FREEWARE Spectral Calculator on JavaScript. Help is needed!

[lazzz]

I put that message here because the author of Freeware Spectral Calculator on JavaScript asked me to do so.


The software was created in January of 2012, it has been changed thousands of times and has been updated on a daily basis.
Recently it was translated to english language by the author.
The author (Michael Sartakov) is a chief prepress technologist and a colorist at printing companies in Moscow and Vladivostok (Russia).
The author asks english native speaking users to help him with the translation of the calculator.
You can find the english version here: http://rudtp.pp.ru/spectralcalc_en.php
and the lang file is here: http://rudtp.pp.ru/spectral_translator.js
Michael would highly appreciate any propositions and wishes of how to make the software better and which functions should be added or improved/
He will track the answers.
He is willing to acknowledge helpers in the copyright section.


Also he'd want to translate the software into german with the help of native speakers.

As for us, this soft is very useful for TVI calibration, profile correction and a lot of other things which we gonna learn soon

 

[lazzz]

My short description of calibration process:

Open the page http://rudtp.pp.ru/spectralcalc_en.php
Enter your measured data in the top text field. You can easily obtain measures with trial version of X-Rite's Measure Tool.
Then click "Color" button to check your solid densities. Correct them and make another press run if needed. You can do that using laptop right near press to save time and paper. But don't forget that ink fades after drying.
When you achieved correct solid ink densities from ISO 12647-2, you can click "TVI" button.
Then save TVI values by clicking the button "Save TVI for calculation of compensation". Open saved .txt file, copy the table with values for one particular ink to clipboard. For example cyan, like that:

100 0
98 2.46
95 4.25
90 6.53
85 7.70
80 9.35
75 10.94
70 11.70
60 14.35
55 12.16
50 12.61
40 11.43
30 8.85
25 7.88
20 7.12
15 5.52
10 3.03
7 2.05
5 1.51
3 1.32
2 0.74
0 0


Then open this page http://rudtp.pp.ru/dgcor/, insert the values into the left field. Then enter the target curve name in the small field below, called "ISO TVI at 50% ". For example if you wanna aim FOGRA 39 Cyan, you should enter "f39c".
If you need interpolation of the data you can enter desired "steps". In the example above we don't have 1% and 99% field (they weren't presented in the initial measured control strip). So we can enter such table:

100
99
98
95
90
85
80
75
70
60
55
50
40
30
25
20
15
10
7
5
3
2
0

Then click "Calculate" button (it's not translated yet, so click "Считать")


You will see the correction values in the right field.

You can plus them to linearisation correction values in your RIP.
Even first run provides good results. But for making your curves perfect you may need from 3 to 8 iterations.
Then you should check you dotgain values, measuring control strips on regular basis. Sometimes you will have to correct compensation curves.