portable network graphics

from The Free On-line Dictionary of Computing (8 July 2008)
Portable Network Graphics
PNG

   <file format> /ping/ (PNG) An extensible {file format} for the
   {lossless}, {portable}, well-compressed storage of {raster
   images}.  PNG provides a patent-free replacement for {GIF} and
   can also replace many common uses of {TIFF}.
   {Indexed-colour}, {greyscale} and {truecolour} images are
   supported, plus an optional {alpha channel}.  Sample depths
   range from 1 to 16 bits.

   PNG is designed for on-line viewing applications, such as the
   {World Wide Web}, so it is fully {streamable} with a
   {progressive display} option.  PNG is robust, providing both
   full file integrity checking and simple detection of common
   transmission errors.  Also, PNG can store {gamma correction}
   and {chromaticity} data for improved colour matching on
   heterogeneous {platforms}.

   {Filename extension}: .png.

   RFC 2083.  W3C PNG pages
   (http://w3.org/Graphics/PNG/).  PNG home page
   (http://wco.com/~png/).

   (1997-08-07)