[argyllcms] Re: Capture video card gamma LUT to ICC profile
- From: Benjamin Shadwick <benshadwick@xxxxxxxxx>
- To: argyllcms@xxxxxxxxxxxxx
- Date: Fri, 3 Feb 2012 10:59:19 -0800
If I combine the -nc and -as parameters, I get a profile that is just under
4KB. The LUT graphs exactly match the one from the ~134KB profile, although
both differ very slightly from the original LUT data. I don't have a
problem with the slight difference, however, as it is imperceptible, and
the original data was created using a software calibration tool anyways
(CLTest).
As for editing the XYZ values, I wouldn't know what I'm doing or why I
should do it. If the argyllcms-generated profile has calculated the XYZ
values based off of the LUT data, then wouldn't that be more appropriate to
use than the XYZ values from the generic profile provided by the monitor
manufacturer for my model of monitor?
Also, each profile has a different set of tags:
- base profile for my monitor model: calt, cprt, K007, desc, wtpt, rXYZ,
gXYZ, bXYZ, rTRC, gTRC, bTRC
- argyllcms-generated 4KB profile: desc, cprt, wtpt, bkpt, clrt, vcgt,
rXYZ, gXYZ, bXYZ, rTRC, gTRC, bTRC
- argyllcms-generated ~134KB profile: desc, cprt, wtpt, bkpt, clrt, vcgt,
A2B0, B2A0, targ, DevD, CIED
On Fri, Feb 3, 2012 at 12:42 AM, Nikolay Pokhilchenko <nikolay_po@xxxxxxx>wrote:
> 03 Feb 2012, 12:01 Benjamin Shadwick wrote:
>
> > The .icm file that I used as a base specific to my monitor that was
> already being used by Windows, which contained no vcgt tag. After running
> the above tools, I got an output .icm file that was much larger (~134KB
> instead of ~1KB) that contains a vcgt tag.
> >
>
> You can check the gamma and XYZ numbers in profile by ICC Profile
> Inspector. The values can be slightly off than the values in original base
> profile because re-profiling. You can tune the values to exact original
> values by Profile Inspector.
> You can provide "-nc" parameter for colprof. The colprof will not include
> target data into Your new profile and You'll get smaller profile size at
> the output.
On Fri, Feb 3, 2012 at 12:14 AM, Graeme Gill <graeme@xxxxxxxxxxxxx> wrote:
> Benjamin Shadwick wrote:
> > being used by Windows, which contained no vcgt tag. After running the
> above
> > tools, I got an output .icm file that was much larger (~134KB instead of
> > ~1KB) that contains a vcgt tag.
>
> The original may have been a matrix profile (look at iccdump output),
> while colprof defaults to cLUT based.
>
> If so try colprof -as.
>
> Graeme Gill.
>
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