Differences between current version and revision by previous author of PNG.
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| Newer page: | version 11 | Last edited on Saturday, April 30, 2005 3:41:00 pm | by AristotlePagaltzis | |
| Older page: | version 7 | Last edited on Thursday, September 4, 2003 11:31:12 am | by JohnMcPherson | Revert |
@@ -1,5 +1,7 @@
-PNG (pronounced "ping") is the
[Acronym] for Portable Network Graphics, a new, losslessly compressed bitmapped graphics format
. It is approved by the [World Wide Web consortium|W3C] as the successor of the [GIF] format. The latter depends on a compression algorithm called LZW which was patented by [Unisys] long ago. In contrast, PNG relies on the patent free LZSS algorithm for compression and is completely unencumbered with licensing fees
.
+An
[Acronym] for __P__ortable __N__etwork __G__raphics
. Pronounced "ping"
.
-Recent versions
of [Mozilla
],
[Opera
], and [Microsoft
] InternetExplorer support
PNG, although the latter doesn't
support alpha channels natively. Rumour has it that the IE engine is too old and out of date to support transparency without lots of hideous hacks. Amusingly(?), while Microsoft can't make these hideous hacks,
[we can
|http://support.microsoft.com/default.aspx?scid=kb;en-us;Q294714]. Since that way
is completely incompatible with every other browser on the world, you should [
use a slightly different approach
|http://webfx.eae.net/dhtml/pngbehavior/pngbehavior.html].
----
-See also
: pngcrush(1),
a [Free] program
to make
your PNG files
as small
as possible, either lossless
or lossy
depending on what
arguments you give it
.
+A modern, losslessly compressed bitmapped graphics FileFormat, designated by the [W3C] as the successor
of the
[GIF
] format.
[PNG
] is completely unencumbered with patents and licensing fees. This is important
, as [GIF] has had problems in that regard (see [Unisys]). There is builtin support for [PNG] in [Mozilla]
and [Opera
].
+
+Recent versions of
InternetExplorer display [
PNG] images as well
, however this browser does not
support alpha channels natively. MicrosoftCorporation explain
[how to use it anyway
| http://support.microsoft.com/default.aspx?scid=kb;en-us;Q294714]. Not surprisingly, their approach to this hideous hack
is completely incompatible with every other browser on the world, you should use [
a slightly different method
| http://webfx.eae.net/dhtml/pngbehavior/pngbehavior.html]. Thankfully, the upcoming InternetExplorer 7 [has had PNG alpha
-transparency support added | http
://blogs.msdn.com/ie/archive/2005/04/26/412263.aspx].
+
+
pngcrush(1) is
a [Free] utility
to shrink
your [
PNG] images
as much
as possible, either losslessly
or lossily
depending on arguments.
