Title:
METHOD FOR BINARIZING LIGHT AND SHADE IMAGE AND RECORDING MEDIUM WHERE BINARIZING PROGRAM IS RECORDED
Document Type and Number:
Japanese Patent JP3636936
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To optimize two parameters of a gradient and a segment corresponding to image properties by determining the local threshold of a partial area by using the decision result of a block and binarizing it by using an interpolating process.
SOLUTION: In a decision process 101 by a background separate straight line, the background separate straight line is used to decide whether each partial area divided is an object block or uniform block on the basis of the density value of the partial area by using the background separate straight line. In a local threshold determining process 102 for the partial area, the local threshold of the partial area is determined on the basis of the decision result by using the density histogram of the partial area or the mean value and standard deviation of the density value, and the local threshold of an adjacent object block. In a pixel interpolating process and binarization 103, the local threshold of each partial area is given to the center of the partial area, thresholds are calculated by the pixels of a light and shade image by using an interpolating process, and then the density value of the image is compared with the threshold of the image to perform binarization.
Inventors:
Norifumi Katabuchi
Shuichi Ohara
Koichi Tanaka
Okuhira Masashi
Shuichi Ohara
Koichi Tanaka
Okuhira Masashi
Application Number:
JP16945399A
Publication Date:
April 06, 2005
Filing Date:
June 16, 1999
Export Citation:
Assignee:
Nippon Telegraph and Telephone Corporation
International Classes:
G06T1/00; G06T5/00; H04N1/403; H04N1/387; (IPC1-7): G06T5/00; G06T1/00; H04N1/387; H04N1/403
Domestic Patent References:
| JP57029189A | ||||
| JP10285399A | ||||
| JP61194580A |
Attorney, Agent or Firm:
Yoshiyoshi Ogasawara
Yutaka Morita
Yutaka Morita