一种小波变换域彩色图像压缩编码方案

A Color Image Compression Scheme in Wavelet Transform Domain

提出了一种基于人眼视觉特性与局部相关的小波域彩色图像编码方案.该方案以嵌入零树小波(EZW)编码思想为基础,通过建立可逆彩色空间变换、丢弃部分高频细节子带、单独编码最低频子带、高频子带自适应EZW编码及多关联预测算术编码等措施,实现彩色图像的自适应压缩编码.实验结果表明,文中算法具有较好的压缩效果和较强的通用性.

In this paper, a color embedded wavelet image compression algorithm based on human visual system and local image characteristics is presented. Firstly, the image is converted from RGB color space to YUV color space by using a reversible transformation to reduce the psychovisual redundancy, and the wavelet subbands of the decomposed color components are selected （to be encoded） according to energy distribution and human visual system. Then the embedded zerotree coding is performed. But unlike embedded zerotree wavelet （EZW） algorithm, the lowest frequency subband is coded separately from other highpass subbands, and the coefficients in high frequency subband is scanned adaptively in the order of human visual system importance. Finally, the complex context modeling is given by utilizing the correlation of wavelet coefficients and is adopted in the arithmetic coding. The experiment results show that the new color image compression scheme performs better than that of color embedded zerotree wavelet （CEZW） and color zerotree wavelet （CZW） in the aspect of recovery image quality and coding/decoding time.