[argyllcms] Re: Making profile of uncalibrated display
- From: Ivan Tsyba <ivantsyba@xxxxxxxxx>
- To: argyllcms@xxxxxxxxxxxxx
- Date: Fri, 20 Apr 2012 23:55:51 +0300
20 квітня 2012 р. 03:12 Graeme Gill <graeme@xxxxxxxxxxxxx> написав:
> Ivan Tsyba wrote:
> > .cal file contains 256 rows RGB_I RGB_R RGB_G RGB_B table and .ti3 file
> contains 48 rows RGB_R
> > RGB_G RGB_B XYZ_X XYZ_Y XYZ_Z table. How to append that 256 elements on
> 48 elements?
> > So it maybe little bit more sophisticated that just replacing RGB values
> from cal to ti3 file?
>
> They are not appended, the values are replaced by their looked up values.
>
> So:
>
> for each row of the .ti3 file., ie:
>
> SAMPLE_ID RGB_R RGB_G RGB_B ....
> .
> 17 1.4275 34.039 73.682 ...
>
> for each of R, G & B, ie:
> G = 34.039
>
> Normalize G = 34.039/100 = 0.34039
>
> Locate lookup point in .cal file for a G value of 0.34039
> by locating the RGB_I value it lies between:
>
> RGB_I RGB_R RGB_G RGB_B
> 0.33725 0.36240 0.39923 0.35515
> 0.34118 0.36562 0.40221 0.35843
>
> Linearly interpolate the G value
> cal_G = (0.34039 - 0.33725)/(0.34118 - 0.33725) * 0.40221
> + (0.34118 - 0.34039)/(0.34118 - 0.33725) * 0.39923
> = 0.40161
>
> [Note (0.34039 - 0.33725)/(0.34118 - 0.33725) =
> 1.0 - (0.34118 - 0.34039)/(0.34118 - 0.33725)]
>
> De-normalize the calibrated G value
>
> cal_G *= 100.0
>
> Replace the G value with its calibrated value in the .ti3 file:
>
> 17 nnnnn 40.161 nnnnn ...
>
> etc.
>
> etc.
>
> Graeme Gill.
>
>
Thanks, this works. Many manual data manipulations, but works.
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