小波变换分解层次对图像压缩效果的影响

Influence of decomposition level of wavelet transform on images compression effect

小波分析(wavelet analysis)是近10年迅速发展起来的新兴学科,具有深刻的理论意义和广泛的应用范围。简述了小波分析的基本原理,重点地分析了采用嵌入式小波零树编码时,小波变换分解层次对SST(空间太阳望远镜)图像仿真压缩效果的影响。结果表明,随着压缩倍数的增加,所需小波变换的分解层次亦应增加;但当小波变换的分解层次增加到某一值时,信噪比和峰值信噪比将基本保持不变。压缩倍数和小波变换的分解层次之间存在一个较佳匹配问题,对此进行了较为详细的讨论。

Wavelet analysis has been a burgeoning technique in the past 10 years, with profound theoretical significance and broad application scopes. In this article, the basic principle of wavelet transform is briefly described, focusing on the influence of decomposition level of wavelet transform on emulate compression effect of SST （space solar telescope） images, when adopting embedded zerotree wavelet coding. The results show that the necessary decomposition levels of wavelet transform should be increased with the multiplying of compression. But when it is increased to a certain level, signal-to-noise and peak signal to noise ratios will keep steadiness. The matching between compression multiple and the decomposition level of wavelet transform is also discussed in detail.