Videophone services over IP (Internet protocol) will become key services in the next-generation network (NGN). To provide a high-quality service for users, designing and managing the quality of experience (QoE) appropriately is extremely important. To do this, developing an objective quality assessment method that estimates subjective quality by using quality parameters of the videophone system is desirable. We propose a parametric-planning model for assessing video quality affected by coding and packet loss. The results indicated quality estimation accuracy was sufficient for practical use because the estimation errors of our model were equivalent to the statistical reliability of subjective assessment. Therefore, our model could be applied to effective design of video quality for videophone applications and networks. As an example of using our model, we show video-quality planning of videophone services.

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IPTV using Internet protocols, streaming-based mobile broadcasting such as terrestrial 1-segment broadcasting and digital audio broadcasting started recently. Download-based broadcasting services in IP networks and digital broadcasting that plays back stored content on receivers are now being considered. These broadcasting services require a function that allows only subscribers to view video content in addition to a function for playing content at a deteriorated quality to encourage viewers to purchase the content. Therefore, broadcasters require a digital video scrambling method with variable concealed levels to control the video quality of stored content. We propose a low complexity video scrambling method with variable concealed levels for H.264/AVC video coding. This method can handle H.264/AVC coding content, and its processing load for controlling the concealed level is low. We also verify that the proposed method is feasible for actual services by evaluating video quality and implementation.

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Videophone services over IP (Internet protocol) will become key services in the next-generation network (NGN). To provide a high-quality service for users, designing and managing the quality of experience (QoE) appropriately is extremely important. To do this, developing an objective quality assessment method that estimates subjective quality by using quality parameters of the videophone system is desirable. We propose a parametric-planning model for assessing video quality affected by coding and packet loss. The results indicated quality estimation accuracy was sufficient for practical use because the estimation errors of our model were equivalent to the statistical reliability of subjective assessment. Therefore, our model could be applied to effective design of video quality for videophone applications and networks. As an example of using our model, we show video-quality planning of videophone services.

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We developed a simple system to estimate visual attention by measuring a mouse's activities. The display image is composed of a central and a peripheral visual field image. These images were produced based on human characteristics of vision. The peripheral visual field image was made using a Gauss filter. A small circular window was made on the peripheral visual field image, and the image observed from this small window was at the center of the visual field. The movement of this small window was synchronized with the mouse's activities. We analyzed visual attention using three images to 64 subjects with this system and confirmed its effectiveness.

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For broadcasting-communications linkage services, sharing of the delivery network and platform has been achieved, and there will be more demand for attractive services and applications in the future. We propose a metadata conversion method that automatically converts service information on digital broadcasting into XML program metadata and shares program information between broadcasting and communication services. Moreover, we propose a program navigation method, which uses program metadata for expansion of watching programs.

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We describe the development of a high-efficiency HF power amplifier. We fabricated a new wideband power amplifier operating at short wave bands (3MHz-26MHz) using a class-E amplifier with a high output power efficiency of 74% at 25.5MHz. This target performance is obtained by controlling the shunt capacity for wideband operation. In addition, a low-loss characteristic of about 0.4dB and under and wideband characteristics were obtained. A balun using a transformer with coaxial cables and a tuned output circuit combiner including stray capacitance and inductance are employed for realizing this performance.

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We propose a new method for determining the correspondence between audio and visual events based on the selective attention which is observed in a living organism. For auditory attention, our system recognizes a target sound in noisy environments using an auditory filter that focuses on a specific period corresponding to visual events. It was confirmed that the success rate of correspondence between audio and visual events increased from 78.6% without the auditory filter, to 95.2% with the auditory filter. This certifies the importance of visual information for auditory attention. We also realized a visual attention of localizing a sound source and adjusting the line of sight and the iris of a camera when the system perceived a sound, but could not obtain visual information. The success rate of experiments based on visual attention is 93.3%. These results show the effectiveness of the proposed method.

