Determination of Sewer Structure Using a Moving Camera

This paper presents a novel method of obtaining an accurate estimate of the shape of a sewer from a sequence of images captured by a camera moving along its length. An image flow technique is first applied. This gathers information from the whole image plane to produce a global description of the changes in the image feature positions due to camera movement. Given this description, the motion of the camera may be estimated. The motion parameters obtained are then exploited by a structure form motion technique which estimates the shape of the sewer pipe by considering the motion of individual image features. Sewer shape data is managed by a specially developed graphical user interface which allows the user to view the shape of the sewer section from different view angles.