Photo-mosaicing of images of pipe inner surface

Abstract

This paper describes the algorithm for the construction of continuous visually consistent images of the inner surface of a pipe from a sequence of images acquired by a wide-angle camera that traveled inside the pipe. The algorithm is designed to be a proof of concept and performs well on simulated data (rendered images) even when camera poses (attitude and location) have errors as much as 5%. Photo-mosaics are suitable for traditional (visual) inspection or automatic processing for the detection of manufacturing faults, corroded areas, and cracks. It is demonstrated that the quality of the resulting mosaic depends how the camera is oriented with respect to the pipe axis and that the traditional orientation with an almost collinear camera optical axis and the pipe axis is not the optimal choice. The proposed system is useful for inspection of pipelines that cannot accommodate traditional devices (e.g., pipeline inspection gauges or crawlers), for example, small-scale boilers and gas systems.