摘要： 图像数据量大、冗余度高，其实时加密问题亟待解决。图像部分加密方法只加密图像压缩编码的部分重要数据，是一种可行的实时加密方案。该文研究图像压缩编码的多级树集合分裂算法，分析灰度图像SPIHT中不同类型编码数据对图像重建的作用，确定了其中的重要数据，并将其用流密码进行了加密。仿真结果表明，该方法只加密图像编码的很少部分数据，便可达到图像保密的目的。

关键词: 图像压缩, 小波变换, 多级树集合分裂算法, 部分加密

Abstract: Due to big size and high redundancy, real-time image encryption is becoming a problem. Partial encryption of image encrypts only the important parts of the compressed image data, thus it is a feasible scheme for encrypting images in real time. This paper presents a partial encryption of gray images compressed by Set Partitioning In Hierarchical Trees(SPIHT). The significance of different types of SPIHT coded bits is analyzed, the most significant bits for reconstructing images are selected and then encrypted using a stream cipher. Computer simulations results demonstrate that the proposed method can achieve image security by encrypting only small parts of the SPIHT coded image.

Key words: image compression, wavelet transform, Set Partitioning In Hierarchical Trees(SPIHT), partial encryption

中图分类号: 

• TP309