ABSTRACT
Transform coding (TC) is efficient coding scheme based on utilization of interpixel correlation. In TC, the main idea is that if the transformed version of a signal is less correlated compared with the original signal, then quantizing and encoding the transformed signal may lead to data compression. Transforming a set of statistically dependent data into another set of uncorrelated data, then discarding the insignificant transform coefficients using the Hotelling transform, can be viewed as a statistical interpretation of TC. The chapter discusses a general formulation of a linear unitary two-dimensional image transform and provides basis image interpretation of TC. A transform is said to be orthogonal if the transform matrix is orthogonal. The motivation behind TC is that with a proper transform, hence, a proper set of basis images, the transform coefficients are more independent than the gray scales of the original input image.
