摘要
近来,基于小波变换的各种压缩算法大量出现。但在低比特率情况下,由于小波系数的量化将导致各种量化噪声,严重破坏了压缩图像的质量。针对这种情况,提出了一种基于复原理论的小波变换压缩图像后处理算法。在建立的后处理模型上,应用约束最小二乘法求解。通过试验,给出了最优参数的指导值选取。试验结果表明,该算法可以提高低比特率下压缩图像的视觉效果,同时PSNR也有一定的提高。和其它算法的对比试验表明,该算法在低比特率情况下有一定的优越性。
Recently,image compression algorithms based on Discrete Wavelet Transfonn（DWT） emerge in plenty.But at low bitrate,coded images suffer from serious quantization noise,which will degrade the quality of coded images.In this paper,a new postprocessing algorithm based on image restore theory is proposed.Based on the proposed postprocessing model,constrained Least-squares method is used to restore the coded image.Guidable optimal parameters selection is given based on numerical simulation trials.Results show that the proposed algorithm can improve the visual effects of the coded images as well as the PSNR gain.Compared with other existent algorithms,the proposed algorithm shows its advantages especially at low bit-rate.
出处
《计算机工程与应用》
CSCD
北大核心
2007年第29期74-77,共4页
Computer Engineering and Applications
基金
内蒙古工业大学重点研究项目( No.ZD200601)
关键词
压缩图像后处理
最小二乘
小波变换
图像复原
compressed image postprocessing
least-squares method
DWT
image restoration
