Abstract
As compared to scanners, cameras offer fast, flexible and non-contact document imaging, but with distortions like uneven shading and warped shape. Therefore, camera-captured document images need preprocessing steps like binarization and textline detection for dewarping so that traditional document image processing steps can be applied on them. Previous approaches of binarization and curled textline detection are sensitive to distortions and loose some crucial image information during each step, which badly affects dewarping and further processing. Here we introduce a novel algorithm for curled textline region detection directly from a grayscale camera-captured document image, in which matched filter bank approach is used for enhancing textline structure and then ridges detection is applied for finding central line of curled textlines. The resulting ridges can be potentially used for binarization, dewarping or designing new techniques for camera-captured document image processing. Our approach is robust against bad shading and high degrees of curl. We have achieved around 91% detection accuracy on the dataset of CBDAR 2007 document image dewarping contest.
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Shafait, F., Keysers, D., Breuel, T.M.: Efficient implementation of local adaptive thresholding techniques using integral images. In: Proc. Document Recognition and Retrieval XV, San Jose, CA, USA, vol. 6815, p. 81510 (2008)
Zhang, Z., Tan, C.L.: Correcting document image warping based on regression of curved text lines. In: Proc. 7th Int. Conf. on Document Analysis and Recognition, Edinburgh, Scotland, pp. 589–593 (2003)
Lu, S.J., Tan, C.L.: The restoration of camera documents through image segmentation. In: Proc. 7th IAPR workshop on Document Analysis Systems, Nelson, New Zealand, pp. 484–495 (2006)
Fu, B., Wu, M., Li, R., Li, W., Xu, Z.: A model-based book dewarping method using text line detection. In: Proc. 2nd Int. Workshop on Camera Based Document Analysis and Recognition, Curitiba, Barazil, pp. 63–70 (2007)
Gatos, B., Pratikakis, I., Ntirogiannis, K.: Segmentation based recovery of arbitrarily warped document images. In: Proc. 9th Int. Conf. on Document Analysis and Recognition, Curitiba, Barazil, pp. 989–993 (2007)
Stamatopoulos, N., Gatos, B., Pratikakis, I., Perantonis, S.J.: A two-step dewarping of camera document images. In: Proc. 8th IAPR Workshop on Document Analysis Systems, Nara, Japan, pp. 209–216 (2008)
Ulges, A., Lampert, C.H., Breuel, T.M.: Document image dewarping using robust estimation of curled text lines. In: Proc. 8th Int. Conf. on Document Analysis and Recognition, Seoul, Korea, pp. 1001–1005 (2005)
Bukhari, S.S., Shafait, F., Breuel, T.M.: Segmentation of curled textlines using active contours. In: Proc. 8th IAPR Workshop on Document Analysis Systems, Nara, Japan, pp. 270–277 (2008)
Bukhari, S.S., Shafait, F., Breuel, T.M.: Coupled snakelet model for curled textline segmentation of camera-captured document images. In: Proc. 10th Int. Conf. on Document Analysis and Recognition, Barcelona, Spain (2009)
Bukhari, S.S., Shafait, F., Breuel, T.M.: Script-independent handwritten textlines segmentation using active contours. In: Proc. 10th Int. Conf. on Document Analysis and Recognition, Barcelona, Spain (2009)
Horn, B.K.P.: Shape from shading: A method for obtaining the shape of a smooth opaque object from one view. PhD Thesis, MIT (1970)
Riley, M.D.: Time-frequency representation for speech signals. PhD Thesis, MIT (1987)
Li, Y., Zheng, Y., Doermann, D., Jaeger, S.: Script-independent text line segmentation in freestyle handwritten documents. IEEE Transactions on Pattern Analysis and Machine Intelligence 30(8), 1313–1329 (2008)
Du, X., Pan, W., Bui, T.D.: Text line segmentation in handwritten documents using Mumford-Shah model. In: Proc. Int. Conf. on Frontiers in Handwriting Recognition, Montreal, Canada, pp. 1–6 (2008)
Shafait, F., Breuel, T.M.: Document image dewarping contest. In: Proc. 2nd Int. Workshop on Camera Based Document Analysis and Recognition, Curitiba, Brazil, pp. 181–188 (2007)
Shafait, F., Keysers, D., Breuel, T.M.: Performance evaluation and benchmarking of six page segmentation algorithms. IEEE Transactions on Pattern Analysis and Machine Intelligence 30(6), 941–954 (2008)
Gatos, B., Antonacopoulos, A., Stamatopoulos, N.: ICDAR 2007 handwriting segmenentation contest. In: Proc. 9th Intelligence Conf. on Document Analysis and Recognition, Curitiba, Brazil, pp. 1284–1288 (2007)
Shafait, F., Keysers, D., Breuel, T.M.: Pixel-accurate representation and evaluation of page segmentation in document images. In: Proc. Int. Conf. on Pattern Recognition, Hong Kong, China, August 2006, pp. 872–875 (2006)
Breuel, T.M.: Representations and metrics for off-line handwriting segmentation. In: Proc. 8th Int. Workshop on Frontiers in Handwriting Recognition, Ontario, Canada, pp. 428–433 (2002)
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Bukhari, S.S., Shafait, F., Breuel, T.M. (2009). Ridges Based Curled Textline Region Detection from Grayscale Camera-Captured Document Images. In: Jiang, X., Petkov, N. (eds) Computer Analysis of Images and Patterns. CAIP 2009. Lecture Notes in Computer Science, vol 5702. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-03767-2_21
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DOI: https://doi.org/10.1007/978-3-642-03767-2_21
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