Automatic extraction of coordinate grid lines from scanned mining maps

Based on the theory of mathematical morphology, a series of morphologic transforming models were constructed to extract coordinate grid lines automatically from scanned mining maps in which the coordinate grid lines are perpendicular to each other and long enough in both horizontal and vertical directions. Other morphologic transforming models were designed to repair the ruptures of other linear features caused by extraction of coordinate grid lines. The experimental results show that these models work efficiently.