[ELGIS] POLL: 12 bit JPEG compression in TIFF

[Peter Hopfgartner]

On 08/01/2011 09:24 AM, Mathieu Baudier wrote:
>> you will have trouble opening 12 bit JPEGS with most image editing service,
>> see http://en.wikipedia.org/wiki/JPEG. Anyway, on EL, once that GDAL has
>> this option included, all GDAL-based software should be able to read/write
>> this format (QGIS, MapServer, ....).
>> I do not know anything about 10 bit color depth, olny 8 bot and 12 bit.
> Are we talking here about JPEG or TIFF with JPEG compression?
>
Personally it's TIFF with JPEG compression which I'm interested in. I'll 
do some tests in next days. It's mainly to store orthophotos in a more 
space efficient way without losing top much quality.
> Would it become the default for generated JPEG/TIFF, or would it just
> be an option?
>
Hmmm, the issue was raised when converting TIFFS with 12 - bit channels. 
I do not know what happens, when new images are created.
> What would be the drawbacks if this is only an additional capability?
I do not know of any direct drawback, except that internal libjpeg and 
libtiff/libgeotiff are used, instead of the system shared libs.

Peter