Image analysis – Histogram processing – For setting a threshold
Patent
1996-08-09
1998-07-14
Razavi, Michael T.
Image analysis
Histogram processing
For setting a threshold
382271, G06T 540
Patent
active
057816581
ABSTRACT:
A method of multithresholding a document image considers both local and global information in determining the number of thresholded levels contained in a gray-scale image. A gray-scale image is comprised of a plurality of pixels. Each pixel has an intensity value. Local regions of pixels having similar intensity values are identified and compiled into a global representation of the image. Intensity ranges are identified in the global representation in which the number of regions of pixels are approximately constant. An intensity value is identified within each range which represents the most constant point within the representation range. The number of threshold levels is set equal to the number of ranges in the representation.
REFERENCES:
patent: 4504972 (1985-03-01), Scherl et al.
patent: 4673977 (1987-06-01), Stelzenmuller
patent: 4879753 (1989-11-01), El-Sherbini
patent: 5073954 (1991-12-01), Van Tyne et al.
patent: 5179599 (1993-01-01), Formanek
patent: 5450502 (1995-09-01), Eschbach et al.
Liu et al. "An Object Attribute Thresholding Algorithm for Document Image Binarization." Proc. Second Int. Conf. on Document Analysis and Recognition. Oct. 1993, pp. 278-281.
J. M. White, G. D. Rohrer, "Image Thresholding for Optical Character Recognition and Other Applications Requiring Character Image Extraction", IBM J. Res. Develop., vol. 27, No. 4, Jul. 1983, pp. 400-411.
T. Pun, "Entropic Thresholding, A New Approach", Computer Graphics and Image Processing, vol. 16, pp. 210-239 (1981).
J. N. Kapur, P. K. Sahoo, A. K. C. Wong, "A New Method for Gray-Level Picture Thresholding Using the Entropy of the Histogram", Computer Vision, Graphics, and Image Processing, vol. 29, pp. 273-285 (1985).
W-Hsiang Tsai, "Moment-Preserving Thresholding: A New Approach", Computer Vision, Graphics and Image Processing vol. 29, pp. 377-393 (1985).
N. Otsu, "A Threshold Selection Method from Gray-Level Histograms", IEEE Transactions on Systems, Man, and Cybernetics, vol. SMC-9, pp. 62-66, Jan. 1979.
Chang Jon
Lucent Technologies - Inc.
Razavi Michael T.
LandOfFree
Method of thresholding document images does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of thresholding document images, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of thresholding document images will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1891422