Image analysis – Histogram processing – For setting a threshold
Patent
1991-10-04
1994-09-27
Boudreau, Leo H.
Image analysis
Histogram processing
For setting a threshold
382 55, 382 42, G06K 936, G06K 944
Patent
active
053513142
ABSTRACT:
Method and apparatus for image enhancement involving smoothing and thinning input image data, segmenting adjacent characters in the smoothed and thinned data, and identifying a segmented character based on a comparison of the segmented character to a dictionary of characters. Smoothing and thinning may be provided by applying to each pixel of input image data a filter whose spread depends on variations in image intensity of surrounding pixels to obtain filtered image data, deriving inverted image data from first difference data of the filtered image data and multiplying the inverted image data and the filtered image data to obtain smoothed and thinned image data. The filters may be Gaussians whose spreads are inversely proportionate to variations in input image intensity plus a constant and the filters may be applied to the image data using a variably filled mask of filter values.
REFERENCES:
patent: 4197583 (1980-04-01), Westell et al.
patent: 4692943 (1987-09-01), Pietzsch et al.
patent: 4855933 (1989-08-01), Kondo
patent: 4884225 (1989-11-01), Fogarty et al.
patent: 4891750 (1990-01-01), Pastor et al.
patent: 5119444 (1992-06-01), Nishihara
J. M. Coggins, et al., "Printed Character Recognition Using An Artificial Visual System", Proceedings of the 1986 IEEE International Conference on Systems, Man & Cybernetics, vol. 2, No. 14, Oct. 1968, pp. 1612-1616.
T. Poggio, et al., "Ill-Posed Problems And Regularization Analysis In Early Vision", MIT AI Lab Memo No. 773, Apr., 1984.
J. F. Canny, "Finding Edges And Lines In Images", MIT AI Lab, Tech. Rep. No. 720, Jun., 1983.
T. Poggio, et al., "A Regularized Solution To Edge Detection", MIT AI Memo 833, May, 1983.
T. Poggio, "Vision By Man And Machine: How The Brain Processes Visual Information May Be Suggested By Studies In Computer Vision (and vice versa)", MIT AI Memo 776, Mar., 1984.
A. P. Witkin, "Scale-space Filtering", Proc. Int. Joint Conf. Artif. Intell., West Germany, Aug., 1983.
T. N. Cornsweet, et al., "Intensity-Dependent Spread Summation", JOSA, vol. 2, No. 10, Oct., 1985.
D. Marr, et al., "Theory Of Edge Detection", Proc. R. Soc. London, pp. 187-217, 1980.
H. B. Barlow, "Increment Thresholds At Low Intensities Considered as Signal/Noise Discriminations", J. Physiol. (London), col. 136, pp. 469-488, 1957.
V. D. Glezer, "The Receptive Fields Of The Retina", Vision Res., vol. 5, 1965, pp. 497-525.
M. R. Vaezi, A Model for the Spatial Characteristics of the Human Retina: Optimum Intensity Dependent Spread Filters, Dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Engineering. Dec. 1990.
M. Vaezi, et al., "Optimum Intensity-Dependent Spread Filters In Image Processing", Proc. SPIE/SPSE Symposium on Electronic Imaging Conf., Feb., 1991.
Cornsweet, T. "Intensity-dependent spread-A Theory of human vision and a machine vision filter with Interesting Properties" Sixth Multidimensional Signal Processing Workshop Cat. No. 89TH0290-7 Sep. 6-8 1989.
Boudreau Leo H.
Canon Information & Systems, Inc.
Prikockis Larry J.
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