Layer Selection in Progressive Transmission of Motion-Compensated JPEG2000 Video

MCJ2K (Motion-Compensated JPEG2000) is a video codec based on MCTF (Motion- Compensated Temporal Filtering) and J2K (JPEG2000). MCTF analyzes a sequence of images, generating a collection of temporal sub-bands, which are compressed with J2K. The R/D (Rate-Distortion) performance in MCJ2K is better than the MJ2K (Motion JPEG2000) extension, especially if there is a high level of temporal redundancy. MCJ2K codestreams can be served by standard JPIP (J2K Interactive Protocol) servers, thanks to the use of only J2K standard file formats. In bandwidth-constrained scenarios, an important issue in MCJ2K is determining the amount of data of each temporal sub-band that must be transmitted to maximize the quality of the reconstructions at the client side. To solve this problem, we have proposed two rate-allocation algorithms which provide reconstructions that are progressive in quality. The first, OSLA (Optimized Sub-band Layers Allocation), determines the best progression of quality layers, but is computationally expensive. The second, ESLA (Estimated-Slope sub-band Layers Allocation), is sub-optimal in most cases, but much faster and more convenient for real-time streaming scenarios. An experimental comparison shows that even when a straightforward motion compensation scheme is used, the R/D performance of MCJ2K competitive is compared not only to MJ2K, but also with respect to other standard scalable video codecs

Efficient Point-Cloud Processing with Primitive Shapes

This thesis presents methods for efficient processing of point-clouds based on primitive shapes. The set of considered simple parametric shapes consists of planes, spheres, cylinders, cones and tori. The algorithms developed in this work are targeted at scenarios in which the occurring surfaces can be well represented by this set of shape primitives which is the case in many man-made environments such as e.g. industrial compounds, cities or building interiors. A primitive subsumes a set of corresponding points in the point-cloud and serves as a proxy for them. Therefore primitives are well suited to directly address the unavoidable oversampling of large point-clouds and lay the foundation for efficient point-cloud processing algorithms. The first contribution of this thesis is a novel shape primitive detection method that is efficient even on very large and noisy point-clouds. Several applications for the detected primitives are subsequently explored, resulting in a set of novel algorithms for primitive-based point-cloud processing in the areas of compression, recognition and completion. Each of these application directly exploits and benefits from one or more of the detected primitives' properties such as approximation, abstraction, segmentation and continuability

Spline wavelet image coding and synthesis for a VLSI based difference engine

Bibliography: leaves 142-146.The efficiency of an image compression/synthesis system based on a spline multi-resolution analysis (MRA) is investigated. The proposed system uses a quadratic spline wavelet transform combined with minimum-mean squared error vector quantization to achieve image compression. Image synthesis is accomplished by utilizing the properties of the MRA and the architecture of a custom designed display processor, the Difference Engine. The latter is ideally suited to rendering images with polynomial intensity profiles, such as those generated by the proposed spline :V1RA. Based on these properties, an adaptive image synthesis system is developed which enables one to reduce the number of instruction cycles required to reproduce images compressed using the quadratic spline wavelet transform. This adaptive approach is computationally simple and fairly robust. In addition, there is little overhead involved in its implementation

Proceedings of the Scientific Data Compression Workshop

Continuing advances in space and Earth science requires increasing amounts of data to be gathered from spaceborne sensors. NASA expects to launch sensors during the next two decades which will be capable of producing an aggregate of 1500 Megabits per second if operated simultaneously. Such high data rates cause stresses in all aspects of end-to-end data systems. Technologies and techniques are needed to relieve such stresses. Potential solutions to the massive data rate problems are: data editing, greater transmission bandwidths, higher density and faster media, and data compression. Through four subpanels on Science Payload Operations, Multispectral Imaging, Microwave Remote Sensing and Science Data Management, recommendations were made for research in data compression and scientific data applications to space platforms

Stereoscopic video coding.

