基于人眼视觉特性的低比特率图像压缩编码

Improved low bit-rate image coding scheme based on human visual system

为了提高编码速度和改进视觉效果,提出了一种改进的低比特率SPIHT算法。算法首先用提升小波对原始图像进行分解,再结合人眼视觉掩蔽特性,对不同区域内图像信息所对应的小波系数赋予不同视觉权值,以保证优先传输视觉上的最重要系数,最后根据系数重要性,对低频系数采用新的排列结构,并采用SPIHT编码思想完成图像压缩。实验结果表明,该算法压缩效果优于SPIHT图像压缩方案,特别在低比特率下。

A improved low bit-rate image coding scheme is presented.The lifting wavelet transform is applied to the original image,and the visual gains are achieved by exploiting Human Visual System（HVS） characteristics to weigh wavelet coefficients according to their perceptual importance.Lastly,the lower frequency exploits a new partitioning structure based on the importance of coefficients.The experimental results show that the modified image compression scheme provides higher perceptual quality and higher PSNR than SPIHT,especially at low bit rates.