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From "Charles Matthew Chen" <charlesmc...@gmail.com>
Subject Re: JPEG Support
Date Wed, 09 Apr 2008 02:34:12 GMT
Hi,

   My personal feeling about implementing JPEG:

 * not sure if there is a patent issue.
 * definitely "quite a bit of work."
 * a pure-java implementation will always be slower than a native
(c/c++) implementation.

   There might be virtue in adding pure-Java jpeg decode/encode
support to Sanselan, but the case is hard to make.  People use JPEG in
a different way than other formats.  They use it for large collections
of large images.  Performance matters.  Users are going to turn to a
native implementation.  Why rewrite the excellent and mature libjpeg?

   Its hard to imagine us even doing better (in terms of stability,
maturity and performance) than ImageIO or JAI, which are readily
available.

Charles


On Tue, Apr 8, 2008 at 11:26 PM, Jeremias Maerki <dev@jeremias-maerki.ch> wrote:
> I think there are no severe problems that should keep the ASF from
>  producing a full implementation. There is some interesting information
>  on Wikipedia:
>  http://en.wikipedia.org/wiki/JPEG#Potential_patent_issues
>
>  In terms of full support, the rest of the above Wiki page should give an
>  idea what kinds of steps are involved in encoding and decoding a JPEG
>  image. Obviously, this thing has to be as fast as possible. Harmony used
>  libjpeg (in C) for the JPEG codec:
>  http://svn.apache.org/repos/asf/harmony/enhanced/classlib/trunk/modules/imageio/src/main/native/jpegencoder
>  Of course, we could do it the same way, but a plain Java implementation
>  would really be great because there are no problems with different
>  platforms even if that means a possible, little performance impact. At
>  any rate, I guess it's quite a bit of work. Anyway, the decoder is
>  probably more important than the encoder. Well, at least to me. ;-)
>
>
>
>  On 08.04.2008 11:35:07 Carsten Ziegeler wrote:
>  > Just curious, what needs to be done to get full jpeg support? Are there
>  > any legal problems?
>  >
>  > Carsten
>  > --
>  > Carsten Ziegeler
>  > cziegeler@apache.org
>
>
>
>  Jeremias Maerki
>
>

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