For remote communication, it is very hard to convey emotional message, or atmosphere of conversation to the opponent people who are located in a geographically difference place. For Email messages, emoticon, or face mark symbols are often used to express emotion, which works well to show emotion in an explicit way. Even though, the opponent face is show on the screen in remote video communication, emotional expression over the network is not similar to face-to-face meeting. In a face-to-face meeting, atmosphere of the conversation is shared in an implicit manner as opposed to the explicit explanation using words, sign, or pictures.
This research proposes an idea of implicit representation of emotional messages using light illumination [Lin, T.I. 2004; Vandewalle, G. 2010] with 1/f-fluctuation. It is reported that the 1/f-fluctuation makes a relaxed mental state. Therefore, ambient lighting with 1/f-fluctuation could provide a comfortable (and/or uncomfortable) atmosphere. In addition to this, this study aims to present emotional message in the illumination. In order to do so, four different types of 1/f-fluctuation pattern were created to represent four different types of typical human emotion, including joy, anger, pathos, and humor. The paper explains how the idea was implemented, using light illumination of four types of emotion based on the user experiments. According to some feasibility experiments, these four types of illumination were recognized to express each type of emotion. Applying emotional message representation with 1/f-fluctuation in the illumination of video conference speaker, implicit emotional message was presented during the conversation. Then the paper discusses the feasibility of the idea for ambient human interface.