We focused on the binocular color difference of an anaglyph image. The effect of color difference between stereo pair images on depth perception from binocular disparity was investigated. A Wheatstone mirror stereoscope was used to conduct experiments at and above threshold of the depth perception. Two stereograms were used; one was white for both eyes and the other was red for one eye and blue for the other. The results showed that binocular color difference does not modulate the depth perception caused by disparity.

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We present a 3-D modeling system that uses hand gestures for quickly and easily designing freeform models. The user illustrates a 3-D freeform in the air and the system automatically constructs plausible 3-D polygonal surfaces. A stereo camera captures the users' hands. We obtain a set of a vast number of points in a 3-D space that presents the freeform. The points are organized using voxel representation to remove redundancy of the points. The organized points are rendered using the Marching cubes method. Our informal study on first-time users showed that a first-time user typically masters the operations within a minute and can construct interesting 3-D models within seconds.

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The motivation for this work is that a deeper understanding of tactile perception could guide the development of highly realistic tactile displays. We think the touch version of 'memory color', 'memory tactile' exists in the reproduction of the tactile stimulation. The term 'memory tactile' is used here in the same way as 'memory color' to describe tactile senses that are recalled in association with familiar objects which we frequently touch in our daily life. We carried out an experiment using the diameter of a cap of a familiar PET bottle to investigate how the remembered diameter differs from the actual size. The result showed that the diameter recalled through tactile perception was 11% bigger than the actual diameter. Therefore, the result suggests that 'memory tactile' exists and it is 11% (4mm) bigger than the actual size of a cap of a PET bottle.

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We investigated visual motion perception by galvanic vestibular stimulation with a direct current. The results of our experiments indicate that the apparent motion of a static visual stimulus displayed in front of the observer is a composition of rotation and translation. Furthermore, the perceived direction of it is in the opposite direction of that of the self motion of the observer produced by galvanic vestibular stimulation.

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The effect of changing differential perspective on estimation of time-to-contact was investigated. The stimulus was random dot stereogram forming a plane with a large subtense. We found that subjects estimated more accurately with a changing differential perspective than without one.

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We propose a fast collision detection method that uses graphics hardware and includes self-collision and self-collision and deformable objects as its targets. The method uses a layered depth image (LDI), which is generated by depth peeling, and transform feedback. We modify the depth peeling method so that it can peel object surfaces exactly and uses LDI representations for fast collision detection. In addition, transform feedback makes the collision detection process very fast since there is no need to read back from the GPU to the CPU. The proposed method was implemented in a PC having an NVIDIA GeForce 9800 GT graphics card and applied to two objects consisting of 10,000 triangles in total at an image-space resolution of 400 × 400 pixels. As a result, the collision detection time was about 24 ms with 96% detection.

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We propose a method for presenting visual stimuli to change a driver's sensation of speed on a freeway: utilizing vection, one of the perceptual properties needed for self-motion and show that this method can be used on a freeway with CG simulation movies. Furthermore we investigated the relationship between the velocity of vection-inducing stimuli and the sensation of speed. Our study consists of three experiments. In all experiments, the simulated freeway 3D movies were presented on a wide hemisphere screen and the magnitude of the observer's sensation of speed was measured. Vection-inducing stimuli were produced by flickering in the boards on both sides of the freeway. This flickering yielded apparent motion. We set the speed of the vection-inducing stimuli and that of the driver's car as experimental variables. The observer compared two movies consecutively presented with different conditions and selected the one that gave a sensation of faster speed. The observer's sensation of speed increased linearly with the speed of vection-inducing stimuli. Our study suggests that controlling the speed of vection-inducing stimuli could enable the driver's sensation of speed to be manipulated in real freeways.

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This paper presents a technique for correspondence search between projector and camera images using SIFT (Scale-Invariant Feature Transform) and POC (Phase-Only Correlation). The correspondence search is a key task for camera-based geometric correction of projected imagery. In conventional methods, the correspondence is obtained by projecting the structured light on a projector screen. This paper proposes a geometric correction technique where we use only one snapshot of ordinary video sequences to find projector-camera correspondence. We adopt (i) SIFT-based feature matching to estimate an approximate homography between projector and camera images with a limited number of corresponding points and (ii) POC-based dense sub-pixel correspondence search to adjust precise position of corresponding points. Through a set of experiments, we demonstrate that the proposed technique achieves high-accuracy geometric correction, even if significant brightness change is observed between the original video content to be projected and the real projector image captured by a camera.

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We propose a novel decision tree algorithm that can be used to lower the cost of feature computation while maintaining a high level of classification accuracy. The method determines the branching of each node by using a criterion that integrates the impurity of the data set and the expected computational cost. This approach enables data to be classified quickly and accurately. We also discuss its application to video analysis of shot boundary detection. The experimental results show that the proposed method detected shot boundaries and had a lower computational cost while maintaining the same accuracy as conventional algorithms such as the usual decision tree and support vector machine. Recall and precision were 96% and 90%, respectively, and the processing time was reduced by nearly half compared with that of the conventional algorithm.

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A high-resolution electronic holography system with full color and 12 degrees of viewing-zone angle with no undesirable light was developed. Combined temporal-spatial division multiplexing of multi-angle and multicolor light was used to reconstruct an electronic hologram. To eliminate undesirable light, a half-zone plate hologram was generated and a single-sideband reconstruction method was used. Color aberration and astigmatism caused by the relay-lens and half-mirrors were both analyzed and minimized.

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To study the application of event-related potential (ERP) for evaluating the quality of a picture, a task with pushing a single button was proposed. The ERP was measured for both the original and blurred still pictures that were subjectively evaluated by 3-grade quality scale with the following opinions, ‘the same’, ‘worse’, and ‘much worse’. The results showed that the largest P300 amplitude for the ‘much worse’ opinion appeared, which indicates the potential of the proposed task with pushing a single button.

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