Tetsurou Fujii

Layered coding for ATM based video distribution systems

Abstract This paper discusses packet loss and its protection in an asynchronous transfer mode (ATM) based video distribution system. Packet losses in ATM based networks have such a great impact on the design of coding algorithms and network architectures that they should be exhaustively discussed and resolved. In this paper, first basic configuration of the ATM based video transmission system and its packet-loss protection schemes are discussed. The DCT based layered coding scheme with packet priority classification is proposed as an effective packet-loss protection scheme. Burstiness characteristics of the broadcast video sources are evaluated and modeled to clarify statistical multiplexing performance and packet-loss properties. The quality degradation caused by the packet losses is also evaluated by the SNR, and the superior performance of the proposed layered coding scheme is verified.

Application of Super High Definition Images in Telemedicine: System Requirements and Technologies for Teleradiology and Telepathology

It was recognized early on that the digitization of medical information would advance the efficiency of diagnostic technology. However, the digitization of image data, which makes up the majority of medical information, is dependent on advances in technologies such as input, processing, transmission, storage, and display. Insufficient advances in such technologies has effectively limited the digitization of image data for medical use. The result of this has been non-networked systems or LANs confined to a single hospital. Such isolated systems integrate only portions of digital medical images such as x-ray computer tomography (CT), magnetic resonance (MR), and computed radiography (CR).Fortunately, recent advances in the areas of super high definition image I/O, high-quality encoding, super high speed transmission, and high-capacity storage has turned the tide in favor of the digitization and networking of all medical information. This paper will focus on the digitization and networking of medical image information used within hospitals and provide a multifaceted study of the technologies necessary for these advances. This will allow us to discuss the present state of related technical developments and the level that has been attained so far. In addition, we have targeted image information that demands the highest level of quality (radiological and pathological images) for application in medical diagnosis using super high definition images, the image technology being developed by the authors of this paper. We will cover the concrete issues and approaches to solutions that must be investigated when building and networking a digital system.

Transmission characteristics of MPEG2 encoded super high definition images

We have investigated super high definition (SHD) images supporting resolutions beyond 2048/spl times/2048 pixels/frame with 24-bit color separation at 60 frames/s for many professional applications of multimedia communications. However, 6 Gbps is needed to transmit moving SHD image sequences without any compression. This paper expands the MPEG2 standard from main profile at high level (MP@HL) to main profile at super high level (MP@SHL) to transmit SHD images via B-ISDN networks. The transmission of MPEG2 compressed SHD images over ATM networks is simulated. The strong burstiness of compressed SHD images is clarified and the transmission characteristics of these images over 155 Mbps and 600 Mbps ATM lines are determined.

Implementation of super high definition image processing on HiPIPE

In order to manipulate SHD (super high definition) images, a novel parallel processing unit called HiPIPE (Highly Parallel Image Processing Engine) is developed as a project of NOVI-II. The engine is connected to an SHD image display unit and an image data storage unit. Extremely high computational power is obtained by a multicomputer type parallel processing technique. 128 processing elements are connected by a mesh network. Various image coding schemes are carefully explored from the viewpoint of parallel processing, and the problem of processor connections is examined. A novel load-balancing technique, called 2-dimensional butterfly data shuffling, is developed and implemented. The current version of HiPIPE uses just 128 scalar processing elements and has more than twice the power of a single-processor CRAY-2 for a still SHD image coding task.<<ETX>>

Application of super high definition images in telepathology and teleradiology

This paper focuses on the digitization and networking of medical image information used within and among hospitals. We have targeted image information that demands the highest level of quality (radiological and pathological images) for application in medical diagnosis using super high definition (SHD) images, whose resolution is more than 2000/spl times/2000 pixels. To prove its quality and effectiveness, SHD image stations and a digital microscope are developed, and connected to an ATM network. With this networked SHD image system, all functions requested for medical information is really evaluated including, processing algorithms, coding algorithms, and transmission protocol.

Source coding of super high definition images with discrete cosine transform

This paper discusses the bit-rate compression of super high definition images with Discrete Cosine Transform (DCT). Super high definition images with more than 2048x2048 pixels of resolution are introduced as the next generation image category beyond HDTV. In order to develop bit-rate reduction algorithms an image I/O system for super high definition still images is assembled. A traditional DCT based coding algorithm called Scene Adaptive Coder (SAC) is applied to super high definition images and related problems are clarified. A new coding algorithm is proposed which takes human visual perception characteristics into consideration and its coding performance is examined for super high definition images.

Layered I/O architecture in a multicomputer type DSP system for video communications

A layered I/O architecture in a multicomputer-type DSP system is described that achieves efficient load balancing and high-speed video data distribution/gathering for real-time video processing. The layered structure is based on global distribution using buses and local distribution serial links. In addition to multiple homogeneous processing elements, the concept of bus nodes with high data distribution rates is introduced. System performance is evaluated by computer simulation focusing on load balancing efficiency using a typical video processing algorithm. It is shown that load balancing, which combines task assignment control with large-grain data flow, can provide high performance.<<ETX>>

A 12.8 GFLOPS multi-DSP system for super high definition image processing

A multicomputer-type parallel processing system has been developed that offers a peak performance of 12.8 GFLOPS. This system is called NOVI-II HiPIPE, and was designed for super-high-definition (SHD) image processing. SHD image is a new image medium and its resolution is higher than that of HDTV. Because SHD image processing requires computing power that exceeds the ability of any single digital signal processor (DSP), current or anticipated, NOVI-II HiPIPE uses a multicomputer-type parallel processing architecture. A 100-MFLOPS vector processor serves as the backend processor of each processing element. The current version of NOVI-II HiPIPE uses 128 mesh connected processing elements and 128 vector processors. The configuration and performance of NOVI-II HiPIPE are described.<<ETX>>

Media integration platform on superhigh-definition images: parallel digital signal processor approach

This paper presents a new media integration platform based on super high definition (SHD) digital images and a high performance image processing system that adopts parallel digital processing. The new platform will encourage the integration of all existing media to realize rich and realistic visual communication over B-ISDN. SHD images have a resolution of more than 2048 X 2048 pixels and the frame rate is more than 60 frames/sec. To achieve the real-time compression of SHD moving images, parallel signal processing systems with a peak performance of 0.5 Tera Flops will be necessary. The specification requirements, focusing on the digital signal processing systems needed to achieve SHD image communication, are discussed.

Homogeneous multicomputer type DSP system NOVI for parallel signal processing

The architecture and performance of a multicomputer-type digital signal processing (DSP) system are discussed. The DSP system, called NOVI, has been created to examine methods for organizing parallel DSP systems and developing parallel programs for a wide range of digital signal processing applications. NOVI presently consists of 36 processing elements (PEs), each using an Inmos Transputer as a CPU. Its parallel-program-development assistant (PDA) system facilitates powerful debugging functions to observe all PE state without any interference to parallel program execution. A parallel-program-development technique using the PDA is discussed. A load-balancing technique on a multicomputer-type DSP is also discussed, focusing on low-bit-rate motion-picture coding. The balancing technique is based on interframe prediction and layered large-grain data flow. The expected performance of the NOVI system is discussed.<<ETX>>