Isao Furukawa

Super-high-definition digital movie system

We have developed a digital move communication system for SHD images. The system can transmit extra high quality digital full color movies of 2048 by 2048 pixel resolution using 622 Mbps ATM transmission systems, and display them at the frame rate of 60 frames per second. The system consists of an image data server, ATM transport interfaces, a real-time JPEG decoder and an SHD image display frame buffer. The motion SHD images have such high quality that the system has been designed for professional movie applications such as tele- medicine, education and commercial movie theaters. The image data server is constructed on a workstation to store motion image data and transmit them to the decoder via 622 Mbps ATM links. The real-time decoder is a parallel DSP system to decode the received movie data stream into raw SHD move images. The frame buffer is connected to the decoder via optical links offering at total of 12 Gbps to show complete movie images on CRTs or large size projectors.

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.

Hierarchical coding of super high definition images with subband+multistage VQ

A subband based hierarchical coding algorithm is proposed and an examination is made of its coding performance for super high definition images. Several quadrature mirror filters are examined from the viewpoints of reconstruction accuracy, coding gain, and low pass characteristics. The two-stage vector quantization scheme is also introduced to control quantization accuracy in each subband. Hierarchical image reconstruction and efficient bit-rate compression can simultaneously be obtained by using the proposed algorithm.<<ETX>>

Super high definition image digitizing system

A very-high-resolution image digitizing system that handles both still and motion images is presented. The system mainly consists of a high-resolution CCD line scanner and high-precision film transport equipment. Resolution characteristics are measured directly using test charts, and resolution of over 2048 pixels is obtained in both the vertical and horizontal direction. Therefore, this system can generate test sequences for super-high-definition images that have at least 2048*2048 pixels. Various corrections, such as shading-, gamma-, and color-correction and edge enhancement, are made, and good reproductions of original photo images are obtained. Sixteen standard images are digitized and prepared for coding simulations and other applications.<<ETX>>

Inter-hospital PACS designed for teleradiology and teleconference using a secured high-speed network

We developed a tele-radiology and tele-conference system between our related hospitals. This system consisted of the image database, the WWW server, WWW browsers, high resolution CRT displays, the videoconference system and an asynchronous transfer mode (ATM) network. In advance X-ray images were stored into the Image Save And Carry magneto- optical (MO) disks, then images on the MO were transferred to the image database. The image database was created from MO disks. Total amount of images reached 100 GB and the number of the image was 65,000. The ATM network connected the hospitals each other. The ATM network device provided the permanent virtual circuit function. The transmission speed was from 6Mbit/second to 155 Mbit/second. The client station consisted of the WWW browser and the super high definition CRT display which had the 2k X 2k full color frame memory and 54 X 54 cm square display area. The result of the query was transformed to a hypertext markup language. Then a browser on a client machine displayed the result. The server could retrieve some images in about ten seconds and transmit an image from a server to a client in 2-10 seconds that depend on the network speed. At the tele- radiology, both terminals could display same image and physicians could talk each other by the videoconference system. We solved the security problems by the PVC methods and the on time password device. The ATM network showed the high transmission performance and good security. Physicians were able to use this system with no special training and this system brought us an effective utilization of the image.

Performance analysis of compression techniques for pathological microscopic images

Telepathology is aiming at pathological diagnoses based on microscopic images of cell samples through broadband networks. The number of pixels in pathological microscopic (PM) images is said to be approximately 4 to 6 million. In this paper, digital PM images are made without films using a super high definition (SHD) image prototype system, which has more than double the number of pixels and frame frequency than those of HDTV images. First, color distribution and a spatial spectrum are analyzed in order to estimate compression characteristics of the images. In addition, the lossless and lossy JPEG coding characteristics are investigated. In the lossless compression, the PM images have compression ratios which are very close to 1, while the general images have compression ratios around 2. The PM image compression ratios in the lossy JPEG coding, where the L*a*b* color difference is less than 2 to 3, are found to almost equal those of the lossless JPEG (Joint Photographic Coding Experts Group) using arithmetic coding. The PM image coding performance in the lossy JPEG coding is also found to be inferior to that of general images including still life images, portraits, and landscapes.

Required quantizing resolution for perceptually linearized medical x-ray images on display monitor

This paper theoretically clarifies required quantizing resolution to display digitized x-ray images on a cathode-ray-tube (CRT) monitor provided that the observer not recognize contours that do not exist in original x-ray film images. Human visual system for luminance difference discrimination is an important factor in determining required quantizing resolution. We therefore carry out an analysis using the Barten model, which provides good fit of many experimental data. First, we clarify the required quantizing resolution for the density input to film and that for the voltage input to a CRT monitor. Then, we present the design results of the look-up table for perceptually linear transform for a CRT that can reproduce the luminance difference information in film images, and clarify the validity of our theoretical studies.

Film-based motion picture digitizing system for super-high-definition images

This paper describes the configuration of a super high definition (SHD) motion picture film digitizing system and performance evaluation results. A still/motion picture film digitizing system is developed using a CCD line image digitizer, which can capture images at a maximum resolution of 4096 X 4096 pixels, 12 bits/pixel. Motion picture sequences are obtained on a frame by frame basis from a 70 mm motion picture film with the aperture size of 57 X 57 mm. Several versions of SHD motion picture test sequences were so digitized and the frame to frame positioning error was within +/- 1 pixel/2048 pixels. An SHD image processing software environment was newly developed to provide all of the image processing functions needed in the digitizing system and a comfortable user interface. A color matching method, which is based on direct color measurement/approximation between the original image and the reproduced image, was proposed for the digitizing system. A color matching experiment was performed between a film projector and a CRT display. The improvement ratio of mean squared color distance was 1.30. Although the improvement ratio is relatively small, a noticeable improvement in color reproduction accuracy was observed.

Hierarchical sub-band coding of super high definition image with adaptive block-size multistage VQ

Abstract A hierarchical image coding algorithm based on sub-band coding and adaptive block-size multistage vector quantization (VQ) is proposed, and its coding performance is examined for super high definition (SHD) image. First, the concept on SHD image is briefly described. Next, the signal power spectrum is evaluated, and the sub-band analysis pattern is determined from its characteristics. Several quadrature mirror filters are examined from the viewpoints of reconstruction accuracy, coding gain, and low-pass signal quality. Then an optimum filter is selected for the sub-band analysis. The two-stage VQ using the adaptive bit allocation is also introduced to control quantization accuracy and to achieve high-quality image reproduction. Coding performance and hierarchical image reconstruction are demonstrated using SNR and some photographs.

Super high-definition still/motion images digitizing system and standard test images

This paper presents a very high resolution image digitizing system that handles both still and motion images, and the standard test images captured by the system. The system consists of a high resolution CCD line scanner and high precision film transport unit. Resolution characteristics are directly measured using test charts, and a resolution of over 2048 pixels is obtained in the vertical and horizontal direction. Various corrections, such as shading-, gamma-, color-correction, and edge enhancement are made, and good reproductions of the original photo images are obtained. Sixteen still standard images are digitized, and prepared for coding simulations and other applications. In the near future, motion standard test images will be digitized.