Automatic alignment and graph map building of panoramas

Panoramic cameras can capture a 360° view from a point providing new capabilities for multimedia, tele-presence and robotic applications. For example, virtual walk-throughs of an environment can be created from a sequence of panoramic images, where perspective views are created according to a user´s position and view direction. For this and other applications, the panoramic images need to be aligned to one another and a topological or metric map created. An automatic method to achieve this would remove a lot of tedious preparations for multimedia systems and enable robotic positioning systems. This paper presents three methods to address these problems; finding the relative orientation between panoramas, using the essential matrix is created to determine the relative rotation and translation direction, and an image search based algorithm to detect when the camera path crosses over itself for creating a topological map. The SIFT feature detector is used to find correspondences between panoramic images. Experimental results are shown for determining the rotation and cross-overs.