Shigeo Asahara

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.

Evaluation of viewing distance vs. TV size on visual fatigue in a home viewing environment

We evaluated viewing distance vs. TV size on visual fatigue using two kinds of visual content: a 42-inch PDP display (Experiments 1 and 2), and the effect of TV size on visual fatigue with a 65-inch PDP display (Experiment 3). The results indicate that optimum viewing distance for less visual fatigue lies between 165 and 220 cm, indicating as a semi-absolute distance, rather than the strict relative distance like three times of the screen height (3H).

Relationship between Viewing Distance and Visual Fatigue in Relation to Feeling of Involvement

In this study, we carried out experiments to measure the effect of viewing distance on visual fatigue using two kinds of visual content. Both experiments showed that visual fatigue reached a minimum at a distance of 3 to 4 times the height of the display (3---4H) and that sympathetic nerve activity peaked at around 3H. These results indicate that the viewing distance for less visual fatigue and a closer feeling of involvement might be in between the two distances. These indices, which we adopt in this study, have the potential to be effective evaluation indices for measuring visual fatigue taking feeling of involvement into consideration.

Measurement of visual fat igue for large-sized TVs in a home viewing environment

The authors report here the result of the evaluation experiments that measured visual fatigue for large-sized TVs in a home viewing environment using 42-inch and 65-inch PDP displays by physiological and psychological measurements. Our results indicate that the optimum viewing distance for minimizing visual fatigue lies between 165 and 220 cm, a semi-absolute distance, rather than a strict relative distance such as three times the screen height (3H). Moreover these results indicate that the viewing distance for less visual fatigue and a closer feeling of involvement might be in between the two distances.

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.

Relationship between Emotional State and Pupil Diameter Variability under Various Types of Workload Stress

We carried out two experiments to explore the relationship between the frequency characteristic of pupil diameter variability and emotional state under various types of workload. The workload required the subjects to listen to spoken words and categorize them. The difficulty of the task was adjusted by changing the time interval of the stimulus presentation in Experiment 1 (time-based task) and the number of categories in Experiment 2 (cognitive-based task). Pupil diameter was monitored and recorded using an infrared video camera while observers were performing the tasks. In both experiments, a significant correlation was observed between the frequency characteristic of pupil diameter variability and emotional state. Our results indicated the frequency characteristic of pupil diameter variability to be a potentially useful index for evaluating mental stress.

Relationship between Emotional State and Physiological and Psychological Measurements Using Various Types of Video Content during TV Viewing

Using 42-inch plasma screens and showing four kinds of content, we experimentally evaluated the relationship between TV viewers’ emotional state and selected physiological and psychological indices. Our results indicate that near-infrared spectroscopy (NIRS), representing nervous system activity, is a potentially useful index for evaluating emotional states that include “stressed—relaxed,” “comfortable—uncomfortable,” and “like—dislike.” However, LF/HF and HR are affected by complex emotional states in each subject.

P-29: Physiological and Psychological Measurements of Visual Fatigue for TVs in a Home Viewing Environment

In this study, we experimentally evaluated visual fatigue for large-Sized TVs in a home viewing environment by physiological and psychological measurements using 42- and 65-inch PDP displays with two kinds of content. for less visual fatigue, the results indicate that the optimum viewing distance lies between 165 and 220 cm, indicating a semi-absolute distance, rather than such a strict relative distance as three times the screen height (3H). Moreover these results indicate that the viewing distance for less visual fatigue and a closer feeling of involvement might be found in between the two distances.