小波零树编码算法的改进与实现

Improvement and Implementation of Wavelet Zero-Tree Coding Algorithm

在嵌入式小波零树编码理论的基础上,探讨了一种改进的图像编码算法.通过结合空间方向树结构的分层树集合分割排序编码理论,继承了原小波零树编码算法的逐次逼近量化的思想.改进算法仍然采用了一种零树结构,但不仅把零树作为一个集合,而且把剩余树也作为一个集合进行处理.这样,被去除的节点存储在另一集合里,将不被重复扫描,从而提高了压缩的效率.实验仿真证明,这种改进编码算法能在一定程度上提高图像压缩效率和编码质量.

Based on the embedded wavelet zero-tree coding algorithm, an image coding algorithm,improved wavelet zero-tree coding algorithm, was proposed. Through combining the hierarchical classification tree partition sorting coding principle of space direction trees, the improved algorithm inherits the successive approximation thought of the wavelet zero-tree coding algorithm. This algorithm also adopts the zero-tree structure, but distinguished from its origin algorithm, it takes not only the zero-tree but also the rest trees as a set. As a result, the improved algorithm can raise the efficiency of image compression since it need not scan those wiped-off points stored in the other set. The simulation has proved that the improved wavelet zero-tree coding algorithm can improve the efficiency and quality of compressed images to some extent.