This is about getting a clean sample palette as a starting point for painting in ArtRage.
Ever noticed how picking a color from a reference pic can be dicey? Not all the colors of all the pixels are clean, because they are optically blending. Zoom way in and you will see how the diverse pixels are sitting aside each other -- expecially if you're working from a printed photo.
Well, if you have Photoshop, there's an easy way to break a full value and color picture down into a managable palette of clean color that you know will be pure when picking/sampling a color to paint with. (If you don't have Photoshop, there are undoubtedly other ways of getting at this. But this is the principle.)
1) Open your original picture in PS.