Conventional indoor location positioning technology generally uses WLAN, GPS, and Bluetooth technologies. However, this technique may cause an error due to the strength of the received signal in an indoor environment. An indoor location positioning method that does not use a sensor is a method of referencing a 3D building model. This paper proposes a method of indoor location positioning using reference to a 3D building model, which is one of the indoor location recognition methods. The proposed method uses an image to recognize and use a permanent static object in a building, such as a door in the image, to predict and calculate the real-world distance ratio between the static object and the static object. After estimating real-world distance ratio, we compare estimated distance ratio with the real distance ratio to estimate the camera position. Through this method, it is expected that the indoor location can be recognized inexpensively with a single image without special infrastructure or sensors.
