Camera Parameters Estimation from Hand-labelled Sun Sositions in Image Sequences

We present a novel technique to determine camera parameters when the sun is visible in an image sequence. The technique requires a user to label the position of the sun in a few images. We show that it can be used to successfully recover the camera focal length, as well as its azimuth and zenith angles. The method is thoroughly evaluated on synthetic data under a wide range of operating conditions, and representative examples are shown on real data. Ground truth parameters can be recovered with less than 3% error in challenging cases.