Hi.
I'm retouching a portrait and in a tutorial I saw a wanderful technique that consist in turn the image onto a CMYK mode and copy the yellow channel. After that I muct to invert this channel in order to fix the flaws problems, but... I do not understand why I have to do that. I just don't want to follow a tutorial. I want to know why I am aplying that particular technique. Then Why I have to invert the yellow channel?.
Thanks.