Generalized Lifting with adaptive local pdf estimation for image coding

In this paper we introduce an adaptive local pdf estimation strategy for the construction of Generalized Lifting (GL) mappings in the wavelet domain. Our approach consists in trying to estimate the local pdf of the wavelet coefficients conditioned to a context formed by neighboring coefficients. To this end, we search in a small causal window for similar contexts. This strategy is independent of the wavelet filters used to transform the image. Experimental results exhibit interesting gains in terms of energy reduction comparable to those obtained in [8]. In order to take benefit from this energy reduction, specific entropy encoder should be designed in the future.