[CREATE] Re: Open File Format for Raster/Bitmaps Graphics

[Leonard Rosenthol]

At 09:09 AM 3/21/2006, Kai-Uwe Behrmann wrote:
>In the sense of seeking in a jpeg file inside the zip file, 
>through  libjpeg - No.

         Depends, actually.

         First, whether the "file" inside the ZIP archive is 
compressed or not.  Non-compressed data is just as seekable as it 
would be outside an archive.   Since a JPEG is already compressed, I 
can't see any reason to "recompress it" in the archive, so you could 
seek with libjpeg just fine!

         Second, whether any form of "caching" is implemented - such 
that decompression and data access is handled "transparently" to the caller.


>A zip file is seekable on a too low programming level. Without a general
>purpose library, which handles this low level stuff, there will remain
>many applications without proper support for the new format or perhaps
>slow down the desktop.

         This would fall on my second item, when compression inside 
the archive is implemented - and I would agree.  BUT if the archive 
is JUST a wrapper/container and does NOT provide additional 
compression (that's left to JPEG, PNG, TIFF, etc.) - then I don't see 
any problem with acceptable.


>For a general exchange format it would be desireable to support:
>o seeking (inside of the contained files)
>o selfexplaining - would be really nice
>o easy programmable

         I would say that ZIP (or better JAR, since it has the 
required manifest) would fit that bill.


Leonard

---------------------------------------------------------------------------
Leonard Rosenthol                            <mailto:leonardr at pdfsages.com>
Chief Technical Officer                      <http://www.pdfsages.com>
PDF Sages, Inc.                              215-938-7080 (voice)
                                              215-938-0880 (fax)