Contrast enhancement of digital images

Details Contrast enhancement of digital images Contrast enhancement of digital images

2006-09-05

2006-09-05

Lee, Michael H. (Department: 2622)

Television

Image signal processing circuitry specific to television

Gray scale transformation

C382S274000

Reexamination Certificate

active

07102697

ABSTRACT:
An adaptive histogram equalization method is introduced which allows the histogram equalization amount to automatically adapt to the original image contrasts, which can be measured from the originals. Contrast over-enhancement is avoided by limiting the spatial frequency response of the histogram. Besides that, methods to remedy the brightness change problem encountered by histogram equalization are described.

REFERENCES:
patent: 5537071 (1996-07-01), Jaspers
patent: 5857033 (1999-01-01), Kim
patent: 5923383 (1999-07-01), Kim
patent: 6049626 (2000-04-01), Kim
patent: 6148103 (2000-11-01), Nenonen
patent: 6373533 (2002-04-01), Kawabata et al.
patent: 6650774 (2003-11-01), Szeliski
patent: 0 383 269 (1990-08-01), None
patent: 1 022 679 (2000-07-01), None
Gonzalez, R:, Woods, R.: “Digital Image Processing” 1992, Addison-Wesley, Reading, MA, USA, XP002206096, p. 173-180.
Alex Stark J: “Adaptive Image Contrast Enhancement Using Generalizations of Histogram Equalization” IEEE Transactions on Image Processing, IEEE Inc. New York, US, vol. 9, No. 5, May 2000, pp. 889-896, XP000958400.
Kim S-Y et al: “Image Contrast Enhancement Based on the Piecewise-Linear Approximation of CDF” IEEE Transactions on Consumer Electronics, IEEE Inc. New York, US, vol. 45, No. 3, Aug. 1999, pp. 828-834, XP000927001.
Jia-Guu Leu: “Image Contrast Enhancement Based on the Intensities of Edge Pixels” CVGIP Graphical Models and Image Processing, Academic Press, Duluth, MA, US, vol. 54, No. 6, Nov. 1, 1992, pp. 497-506, XP000332318.

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