Document image preprocessing based on optimal Boolean filters

M. B. H. Ali, Background noise detection and cleaning in document images, Proceedings of IEEE International Conference on Pattern recognition, 1996, pp. 758–762. E. J. Coyle, J.-H. Lin, Stack filters and the mean absolute error criterion, IEEE Trans. Acoust. Speech Signal Process. 36 (August 1988) 1244–1254. H.-S, Don, A noise attribute thresholdong method for document image binarization, Proceedings of the Third International Conference on Document Analysis and Recognition, 1995, pp. 231–234. M. Gabbouj, E. J. Coyle, On the LP which finds a MMAE stack filter, IEEE Trans. Signal Process. 39(11) (November 1991) 2419–2424. Gonzalez, 1992 K. D. Lee, Y. H. Lee, Threshold Boolean filter, IEEE Trans. Signal Process. 42 (8) (August 1994) 2022–2036. Liang, 1994, A morphological approach to text string extraction from regular periodic overlapping text/background images, CVGIP, 56, 402 J.-H. Lin, E. J. Coyle, Minimum mean absolute error estimation over the class of generalized stack filters, IEEE Trans. Acoust. Speech Signal Process. 38(4) (April 1990) 663–678. J.-H. Lin, Y.-T. Kim, Fast algorithms for training stack filters, IEEE Trans. Signal Process. 42(4) (April 1994) 772–781. J.-H. Lin, T. M. Sellke, E. J. Coyle, Adaptive stack filtering under the mean absolute error criterion, IEEE Trans. Acoust. Speech Signal Process. 38 (April 1990) 938–954. Muroga, 1971 A. Rosenfeld, On connectivity properties of gray pictures, Pattern Recognition (16) (1983) 47–50. M. Sawaki, N. Hagita, Text-line extraction and character recognition of document headlines with graphical designs using complementary similarity measure, IEEE Trans. Pattern Anal. Mach. Intell. 20 (10) (October 1998) 1103–1109. I. Tabus, D. Petrescu, M. Gabbouj, A training framework for stack and Boolean filtering – fast optimal design procedures and robustness case study, IEEE Trans. Image Process. 5 (6) (June 1996) 809–825. Y. Wang, P. Bhatacharya, Image analysis and segmentation using gray connected components, Proceedings of IEEE International Conference on Systems, Man and Cybernetics, 1996, pp. 444–449. P. D. Wendt, E. J. Coyle, N. C. Gallagher, Stack filters, IEEE Trans. Acoust. Speech Signal Process. ASSP-34 (4) (August 1986), 898–911. White, 1983, Image thresholding for optical character recognition and other applications requiring character image extraction, IBM J. Res. Dev., 27, 400, 10.1147/rd.274.0400 Zeng, 1991, A unified design method for rank orderstack, and generalized stack filters based on classical Bayes decision, IEEE Trans. Circuits Systems,, 38, 1003, 10.1109/31.83872