by Roland Siu-kwong Ip.Thesis (M.Phil.)--Chinese University of Hong Kong, 1995.Includes bibliographical references (leaves 101-[105]).Chapter 1 --- Introduction --- p.1Chapter 1.1 --- Motivation --- p.1Chapter 1.2 --- Image Compression --- p.2Chapter 1.2.1 --- Classification of Image Compression --- p.2Chapter 1.2.2 --- Lossy Compression Approaches --- p.3Chapter 1.3 --- Video Compression --- p.4Chapter 1.3.1 --- Video Compression System --- p.5Chapter 1.4 --- Stereoscopic Video Compression --- p.6Chapter 1.5 --- Organization of the thesis --- p.6Chapter 2 --- Motion Video Coding Theory --- p.8Chapter 2.1 --- Introduction --- p.8Chapter 2.2 --- Representations --- p.8Chapter 2.2.1 --- Temporal Processing --- p.13Chapter 2.2.2 --- Spatial Processing --- p.19Chapter 2.3 --- Quantization --- p.25Chapter 2.3.1 --- Scalar Quantization --- p.25Chapter 2.3.2 --- Vector Quantization --- p.27Chapter 2.4 --- Code Word Assignment --- p.29Chapter 2.5 --- Selection of Video Coding Standard --- p.31Chapter 3 --- MPEG Compatible Stereoscopic Coding --- p.34Chapter 3.1 --- Introduction --- p.34Chapter 3.2 --- MPEG Compatibility --- p.36Chapter 3.3 --- Stereoscopic Video Coding --- p.37Chapter 3.3.1 --- Coding by Stereoscopic Differences --- p.37Chapter 3.3.2 --- I-pictures only Disparity Coding --- p.40Chapter 3.4 --- Stereoscopic MPEG Encoder --- p.44Chapter 3.4.1 --- Stereo Disparity Estimator --- p.45Chapter 3.4.2 --- Improved Disparity Estimation --- p.47Chapter 3.4.3 --- Stereo Bitstream Multiplexer --- p.49Chapter 3.5 --- Generic Implementation --- p.50Chapter 3.5.1 --- Macroblock Converter --- p.54Chapter 3.5.2 --- DCT Functional Block --- p.55Chapter 3.5.3 --- Rate Control --- p.57Chapter 3.6 --- Stereoscopic MPEG Decoder --- p.58Chapter 3.6.1 --- Mono Playback --- p.58Chapter 3.6.2 --- Stereo Playback --- p.60Chapter 4 --- Performance Evaluation --- p.63Chapter 4.1 --- Introduction --- p.63Chapter 4.2 --- Test Sequences Generation --- p.63Chapter 4.3 --- Simulation Environment --- p.64Chapter 4.4 --- Simulation Results --- p.65Chapter 4.4.1 --- Objective Results --- p.65Chapter 4.4.2 --- Subjective Results --- p.72Chapter 5 --- Conclusions --- p.80Chapter A --- MPEG ´ؤ An International Standard --- p.83Chapter A.l --- Introduction --- p.83Chapter A.2 --- Preprocessing --- p.84Chapter A.3 --- Data Structure of Pictures --- p.85Chapter A.4 --- Picture Coding --- p.86Chapter A.4.1 --- Coding of Motion Vectors --- p.90Chapter A.4.2 --- Coding of Quantized Coefficients --- p.94References --- p.10

Object-based video representations: shape compression and object segmentation

Object-based video representations are considered to be useful for easing the process of multimedia content production and enhancing user interactivity in multimedia productions. Object-based video presents several new technical challenges, however. Firstly, as with conventional video representations, compression of the video data is a requirement. For object-based representations, it is necessary to compress the shape of each video object as it moves in time. This amounts to the compression of moving binary images. This is achieved by the use of a technique called context-based arithmetic encoding. The technique is utilised by applying it to rectangular pixel blocks and as such it is consistent with the standard tools of video compression. The blockbased application also facilitates well the exploitation of temporal redundancy in the sequence of binary shapes. For the first time, context-based arithmetic encoding is used in conjunction with motion compensation to provide inter-frame compression. The method, described in this thesis, has been thoroughly tested throughout the MPEG-4 core experiment process and due to favourable results, it has been adopted as part of the MPEG-4 video standard. The second challenge lies in the acquisition of the video objects. Under normal conditions, a video sequence is captured as a sequence of frames and there is no inherent information about what objects are in the sequence, not to mention information relating to the shape of each object. Some means for segmenting semantic objects from general video sequences is required. For this purpose, several image analysis tools may be of help and in particular, it is believed that video object tracking algorithms will be important. A new tracking algorithm is developed based on piecewise polynomial motion representations and statistical estimation tools, e.g. the expectationmaximisation method and the minimum description length principle

Entropy in Image Analysis II

Image analysis is a fundamental task for any application where extracting information from images is required. The analysis requires highly sophisticated numerical and analytical methods, particularly for those applications in medicine, security, and other fields where the results of the processing consist of data of vital importance. This fact is evident from all the articles composing the Special Issue "Entropy in Image Analysis II", in which the authors used widely tested methods to verify their results. In the process of reading the present volume, the reader will appreciate the richness of their methods and applications, in particular for medical imaging and image security, and a remarkable cross-fertilization among the proposed research areas