In recent years, location information of people has been attracting a lot of attentions as an element for construct of ubiquitous environment. Especially, high precision of that location information is very important in case of emergency. In order to realize the precision, technical challenges will be how to improve the precision of GPS information. So far, these issues have rarely been studied, however. In this paper, we use GPS on mobile phone as device of obtaining location information. We consider a method to improve the precision with mobile phone camera, and show experiment results by the method.