Fast and efficient spatial scalable image compression using wavelet lower trees

A new image compression algorithm is proposed based on the efficient construction of wavelet coefficient lower trees. This lower-tree wavelet (LTW) encoder presents state-of-the-art compression performance, while its temporal complexity is lower than the one presented in other wavelet coders, like SPIHT and JPEG2000. This fast execution is achieved by means of a simple two-pass coding and one-pass decoding algorithm. On the other hand, its computation does not need additional lists or complex data structures so there is no memory head. A formal description of the algorithm is provided, so that an implementation can be performed straightforwardly. The results show that the codec works faster than SPIHT and JPEG2000 with better performance in terms of rate-distortion metric.