A Medial Axis Based Thinning Strategy for Character Images

Thinning of character images is a big challenge. Removal of strokes or deformities in thinning is a difficult problem. In this paper, we have proposed a medial axis based thinning strategy used for performing skeletonization of printed and handwritten character images. In this method, we have used shape characteristics of text to get skeleton of nearly same as the true character shape. This approach helps to preserve the local features and true shape of the character images. The proposed algorithm produces one pixel width thin skeleton. As a by-product of our thinning approach, the skeleton also gets segmented into strokes in vector form. Hence further stroke segmentation is not required. Experiment is done on printed English and Bengali characters and we obtain less spurious branches comparing with other thinning methods without any post processing.

[1]  Ching Y. Suen,et al.  Thinning Methodologies - A Comprehensive Survey , 1992, IEEE Trans. Pattern Anal. Mach. Intell..

[2]  Ching Y. Suen,et al.  A fast parallel algorithm for thinning digital patterns , 1984, CACM.

[3]  Rafael C. González,et al.  Local Determination of a Moving Contrast Edge , 1985, IEEE Transactions on Pattern Analysis and Machine Intelligence.

[4]  Wing-Nin Leung,et al.  Contour following parallel thinning for simple binary images , 2000, Smc 2000 conference proceedings. 2000 ieee international conference on systems, man and cybernetics. 'cybernetics evolving to systems, humans, organizations, and their complex interactions' (cat. no.0.

[5]  Amitava Datta,et al.  A robust parallel thinning algorithm for binary images , 1994, Pattern Recognit..

[6]  Carlo Arcelli,et al.  Pattern thinning by contour tracing , 1981 .

[7]  Sven J. Dickinson,et al.  Optimal inference for hierarchical skeleton abstraction , 2004, Proceedings of the 17th International Conference on Pattern Recognition, 2004. ICPR 2004..

[8]  Gabriella Sanniti di Baja,et al.  A One-Pass Two-Operation Process to Detect the Skeletal Pixels on the 4-Distance Transform , 1989, IEEE Trans. Pattern Anal. Mach. Intell..

[9]  Jose L. Navalón,et al.  A thinning algorithm based on contours , 1987 .

[10]  Lei Huang,et al.  An improved parallel thinning algorithm , 2003, 2016 International Conference on Wavelet Analysis and Pattern Recognition (ICWAPR).

[11]  Shuyi Zhang,et al.  A Shape-Adaptive Thinning Method for Binary Images , 2008, 2008 International Conference on Cyberworlds.