When an object in a scene is moving slowly and/or the camera is being moved, the observed image sequence contains rich information about both the moving object and the scene. In this case, it seems that we can enhance spatial resolution within a region of interest in the observed image frame by integrating pixels over multiple observed image frames. The interframe-integration task involves a method for estimating interframe pixel correspondence with real pixel accuracy. The principal existing block-matching algorithm can provide highly accurate correspondence estimates only in the case in which a rigid object undergoes translation in a direction parallel to the image plane, it cannot cope with more general types of motion such as rotation. Standard gradient-based algorithms cannot stably provide accurate correspondence estimates for real moving images. In this paper, we present a method for estimating interframe pixel correspondence with real pixel accuracy. The system uses iteratively warping quadrilateral patches covering the region of interest, and is an interframe integration method. Experimental simulations conducted on real moving image sequences demonstrate that the proposed method enhances spatial resolution considerably when a region of interest is limited to one planar surface of an object.

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We previously reported on development of an adaptive transform coding scheme which partitioned an image into variable-shape blocks so that their boundaries could run parallel to the image's principal contours. That scheme also employed an adaptive-smoothing filter which smoothly connected a DC component in each block. Therefore the scheme could diminish interference such as mosquito-noise and blocking-effects. In order to further improve coding performance, this paper proposes two methods. One is related to segmentation, and magnifies movable areas of vertices of blocks to fit more accurately their boundaries to the image's contours. The other one introduces directional autocorrelation models for the purpose of adaptively deriving eigenvectors in each block. Simulation results demonstrate that the proposed scheme using these two methods provides 1-2 dB and 2-3 dB additional improvement in the signal-to-noise ratio over the previous scheme's and JPEG's levels respectively, and reproduces better images than either of these two.

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We propose a novel framework for motion estimation based on pixel-wise matching. The proposed system consists of two steps. First, a distortion plane, which is a function of the displaced-frame difference of a single pixel, is determined and stored for each pixel. Second, motion is estimated based on a criterion which employs an operator working on the obtained distortion planes. The motion vector that gives the minimum (or maximum) value for the criterion is then estimated. The new framework is flexible in allowing selection of various motion models and operators. In this paper, we focus on a nonlinear weighted-summation operator and a majority-decision operator, in order to deal with discontinuities in the motion field. We also discuss a Hough-transform operator for an affine motion model. Experimental results show that the proposed methods allow us to estimate motion with high accuracy.

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Although block-matching algorithms are often used to estimate local motion from moving images, they do not work well the analysis block contains multiple image regions moving in different directions. To solve this problem, we extend the basic concept of the existing block-matching algorithm. The proposed algorithm segments a given analysis block into multiple regions and gives coherent motion for each region. We formulate this segmentation and motion estimation problem into an optimum combination equation, and construct the algorithm. Through computer simulation, we demonstrate that extending the block-matching algorithm make it possible to estimate motions more accurately than is possible with existing block-matching algorithms.

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The basic functions of the new multimedia information broadcasting service, which interactively displays multimedia information, are studied. The system allows retrieval and viewing of the latest information such as news and weather anytime. Information can be decoded and displayed on various receiving display units including HDTV, personal computer, and PDA. Program data will be constructed by combining layout structure, logical structure and link structure to allow interactive viewing of detailed information and related items. Index data will be broadcast to provide user-friendly service. The index data will include a program table, keyword table, as well as category, keywords for each information. A technique to automatically create index data is also studied. Based on the study of basic functions, an experimental system to broadcast through a satellite broadcasting data channel has been developed and its effects have been verified. The system is also promising as a future ISDB information service.

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Time-varying homotopy was developed by defining time in topological homotopy. It achieved real time natural animation of 3D human faces in a virtual teleconferencing system which is part of a virtual teleconferencing system. At that stage, however, time-varying homotopy had not yet been defined physically. To fill this gap, I invented physical time-varying homotopy, which is based on digital control theory. It becomes possible to animate CG (Computer Graphics) objects more naturally in real time. Moreover, I suggest that digital control theory and digital signal processing are useful for applications in virtual teleconferencing systems and general CG animation.

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[in Japanese]

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[in Japanese]

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[in Japanese]

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Since the radiation patterns in small-aperture antennas are wide, they easily affected by ambient noise sources, and so their noise temperatures tend to rise. Especially in times of rainfall, at frequencies higher than 10 GHz, the noise-power values of antennas increase simultaneously with the lowering of signal levels in proportion to rainfall intensity. Consequently, at times of intense rain, the CN ratio lowers rapidly, and this effect is larger when the noise factor of receivers is lower. From this viewpoint, in order to examine how the CN-ratio characteristics of small-aperture antennas change due to propagation state, various measurements of CN ratio, including a long-period measurement, were carried out using antennas differing in aperture and type. With these measurements the degree of the effect of antenna's noise-temperature on the increasing deterioration of CN ratios was shown quantitatively for both low noise-factor and other receivers. It was found that there are certain types of plane-type antennas in which the lowering of CN ratios due to weather-environment conditions such as rainfall, the adhesion of waterdrops, etc. was greater than in parabola-type ones.

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We developed an image-handling system for super-high-resolution images of 3840 x 2070 pixels. In this system, each image is divided into four images using a selection circuit that subsamples in the horizontal and vertical directions. The circuit is placed between the CPU data bus and the frame memory, and the images are distributed to four HDTV frame memories. This allows the CPU to handle one continuous image space, and also permits the use of HDTV techniques and equipment in system construction. We also developed a motion-picture production system using this system, and evaluated the overall spatial frequency characteristics of a 35mm motion picture. Resolution of more than 1600 TV-lines was obtained from an 8-perforation per frame negative film.

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This papers presents a Digitized-FM modulator including a stereo modulator for FM broadcasting services using DDS (Direct Digital Synthesizer). The modulator employs Over Nyquist sampling to reduce the sampling frequency and a time-variant coefficient finite impulse response (FIR) filter which uses an internal sampling clock instead of the audio input sampling clock in order to obtain better frequency stability. This modulator displays a signal-to-noise ratio of 73 dB or better, total harmonic distortion of 0.22% (50 Hz-15 kHz), and a separation of approximately 50 dB.

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[in Japanese]

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