现今，大量的图象与视频信息都是以压缩数据格式进行存储和传输的.DCT(Discrete Cosine Transform离散余弦变换 )是目前应用最为广泛的多媒体数据压缩技术之一.直接在 DCT域实现如视频编辑、特征提取等传统空域处理技术，能够避免繁琐的压缩数据编、解码操作，减少处理时间和数据处理量，节省内存空间.这一技术对于高速海量的数据处理场合，如 Internet信息检索、视频编辑和检索、远程监视图象的理解等，是很有吸引力的，因此其是近年来国际上有关领域的研究热点之一.本文对近年来文献中所见的 DCT域图象处理和特征提取技术进行了回顾和综述，并在此基础上对其发展方向进行了探讨

Nowadays volumes of image and video data are stored and transferred in the form of compressed data structure. The Discrete Cosine Transform(DCT) is one of the most widely used digital compression techniques for multimedia. Data processing such as video editing or feature extraction directly in the DCT domain other than in the pixel domain will save the time needed for the compressed data to be coded or decoded as well as the memory for buffering by processing less data. Such techniques are desirable for the in time massive data processing applications as Internet multimedia retrieval?video editing, therefore have been hotly discussed during recent years. In this paper, we present a review of the data procession techniques in the DCT domain proposed in the literatures, and try to figure out the advance direction in the future.