Online Urdu Handwriting Recognition System Using Geometric Invariant Features
Abstract
Online touch sensitive devices facilitate users by providing an easy way for inputting online handwritten text. Many useful applications are developed for other cursive script language and are practically used in different fields like banking, commerce, academics, administration and education etc. There are also some systems proposed for online Urdu handwriting recognition but either they have low accuracy rates or high constraints on user while writing. Online Urdu handwriting recognition is a difficult task due to its cursive property and writing complexity. The proposed system tries to recognize Urdu characters and words by using geometric features i.e. cosine angles of trajectory, discrete fourier transform of trajectory, inflection points, self-intersections, convex hull, radial feature, grid (orthogonal and perspective), and retina feature. The proposed system is font, rotation, scale and shift invariant due to geometric invariant features. Before feature extraction low pass filtering and resampling is applied on each input stroke trajectory to remove noise caused by input device and hand movement. After feature extraction linear support vector machine is used for training and testing which gives up to 97% classification accuracy on test data. In recognition phase the proposed system gives a very low false rejection rate.
References
A short encyclopedia, “Most widely spoken language of the world” December 1, 2015. [Online]. Available: http://www.einfopedia. com/most-widely- spoken-languages-of-the-world.php. [Accessed: Dec. 12, 2015].
M.A. Khan, A. Habib and M.N. Ali, “Corpus Based Mapping of Urdu Characters for Cell Phones”, Proceedings of the Conference on Language & Technology, Pakistan, vol. CLT09, pp. 121-25, 2009.
M.I. Razzak, A. Belaid and S.A. Hussain, “Effect of ghost character theory on arabic script based languages character recognition”, WASE Global Conference on Image Processing and Analysis, Taiwan, China, GCIA09, inria-00579666, version 1, February, 2009.
Y. Saydam, “Language use in the Ottoman Empire and its problems (1299-1923)”. University of Johannesburg, 2006, [Online]. available:https://ujdigispace.uj.ac.za/bitstream/handle/ 10210/741/YSaydam_thesis_last.pdf, [Accessed March. 14, 2015].
Z. Jan et al. / The Nucleus 53, No. 2 (2016) 89-98
S. Mozaffari, K. Faez, F. Faradji, M. Ziaratban and S.M. Gulzan”, A comprehensive isolated Farsi/Arabic character database for handwritten OCR research”, Tenth International Workshop on Frontiers in Handwriting Recognition, (IWFHR), pp. 385–389, 2006.
Wahab, Mehreen, H. Amin, and F. Ahmad, “Shape analysis of pashto script and creation of image database for OCR”, International Conference on Emerging Technologies, IEEE, Islamabad, Pakistan. pp. 287-90,2009.
A.S. Zahr, “Ligature based optical character recognition of Urdu-Nastaleeq font”, Multi Topic Conference, Karachi, Pakistan, pp. 25-25,2002.
N. Shahzad, B. Paulson, & T. Hammond, “Urdu Qaeda: recognition system for isolated urdu characters”, Proc. of the IUI Workshop on Sketch Recognition, Sanibel Island, Florida, pp. 1-5, 2009.
S. Malik and S.A. Khan, “Urdu online handwriting recognition” Emerging Technologies, Proc. of the IEEE Symposium, pp. 27-31, 2005.
S.A. Husain, A. Sajjad and F. Anwar, “Online Urdu Character Recognition System”, MVA, pp. 98-01, 2007.
M.I. Razzak, S.A. Hussain, M. Sher, and Z.S. Khan. “Combining offline and online preprocessing for online urdu character
recognition”, Proc. of the International Multi Conference of Engineers and Computer Scientists, Hong Kong, vol. 1, pp.18-20, 2009.
M.I. Razzak, F. Anwar, S.A. Husain, A. Belaid and M. Sher. “HMM and fuzzy logic: A hybrid approach for online Urdu script-based languages’ character recognition”, Knowledge-Based Systems, vol. 23, pp. 914-23, 2010.
Q. Safdar and K.U. Khan, “Online Urdu handwritten character recognition: Initial half form single stroke characters”, IEEE 12th International Conference on Frontiers of Information Technology, pp. 292-29, 2014.
R.G. Brown, “Smoothing, forecasting and prediction of discrete time series”, Courier Dover Publications, New York, USA, 2004.
U. Ramer, “An iterative procedure for the polygonal approximation of plane curves”, Computer Graphics and Image Process in, vol. 1, pp. 244-56, 1972.
J.W. Cooley and J.W. Tukey, “An algorithm for the machine calculation of complex fourier series”, Mathematics of computation, vol.19. pp. 297-01, 1965.
R.L. Graham, “An efficient algorithm for determining the convex hull of a finite planar set”, Information Processing Letters, vol. 1, pp. 132-33, 1972p.
