图像编码与运动补偿算法研究

【作者】 刘辰昀；

【导师】 谭鹤良； 彭晓燕；

【作者基本信息】 湖南大学 ， 机械电子工程， 2002， 硕士

【摘要】 随着现代信息社会对通信业务要求的不断增长，图像通信与通信网容量的矛盾日益突出。特别是具有庞大数据量的数字图像通信，更难以传输与存储，极大地制约了图像通信的发展，成为图像通信发展中的“瓶颈”问题。图像压缩编码的目的就是要以尽量少的比特数表征图像，同时保持复原图像的质量，使它符合特定应用场合的要求。 本文主要研究基于小波的图像编码算法及快速DCT算法和钻石运动估值算法。研究了经典算法的不足，提出改进的算法，在相同信噪比的条件下提高了压缩比。 本文由三部分构成：基于小波的图像编码算法、DCT编码算法以及钻石运动估值算法。 第一部分在详细研究小波理论的基础上对小波系数的组织形式进行了讨论，提出改进型Shapiro编码算法，更有效的组织小波系数并对编码序列进行一次预编码，提高了压缩比。 第二部分采用JPEG、H261／H263、MPEG1／2等国际标准中所选择的量化矩阵，根据余弦函数的周期性提出一种基于查表的DCT编码算法。 第三部分针对当前一些运动补偿算法的特点提出了钻石搜索算法，可以提高运动矢量的准确性，并且根据大量实验证明，钻石算法的收敛性非常好。更多还原

【Abstract】 In modern society, with continuous growth of the requirement for communication business, the contradiction between image communication and net capacity is becoming imminent. Especially for large data of digital picture, communication is so difficult to transmit and store that it confine the development of image communication and become the "bottle-neck". The target of image compression is to express image with less byte, as well as maintain the quality of the restore image to meet the requirement of special environment.This thesis analyzes the image-coding algorithm based on wavelet, rapid DCT algorithm and diamond compensation algorithm. This paper analyzes the shortcoming of classical algorithm, puts forward the new algorithm and enhances the compression ratio on the condition of the same SNR.This series is composed of three parts: image code algorithm based on wavelet, DCT coding algorithm and diamond movement compensation algorithm.In the first part of this thesis, on the base of analyzing the wavelet theory and discussing the wavelet coefficient, a kind of Shapiro code algorithm is put forward. It efficiently organizes the wavelet coefficient and enhances the compression.In the second part of this work, According to cosine function’s cycle property and using the quantization square choosed by international standards such as JPEG, H261/H263,MPEG1/2, a kind of DCT coding algorithm that based on tabling is put forward.In the third part of this thesis, according to the characteristic of some movement compensation algorithms, a kind of diamond search algorithm is put forward. It enhances the accuracy and according amount of experiment. According to amount of experiments, diamond algorithm’s convergence property is very sound.更多还原