Dimension sets detection in technical drawings

This paper is primarily devoted to an algorithm for detecting dimension sets in engineering drawings that are drawn to ISO drafting standards. Our approach joins those starting with detection of dimension text while most methods are started with the detection of arrowheads. First, we detect among the segments and arcs resulting from the vectorization process those that fulfill some location constraints. A number of segments and arcs are chosen to be candidate parts of dimension lines according to the position and the geometry of their presumed witness lines. We establish the link between the candidates and the detected primitives which are in correspondence with text blocks. Complete dimension lines are found using tracking and fusion processes. Arrowheads are then located thanks to the position of witness and dimension lines. Experimental results are presented.