A Line Extraction Algorithm for Hand Drawings

摘要

This paper presents an algorithm for extracting lines from hand drawings. It starts from contour pixel tracing, fits them into contour segments, and then extracts skeleton lines from the contour segments. The algorithm finds all contours in one scan of the input matrix without detecting and marking multiple pixels. In line extraction, the method Elastic Contour Segment Tracing is proposed which extracts lines by referring to the contour segments at both sides, overcoming noise and passing through blotted areas by fitting and extrapolation. Experiments on free hand mechanical drawings, sketches, letterumerals, as well as Chinese characters are carried out and satisfactory results are achieved.