Surviving candidates are extended to nearby corners as long as an acceptable fit can be observed. Due to occlusion, an object may appear as two or more disjoint components in the input image. As a result, compatible but disjoint candidates are grouped in this stage. In the final stage, the candidates with the best support are selected. A candidate's support depends on its quality of fit as well as the length of its corresponding segments.
Candidate selection continues until all data is accounted for.
The system was tested on 7 input images of varying complexity. The result is shown in the following figure. Relevant model contours have been registered to the image contour.