Search found 34 matches

by Wolfgang Woehl
2010-02-28T05:33:24-07:00
Forum: Users
Topic: Jpeg2000 encoding for digital cinema
Replies: 18
Views: 43015

Re: Jpeg2000 encoding for digital cinema

EDIT: this would be a proper sRGB linearization, I guess: convert srgb-gradient.tiff -fx "p <= 0.04045 ? p/12.92 : ((p + 0.055) / 1.055) ^ 2.4" linear.tiff See http://en.wikipedia.org/wiki/SRGB#Specification_of_the_transformation for the math and an explanation for why 0.04045 is used instead of 0.0...
by Wolfgang Woehl
2010-02-28T05:09:55-07:00
Forum: Users
Topic: Jpeg2000 encoding for digital cinema
Replies: 18
Views: 43015

Re: Jpeg2000 encoding for digital cinema

This seems relevant to the previous post about proper color handling when resizing. Magick recently brought this to my attention. http://www.4p8.com/eric.brasseur/gamma.html Yes, this needs to get sorted out. My gut reaction is it's okay for imagemagick to not implicitly linearize because the sourc...
by Wolfgang Woehl
2010-02-26T13:14:55-07:00
Forum: Users
Topic: Jpeg2000 encoding for digital cinema
Replies: 18
Views: 43015

Re: Jpeg2000 encoding for digital cinema

Jusiponen, good catch with the -resize, another magick trick in the bag, thank you. Never had issues with playing my panny's 1920x1080 (specified as such in a CPL's ScreenAspectRatio tag), though (tried on XDC G3 and Doremi). I'm avoiding scaling wherever I can. Wrt audio: Yes, let's find a better w...
by Wolfgang Woehl
2010-02-25T16:19:35-07:00
Forum: Users
Topic: Jpeg2000 encoding for digital cinema
Replies: 18
Views: 43015

Re: Jpeg2000 encoding for digital cinema

For this particular conversion the -recolor takes a 3x3 matrix. It should make more sense if I write it like this: -recolor "0.412453 0.357580 0.180423 0.212671 0.715160 0.072169 0.019334 0.119193 0.950227" The matrix above is the standard RGB -> XYZ. More can be found at http://www.brucelindbloom....