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Re: Some comments on <image>

From: Alex Danilo <alex@abbra.com>
Date: Mon, 20 Sep 2010 10:01:43 +1000
Message-Id: <VQQ09L.DXBBH9XELF08@abbra.com>
To: "ddailey" <ddailey@zoominternet.net>
Cc: "Jeff Schiller" <codedread@gmail.com>, <anthony.grasso@cisra.canon.com.au>, "David Woolley" <forums@david-woolley.me.uk>, <www-svg@w3.org>
Most mobile browsers won't.

This is to minimize memory footprint more than a technical
issue.

But GIF isn't continuous tone - it's a palleted colour
format so is pretty lame.

JPEG was the real game changer for browsers that made
the web really take off. Try doing flesh tones in GIF;-)

The spec. sets the minimum requirements. At the time the
spec reached recommendation, GIF was encumbered and a
poor image format anyway, so wouldn't have been included
for those reasons. There are clear rules about use of IP
encumbered things in W3C specs, hence why there is no
video codec mandated either...

Alex

--Original Message--:
>All five of the major released browsers (ASV, FF, Opera, Chrome and Safari) support GIF in SVG. I don't know about IE9 or mobile platforms.
> 
>D
>
>----- Original Message ----- 
>From: Jeff Schiller 
>To: anthony.grasso@cisra.canon.com.au 
>Cc: David Woolley ; ddailey ; www-svg@w3.org 
>Sent: Sunday, September 19, 2010 7:18 PM
>Subject: Re: Some comments on <image>
>
>Out of curiosity - is there any browser that doesn't actually support GIF files in svg:image ?  I'd be surprised...
>
>Jeff
>
>On Sun, Sep 19, 2010 at 4:10 PM, Anthony Grasso <anthony.grasso@cisra.canon.com.au> wrote:
>
>
>
>On 20/09/2010 4:22 AM, David Woolley wrote:
>
>ddailey wrote:
>
>
>1. The spec says "Conforming SVG viewers need to support at least PNG, JPEG
>and SVG format files." Why not GIF? I recall a profound nervousness
>
>I think the basic reason is that PNG can exactly represent any image that GIF
>can represent, except for animations, and usually does so more compactly for
>equal quality, but also has the option of better quality.
>
>
>In saying that, there is nothing stopping an SVG viewer/editor (to my knowledge) from supporting GIF in addition to JPEG and PNG. :) 
>
>
>
>
>that spread like squid ink through the open source community [1] 10 or 12
>years ago as the holders of the GIF patent threatened to go after those who
>used it without license. I believe, however, that the patent has since
>expired. [2] A search of gif in Google images shows about a billion files with
>close to half that number for PNG. In many cases GIF
>
>Image formats are often chosen without any real understanding. There are an
>awful lot JPEG images (or PDF images using DCT) that are totally unsuitable for
>JPEG, either because people believe it produces the best compression for
>everything (and only make one dimensional decisions), or because they don't know
>PNG and paintbrush produces very poor GIFs.
>
>
>files are smaller than PNG files, I think, and lots of the older public
>
>Although it is possible, and may be more common for very small images, the
>compression scheme used in PNG is generally better than that used in GIF (the
>LZW used in GIF, and the actual subject of the patent, is designed as a
>compromise between compression speed and and compression ratio - it was really
>intended for real time compression of streamed data. That in PNG is designed to
>give good compression, at the expense of slow compression speeds.
>
>Apart from the possibility that PNG may have a higher overhead, the other reason
>that you may observe this is that PNG has more possible formats, and, for
>example, paintbrush uses 24 bit unpalletised for PNG and uses a non-optimised
>palette for GIF.
>
>
>domain imagery sites on the web used gif because, well, PNG wasn't available
>then. All the browsers I know of go ahead and support GIF anyhow, but it is
>one thing we can be certain of that no longer has patent entanglements. PNG??
>Who can ever be completely sure until the 20 years pass?
>
>
>It's very likely that any such patent would also affect GIF.
>
>
>
>
>
>
Received on Monday, 20 September 2010 00:02:39 GMT

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