Yuji Ayatsuka

CyberCode: designing augmented reality environments with visual tags

The CyberCode is a visual tagging system based on a 2D-barcode technology and provides several features not provided by other tagging systems. CyberCode tags can be recognized by the low-cost CMOS or CCD cameras found in more and more mobile devices, and it can also be used to determine the 3D position of the tagged object as well as its ID number. This paper describes examples of augmented reality applications based on CyberCode, and discusses some key characteristics of tagging technologies that must be taken into account when designing augmented reality environments.

Augment-able reality: situated communication through physical and digital spaces

Most existing augmented reality systems only provide a method for browsing information that is situated in the real world context. This paper describes a system that allows users to dynamically attach newly created digital information such as voice notes photographs to the physical environment, through wearable computers as well as normal computers. Attached data is stored with contextual tags such as location IDs and object IDs that are obtained by wearable sensors, so the same or other wearable users can notice them when they come to the same context. Similar to the role that Post-it notes play in community messaging, we expect our proposed method to be a fundamental communication platform when wearable computers become commonplace.

SyncTap: An Interaction Technique for Mobile Networking

This paper introduces “SyncTap”, a user interface technique for making a network connection between digital devices. When a user wants to connect two devices, he or she synchronously presses and releases the “connection” buttons on both devices. Then, multicast packets that contain press and release timing are sent to the network. By comparing this timing with locally recorded one, both devices correctly identify each other. This scheme is simple but scalable because it can detect and handle simultaneous overlapping connection requests. It can also be used for making secure connections by exchanging public keys. This paper describes the principle, the protocol, and applications of SyncTap.

Dual touch: a two-handed interface for pen-based PDAs

A new interaction technique called Dual Touch has been developed for pen-based PDAs. It enables a user to operate a PDA by tapping and stroking on the screen with a pen and a thumb. The PDA can detect the combined movements of two points on its pressure-based touchscreen without additional hardware. The user can use the thumb to support the task of the pen.

Adding another communication channel to reality: an experience with a chat-augmented conference

This paper reports our recent experience with a 3-day technical conference, which was fully augmented by a chat system and a telepresence camera. In this trial, the chat acted as a sub-channel to reality; participants both in local and remote conference rooms can freely interchange their thoughts or opinions inspired by presentations through the chat. We observed several interactions between virtual (chat) and real discussions during the conference namely, (1) Chat discussions often activated discussions in the real world, while treating tiny questions, (2) Co-authors could provide supplemental information through the chat while the first author was presenting, and (3) Participants who were not familiar with the research topic could get more understanding from the chat. We also observed the effect of anthropomorphic representation by switching the chat system between textand comic-based.

Popup vernier: a tool for sub-pixel-pitch dragging with smooth mode transition

Dragging is one of the most useful and popular techniques in direct manipulation graphical user interfaces. However, dragging has inherent restrictions caused by pixel resolution of a display. Although in some situations the restriction could be negligible, certain kinds of applications, e.g., real world applications where the range of adjustable parameters vastly exceed the screen resolution, require sub-pixel-pitch dragging. We propose a sub-pixel-pitch dragging tool, popup vernier, plus a methodology to transfer smoothly into ‘vernier mode’ during dragging. A popup vernier consists of locally zoomed grids and vernier scales displayed around them. Verniers provide intuitive manipulation and feedback of fine grain dragging, in that pixel-pitch movements of the grids represent sub-pixel-pitch movements of a dragged object, and the vernier scales show the object’s position at a sub-pixel accuracy. The effectiveness of our technique is verified with a proposed evaluation measure that captures the smoothness of transition from standard mode to vernier mode, based on the Fitts’ law.

ChatScape: a visual informal communication tool in communities

Informal communication in a community is as important as formal meetings. We propose to support on-line informal communication by a visual communication tool, named ChatScape. A message on ChatScape is made of short text and still images. Short text messages are suitable for informal communication, and snapshots of users adds presence and hints of contexts.

Active CyberCode: a directly controllable 2D code

Many augmented reality (AR) applications which overlay computer graphics on a real image have been developed. One of the limitations of such applications is that a user has to control CG objects, invoked by a realworld condition, using a traditional input device like a keyboard or mouse. We developed a directly controllable 2D code called Active CyberCode. A user can give commands by putting his/her finger on a printed button beside the code. The code has fixed and variable parts, and the variable part is recognized as the same as the fixed part. It allows a computer to recognize commands without the need for expensive methods like finger recognition.

Penumbrae for 3D interactions

We propose a new feedback technique for 3D interaction using penumbrae which the objects cast. Rather tlhan generating a real penumbra, which is computationally expensive, a fast, simplified algorithm is employed, which also is better suited for position feedback purposes. User studies show that 1) compared to orthographic shadow projections, 3D spatial recognition and placement tasks are substantially faster with our penumbrae, and 2) the users feel the feedback to be more natural.

Layered penumbrae: an effective 3D feedback technique

Shadows serve as effective cues for a user to recognize spatial relations among objects in 3D space. However simple shadows typically used in 3D interfaces are often insufficient for the purpose, and rendering of shadows with real penumbra are not only too costly for interactive interfaces, but also do not enhance their capabilities as spatial cues. Our proposal, layered penumbra is a new interactive feedback technique that overcomes these deficiencies; it positively enhances the users perception of spatial relations, looks natural to the eye, and furthermore can be rendered fast enough for interactive 3D interfaces. The layered penumbra has three layers (umbra, penumbra, and the middle layer) separated distinctly at their perimeters. A layered penumbra is drawn as a series of simple orthogonal projections of an object locally magnified/shrunken.