A stereo vision system for volume measurements

Discusses the realisation of a passive stereo vision system to analyse coal park images. The system is composed of groups of cameras placed in sufficiently high positions in order to see all the heaps from different points of view. Two towers and five 36 meter high lighting pylons along the perimeter of the park are used to base the camera groups. Each heap is observed from cameras belonging to different groups. The heaps are measured in sequence. Images of the same heap, taken by cameras of at least two different groups, are presented to the operator who identifies some characteristic edge points of the heap. As the cameras and the whole system are calibrated, the 30 coordinates of these points can be calculated starting from their coordinates in different images. The coal volume is evaluated on the basis of a model of the heap and the measurements collected