Shuichi Matsumoto

15/30 Mbit/s Universal Digital TV Codec Using a Median Adaptive Predictive Coding Method

This paper describes a 15/30 Mbit/s TV codec with a new approach to high-efficiency coding for TV signals, i.e., median adaptive prediction. The 15/30 Mbit/s codec, commonly applicable to NTSC, PAL, and SECAM (525/60 and 625/50) systems, uses adaptive prediction incorporating a motion-compensated interframe, an interfield, and an intrafield predictor. Its performance for digital transmission is presented. This universal codec is designed, based on CCIR recommendations concerning digital TV coding parameters for studios (Rec. 601) and general principles on long-distance digital TV transmission (Rec. 604). A field trial of 15 Mbit/s digital TV transmission using this codec between earth stations with a 30 m diameter antenna and a 5 m diameter antenna is reported.

Picture Quality Assessment System by Three-Layered Bottom-up Noise Weighting considering Human Visual Perception

Video compression technologies, such as MPEG-2, are now standardized, and a number of video codecs based on these standards are being developed in many organizations, for use in digital television broadcast and transmission services. The degradation in picture quality produced by video compression is so complicated for human eyes to evaluate that neither a simple signal-to-noise ratio (SNR) nor detailed objective assessment parameters are accurate for this measurement. Studies on picture quality assessment have been conducted based on human visual perception models, which have led to an applicable modeling of the visual process.

Algorithm for Construction of Variable Length Code with Limited Maximum Word Length

As a high efficiency coding method for TV signals, variable length coding, such as Huffman coding, is extremely effective. However, when this variable length coding is applied to an actual TV codec which requires high-speed real-time processing, maximum word length will be limited for the hardware configuration. This correspondence describes an algorithm for the construction of a modified Huffman code with limited maximum word length by means of a top-down procedure meeting this requirement instead of the conventional bottom-up algorithm.

34/45-Mbps 3D HDTV digital coding scheme using modified motion compensation with disparity vectors

This paper describes a digital compression coding scheme for transmitting three dimensional stereo HDTV signals with full resolution at bit-rates around 30 to 40 Mbps to be adapted for PDH networks of the CCITT 3rd digital hierarchy, 34 Mbps and 45 Mbps, SDH networks of 52 Mbps and ATM networks. In order to achieve a satisfactory quality for stereo HDTV pictures, three advanced key technologies are introduced into the MPEG-2 Multi-View Profile, i.e., a modified motion compensation using disparity vectors estimated between the left and right pictures, an adaptive rate control using a common buffer memory for left and right pictures encoding, and a discriminatory bit allocation which results in the improvement of left pictures quality without any degradation of right pictures. From the results of coding experiment conducted to evaluate the coding picture achieved by this coding scheme, it is confirmed that our coding scheme gives satisfactory picture quality even at 34 Mbps including audio and FEC data.

Motion picture coding based on region segmentation using genetic algorithm

The purpose of this paper is to improve the coding efficiency of motion pictures by proposing a region segmentation method using the genetic algorithm (GA). In motion-compensated predictive coding, region segmentation and motion estimation are closely related to each other, and they should be performed so that the coding complexity and S/N are optimized. Their determination can be reformulated as the optimization problem of assigning the motion vectors to each block of the image. Consequently, this paper examines the data type and the processing method of GA so that the optimal region segmentation is obtained. A computer simulation using a test image was performed as an experiment, and the effectiveness of the proposed method was demonstrated.

Flat multi-scalable coding for failure-free video transmission

The conventional full-redundant duplicate transmission scheme, which is often adopted in video transmission that requires high reliability such as contribution and primary distribution, has a drawback in that the efficiency of utilization of transmission links is low. In order to improve this, it would be effective to realize flat multi-scalable video transmission, in which the picture can be reconstructed by using any single channel, while combining more than one channel leads to the reconstruction of the picture with even higher quality. In this paper, for this purpose, the authors propose a complementary sampling method. In this method, the improvement in picture quality is achieved by cancelling out the coding noise which is included in more than one channel. Moreover, it is shown that in this scheme, the objective assessment of picture quality can be performed based only on the received pictures. The authors hope that this study will help to construct a visual communication system with high efficiency and high reliability.

