# [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.