期刊名称：International Journal of Innovative Research in Computer and Communication Engineering
印刷版ISSN：2320-9798
电子版ISSN：2320-9801
出版年度：2014
卷号：2
期号：1
出版社：S&S Publications
摘要：Image transforms are extensively used in image processing and image analysis. Transform is basically a mathematical tool, which allo ws us to move from one domain to another domain. Transforms play a significant role in various image processing applications such as image analysis, image enhancement, image filtering and image compression. Nowadays, almost all digital images are stored in compressed format in order to save the comp utational cost and memory. To save the memory cost, all the image processing techniques like feature extraction, image indexing and watermarking techniques are applied in the compressed domain itself rather than in spatial domain. In this paper, composition of a block from all of its sub-blocks and vice versa ,directly in DCT domain is obtained and showed that the result of both operations are same and the computat ional complexity of the proposed algorithm is lower than that o f the existing ones
关键词：discrete cosine transform; compression; JPEG; region of interest; frequency domain
