Toshiyasu Nakao

Scanning a document with a small camera attached to a mouse

This paper describes our new image input unit for users of personal computers. This unit has a small CCD camera, mainly used for video conferencing, attached to the mouse and digital mosaic processing software. Users normally operate the CCD camera and mouse independently. In this case, when a user wants to input an image of a photograph or document into the personal computer he/she attaches the CCD camera to a slant on the mouse by an attachment. The user then takes partial images by moving the mouse over the photograph or document until the entire desired area is covered. These partial images are then quickly merged into one synthesized image using digital mosaic processing software. This paper also describes a block matching method that accelerates the registration process of the digital mosaic processing software. This method quickly and accurately calculates Helmerts transformation parameter using a block matching method for parallel movement.

Panoramic camera using a mirror rotation mechanism and a fast image mosaicing

We describe a new panoramic camera that incorporates a 2-axis mirror rotation mechanism and a fast image mosaicing method. The mirror is positioned in front of the camera to move the cameras view. Partial images are taken during the mirror rotation. The image mosaicing method projects each partial image onto a projection surface around the rotation center of the mirror to produce a panoramic image. In this process, the projection center is shifted from the original viewpoint of the lens to the mirror rotation center to reduce discontinuity caused by motion parallax from the panoramic image. Our panoramic camera can provide accurate, continuous, high-resolution, large and endless (360 degrees wide) panoramic images with a short panoramic image acquisition time.

A Wireless Dual-Link System for Sensor Network Applications

A reduced-power-consumption wireless ad-hoc multi-hop network system, the dual-link system,is been developed, using the following two technologies: Dual-link communication, which handles two different frequency bands, achieves low-power data transmission through independent optimum settings of both operation periods and communication distances for each band. The selection of frequency bands and operation settings depends on both the data sizes and communication intervals defined for individual applications. This dual-link communication is applicable to various kinds of intermittent communications. A vine-tree network topology that offers low addressing-bit counts and results in low packet-error rates even in low transmission-power communications. Since the topology does not require a routing table for individual nodes, hardware complexity can be kept to a minimum.

360-deg panoramic camera using a mirror rotation mechanism

In this paper, we describe a new panoramic camera that incorporates a 2-axes mirror rotation mechanism and image mosaicing software to get high-resolution panoramic images in a short time. The mirror is located in front of the camera via the mirror rotation mechanism to move the cameras view. Partial images taken with the mirror rotation are merged into a high-resolution panoramic image by mosaicing software. The 2-axes mirror rotation mechanism consist of a mirror pedestal and a cam. The image mosaicing software projects each partial image onto a projection surface around the rotation center of the mirror. In that process, the projection center is shifted from the original principal point of the lens or the viewpoint to the mirror rotation center, and the projection positions for each pixel of partial images are calculated by using the limiting point. With these features, our panoramic camera has four advantages: (1) accurate, continuous, high-resolution, large and endless (360 degrees wide) panoramic images; (2) short panoramic image acquisition time with fast mirror rotation; (3) small body size; and (4) endless (360 degrees wide) fast mirror rotation. We also describe its prototype and its application to the Internet broadcasting of a tennis game.