Redundant representation with complex wavelets: how to achieve sparsity

摘要: Overcomplete transforms, like the dual-tree complex wavelet transform, offer more flexible signal representations than critically-sampled due to their properties of shift invariance and directional selectivity. We show that many transform coefficients can be discarded without much reconstruction quality loss by forcing compensatory changes in remaining coefficients. consider convergence an iterative projection system for achieving usual coding aims good sparsity with low error. Results how these measures translate useful image compression performance.