Image subband coding using an efficient recursive filter bank with complex signals
Hakon Gronning, John Håkon Husøy, Tor Audun Ramstad · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1990
The principle of subband coding has recently been applied for the purpose of image data compression. In this paper we present new results pertaining to our subband coder for images featuring an exact reconstruction parallel complex filter bank based on HR filters. This filter bank is characterized by its low complexity. The main advantage of subband coding is the possibility of separate coding of each subband such that the perceptually important coding noise is minimized. In this paper we exploit the nature of the complex valued subband signals of this particular coder by coding the module and phase rather than the real and imaginary parts. We determine the tolerable quantization noise levels for the module and phase signals in all subbands. These empiricaly derived data are employed in the coding simulations presented. Finally we present coding results for bit rates between 0.25 and 1.0 bits/pel.