【作者】 郑晓燕；

【导师】 林叶锦； 张均东；

【作者基本信息】 大连海事大学 ， 轮机工程， 2007， 硕士

【摘要】 在多媒体技术日益广泛的今天，图像的通信和存储占有重要的位置，数字图像包含信息量巨大的特殊性使得压缩技术成为其关键，因而探索高效图像压缩编码算法无疑将成为国际公认的热点之一。小波理论是近年发展起来的新的数学分支，因其良好的空间一频率局部特性和与人眼视觉特性相符的变换机制，成为当前图像压缩编码的主要研究方向之一，该方法是继傅立叶变换和离散余弦变换后一种新的图像压缩算法，将图像分解成与人类视觉特性相匹配的不同分辨率、不同方向特性的子带，并将能量集中于某些子带，利于编码，且对整幅图进行变换，比传统余弦变换编码有很大提高。 本文首先介绍了图像压缩编码的基本理论和JPEG静态图像压缩标准，为本文的研究方向确定了依据。 接着通过实验比较了JPEG和JPEG2000两种静态图像压缩标准。并详细研究了JPEG2000其中用到的一些核心技术，如EBCOT算法和感兴趣区域编码技术等。 其次描述了小波变换的图像压缩编码，引入了小波变换图像压缩理论基础。分析讨论了小波变换编码在图像压缩领域的优势，探讨了在图像压缩方面对小波基的评价标准，结合实际应用，选择合适的小波基进行图像编码。 然后研究了小波零树压缩编码，对零树编码思想进行了研究，结合目前比较成功的零树编码EZW和SPIHT，提出其存在的优点和不足，尝试提出改进的小波零树编码算法。该算法结合了DPCM和零树编码，并结合视觉特性对阈值进行了更正，减少视觉冗余。设计开发出小波零树图像压缩编码的软件系统，对实验结果进行分析研究，主要从客观信噪比和主观信噪比方面，从而论证所提出的改进的零树编码算法的性能优势，具有实际的应用价值。更多还原

【Abstract】 With the rapid development of multimedia technology in recent years, the digital image transmission plays a very important role in communication fields. Digital images generally include a great deal of information, so the compression technology becomes the key of the research. On this occasion, it inevitably becomes one of the main tasks to seek after the effective image coding algorithm. The theory of wavelet transform is a new math branch developed in recent years. Because of its special characteristics in space-frequency, it has become one of the main research directions in image compression coding. This algorithm is a new image coding algorithm after the Fourier transform and the DCT transform. It divides the image into several subbands in different resolution and different direction, which are compatible with human visual characters. Besides, it can split image energy into some subbands so as to code, and make transform to the whole image, which is better than the DCT transform.Firstly, it introduces the basic principle of the image compression coding and the standard of JEPG still image compression. And make sure the gist of study direction.Then, by experiment we compare the basic principle of JPEG compression standard with that of JPEG2000 still image international compression standard. And some core techniques of JEPG2000 standard are elaborated particular such as EBCOT algorithm and ROI coding.Thirdly, it introduces elementary wavelet theory, the resources of it and the formula for transform. Then discuss its advantages in the field of image coding, its appraise standard of wavelet on image compression, combine the face apply, and choose the propriety wavelet.Next, the technology of wavelet zerotree is introduced, analyze two kinds ofclassical image coding algorithm based on wavelet zerotree idea------EZW and SPIHT.On the basis of them, an improved algorithm is proposed. The algorithm combines the更多还原