The easy block Hadamard transform: A new adaptive directional Hadamard transform for sparse image representation

In order to get an efficient image representation, we introduce a new locally adaptive Hadamard transform, called Easy Block Hadamard Transform (EBHT). EBHT is a type of directional Hadamard transform, which can be adapted to the image geometry in each block. Firstly, the image is divided into eight equalsized squares and the adaptive directional Hadamard filter is employed to get the low-pass data and high-pass data. In the further level of the filter bank algorithm, we just divide the low-pass image into four equal-sized squares. EBHT is very simple, but effective. Numerical results show the excellent efficiency of the EBHT for sparse image representation. (C) 2013 Elsevier GmbH. All rights reserved.