[gdal-dev] 8/12 bit jpeg in tiff dual mode

[Even Rouault]

Frank,

Nice work !

I don't know if you were aware of it, but there was a discussion on libtiff 
list (http://www.asmail.be/msg0054814912.html) where Joris Van Damme 
mentionned a set of 12bit jpeg compressed tiff files he produced with his 
TIFF codec: http://www.awaresystems.be/imaging/tiff/12bpsjpegintiff.zip.

I've tried them, and as anticipated by Joris, some images with exotic 
parameters cannot be read (JPEG compression with planar storage, fillorder 
bit order reversal, ITULAB color space, 4x4 subsampling). But the others work 
fine.

I've adapted the JPEG and NITF drivers so they are able to read and create 
12bit JPEG files when JPEG12_ENABLED=YES (the capability to deal with 12bit 
JPEG already existed when compiled against the MK1 libjpeg). See r17304 to 
r17309 for the related changesets.

Best regards,

Even

Le Friday 26 June 2009 21:22:36 Frank Warmerdam, vous avez écrit :
> Folks,
>
> Over the last few weeks I have been working on support for reading and
> writing TIFF files with 12bit jpeg compressed images.  This is a somewhat
> popular format for scanned airphotos from some vendors.
>
> I have made changes in libjpeg and libtiff upstream, and incorporated these
> updates into GDAL trunk so that now a default build of GDAL trunk should
> support reading and writing 8 and 12 bit jpeg compressed TIFF files.  A
> description of the projects and changes is available at:
>
>    http://trac.osgeo.org/gdal/wiki/TIFF12BitJPEG
>
> I would appreciate testing and feedback on this capability.  I would also
> like to thank Adam Nowaki who assisted with some issues in libtiff related
> to this project.
>
> Best regards,