@Piccolo, what we are talking about is in the Material room on an Image Map node. Look at the attached pic it's one of my Specular Map nodes for one of my characters, if I click on the Image Source I get a pop-up where I can browse for an jpg/psd/etc. Since it is a Spec map I want the Gamma value at 1, the same goes for your Bump, Displacement and Normal maps.

Hope this helps.

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