Skew detection

Details Skew detection Skew detection

2007-10-02

2007-10-02

Patel, Kanjibhai (Department: 2624)

Image analysis

Image transformation or preprocessing

Measuring image properties

C382S308000

Reexamination Certificate

active

10648348

ABSTRACT:
Skew angle in a document image is estimated using operators known from mathematical morphology. Skew angle in a document image (A) is estimated by run-length smoothing the image and then producing a plurality of eroded run-length-smoothed images. The run-length-smoothed image (RLSA(A)) is eroded using a linear structuring element (k2Lα) oriented at each of a plurality of different angles (α). The angle of the linear structuring element which produces an eroded image having the greatest surface area is designated as the skew angle. A plurality of run-length-smoothed images (RLSAα(A)) may be produced, each generated by smoothing the document image using a linear structuring element (k1Lα) oriented at a respective different angle (αi). Then each run-length smoothed image (RLSAα(A)) is eroded using a linear structuring element oriented at the corresponding angle (αi).

REFERENCES:
patent: 5201011 (1993-04-01), Bloomberg et al.
patent: 5276742 (1994-01-01), Dasari et al.
patent: 5848184 (1998-12-01), Taylor et al.
patent: 2003/0190090 (2003-10-01), Beeman et al.
Gatos et al., “Applying Fast Segmentation Techniques At a Binary Image Represented By a Set of Non-Overlapping Blocks”, IEEE Comput. Soc., Sep. 10, 2001, pp. 1147-1151.
Bloomberg et al., “Measuring Document Image Skew and Orientation,” SPIE vol. 2422, Feb. 6, 1995, pp. 302-316.
Fisher et al., “A Rule-Based System for Document Image Segmentation,” IEEE Comp. Soc. Press, vol. 1, Conf. 10, Jun. 16, 1990, pp. 567-572.
Das et al., “A Fast Algorithm for Skew Detection of Document Images Using Morphology,” Int'l Journal on Document Analysis and Recognition, Dec. 2001, vol. 4, No. 2, pp. 109-114.
Chen et al., “An Automatic Algorithm for Text Skew Estimation in Document Images Using Recursive Morphological Transforms,” IEEE Comp. Soc. Press, vol. 3, Conf. 1, Nov. 13, 1994, pp. 139-143.

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