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From: | Thomas Richter |
Subject: | [Openexr-devel] Re: P.S. |
Date: | Mon, 12 Jan 2009 20:27:33 +0100 |
User-agent: | Icedove 1.5.0.14eol (X11/20090106) |
Gregory J. Ward wrote:
Hi Thomas,I have a DVD I can send you -- it's 4 GBytes of data, so a bit too much for my website.I could provide an upload to an sftp server (actually, the JPEG sftp server for test material) if this suits you fine?I don't particularly want to commit my laptop to 3+ hours of upload. Do you need this right away, or can it wait a week or so?
It can definitely wait for a week - I'm traveling the next week (JPEG meeting in SF) - so I won't be able to perform much experiments. A DVD would be fine as well.
Actually, I was referring to Dolby Canada's format -- not very well advertised, obviously. It's a backwards-compatible extension tostandard JPEG for HDR content, described in the following CIC 2005 paper:http://www.anyhere.com/gward/papers/cic05.pdf
Thanks for this work - I had the time to go through it, I like it, and I find a lot of good starting points for further research.
The maximum capacity of this extension is about 9 or 10 orders of magnitude, so I'm not sure it fits with your priorities, but I can provide you with the libraries if you want to include it in your evaluations.If possible, sure. However, libraries for which operating system? Since the complete evaluation tool-chain is script-driven and Linux-based, I would prefer simple command line front-ends in the form of binaries for AMD64 systems that compress and expand images from a documented format (openexr would be great ;-) to the HDR-JPEG, and back. It's a 64 bit system because some of the evaluation algorithms require really *a lot* of memory. Libraries or plugins for photoshop wouldn't help, unfortunately. This is a) because we don't have photoshop here, and b) it doesn't work on Linux, either. (-: Alternatively, if this is an option for you, source code would do it if you can release it under a license that would allow testing; if this requires a NDA, let me know.I don't have the rights to distribute source code with or w/o an NDA at this time, but getting you a Linux binary isn't a big deal. It might not be 64-bit, but it should still run on an AMD64. Try grabbing the archive:http://www.anyhere.com/gward/pickup/hdrgen_linux.tar.gzIn the bin directory should be an executable called "hdrcvt" that will convert from most any HDR format to and from JPEG-HDR, like so:hdrcvt -q qual_setting input.{hdr|exr|tif} converted.jpg Converting back is just: hdrcvt -q 100 converted.jpg comparison.{exr|hdr|tif}Setting the quality to 100 on the reverse conversion forces IEEE floating point output in the case of TIFF, but doesn't affect EXR.Also, if you want that test image I mentioned, it's on my website at: http://www.anyhere.com/gward/pickup/test1flt.tif
Thanks, I picked the binary, it works fine here - from the scratch, no trouble - and tests are running (on the ILM test material right now). Thus, I really don't need any sources.
Would you be interested in the results? Is it acceptable to present the results in a scientific work and/or in the ISO committee? If so, please let me know under which conditions.
Thanks a lot, this is a very helpful discussion. Thomas
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