Detection of dimension sets in engineering drawings

A system for detecting dimension sets in engineering drawings that are drawn to ANSI drafting standards is presented. A new rule-based text/graphics separation algorithm and a model-based procedure for detecting arrowheads in any orientation have been developed. Arrowhead tracking and search methods are used to extract leaders, tails, and witness lines from segmented images containing only graphics. Text blocks and feature control frames extracted from the segmented images are then associated with their corresponding leaders to obtain complete dimension sets. Object lines are then separated from centerlines and hatching lines. Experimental results are presented.<
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