3045 Mbps digital coding system for transmission of (4:2:2) digital component TV signals recommended by CCIR

Abstract In recent years, the digitalization of transmission links and studio equipment has progressed rapidly in many countries. Considering this background, CCIR has aimed at standardizing a unified high-efficiency bit-reduction coding system, which is indispensable for reducing the cost of digital transmission of TV programs. In this paper, the 30 45 Mbps coding system that we proposed in the expert group assembled for this standardization is presented. The design of this system is based on the 15 30 Mbps universal TV coding system that we developed to transmit two or four TV programs simultaneously through a single transponder of an INTELSAT satellite with 36-MHz bandwidth. First, details of the system configuration are given. Then, the systems coding performance using actual hardware and its transmission performance over an actual digital transmission link are presented. It is concluded that the coding system gives very high performance as well as multichannel sound signals. Finally, the necessity of improving the facility of the coding system for commercial use is discussed.

Scientific Grid Activities and PKI Deployment in the Cybermedia Center, Osaka University

The Cybermedia Center (CMC), Osaka University, is a research institution that offers knowledge and technology resources obtained from advanced researches in the areas of large-scale computation, information and communication, multimedia content and education. Currently, CMC is involved in Japanese national Grid projects such as JGN II (Japan Gigabit Network), NAREGI and BioGrid. Not limited to Japan, CMC also actively takes part in international activities such as PRAGMA. In these projects and international collaborations, CMC has developed a Grid system that allows scientists to perform their analysis by remote-controlling the worlds largest ultra-high voltage electron microscope located in Osaka University. In another undertaking, CMC has assumed a leadership role in BioGrid by sharing its experiences and knowledge on the system development for the area of biology.In this paper, we will give an overview of the BioGrid project and introduce the progress of the Telescience unit, which collaborates with the Telescience Project led by the National Center for Microscopy and Imaging Research (NCMIR). Furthermore, CMC collaborates with seven Computing Centers in Japan, NAREGI and National Institute of Informatics to deploy PKI base authentication infrastructure. The current status of this project and future collaboration with Grid Projects will be delineated in this paper.

120/140 Mbit/s portable HDTV codec and its transmission performance in a field trial via INTELSAT satellite

Abstract This paper describes a portable HDTV digital codec and its transmission performance obtained in a transpacific field trial via an INTELSAT satellite with a transportable small earth station. This portable codec is designed for transmitting HDTV programs including 4 channels of high quality sound via a 72 MHz bandwidth transponder in an INTELSAT satellite, or via an ISDN H 4 channel in an optical fiber submarine cable. In order to realize the portable hardware for practical applications, the codec employs bit-reduction techniques whose algorithms are extremely simple from the viewpoint of hardware construction but are effective in achieving a high coding picture quality. From the results obtained in the field trial, it is concluded that an end-to-end international digital transmission of HDTV programs, wherein HDTV programs can be directly transmitted from the place of an event to a theater, is commercially viable using the codec in conjunction with the small earth station.

WHT-based composite motion compensated NTSC interframe direct coding

The motion compensated interframe differential pulse code modulation (DPCM) and discrete cosine transform (DCT) hybrid (MC DCT) coding was nominated as a standard scheme for component TV signals by ISO and ITU-R. However, in cases where an NTSC composite TV signal is used such as the United States and Japan, applying the MC DCT scheme with its luminance/chrominance separating and composing process causes unavoidable quality degradation. The reason for this additional process required for MC DCT is that a composite TV signal presents a color subcarrier phase shift problem in which the color subcarrier phase varies between a coding block and reference block according to the motion vector. In this paper, we propose a Walsh Hadamard transform (WHT)-based composite motion compensated NTSC interframe direct coding scheme. In this scheme, phase shifts of a color subcarrier and modulated chrominance components between a coding block and reference block can be effectively compensated by a simple process of coefficient permutation and polarity changes of several pairs of WHT coefficients to which 100% of the subcarrier energy and most of the modulated chrominance components energy are packed. In the motion compensated DCT scheme, however, the energy of the color subcarrier and modulated chrominance components are spread over too many coefficients and a pair-based coefficient handling rule is not given to solve this problem. This paper demonstrates that the proposed scheme provides higher coding performance for a composite NTSC signal than does the motion compensated DCT scheme with its luminance/chrominance separating and composing process.