基于DCT变换的内嵌静止图像压缩算法

提出了一种有效的基于离散余弦变换(DCT)的内嵌子带图像编码算法.Xiong等人提出的EZDCT算法采用零树结构实现了一种内嵌DCT编码器,且其性能优于JPEG.本文指出DCT的零树结构在内嵌DCT算法中并非很有效,同时提出了一种不依赖零树结构的简便、高效的内嵌DCT子带编码算法.实验结果表明本文算的压缩性能(PSNR)比EZDCT高约0.5~1.5dB,且接近当前最通用的内嵌小波SPIHT算法,在对某些图像压缩时还优于SPIHT算法.

Still Image Compression Using Embedded DCT Approach

An efficient embedded subband image coding algorithm based on the discrete cosine transform (DCT) is presented in this paper.Xiong et al.'s EZDCT scheme employs the zerotree structure and fulfills a DCT-based embedded zerotree quantizer with its performance outperforming any other DCT-based coders,including the baseline JPEG and improved JPEG.We point out the zerotree structure of DCT coefficients is not effcient in embedded codec.We proposed an effcient embedded subband coder for the DCT image (ESDCT),without relying on the zerotree structure.A comparison reveals that the PSNR results of our ESDCT are 0.5-1.5 dB higher than those of EZDCT.The compression performance is close to the popular embedded wavelet-based SPIHT,slightly superior to SPIHT in some cases.