- From: Jeff Schiller <codedread@gmail.com>
- Date: Sun, 19 Sep 2010 16:18:19 -0700
- To: anthony.grasso@cisra.canon.com.au
- Cc: David Woolley <forums@david-woolley.me.uk>, ddailey <ddailey@zoominternet.net>, www-svg@w3.org
- Message-ID: <AANLkTinFznROjH45UUZZ4cC_GXuqWcdiWmcO-pT0QLFq@mail.gmail.com>
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 Sunday, 19 September 2010 23:19:07 UTC