A novel low complexity and efficient progressive quadtree wavelet encoder

In this paper the progressive quadtree wavelet (PQW) codec for lossy image compression is presented. PQW is based on the well known quadtree technique, applied in the wavelet transform domain. The proposed algorithm is designed with the aim of achieving low complexity and reduced memory requirements, keeping in mind applications such as Internet browsing on wireless (e.g. UMTS) channels. Besides its lower complexity, PQW provides the same subjective performance as the popular SPIHT codec while, in terms of the peak signal-to-noise ratio, it exhibits a slight performance loss of about 0.5 dB.