This Article 
   
 Share 
   
 Bibliographic References 
   
 Add to: 
 
Digg
Furl
Spurl
Blink
Simpy
Google
Del.icio.us
Y!MyWeb
 
 Search 
   
Equivalence of Different Methods for Slant and Skew Corrections in Word Recognition Applications
March 2001 (vol. 23 no. 3)
pp. 323-326

Abstract—Normalization of slant and skew is often used in processing a word image before recognition. In this paper, we prove the theoretical equivalence of different methods for slant and skew corrections. In particular, we show that correcting first for skew by rotation and then for slant by a shear transformation in the horizontal direction is equivalent to first correcting for slant by a shear transformation in the horizontal direction and then for skew by a shear transformation in the vertical direction. Our proof can be easily modified to prove equivalence of other methods for correcting the slant and skew.

[1] M. Brown and S. Ganapathy, “Preprocessing Techniques for Cursive Word Recognition,” Pattern Recognition, vol. 16, no. 5, pp. 447-458, 1983.
[2] P. Gader, M. Whalen, M. Ganzberger, and D. Hepp, “Handprinted Word Recognition on a NIST Data Set,” Machine Vision and Applications, vol. 8, pp. 31-40, 1995.
[3] W. Guerfali and R. Plamondon, “Normalizing and Restoring Online Handwriting,” Pattern Recognition, vol. 26, no. 3, pp. 419-431, 1993.
[4] G. Kim and V. Govindaraju, “Efficient Chain Code-Based Image Manipulation for Handwritten Word Recognition,” Proc. SPIE Symp. Electronic Imaging Science and Technology, pp. 262-272, 1996.
[5] G. Kim and V. Govindaraju, “A Lexicon Driven Approach to Handwritten Word Recognition for Real Time Applications,“ IEEE Trans. Pattern Analysis and Machine Intelligence, vol. 19, no. 4, pp. 366-379, Apr. 1997.
[6] F. Kimura, M. Sridhar, and Z. Chen, “Improvements of a Lexicon Directed Algorithm for Recognition of Unconstrained Handwritten Words,” Proc. Second Int'l Conf. Document Analysis and Recognition, pp. 18-22, 1993.
[7] A. Senior, “Off-Line Handwriting Recognition: A Review and Experiments,” Technical Report CUED/F-INFENG/TR 105, Eng. Dept., Cambridge Univ., Cambridge, England, Dec. 1992. available via FTP or fromhttp://espresso.ee.sun.ac.za/~schwardt/papers pimage.html.
[8] P. Slavík and V. Govindaraju, “An Overview of Run-Length Encoding of Handwritten Word Images,” Technical Report 2000-09, Dept. of Computer Science, SUNY at Buffalo, Aug. 1999. http://www.cse.buffalo.edutech-reports/.
[9] Ø.D. Trier, A.K. Jain, and T. Taxt, “Feature Extraction Methods for Character Recognition—A Survey,” Pattern Recognition, vol. 29, no. 4, pp. 641-662, 1996.

Index Terms:
Image preprocessing, slant normalization, skew normalization, handwriting recognition.
Citation:
Petr Slavík, Venu Govindaraju, "Equivalence of Different Methods for Slant and Skew Corrections in Word Recognition Applications," IEEE Transactions on Pattern Analysis and Machine Intelligence, vol. 23, no. 3, pp. 323-326, March 2001, doi:10.1109/34.910885
Usage of this product signifies your acceptance of the Terms of Use.