Metadata Generation for Digital Photograph by using Smartphone's Sensors

Recently, taking photographs by using camera function of a smartphone for many purpose as well as a digital camera only for photo shooting becomes common. Metadata of digital photographs are add to the photographs at the shooting behavior. There are various kinds of services using these metadata. The existing photographs shot by a digital camera and smartphone’s camera function include many metadata based on the Exif format. By using smartphone’s sensors, it is possible to generate new kind of metadata for a photograph. For the purpose of sightseeing, persons such as photographers and travelers browse and share many photographs and the metadata. This paper proposes a method for generating photograph’s metadata by using multiple sensors equipped with a smartphone such as an acceleration sensor, direction sensor and camera function. In this study, we focus on sightseeing applications, and consider metadata available for the purpose. Our method uses an acceleration sensor, a direction and a face recognition function for generating metadata: a photographer’s action, direction and number of persons in a photograph respectively. We implemented the prototype system on a smartphone and conducted the preliminary experiments.