Study and simulation of low rate video coding schemes

The semiannual report is included. Topics covered include communication, information science, data compression, remote sensing, color mapped images, robust coding scheme for packet video, recursively indexed differential pulse code modulation, image compression technique for use on token ring networks, and joint source/channel coder design

Secured and progressive transmission of compressed images on the Internet: application to telemedicine

International audienceWithin the framework of telemedicine, the amount of images leads first to use efficient lossless compression methods for the aim of storing information. Furthermore, multiresolution scheme including Region of Interest (ROI) processing is an important feature for a remote access to medical images. What is more, the securization of sensitive data (e.g. metadata from DICOM images) constitutes one more expected functionality: indeed the lost of IP packets could have tragic effects on a given diagnosis. For this purpose, we present in this paper an original scalable image compression technique (LAR method) used in association with a channel coding method based on the Mojette Transform, so that a hierarchical priority encoding system is elaborated. This system provides a solution for secured transmission of medical images through low-bandwidth networks such as the Internet

A Survey on Multimedia-Based Cross-Layer Optimization in Visual Sensor Networks

Visual sensor networks (VSNs) comprised of battery-operated electronic devices endowed with low-resolution cameras have expanded the applicability of a series of monitoring applications. Those types of sensors are interconnected by ad hoc error-prone wireless links, imposing stringent restrictions on available bandwidth, end-to-end delay and packet error rates. In such context, multimedia coding is required for data compression and error-resilience, also ensuring energy preservation over the path(s) toward the sink and improving the end-to-end perceptual quality of the received media. Cross-layer optimization may enhance the expected efficiency of VSNs applications, disrupting the conventional information flow of the protocol layers. When the inner characteristics of the multimedia coding techniques are exploited by cross-layer protocols and architectures, higher efficiency may be obtained in visual sensor networks. This paper surveys recent research on multimedia-based cross-layer optimization, presenting the proposed strategies and mechanisms for transmission rate adjustment, congestion control, multipath selection, energy preservation and error recovery. We note that many multimedia-based cross-layer optimization solutions have been proposed in recent years, each one bringing a wealth of contributions to visual sensor networks

The 1993 Space and Earth Science Data Compression Workshop

The Earth Observing System Data and Information System (EOSDIS) is described in terms of its data volume, data rate, and data distribution requirements. Opportunities for data compression in EOSDIS are discussed

Studies and simulations of the DigiCipher system

During this period the development of simulators for the various high definition television (HDTV) systems proposed to the FCC was continued. The FCC has indicated that it wants the various proposers to collaborate on a single system. Based on all available information this system will look very much like the advanced digital television (ADTV) system with major contributions only from the DigiCipher system. The results of our simulations of the DigiCipher system are described. This simulator was tested using test sequences from the MPEG committee. The results are extrapolated to HDTV video sequences. Once again, some caveats are in order. The sequences used for testing the simulator and generating the results are those used for testing the MPEG algorithm. The sequences are of much lower resolution than the HDTV sequences would be, and therefore the extrapolations are not totally accurate. One would expect to get significantly higher compression in terms of bits per pixel with sequences that are of higher resolution. However, the simulator itself is a valid one, and should HDTV sequences become available, they could be used directly with the simulator. A brief overview of the DigiCipher system is given. Some coding results obtained using the simulator are looked at. These results are compared to those obtained using the ADTV system. These results are evaluated in the context of the CCSDS specifications and make some suggestions as to how the DigiCipher system could be implemented in the NASA network. Simulations such as the ones reported can be biased depending on the particular source sequence used. In order to get more complete information about the system one needs to obtain a reasonable set of models which mirror the various kinds of sources encountered during video coding. A set of models which can be used to effectively model the various possible scenarios is provided. As this is somewhat tangential to the other work reported, the results are included as an appendix

Error-resilient coding tools in MPEG-4.

by Cheng Shu Ling.Thesis submitted in: July 1997.Thesis (M.Phil.)--Chinese University of Hong Kong, 1998.Includes bibliographical references (leaves 70-71).Abstract also in Chinese.Chapter Chapter 1 --- Introduction --- p.1Chapter 1.1 --- Image Coding Standard: JPEG --- p.1Chapter 1.2 --- Video Coding Standard: MPEG --- p.6Chapter 1.2.1 --- MPEG history --- p.6Chapter 1.2.2 --- MPEG video compression algorithm overview --- p.8Chapter 1.2.3 --- More MPEG features --- p.10Chapter 1.3 --- Summary --- p.17Chapter Chapter 2 --- Error Resiliency --- p.18Chapter 2.1 --- Introduction --- p.18Chapter 2.2 --- Traditional approaches --- p.19Chapter 2.2.1 --- Channel coding --- p.19Chapter 2.2.2 --- ARQ --- p.20Chapter 2.2.3 --- Multi-layer coding --- p.20Chapter 2.2.4 --- Error Concealment --- p.20Chapter 2.3 --- MPEG-4 work on error resilience --- p.21Chapter 2.3.1 --- Resynchronization --- p.21Chapter 2.3.2 --- Data Recovery --- p.25Chapter 2.3.3 --- Error Concealment --- p.28Chapter 2.4 --- Summary --- p.29Chapter Chapter 3 --- Fixed length codes --- p.30Chapter 3.1 --- Introduction --- p.30Chapter 3.2 --- Tunstall code --- p.31Chapter 3.3 --- Lempel-Ziv code --- p.34Chapter 3.3.1 --- LZ-77 --- p.35Chapter 3.3.2 --- LZ-78 --- p.36Chapter 3.4 --- Simulation --- p.38Chapter 3.4.1 --- Experiment Setup --- p.38Chapter 3.4.2 --- Results --- p.39Chapter 3.4.3 --- Concluding Remarks --- p.42Chapter Chapter 4 --- Self-Synchronizable codes --- p.44Chapter 4.1 --- Introduction --- p.44Chapter 4.2 --- Scholtz synchronizable code --- p.45Chapter 4.2.1 --- Definition --- p.45Chapter 4.2.2 --- Construction procedure --- p.45Chapter 4.2.3 --- Synchronizer --- p.48Chapter 4.2.4 --- Effects of errors --- p.51Chapter 4.3 --- Simulation --- p.52Chapter 4.3.1 --- Experiment Setup --- p.52Chapter 4.3.2 --- Results --- p.56Chapter 4.4 --- Concluding Remarks --- p.68Chapter Chapter 5 --- Conclusions --- p.69References --- p.7

A constrained joint source/channel coder design and vector quantization of nonstationary sources

The emergence of broadband ISDN as the network for the future brings with it the promise of integration of all proposed services in a flexible environment. In order to achieve this flexibility, asynchronous transfer mode (ATM) has been proposed as the transfer technique. During this period a study was conducted on the bridging of network transmission performance and video coding. The successful transmission of variable bit rate video over ATM networks relies on the interaction between the video coding algorithm and the ATM networks. Two aspects of networks that determine the efficiency of video transmission are the resource allocation algorithm and the congestion control algorithm. These are explained in this report. Vector quantization (VQ) is one of the more popular compression techniques to appear in the last twenty years. Numerous compression techniques, which incorporate VQ, have been proposed. While the LBG VQ provides excellent compression, there are also several drawbacks to the use of the LBG quantizers including search complexity and memory requirements, and a mismatch between the codebook and the inputs. The latter mainly stems from the fact that the VQ is generally designed for a specific rate and a specific class of inputs. In this work, an adaptive technique is proposed for vector quantization of images and video sequences. This technique is an extension of the recursively indexed scalar quantization (RISQ) algorithm

Efficient compression of motion compensated residuals

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