chapter  6
20 Pages

Image Data Formats and Image Compression

WithElizabeth Berry

Image data formats are an essential part of image processing activity because they define how the image data are stored and which additional information is saved together with the image data. Image compression is often a component feature of an image file format because it can reduce the size of the file for storage and transmission. A digital image is a computer file containing a list of numbers that represent the gray values of the pixels in an image. The limitations of general formats mean that medical imaging systems use special formats that allow space to store not just image data but also the associated metadata about patient, equipment and acquisition. Image compression techniques reduce the amount of data needed to represent an image. There are two types of compression: lossless and lossy. The principle of run length encoding is based on the observation that nearby pixels in an image tend to have the same gray value.