Sketch based and context sensitive coding of Laplacian pyramids

An improvement in pyramidal coding is described which goes beyond first-order statistics by exploiting structural redundancies within Laplacian pyramids. Their three-dimensional structures are described with a novel sketch pyramid, which is used in a new context-sensitive method for coding Laplacian pyramids. This approach is enhanced by using the Gaussian function as the generating kernel, and the sinc function for the expansion filter. The compression ratios obtained from pyramidal coding are improved by a factor ranging from around 2.5 to 4, depending on scene complexity. Example results are given