W3C home > Mailing lists > Public > public-respimg@w3.org > March 2012

Re: what about progressively encoded images and http range requests?

From: Le Roux Bodenstein <lerouxb@gmail.com>
Date: Wed, 28 Mar 2012 21:51:53 +0200
Message-ID: <CAD_aen77iNANQYJtNKDY=QdQP91MUzrkW1NKJyxSqeRdB9GdEQ@mail.gmail.com>
To: Adrian Roselli <Roselli@algonquinstudios.com>
Cc: public-respimg@w3.org
> My concern is then over defining a new image format, garnering support
> in tools and browsers, and bypassing any patent issues.

Or you could just use an existing format like JPEG 2000:
http://en.wikipedia.org/wiki/JPEG_2000

from the article: "The codestream obtained after compression of an
image with JPEG 2000 is scalable in nature, meaning that it can be
decoded in a number of ways; for instance, by truncating the
codestream at any point, one may obtain a representation of the image
at a lower resolution"

Wavelet compression appears to be made to solve exactly this problem.

JPEG 2000 already has support in some browsers and there have already
been discussions about making it a standard in the past. Actually I
don't think the standards specify any specific image formats as it is.

Tools like imagemagick already support it:
http://www.imagemagick.org/script/jp2.php

I'll put together a demo some time soon to see how the quality and
file size compares. Maybe this just isn't workable anyway.

It would require changes in browsers, yes.
Received on Wednesday, 28 March 2012 19:52:22 UTC

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