what do i need to change a regular picture to an outline picture?

Answer 1

Do you mean a silhouette? If there is a high contrast between the person and their background, you can first desaturate the image (grayscale), then use the Threshold algorithm, or the Brightness/Contrast control in your image editor to totally obliterate all features except for very dark regions and very light regions. You can modify this to be smoother and so on afterwards with other tools.
If there is not enough contrast for this to be effective, you will have to select the person yourself. The QuickMask tool in Photoshop, along with the Background Eraser and the ability to make masks from color channels are great ways of selecting out hard-to-separate objects. See http://www.graphic-design.com/Photoshop/tutorials/quickmask.html .