Portable Network Graphics
<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://www.w3.org/Graphics/PNG/).
PNG home page (http://www.wco.com/~png/).
