ABSTRACT
This chapter covers the commonly used contrast adjustment tools that are often the last step of the optimization process. There is a brief introduction into the Photoshop workspace, a review of the tools relevant to forensic image processing and where to find them, followed by contrast adjustment functions and how they work. The toolbar in Photoshop runs vertically down the left side of the desktop. The functions of the toolbar include move tool, selection tools, crop tool, eyedropper, brushes, text tool, hand tool, zoom tool, edit toolbar, foreground and background colors. The Photoshop default setting for the eyedropper tool in the tool options bar is "point sample." All contrast adjustment tools have the potential to clip data. This may seem an alarming statement, and it is, but it does not mean that contrast tools must be avoided carte blanche. The size and strength of the halo effects can be tailored specifically for the image being sharpened.
