Content-based Retrieval of Compressed Images.
Gerald Schaefer · DATESO · 2010
Content-based image retrieval allows search for pictures in large image databases without keyword or text annotations. Much pro- gress has been made in deriving useful image features with most of these features being extracted from (uncompressed) pixel data. However, the vast majority of images today are stored in compressed form due to lim- itations in terms of storage and bandwidth resources. In this paper, we therefore investigate a dierent approach, namely that of compressed- domain image retrieval, and present some compressed-domain image re- trieval techniques that we have developed over the past years. In partic- ular, a method for retrieving images compressed by vector quantisation, that uses codebook information as image features, is presented. Retrieval of losslessly compressed images obtained using lossless JPEG, can be re- trieved using information derived from the Human coding tables of t he compressed files. Finally, CVPIC, a 4-th criterion image compression technique is introduced and it is demonstrated that compressed-domain image retrieval based on CVPIC is not only able to match the perfor- mance of common retrieval techniques on uncompressed images, but even clearly outperforms these.