JPS5773572A - Digital automatic shading corrector - Google Patents

Digital automatic shading corrector

Info

Publication number
JPS5773572A
JPS5773572A JP55149799A JP14979980A JPS5773572A JP S5773572 A JPS5773572 A JP S5773572A JP 55149799 A JP55149799 A JP 55149799A JP 14979980 A JP14979980 A JP 14979980A JP S5773572 A JPS5773572 A JP S5773572A
Authority
JP
Japan
Prior art keywords
video signal
multiplier
output
amplitude
rom10
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP55149799A
Other languages
Japanese (ja)
Inventor
Yukihiro Matsuda
Koji Ishikawa
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NEC Corp
Original Assignee
NEC Corp
Nippon Electric Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by NEC Corp, Nippon Electric Co Ltd filed Critical NEC Corp
Priority to JP55149799A priority Critical patent/JPS5773572A/en
Publication of JPS5773572A publication Critical patent/JPS5773572A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
    • H04N1/40—Picture signal circuits
    • H04N1/401—Compensating positionally unequal response of the pick-up or reproducing head

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Picture Signal Circuits (AREA)
  • Facsimile Image Signal Circuits (AREA)

Abstract

PURPOSE:To enable correction with good accuracy, by making the correction of shading automatically and digitally through the use of RAM, ROM and multiplier. CONSTITUTION:A digital video signal in which the maximum amplitude is controlled to a constant value through AGC is inputted from a terminal 5. A switch 7 is selected to an RAM8 with a control circuit 6, white plate is read at that time and the video signal for one scanning's share is stored in the RAM8. The output from an ROM10 is a reciprocal to the amplitude of the video signal when the white plate is read. When a video reader reads an original, a control circuit 6 switches a switch 7 to a multiplier 9 side. The video signal reading the original and the output of the ROM10 are multiplied at the multiplier 9 and a video signal with variance in amplitude due to shading can be obtained from an output terminal 11.
JP55149799A 1980-10-24 1980-10-24 Digital automatic shading corrector Pending JPS5773572A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP55149799A JPS5773572A (en) 1980-10-24 1980-10-24 Digital automatic shading corrector

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP55149799A JPS5773572A (en) 1980-10-24 1980-10-24 Digital automatic shading corrector

Publications (1)

Publication Number Publication Date
JPS5773572A true JPS5773572A (en) 1982-05-08

Family

ID=15482962

Family Applications (1)

Application Number Title Priority Date Filing Date
JP55149799A Pending JPS5773572A (en) 1980-10-24 1980-10-24 Digital automatic shading corrector

Country Status (1)

Country Link
JP (1) JPS5773572A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58223964A (en) * 1982-06-22 1983-12-26 Konishiroku Photo Ind Co Ltd Shading compensating circuit
JPS6129275A (en) * 1984-07-19 1986-02-10 Matsushita Electric Ind Co Ltd Method of correcting half tone picture
US5214520A (en) * 1989-11-27 1993-05-25 Ricoh Comany, Ltd. Image data reading apparatus

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS557957A (en) * 1978-07-03 1980-01-21 Nippon Denso Co Ltd Fuel injection valve for engine

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS557957A (en) * 1978-07-03 1980-01-21 Nippon Denso Co Ltd Fuel injection valve for engine

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58223964A (en) * 1982-06-22 1983-12-26 Konishiroku Photo Ind Co Ltd Shading compensating circuit
JPH0354510B2 (en) * 1982-06-22 1991-08-20
JPS6129275A (en) * 1984-07-19 1986-02-10 Matsushita Electric Ind Co Ltd Method of correcting half tone picture
US5214520A (en) * 1989-11-27 1993-05-25 Ricoh Comany, Ltd. Image data reading apparatus

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