A polarization camera that can capture polarization images and a color image at the same time is used. Specifically, a clear sky polarization image, which provides information about the polarization of a part of the sky, is captured by a clear sky polarization image capturing section 100. And by reference to the information provided by a sun position determining section 1301 that determines the sun's position at the time of shooting, a camera direction estimating section 101 determines in what direction and in what area of the whole sky the clear sky polarization image is located as a polarization pattern. Finally, information about what direction or orientation on the globe the camera (image capture device) is now facing is output. In this manner, the direction of the camera and the relative position of the camera with respect to the sun can be known without providing a sensor separately and without capturing the whole sky or the sun.