[magick-developers] source of Photo CD problems?

[Nathan Willis]

I've done some searching on the mailing lists and forum, and periodically,
someone will pop up complaining about the quality of images converted from
Kodak Photo CD (PCD) format.

I found something that might explain what the problem is.  Ted Felix has an
entire section ([url]http://tedfelix.com/PhotoCD[/url]) on his site about
PCD images, and according to him Kodak's software and a lot of others
misread the luminance data, using a LUT that compresses the highlights
incorrectly.  He says that the white papers at Kodak indicate that the
luminance data in the files is actually linear in the range (0,346) -- and
he patched their Windows DLL to replace the LUT and gets better images.

A couple of readers sent him examples converted from IM.  I tried the
reference image on his site -- plain grayscale swatches -- and it certainly
appears to be true.

Has anyone else heard of this before?  It's not clear to me how old the info
on the site is; I emailed Felix and have not heard back.

NW