Design of 2D directional adaptive filter banks and its application to image coding

在本研究中，我们提出一个二维不可分离的自适应方向提升离散小波变换（DWT）结构及其在图像编码中的应用。虽然已经提出了一个二维不可分离的提升结构的9/7 DWT通过互换一些提升，我们推广了二维不可分离的提升结构的DWT的多相表示。在此基础上，通过引入自适应方向滤波，实现了二维不可分ADL结构，并将其应用于图像编码中。我们提出的方法比一维ADL简单，并且可以选择与一维ADL不同的变换方向。仿真结果表明，该方法对有损和无损图像编码性能都是有效的。

In this research, we propose a two dimensional(2D) non-separable adaptive directional lifting(ADL) structure for discrete wavelet transform(DWT) and its image coding application. Although a 2D non-separable lifting structure of 9/7 DWT has been proposed by interchanging some lifting, we generalize a polyphase representation of 2D non-separable lifting structure of DWT. Furthermore, by introducing the adaptive directional filteringing to the generalized structure, the 2D non-separable ADL structure is realized and applied into image coding. Our proposed method is simpler than the 1D ADL, and can select the different transforming direction with 1D ADL. Through the simulations, the proposed method is shown to be efficient for the lossy and lossless image coding performance.