一种自适应整数小波变换方法

本文给出了一种自适应整数小波变换方法。构造整数小波变换的方法通常是由提升结构得到。本文也正是基于一种具有完全重构的自适应提升结构而得到自适应整数小波变换。G.Piella给出的自适应提升结构,由于它严格限制更新步骤中滤波器系数之和为1,使得不易于用它构造整数变换。为了得到整数变换,本文将它推广到更一般的情形。由这种自适应提升结构得到的自适应整数变换对图像中的边缘点和均匀区域有区别地对待,而且对整数信号进行变换没有舍入误差。这些性质在数字图像数据压缩中有重要应用。

Adaptive Wavelet Transform That Map Integers To Integers

An adaptive wavelet transform that maps integers to integers will be presented in this paper. The wavelet transform that maps integers to integers was constructed generally by lifting schemes. Also basing on the adaptive lifting scheme with perfect reconstruction, we get the adaptive transform. Using lifting scheme presented by G. Piella, It is difficult to construct transform that maps integers to integers because of restrict on the sum of coefficients of update step. In order to get the transform, results will be extended to more general cases. The adaptive transform treats edges and homogeneous regions in image differently , furthermore, if input signals are integers, the transform has no truncation error. These properties have important applications in compression of digital image.