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A new extended color space camera, "XTF (eXtended Tri-angular Format) ", is proposed, where, through the use of YRGB color separation, RGB color signals are modified to obtain negative primary colors (those outside the RGB triangle) : the difference between Y (a taken luminance signal) and Y (' the calculated luminance signal, i.e., the weighted sum of taken R, G and B colors) is allotted to the taken R, G, B colors. The ratios of allotting it to these colors are decided, e.g., inversely-proportional to these taken color signals, respectively. Computer simulation confirmed that the "XTF" camera performs well.

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We have developed a prototype single-chip color HDTV camera for broadcasting. This camera uses a 1.25-inch 8.9-M-pixel CMOS image sensor for obtaining enough resolution characteristics and signal-to-noise ratio (SNR) in a single-chip color system. The camera has an HD-SDI output and a body weight of only 1.4 kg (3.1 lb). The measured resolution was more than 35% on a modulation transfer function (MTF) (45% on a square wave response) at 800 TV-lines. The sensitivity was an f-stop of 11 at 2000 lux with a dynamic range of 400%, and the SNR was 60 dB. These characteristics were as high as those with conventional 2.2-M-pixel 3-CCD HDTV cameras. The measured color difference (delta-E) between this camera and a 3CCD camera on a CIELAB color space was about 9.3. Our simulation showed that the delta-E was about 1.8 with a linear matrix color correction.

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We propose a color reproduction model concerned for aging a crystalline lens and a method to correct the color schemes on data contents that are imperceptible to the elderly. We assumed that the spectral distribution of the contents is defined with a certain LCD spectrum. Our proposed color reproduction model uses the optical density function of crystalline lenses formatted by Pokorny et al. First, we analyze the effect of aging on color perception using this model. We show that the difference in color perception between the young and the elderly depends on color lightness and hue. Second we show that the spectral compensation of all the screen colors that decrease the spectral transmittance of aged crystalline lenses causes an increase in imperceptibility. Finally, a method using a color palette is proposed for changing the colors in regions that are identified to be imperceptible to the elderly. From these studies, an evaluation and correction support system of color schemes has been prototyped.

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We propose a method for fusing multiple images into a single one. Our method is an extension of a technique for enhancing the contrast of a single image to multiple ones. First, we calculate the logarithm of pixel values in component images and smooth them using a bilateral filter. The smoothed image is the basic component and the difference between the original image and its basic component is the detailed component. We then compress the basic component and add it to the detailed component. Finally we recover the pixel values with an exponential function to obtain contrast-enhanced images. When adding detailed components together, we weigh both components according to their magnitude to preserve salient information in both component images. We tested this method with flash shot, multiple exposure, multiple focus, multiple light and multimodal medical images.

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In general, the relative position between the centers of the pupil and corneal reflection are used for precise eye-gaze detection. Recently, for stable pupil detection under various ambient light conditions, the pupil has been detected by the difference between the bright and dark pupil images. However, due to the difference in acquisition timing between the bright and dark images, the precision of the pupil position easily decreases when the head moves. We propose a compensation method which differentiates those pupil images after shifting one of the images so that the positions of corneal reflections in both images should match, and show its effectiveness.

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Superimposition of reproduced rays from sub-holograms is a useful method for view-zone expansion, image-size enlargement, or colorization of electronic-holography. For this superimposition, half- mirrors are preferable because of their size and weight. However, slanted half- mirrors in the ray-axis cause astigmatism in the reproduced images. We analyze this phenomenon and formulated it mathematically. Then, a novel compensation method is proposed by introducing a linear light source with an inverse astigmatism replacing the object sample points. Experimental results show the efficacy of this method.

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We describe how to reduce interference between elemental images suitable for production of holograms during integral photography pickup that uses a lens array composed of typical convex lenses used as elemental lenses. We propose the use of an optical system that consists of both a field lens and an aperture that is located in the focal plane of the field lens. The system is arranged between the lens array and the camera used for taking elemental images. Diffraction patterns in the focal plane of the field lens of beams going through elemental lenses were calculated with the Fresnel-Kirchhoff diffraction formula. Consequently, we clarified that the system was able to limit the incident angle of the beam passing through the elemental lenses with the size of the aperture located in the focal plane. In addition, we carried out an optical experiment and proved that using the optical system reduced the interference between the elemental images.

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