Reference line extraction for automated data-entry system using wavelet transform
Sakreya Chitwong, Seksan Phonsri, Punya Thitimajshima · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1999
It is common that most document forms opt for the use of straight line as a reference position for filled information. The automated data-entry systems of such documents require an ability to search these reference lines so that the location of information in the forms can be known. This paper proposes a wavelet-based algorithm for extracting these reference lines in business forms. Stationary wavelet transform is used to transform a gray-level document image into different frequency-band images. The horizontal detail subband is then selected and passed through a post-processing to produce a binary bitmap of reference lines. The experimental results on synthetic and real document images will be given to illustrate the usefulness of such an algorithm.