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MEETING -- San Francisco Region

Thursday, February 6, 2003 (1st Thursday)
7-9pm (Arriving at 8pm is ok for those working late.)

Free!

Fresh Choice Restaurant 510-243-0198
Hilltop Mall
2443 Hilltop Mall Rd.
Richmond, CA 94806

Fresh Choice is a cafeteria and inexpensive. You buy your own dinner. Directions.

First time we've met at Fresh Choice. Headcount 5: Robin R., Greg W., Beverly and Bill, Rafael.

Greg described his Radiance HDR format as RGBE 8-bit + 8-bit exponent scaled to Tall Mary. Can cause banding on a primarily magenta image because of green channel predominance in human vision. His TIFF LogLuv format corrects for that. TIFF LogLUV format is 3x8-bit + 16bit log. Lookup + 3 multiplies -- very fast. OpenEXR seems much slower. Greg gave a demo of his Mac open source HDR image browser Photosphere that does tone mapping. RaniMove is in Radiance, which is actually 60 or 70 programs, open source now. Doing people or "mixed reality" is hard, not supported in Radiance. Greg has submitted a SIGGRAPH paper.

Bill does previz on Avid for ILM. Pick three takes and try them all. Timing is important. ILM learned the hard way that speed of ships may not cut together for pacing.

Robin described his Film Gimp project. Film Gimp supports HDR, LogLuv (as part of TIFF), and OpenEXR. Rafael did a traveling matte composite in GIMP and wants blue screen for Film Gimp.

Bill and Robin got into a discussion of auteur rights over film editing, whether the viewer should be permitted to block objectionable content in movies.

---

On the topic of image formats

From: <larry@marso.com>
To: <filmgimp-developer@lists.sourceforge.net>
Sent: Friday, November 01, 2002 12:25 PM
Subject: [FilmGimp] applications to digital SLRs

Just wanted to let folks know there exist linux routines for conversion of 12-bit linear RAW data from the CCD/CMOS of the current best digital SLRs out there, including the top Canon and Nikon models.

http://www2.primushost.com/~dcoffin/powershot/crw.c

some accompanying text and explanation:

http://www2.primushost.com/~dcoffin/powershot/

I believe this is the engine incorporated in the Bibble product for the windows/mac platforms, from

http://www.bibblelabs.com

crw outputs .psd files (Photoshop), which can be converted by ImageMagick to 16-bit TIFF, which open in filmgimp CVS and, I would guess, filmgimp-0.5.

For example:

>crw -d -3 DSC_0729.NEF

Loading NIKON D100 image from DSC_0729.NEF...
Dillon interpolation...
Writing data to DSC_0729.psd...

> convert DSC_0729.psd DSC_0729.tiff

>ls -l *729*

-rw-r--r-- 1 larry larry 9931160 Nov 1 12:42 DSC_0729.NEF
-rw-r--r-- 1 larry larry 36760000 Nov 1 12:43 DSC_0729.psd
-rw-r--r-- 1 larry larry 36776380 Nov 1 12:43 DSC_0729.tiff

You can perform level/curve operations, for example, in the full 16-bit colorspace, which substantially improves the quality of the final product -- even if you must do additional modifications in 8-bit gimp.