A vision system for the PISCIS project is described. This is a proposed project for the use of an untethered autonomous underwater vehicle (AUV) for pipeline inspection. The vision system is termed PVS (PISCIS vision system). It will assist the AUV in finding and following the pipeline. Robust image interpretation is important as humans can not interact with the vision system and correct errors. The image quality is reduced by backscatter, light absorption, and marine material on the pipelines. The PVS is fixed to a moving vehicle and must rely on a heading sensor and an altitude sonar to match images features with pipeline models. The models are retrieved from a map based on the vehicle's position.>

A 2D vision based pipeline tracking system is described for an autonomous underwater vehicle (AUV). A model-based recognition approach is used. From a 2D camera image rectangles are extracted. The real-world size and direction of each rectangle are estimated with the aid of input from a sonar and a compass. The rectangle that is consistent with the diameter and local direction of the pipeline is used to guide the AUV along the pipeline.>