Building panoramas from photographs taken with an uncalibrated hand-held camera

This paper presents a method for building a full view cylindrical panorama from uncalibrated photos taken naturally with an ordinary hand-held camera held at an approximately fixed location. Such photos usually have large perspective distortion, small overlap, brightness differences, and camera rotations such as tilt and roll. These characteristics make both image alignment and panorama building more difficult than using photos taken by cameras calibrated by special equipment. To align such images, simple registration techniques cannot be applied directly. This paper shows how these images can be registered by a particular robust feature matching scheme, which contains robust information of gradient direction; this paper also proposes a reliable initial parameter estimation method as well as an iterative approach with linear steps to perspective transformation parameter optimization for pairs of adjacent images. Experiments show that the method yields good results even when the overlap region of adjacent photos is as small as 16%.