Title:
IMAGE DATA PROCESSOR, IMAGE READER AND IMAGE FORMING DEVICE
Document Type and Number:
Japanese Patent JP3958923
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide an image processor that can automatically eliminate a high background level over a wide range where a background level is fluctuated even on one line, process characters and a line drawing of a blue print clipped and pasted on white paper so as to be sharply copied, and select optimum background elimination processing corresponding to a large variety of the background of an original image.
SOLUTION: Applying weight summation to target image data IDn and a background level JODn-1 employed for preceding image data calculates a background level JODn to be applied to the target image data and also calculates background elimination data AODn=IDn-M.JODn. A 1st or 2nd ratio that is expressed by a fraction whose numerator is a maximum value HD taken by data and whose denominator includes the background level M.JODn is multiplied with the background elimination data AODn (Equation (3) or (4)) to correct the contrast. An operation section OPB can designate which of the Equation (3), (4) and either of them automatically selected. In the case of automatically selecting either of them, the Equation (3) is used when the background level JOD is high and the Equation (4) is used when the background level JOD is low.
Inventors:
Yuji Takahashi
Hiroyuki Kawamoto
Hiroyuki Kawamoto
Application Number:
JP2000269934A
Publication Date:
August 15, 2007
Filing Date:
September 06, 2000
Export Citation:
Assignee:
株式会社リコー
International Classes:
G06T1/00; H04N1/407; H04N1/00; (IPC1-7): H04N1/407; G06T1/00; H04N1/00
Domestic Patent References:
| JP5199414A | ||||
| JP5063972A | ||||
| JP7170401A |
Attorney, Agent or Firm:
Nobuoki Sugi
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