A study on the applicability of facial expression chart for display systems

Existing display systems are sometimes insufficient to display the information to be conveyed. For example, a room temperature meter displays the room temperature as a bar graph or numerical value, but the sensible temperature differs depending on the season: the same 20 degrees centigrade can be cold in summer but warm in winter. Additionally, elderly people may have a dull sense of temperature and hence not notice the room temperature even if the change is significant. A display system showing not only the temperature but also the four seasons in the year, level of comfort and color code for danger (red: dangerous, yellow: caution, green: safe) can be easier for users to understand. However, displaying various information simultaneously can overburden the users since it requires intensive and swift processing of incoming information. To address these problems, this paper considers a display system with facial expressions: information to be displayed are translated to part and condition of the face to construct a face chart. The shape, size, position, color or movement of the chart are determined by the information. Morphological visual data transmission is superior in speed, recognizability, accuracy and multiple data transmissions. For human beings, faces are the most significant clue for identifying others. Facial expressions are mainly expressed by the muscles around the eyes. Eyes often shows the emotional state of the person. This paper aims to evaluate the effect of the display system using the features of facial expression. We first examine the accuracy of facial expressions of taste and emotion and their recognition by conducting questionnaire experiments. In the next step, we evaluate the ability of facial expression in simultaneous information transmission and its impact to observers. Finally, we propose an indoor environment display system using face expression as its application. Main results are as follows: as for taste, sweetness (76.5 %) and acidity (72.8 %) had high recognition rates; as for emotion, joy (96.3 %) and surprise (76.5 %) had high recognition rates; taste and joy matching experiments showed high matching rate between sweetness and joy (94.3 %); an experiment to evaluate a Japanese sweetshop showed sufficient simultaneous information transmission result (74.8 %); an experiment for time indication showed the facial expression method had the highest impact ability. These results show the effectiveness of facial expression system.