RGB to HSV transformation

Hello there,

Is there any tutorial available on how to do an RGB to HSI (seems to be ‘v’ in the case of SNAP) transformation?

I’ve got a three-date set of S1 data that I’ve saved as RGB. I want to transform this to HSI so I can replace the ‘I’ with elevation. When I try to simply enter my three RGB channels into the HSV dialog, I get errors.

Thanks for any info