I knew I was right. (You guys just proved an old argument I had with someone). Oh, the joys of self gratification.
Ron Ganbar email: [email protected] tel: +44 (0)7968 007 309 [UK] +972 (0)54 255 9765 [Israel] url: http://ronganbar.wordpress.com/ On 15 November 2011 10:28, Ivan Busquets <[email protected]> wrote: > Hi Gavin, > > As you said yourself, the equation cannot be solved UNLESS you know both > variables on one of the sides. > In other words, you'd need to have the BG image in order to prep a FG > image so it can be comped in sRGB space and match the results of a linear > comp. > > So is there no way to output a PSD or PNG or TIFF which will look the same >> as my composite in Nuke over a white background? > > > If you need to get the same results on a white background, you could prep > your FG element such that: > > X = ( (FG * alpha + (1 - alpha)) ^ 2.2 - (1 - alpha) / alpha ) ^ > (1/2.2) > > Where X is the FG image you'd want to export to be comped on a white BG. > But of course, this will only give you a match when comping the FG over a > WHITE BG. If the BG changes, then you'd need to prep a different FG to go > with it. > > Hope that helps. > > Cheers, > Ivan > > > > On Mon, Nov 14, 2011 at 12:13 PM, Gavin Greenwalt <[email protected] > > wrote: > >> How are Nuke users handling workflows in which they need to deliver >> images with alpha that will be composited in sRGB space not linear space? >> >> Essentially we have a situation where you would need to find equations >> for u and v such that (xy + z(1-y))^(1-2.2) = (uv + z^(1-2.2)(1-v)). >> >> My initial impression is that it's impossible since the simplified >> version of this conundrum would be (x+y)^2 = (u+v) which I believe is >> mathematically impossible to solve... right? So is there no way to output >> a PSD or PNG or TIFF which will look the same as my composite in Nuke over >> a white background? >> >> Thanks, >> Gavin >> >> _______________________________________________ >> Nuke-users mailing list >> [email protected], http://forums.thefoundry.co.uk/ >> http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users >> > > > _______________________________________________ > Nuke-users mailing list > [email protected], http://forums.thefoundry.co.uk/ > http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users >
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