3 and zlib 1.1.3.  rpng is a simple PNG
viewer that can display transparent PNGs with a specified background
color; for example,

	rpng -bgcolor #ff0000 toucan.png

would display the image with a red background.  rpng2 is a progressive
viewer that simulates a web browser in some respects; it can display
images against either a background color or a dynamically generated
background image.  For example:

	rpng2 -bgpat 16 toucan.png

wpng is a purely command-line image converter from NetPBM format (.pgm
or .ppm) to PNG; for example,

	wpng -time < toucan.ppm > toucan.png

would convert the specified PPM file (using redirection) to PNG, auto-
matically setting the PNG modification-time chunk.

In all three cases, type the name of the program without any arguments
for a usage summary.

Please see http://www.cdrom.com/pub/png/pngbook.html for further infor-
mation and links to the source code, and Chapters 13-15 of the book for
detailed discussion of the three programs.

Greg Roelofs
22 September 1999
