2017.07.24 00:34 "Re: [Tiff] JPEG2000 codec", by Kemp Watson

For my 2 cents on this, and as a user who routinely uses unusual codecs in TIFF, I believe the ramifications of this are potentially dangerousŠ in the sense that there are dozens of codecs out there, and there will always be more coming.

For libtiff to support them internally, is a hefty undertaking, and raises the question ³what is libtiff²? Already, it¹s gone beyond TIFF 6.0 and TechNote #2 by adopting BigTIFF, which has no official spec.

Further, how to choose the Œright¹ JPEG 2000 implementation? Kakadu is the Œofficial¹ one, and it¹s up to 11 grand to buy. OpenJPEG is an alternative, but far less performant.

My take on this is that the right way to do this is to treat the data as opaque - there is already a mechanism to define new codecs: Aperio defined 33003 and 33005 for JPEG 2000, which is bizarre since codec 34712 was already defined for JPEG 2000; we at Objective have defined 34933 for PNG and 34934 for JPEG XR. BTW, I note that sometime over the last few months, Adobe seems to have taken down the registry, along with their entire developer site, showing yet again that they are a Company that Cares about TIFF.

What would certainly be helpful, is to have a set of Œwrappers¹ OUTSIDE of libtiff, that pull in libtiff and other codec code, that could be commonly used; but I¹d not like to see it tight into libtiff itself.

It¹s always struck me as a bit odd to put JPEG 2000 into TIFF - JPEG 2000 supports multiresolution images and striped or tiled data already, and i can¹t see much advantage to wrapping it with yet another containerŠ could you identify your use case?

W. Kemp Watson

kemp@objectivepathology.com

Objective Pathology Services Limited

8250 Lawson Road
Milton, Ontario
Canada L9T 5C6

www.objectivepathology.com
tel. +1 (416) 970-7284

On 2017-07-23, 6:15 PM, "Roger Leigh" <tiff-bounces@lists.maptools.org on behalf of rleigh@codelibre.net> wrote:

I just wanted to check in to ask if anyone was working on JPEG2000 support for libtiff using e.g. OpenJPEG?

I know it's possible to use JPEG2000 as a format independently, but there are files out there using JPEG2000 compression in a TIFF container, and it would be great to be able to read and write such files.