Embedded zerotree image coding using low complexity IIR filter banks

Compares for image coding applications a low-complexity IIR wavelet based on an all-pass polyphase decomposition to a pair of linear phase biorthogonal wavelets. To code the wavelet coefficients, the authors use Shapiro´s (1993) zerotree algorithm which has the virtues of being both efficient and delivering excellent performance (in a rate-distortion sense). They consider a variety of methods for eliminating filter transients at the image boundaries including circular convolution, symmetric extension (for the biorthogonal wavelets), and direct transmission (for the IIR wavelet). By also coding the filter states in a zerotree form, they find that direct transmission generally performs better than circular convolution. Finally, they show that the use of this IIR wavelet provides equivalent performance to the biorthogonal wavelets at greatly reduced computational complexity