https://bugzilla.wikimedia.org/show_bug.cgi?id=17505





--- Comment #2 from [email protected]  2009-02-17 20:17:28 UTC ---
1) I am not aware of any patent issues with either the two file formats or tone
mapping operators.

2) If by "working" you mean libraries for reading the file formats:
* You don't need any for RGBE because the file format is trivial.
* There is a library to read OpenEXR. The OpenEXR home page [1] says "ILM has
released OpenEXR as free software. [...] The OpenEXR software distribution is
now licensed under the modified BSD license"

If you mean libraries for tone mapping:
* qtpfsgui [2] is a software under GPL which includes different tone mapping
operators, but the implementation may be of doubtful quality.
* Many of the so-called "global" tone mapping algorithms such as [4] or [5]/[6]
are easy to implement on your own because they just apply a logarithm-like
formula over each pixel. The source code in [6] has very liberal licensing
terms.

If you mean programs to display HDR images, there is HDR View, OpenEXR Viewer,
Jahplayer or Adobe Bridge, to name a few.

3) Global tone mapping algorithms are quite fast because they work
independently over each pixel, and a good compiler can make use of SIMD.
According to [3], Ward's scale factor [4] is the fastest, and took ~1 second to
render a 1,600 x 1,200 image on an Apple iBook G3 running at 800 MHz.

[1] http://www.openexr.com/
[2] http://qtpfsgui.sourceforge.net/sfproject.php
[3] Erik Reinhard et al.: "High Dynamic Range Imaging", p. 358. Morgan
Kaufmann, 2006.
[4] Greg Ward: "A contrast-based scalefactor for luminance display", in
"Graphics Gems IV", pp. 415-421. Academic Press Professional, 1994.
[5] http://www.cs.utah.edu/~reinhard/cdrom/source.html
[6] http://www.cs.ucf.edu/~reinhard/Reinhard02/


-- 
Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.
You are on the CC list for the bug.

_______________________________________________
Wikibugs-l mailing list
[email protected]
https://lists.wikimedia.org/mailman/listinfo/wikibugs-l

Reply via email to