StateSnap: A Snapshot-based Interface for State-Reproductable Operation of Networked Appliances Naohiko Kohtake, Takeshi Iwamoto, Genta Suzuki, Shun Aoki, Kazunori Takashio, Hideyuki Tokuda Graduate School of Media and Governance, Keio University Delta S213, Endo 5322, Fujisawa, Kanagawa 2528520, Japan {nao, iwaiwa, genta, shunaoki, kaz, hxt}@ht.sfc.keio.ac.jp Abstract This paper describes a snapshot-based interface for net- worked appliances operations that allows users to store and reproduce the conditions of media contents in those appli- ances by means of photographed image data of the net- worked appliances. The conditions of the appliances are stored as metadata in photographed image data and dis- played over a display of each appliance. A user can re- produce the state of the appliances with those image data. Furthermore, such a reproduction can be made on other appliances with the same function. Storing the information as image data makes it easy for a user to refer to an exact data out of an enormous amount of data. One of advantages of this system is that, by photographing many appliances at the same time, one image data can hold various appliances’ conditions. We have developed a prototype system to realize the proposed interface and some applications to confirm its effective usage. We have also confirmed its possibility for practical use through an evaluation of the system’s perfor- mance. 1. Introduction Thanks to recent improvements in the field of digital and network technologies, network connection is extend- ing rapidly beyond personal computers to embrace home appliances such as televisions, air-conditioners, and refrig- erators; such network-connected appliances, often called networked appliances. With a variety of these utilization forms, for instance, we can set a video cassette recorder to automatically record a television program remotely from outside. In addition,security sensor systems at homes or of- fices can be used to call to their owners’ cell phones when they find emergencies. Accompanying the spread of net- worked appliances 、interfaces dealing with them are be- ginning to influence their use. Until now, with regard to interfaces when handling computers, in the case of connect- ing to another computer via a network, the connection had been implemented by distinguishing directions to be con- nected with the hosts’ names or network addresses. More- over, in the case of handling electronic data such as picture data, processing had been implemented by discrimination of the data name or revised dates. However, in comparison to computer users who are mainly engineers or experts, net- worked appliances’ users are varied. Therefore, a friendly interface that everyone, irrespective of age or sex, can use is desired. The research to realize such an interface has been conducted [4][8][12]. A new usage system that records a particular state of net- worked appliances connected to a network and reproduces the state at another location a few hours later has been re- alized. For example, if a user watches a video halfway at home and wants to resume it at the same scene on another display or a mobile computer; he can access the video and watch it anywhere if the video is accessible via a network. However, to watch the video again at home, the user has to search the scene that he has paused, which is troublesome. In such a case, if a user has the means to preserve the state of the networked appliance as a snapshot by photograph- ing the scene of the video, he can then search the state by intuition as soon as possible and replay the video from the scene. Up to now, “research that enables users to store and re- produce a state of target objects” and “research that enables users to specify a target object by photographing” have been investigated. The former research [6][10] is aimed mainly at the desktop-computer environment and enables users to reproduce environments stored in the past. In addition, the latter research [1][2][5] recognizes and designates a target or a tag installed around the target by photographing the tar- get object, and enables users to obtain information about the target object and to connect the target to a network. We propose a “StateSnap” interface, which utilizes the metaphor of photographing a snapshot by a camera, as a technique to record a state of networked appliances’ me-