Application of multitransforms for lossy image representation

The multitransform technique is applied for lossy image representation. The image is first divided into smaller non-overlapping subimages. Each subimage is resolved into two dimensional (2-D) subsignals, which are then compactly represented in a particular transform domain. This leads to an efficient representation of the subimage by superimposing the dominant coefficients corresponding to each subsignal. An adaptive algorithm in conjunction with an optimization strategy are developed to minimize the difference between the original and the reconstructed subimage. Extensive simulations verify that, for a given number of retained coefficients, the combination of the DCT and Haar transforms yields a more compact representation than using DCT or Haar alone