Rapid Form Frame-line Detection with Arbitrary Skew Angle
ZHOU Shao-guang, ZHAO Jian-quan (Department of Surveying and Mapping Engineering, Hohai University, Nanjing 210098)
More and more attention is paid to form extraction in recent years, and a number of efficient results are obtained. Some of the presented algorithms can be used to process a form image with an arbitrary skew angle, but they are not the most efficient methods. A projection approach can detect form frame-lines more efficiently but fail to detect any line when the form slants severely. A new idea is given here to measure this sort of skew angle rapidly, it first detects one of the form’s frame lines by using the structural characteristics of digital lines, and then calculates the skew angle’s value. Along the directions determined by the angle, the form frame-lines are searched out. The method is both efficient and anti-skew.
【CateGory Index】： TP391.41