Binarization using a local average, and using error diffusion

Details Binarization using a local average, and using error diffusion Binarization using a local average, and using error diffusion

1995-06-07

2000-10-17

Mehta, Bravesh

Image analysis

Image enhancement or restoration

Variable threshold, gain, or slice level

358456, 358466, G06K 938

Patent

active

061343552

ABSTRACT:
There is provided an image processing apparatus such as facsimile apparatus or digital copying machine for digitizing image data into two values or multi-values. The apparatus comprises: an input device to input data of a target pixel to be digitized; a calculating circuit to obtain an average density value of a predetermined region; a digitizing circuit such as a binarizing circuit for digitizing or binarizing the target pixel data on the basis of the average density value obtained by the calculating circuit; and a correction circuit to correct a difference which occurs upon digitization by the digitizing circuit. The calculating circuit calculates the average density value m.sub.1 of the pre-determined region when the target pixel data was binarized to 1 and the average density value m.sub.2 of the predetermined region when the target pixel data was binarized to 0 by using a predetermined weighting mask. The digitizing circuit binarizes the target pixel data by using (m.sub.1 +m.sub.2)/2 as a threshold value. When the difference between the target pixel data and the average density value is within a predetermined value, the difference is corrected, so that an image of excellent gradation can be reproduced. When it is equal to or larger than the predetermined value, the difference is not corrected, so that the resolution of a character portion such as an edge portion can be improved.

REFERENCES:
patent: 4371179 (1983-02-01), Kato et al.
patent: 4667249 (1987-05-01), Owada et al.
patent: 4841374 (1989-06-01), Kotani et al.
patent: 4853792 (1989-08-01), Katsuta et al.
patent: 4975786 (1990-12-01), Katayama et al.
patent: 5055942 (1991-10-01), Levien

Affiliated with

Also associated with

Rating

Binarization using a local average, and using error diffusion does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Binarization using a local average, and using error diffusion, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Binarization using a local average, and using error diffusion will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-477201