jayanta mukhopadhyay - image and video processing in the compressed domain

[...]... developing algorithms We may consider emphasizing or deemphasizing some factors after analyzing their role in the reconstruction of the image © 2011 by Taylor and Francis Group, LLC 8 Image and Video Processing in the Compressed Domain Compressed Image Entropy Decoding Alternative Representation Processing in the domain of Alternative Representation Output Image in the Compressed Form Entropy Encoding... images in the compressed form instead of working with their original representations in the spatial domain For example, in a DCT-based image representation, we may compute © 2011 by Taylor and Francis Group, LLC 7 Image and Video Compression: An Overview Output Compressed Image Input Compressed Image Decompression Processing in Spatial Domain Compression Figure 1.2: Basic steps in processing with compressed. .. representation in a different domain other than their original domains of representation, which are spatial and spatiotemporal for images and videos, respectively Two such popular representations of images and videos are formed by their discrete cosine transforms (DCT) [3] and discrete wavelet transforms (DWT) [92] We refer to these domains as compressed domains or domains of compression Since images and videos... which the first one, H.261, was published in 1990, and it greatly in uenced the subsequent video coding standards Later, this standard evolved as H.263 and H.264 in 1998 and 2003, respectively The committee looking after the development of these compression standards is known as the Video Coding Expert Group (VCEG) (formerly called the ITU-T) In 2003 they formed a Joint Video Team (JVT) with MPEG, and the. .. as processing in the compressed domain However, we should also be concerned about the efficiency of the processing algorithm in the compressed domain If this algorithm takes longer time than its equivalent operation in the spatial domain, the saving in computation of reconstruction and derivation of alternative representation (or inverse transform and forward transform operations of transform coding)... representing images with transform coefficients They have the desirable properties of re- © 2011 by Taylor and Francis Group, LLC 6 Image and Video Processing in the Compressed Domain constructibility, low redundancy, and factorization in representation of images Due to the last property, they are quite useful in approximating images with less number of coefficients, which inherently reduces the storage... yet powerful digital cameras and video recorders in the consumer world has further accelerated the pace of research and development in processing these media One of the very initial tasks of processing these data is to compress them prior to their storage and/ or transmission By compressing data, we want to reduce the size required for their representation For image and video, this is usually achieved... Processed Output in Alternative Representation Figure 1.3: Processing in the domain of alternative representation 1.3 Overview of Different Image and Video Compression Techniques and Standards Various image and video compression techniques have been advanced by researchers starting from the early eighties Different international bodies such as the International Standard Organization (ISO) and the International... MPEG-2 [135] is targeted at applications with higher bit rates The MPEG-4 [135] standard added more features in the process of compression for achieving a higher compression rate and making the standard suitable for both high and low bit rate applications The ITU (then the CCITT) initiated the standardization of video compression prior to the ISO They have recommended different H.26x video coding standards,... are increasingly available in these forms, there is a need for their direct analysis in those spaces This potentially makes the processing faster by avoiding the overhead of decompression and recompression of the data Further, a smaller data size in the compressed domain provides an additional advantage of keeping the memory requirement low However, we should make a careful cost-benefit analysis in terms . Subsequently, their application in designing image and video processing algo rithms in the compr e ssed domain are dis- cussed. To provide better understanding of the domain of research, different image and. resizing, transcoding, etc. In addition, different other applications in the compressed domain such as video and image e diting, digital watermarking and steganography, image and video indexing,. types of image and video processing operations performed in the compressed domain are discussed in subsequent chapters. This includes filter- ing, enhancement and color restoration, image and video