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How to make your own transfer function!

RalphLambrecht

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Hi everyone,

I like to share a spreadsheet for automating the process of creating a transfer function for digital and hybrid processes. I just posted it on my websites and thought you might want to check it out. To visit, just click on either of the links below or paste the URL into your browser. Then scroll down to 'Creating a Transfer Function' and download the .xls or the .xlsx and the .pdf file for instructions.

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Take a look and let me know what you think!
 

R Shaffer

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Ralph,

Your spreadsheet is very interesting in that it translates from density to %K.

I inquired about this here a year or so ago and Clay was kind enough to post a spreadsheet for the Yule Nielsen Formula. I have used that to create several curves that I am quite fond of. There are differences between a curve measured in %K from a scanner and a logarithmic curve from measured density.

I would be curious as to what formula that is you are using for your translation and how you would use your spreadsheet if your D-max is around 1.3 to 1.5 for pt/pd for example.

Very nice spreadsheet either way.
 
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RalphLambrecht

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... I would be curious as to what formula that is you are using for your translation and how you would use your spreadsheet if your D-max is around 1.3 to 1.5 for pt/pd for example. ...

Thanks. I use a corrected (capped, normalized and scaled) gamma function to calculate the rendering intent. The result is similar to what Adobe calls 'relative colorimetric' but is limited to contrast to work for monochrome prints.

The workbook includes three tabs, two for an absolute Dmax of up to 2.1 and one for up to 1.65. I can add a specialized rendering for pt/pd prints if so desired.