Since conventional cameras can not image complete 360 degree environments, several smaller images taken from the same center of projection are often combined to create a complete scene. Hand held video cameras provide a convenient way to capture a sequence of images. A wide range of image registration techniques exist. We introduce a new method based on phase correlation, a widely used and robust Fourier technique.
Phase correlation is limited to registration of image translation, rotation and scaling.
Unfortunately images in a mosaic are typically related by a projective transform. We first use phase correlation to find the rigid motion approximate registration of image pairs. The fixed camera center of projection allows us to use geometric calculations to obtain the true projective relation between the images. Finally we address the issue of global registration. In a large sequence of images there is often accumulated error that prevents a consistant alignment of all images together.