Chapter 11 - Digital Image Processing of Evidentiary Photography

Abstract

The objective of this chapter is to help foster a better understanding of the imaging process as well as provide a better understanding of the tools in Adobe Photoshop used during the imaging process. It focuses on the use of Adobe Photoshop as this program is too sophisticated and too widely used in the law enforcement community to be ignored. Digital images come from a number of sources, such as digital cameras, film scanners, flatbed scanners, and video cameras. In addition, the digital images can also come in an array of formats, such as RAW, TIF, JPG, and BMP. The digital image files can also come in a wide range of resolutions, even if they come from the same source. In some instances, basic image enhancement techniques can be used effectively and efficiently to enhance the digital image. In other cases, more advanced techniques are required. But, regardless of the type of processing being done, one should always follow the three golden rules: follow established/approved procedures, use approved digital imaging technologies properly, and use commonly accepted image-processing techniques. One should also remember that no matter how many digital image–editing tools one has at the disposal, what one can do during the image enhancement process, as well as how successful that process is, depends on how the image is originally captured.