Abstract Correct recognition of dashed lines is essential for high-level technical drawing understanding.
Automatic solution is quite difficult due to the limitations of machine vision algorithm.
In order to promote development of better techniques, a dashed line detection contest was held at the Pennsylvania State University during the First International Workshop on Graphics Recognition, August 9-11, 1995. This paper presents dashed line detection techniques which won the first place in the contest. It successfully detected the dashed lines in all drawings. The underlying mechanism is a sequential stepwise recovery of components that meet certain continuity conditions. Results of experiments are presented and discussed.