Title:
IMAGE THRESHOLD PROCESSING UNIT
Document Type and Number:
Japanese Patent JP3123324
Kind Code:
B2
Abstract:
PURPOSE: To allow the image threshold processing unit for thresholding an image obtained from an optical sensor with high precision.
CONSTITUTION: The image threshold processing unit provided with an optical sensor 1 having a light emitting device and a light receiving device and with a binary image generating section 5 slicing a picture signal obtained by the light receiving device when a medium rushes into a sensing area of the optical sensor at a predetermined slice level to obtain a binary image of the medium includes a sensor characteristic memory 3 storing offset values obtained by measuring dark currents of the light receiving device and a slice level decision section 4 that adds an offset and a predetermined dynamic range to obtain a light receiving quantity proportional to a contrast of the medium and dividing a value obtained internally dividing a quantity between a maximum light receiving quantity and a light receiving quantity equivalent to the obtained sum as a slice level for the optical sensor. Then the slice level decision section 4 decides a slice level depending on a characteristic of each optical sensor.
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Inventors:
Masanori Mukai
Application Number:
JP31388393A
Publication Date:
January 09, 2001
Filing Date:
December 15, 1993
Export Citation:
Assignee:
富士通株式会社
International Classes:
G06T1/00; H04N1/04; H04N1/407; (IPC1-7): H04N1/407; G06T1/00; H04N1/04
Domestic Patent References:
| JP6081976A | ||||
| JP4181235A | ||||
| JP4302375A |
Attorney, Agent or Firm:
Teiichi Igeta