Direction-adaptive discrete wavelet transform for image compression
Direction-adaptive discrete wavelet transform for image compression
复制标题
DOI：
10.1109/tip.2007.894242
复制
发表时间：
2007-05-01
影响因子：
10.6
通讯作者：
Girod, Bernd
中科院分区：
文献类型：
--
作者：
Chang, Chuo-Ling;Girod, Bernd
我们提出了一个方向自适应小波变换（DA-DWT），局部适应过滤方向的图像内容的基础上，方向提升。利用自适应变换，提高了图像尖锐特征的能量压缩性。提出了一种基于各向异性统计图像模型的数学分析，以量化通过调整滤波方向所实现的理论增益。分析表明，所提出的DA-DWT是更有效的比其他提升为基础的方法。实验结果报告的增益高达2.5 dB的PSNR超过传统的DWT的典型测试图像。主观上，从DA-DWT重建更好地代表了图像中的结构，在视觉上更令人愉快。
We propose a direction-adaptive DWT (DA-DWT) that locally adapts the filtering directions to image content based on directional lifting. With the adaptive transform, energy compaction is improved for sharp image features. A mathematical analysis based on an anisotropic statistical image model is presented to quantify the theoretical gain achieved by adapting the filtering directions. The analysis indicates that the proposed DA-DWT is more effective than other lifting-based approaches. Experimental results report a gain of up to 2.5 dB in PSNR over the conventional DWT for typical test images. Subjectively, the reconstruction from the DA-DWT better represents the structure in the image and is visually more pleasing.