Toshiya Naka

A compression/decompression method for streaming based humanoid animation

In VRML, a modeling language for describing 3D objects on the internet, the specification to realize lifelike movement of a 3D character with a skeletal structure (such as a human) has been standardized as VRML Humanoid Animation Ver.1.0 (H-Anim Ver.1.0) in the H-Anim WG of the VRML Consortium. To extend this specification, we suggest a method that makes it possible to send/receive motion data in real time on a network with narrow bandwidth such as a telephone line. Moreover, by sending the motion data with streaming data from server to client, the time required before playback can be greatly reduced. This technology uses basic techniques that can be applied widely to webbased 3D applications, broadcasting contents etc.

A spatial hierarchical compression method for 3D streaming animation

When distributing 3D contents real-time over a network with a narrow bandwidth such as a telephone line, methods for streaming and data compression can be considered indispensable. In previous work, we made possible the real-time streaming of 3D animation data on a network with a narrow bandwidth such as a telephone line by partitioning motion data for humanoid characters (data obtained by motion capture, for example full frame data at 30 frames/sec) into packets and then carrying out compression by culling data along the time axis. However, as a 3D scene becomes more complex, the number of humanoid characters also increases. Accordingly, the transmission rate also increases, becoming greater than the available bandwidth and making real-time distribution impossible. In this paper, we concentrate on the problem of real-time distribution, describing a new data packet format which allows flexible scalability of the transmission rate, and a data compression method, SHCM, which maximizes the features of this format using a 3D scene structure. Because compression using a 3D scene structure aims to obtain the optimal overall compression rate by altering the compression rate for each object, based on information on the position in 3D space relative to the behavior (motion) data of each object, its application to MPEG4 can be expected. Using this method the real-time distribution of 3D contents becomes possible despite the bandwidth restrictions of an ordinary telephone line.

WonderSpace: web based humanoid animation

Abstract In VRML, a modeling language for 3D objects on the Internet, the specification to realize life-like movement of a 3D character with a skeletal structure (such as a human) has been standardized as the VRML Humanoid Animation (H-Anim) Specification Ver.1.0 in the H-Anim WG of the VRML Consortium. To extend this specification, we suggest a method named “WonderSpace”, it is possible to send/receive motion data in real time on a network with a narrow band width such as a telephone line. Moreover, by sending motion data with streaming data from server to client, the time required before playback can be greatly reduced.

WonderSpace: interactive 3D animation browser

V IS U A L P R O C E E D IN G S E L E C T R IC G A R D E N WonderSpace is a browser for visualizing a virtual world in cyberspace, where lifelike creatures act according to VRML 2.0 and a specification for skeleton animation. Through human-like avatars, WonderSpace realizes voice or sound communication in multi-user cyberspace. Technical features include compression/decompression of shape data and motion data, modified motions generated from a base motion, motion connecting, and synchronizing motion with sound. At SIGGRAPH 97, WonderSpace technology provides three interactive experiences:

Proposal of the Effective Method of Generating Characteristic Gestures in Nonverbal Communication

According to the rapid spread of the Internet, the new devices and web applications using the newest multimedia technologies are proposed one after another and they become commodity in an instant. In these new web communications, the natural and intelligible interaction corresponding to the user’s various demands is required. In the communication in which persons do the direct dialogue in the interaction not only on the web but also in real world, it is widely known by the psychology field that the nonverbal information which is hard to express in words such as expression of face and gesture is playing the important role. In our research, the new analysis method of interaction using the dynamical model is proposed and paid our attention to the characteristic gestures especially. These gestures are the special motions such as lively or powerful actions which used effectively in Kabuki, anime, dance and the special gestures in the speech and presentation of attracting audiences. By analyzing the mechanisms of these characteristic gestures mathematically, we can design the new interactive interfaces easily which are natural and familiar for all users.

How can we make IT devices easy for older adults? effects of repetitive basic operation training and help-guidance on learning of electronic program guide system

Older adults have difficulties in using unfamiliar IT appliances because they look poor to learn operations in trial-and-error fashion. To find a different way for older adults to learn operations effectively, an experiment like usability testing with Electronic Program Guide (EPG) system on a HDD/DVD recorder was executed. Unfocused general information was not helpful for learning new operations. Repeated practice of basic operations with timely help-guidance messages facilitated the acquisition of targeted elementary actions and made them easy to learn new elementary actions as well as new complicated operations. It was suggested that older adults could learn better from successful operations than from trial-and-errors, which may induce harmful error spiral. It is necessary to investigate how to avoid error spiral in self-learning environment in home use.

A Proposed Dynamical Analytic Method for Characteristic Gestures in Human Communication

In human communication, nonverbal information such as gestures and facial expressions often plays a greater role than language; and some gesture-driven operations of the latest mobile devices have proved to be easy-to-use and intuitive interfaces. In this paper we propose a method of analyzing gestures that focuses on human communication based on the dynamical kinematic model. We have extended the analysis method of our proposed approach to take into account additional effects, such as those exerted by external forces, and we analyze the effects over the entire body of forces generated by gestures. We found that the degree of exaggeration could be quantified by the value of, and changes in, torque values. Moreover, when calculating them taking into account external forces and the moment of drag that is acting on both feet, it is possible to determine the twisting torque of the main joints with a high degree of precision. We also noted “preparation” or “follow-through” motions just before and after the emphasized motion, and found that each behavior can be quantified by an “undershoot” or “overshoot” value of changes in torque.

Web-based nonverbal communication interface using 3D agents with natural gestures

In this paper, we assumed that the nonverbal communication by using 3DAgents with natural gestures had various advantages compared with only the traditional voice and video communication, and we developed the IMoTS (Interactive Motion Tracking System) to verify this hypothesis. The features of this system are that the natural gestures of 3DAgents are captured easily by using interactive GUI from the 2D video images in which some characteristic human behaviors are captured, transmitted, and reproduced by natural gestures of 3DAgents. From the experimental results, we showed that the accuracy of captured gestures which often used in web communications was within the level of detectable limit. And we found that human behaviors could be characterized by the mathematical formula, and some of the information could be transmitted, especially some personalities such as quirks and likeness had the predominant effects of impressions and memories of human.

The Application of Dynamic Analysis to Hand Gestures

In designing new user interfaces for the latest mobile devices, such as tablets and smartphones, intuitiveness and simplicity are very important factors. Interacting with hand-gestures is one of the best choices for enabling the ease of use of such products. However, there are several disadvantages to this kind of intuitive interface: one of the chief problems with gesture-based interaction is that it is difficult to distinguish reliably between unconscious and intentional gestures. To resolve this ambiguity, the authors have proposed a quantitative analysis method of human gestures using dynamics. We discovered a close correlation between intended gestures and the torque applied to each joint; however, our previous model was designed for the quantitative analysis of gesture interaction mechanisms in full-body motions. In this paper, we expand our dynamic motion analysis to finger gestures, and reveal that our proposed method is applicable to dynamic motion analysis of basic finger operations.

A new color conversion method for realistic light simulation

In this paper a new color conversion method to replace the RGB approximation based on the perceived change in color when a colored light source illuminates a surface is proposed. In our study 1200 uniformly distributed samples were taken from Commission Internationale de l’Eclairage 1976 L*a*b* uniform color space and used to construct a uniform subset. Photographic patches of the colors in this subset were then subjected to color light sources and the color changes were measured. From these measurements rules which govern the corresponding change within the color space were determined. Changes within the color space were then defined by simple linear equations for any light source illuminating any surface. Lastly, experiments were conducted to confirm that color conversion within the CIE color space generates more realistic images than RGB approximations for a variety of light sources.