Yu SHEBUYAand Hiroshi TAMURA Kyoto Institute of Technology
Since several years ago, multimedia has been expected to make an effective human-computer interaction. Until now, multimedia might be mainly used for "output", that is information flow from machine to user. There is another direction of information flow, that is "input" from user to machine. Traditional type of input method is keyboard, mouse, touch screen, and so on. Few years ago, we introduced an another interaction method named "Action Interface" ( Shibuya 1998), a kind of gesture interfaces. In the Action Interface, user's body image is captured and his action is detected by the system. Depends on his action, the system makes suitable reactions to the user.
There are several commercial or experimental uses of human action for humancomputer interface. In the MANDALAO©VR system (Vivid), a player's body image is captured, then combined with computer graphics, and finally displayed on the monitor in front of the player. The player can make a tune with virtual musical instruments displayed on the monitor. Trans Plant ( Christa, 1995) is an artistic use of combined users' live body image and computer graphics. Depending on the players' movement, artificial plants are growing up. Reality Fusion provides an interface that enables users to interact with a computer simply by using hand or body motion ( Reality Fusion, 1997).
Now a day, it is easy and not so expensive to combine a video camera with PC. The video camera has a possibility to be an another input method in humancomputer interaction. Multimedia should be used for "input". With thinking about these situations, and applying the method of Action Interface, an another type of interface is introduced in this paper. This interface is called "Variable Sheet interface".
Variable Sheet is a sheet on which some pictures are drawn. With changing the pictures, user can make various interactions with the system. For example, if a