[ptx] Display gamma (was:Vignetting correction in nona)

[douglas wilkins]

Hi there,

--- Kai-Uwe Behrmann <ku.b at gmx.de> wrote:

> Wouldnt Display gamma be a toppic to do together with colour management, as
Douglas Wilkins allready planed?

I would have thought so :-)
And now that 0.5 has been released, I think it is time to put some thought into
the colour management in hugin.

As I see it, there are two areas that need to be addressed. Firstly, ensuring
that embedded ICC profiles are passed through correctly. Unlike an normal image
editing application, there is no need for hugin to modify the embedded ICC
profile or add one if there is no profile. 

Secondly, to colour manage the actual images in hugin for accurate display.
Modifying the display gamma "on the fly" would fall into this area I guess.
Again, hugin is slightly different and would probably only require an input and
display profile since we are not doing any colour manipulation, but I welcome
input on this.

Finally, I was thinking of using lcms for the colour management, mostly because
I am familiar with it ;-), but also because it is reasonably mature and
complete. It will add an additional dependancy though.

> 
> Beside this, when I load from a newer dcraw (version > 7.0) the images 
> come corrected by an internal matrix plus gamma. They look much like 
> theyre 8-bit sisters.

Yes, dcraw has come a long way. The only problem that I have with it now is
that it assumes a sRGB output profile (look at xyz_rgb)and most cameras are
capable of a far bigger gamut...

regards,
Doug



	
	
		
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