Decimation-Interpolation Structures for Image Communications and Improvement using the Lifting Scheme

This paper presents an analysis of Decimation-Interpolation (DI) structures for image communications, and proposes an improvement method of DI structures. Decimation and interpolation techniques are important to efficiently transmit or store images in image communications systems such as digital multimedia broadcasting systems. The conventional design of DI structures is mainly based on the design of decimation and interpolation filters independently. Thus, the designs of the two filters are converged to a lowpass filter design. However, the conventional approach is possibly limited in performance and complexity. In this paper, we introduce some combinations of decimation and interpolation filters, and analyze the effect of the combinations in the spectral domain. We evaluate the combinations by conducting many experiments. Experimental results indicate that a good combination of the two filters provides a superior performance. On this basis, we propose an improvement method of the given DI structure. The proposed method is based on the lifting scheme whose structure is adaptable to the DI structure. Another simulation results show that the proposed method increases the performance of the given DI structure in terms of PSNR.(1)