Some communications (e.g. cables and pipelines with small diameter) can be detected on photo and video images as a pair of parallel lengthy lines. The basic function of VIC is data collection about inspected object and its identification (detection) on a seabed. Object identification consists of search of the longest straight line presented on the image. Hough transformation is used as the basic mathematical tool (Scherbatyuk, 1998). The recognition system output includes (fig. 1):
1. direction of the recognized object at<VIC>;
2. distance from video camera to the object pf<VIC>;
3. length of a visible part of the object lt<VIC>.
The position-direction vector rKVIC>=[XKVIC>,YKVIC>,$KVIC>]T of recognized object in absolute coordinate system for a camera directed downwards perpendicularly to AUV shape is calculated as follows (neglecting AUV pitch and roll which during object inspection do not exceed several degrees):
Was this article helpful?