GIF

GIF (Graphics Interchange Format) is a bitmap image format for pictures that use 256 (or fewer) distinct colors (though there is a workaround for this limitation). and animations that use 256 (or fewer) distinct colors per frame. GIFs are compressed files, and are employed specifically to reduce the amount of time it takes to transfer images over a network connection. The format was introduced by CompuServe in 1987 and has since come into widespread usage on the World Wide Web.

Alternatives

The PNG format was specifically designed to replace GIF for use as a single-image web format. PNG offers better compression and more features than GIF. The format is rapidly replacing GIF for still images, mostly on web sites of computer enthusiasts protesting Unisys's license policies and on some cartoon sites that take advantage of PNG's tighter compression to save on internet bandwidth charges.

Related Topics:
PNG - Cartoon - Bandwidth

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All the features of GIF except animation are supported by PNG. As new web browsers support PNG, most GIF images could be replaced by PNG images. The most recent versions of Internet Explorer for Windows, however, do not support PNG's 8-bit alpha transparency through the normal img tag, a feature absent from GIF images which only provides 1-bit transparency, that is, pixels are either fully transparent or fully opaque. This is not a problem with many other web browsers. Version 7 of the browser, however, will finally support this missing feature http://blogs.msdn.com/ie/archive/2005/04/22/410963.aspx.

Related Topics:
Web browser - Internet Explorer - Windows

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The mistaken belief that PNG files are larger than GIF for the same images can generally be traced back to one of two things:

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• People making the unfair comparison of the file size of 8 bit GIF with 24 bit PNG.
• The poor PNG support in older versions of Adobe Photoshop.

MNG, the animation-supporting relative of PNG, reached version 1.0 in 2001, but few applications support it. It has therefore had little impact on the use of GIFs for animation. Today animations may be the only field where GIF is needed, because of the lack of web browser support for MNG.

Related Topics:
MNG - 2001

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In 2004, a proposed extension to the PNG format, called APNG was suggested. It would add the ability to animate PNG files, while retaining backwards compatibility in decoders which cannot understand the animation chunk. Such decoders would simply display it as though it were a single image PNG file.

Related Topics:
2004 - APNG

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