<title>Extraction of object lines in engineering drawings</title>

Abstract

Classification of object lines in mechanical part drawings is a critical problem for automated conversion of drawings from paper medium to CAD databases. We describe new methods for classifying object lines. These methods include section line detection, hidden line detection, centerline detection and object line extraction. A self-supervised approach which includes a spacing estimation step and a recognition step to extract section lines is described. A general purpose algorithm which not only detects dashed lines hut also classifies them based on their attributes is described. These attributes are used for classification of detected dashed lines as hidden lines or centerlines. Object line extraction facilitates intelligent interpretation of geometric objects for integration with CAD/CAM systems.

<title>Recognition of thick closed polygons in engineering drawing images</title>

“…Recognition of some entities has been considered in papers [7][8][9], however we should note that this problem is far from its solution. Recognition of some entities has been considered in papers [7][8][9], however we should note that this problem is far from its solution.…”