JPS56111373A - Picture scanning method - Google Patents

Picture scanning method

Info

Publication number
JPS56111373A
JPS56111373A JP1435780A JP1435780A JPS56111373A JP S56111373 A JPS56111373 A JP S56111373A JP 1435780 A JP1435780 A JP 1435780A JP 1435780 A JP1435780 A JP 1435780A JP S56111373 A JPS56111373 A JP S56111373A
Authority
JP
Japan
Prior art keywords
original
variable density
gradation
dither matrix
scanning element
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
JP1435780A
Other languages
Japanese (ja)
Inventor
Tadashi Yoshida
Yukio Sato
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.)
Canon Inc
Original Assignee
Canon Inc
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 Canon Inc filed Critical Canon Inc
Priority to JP1435780A priority Critical patent/JPS56111373A/en
Publication of JPS56111373A publication Critical patent/JPS56111373A/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
    • H04N1/407—Control or modification of tonal gradation or of extreme levels, e.g. background level

Landscapes

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

Abstract

PURPOSE:To prevent deterioration of the gradation representability, which is caused by variable density of an original, by detecting a variable density level of the original by other detection element at the same time when the original is scanned by the solid scanning element, and setting a threshold level of dither matrix. CONSTITUTION:An original 1 is scanned by the solid scanning element 4, and a gradation signal is output by the dither matrix. At the same time when said scanning is executed, variable density of the original is detected by the photodetector 5 which has been installed in front of the solid scanning element 4 in the subscanning direction D2. This detection output S is made a reference level of the dither. In this way, a threshold level of the dither matrix is set in accordance with variable density of the original, and the gradation representability is not deteriorated even when variable density of an original has been changed.
JP1435780A 1980-02-08 1980-02-08 Picture scanning method Pending JPS56111373A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP1435780A JPS56111373A (en) 1980-02-08 1980-02-08 Picture scanning method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP1435780A JPS56111373A (en) 1980-02-08 1980-02-08 Picture scanning method

Publications (1)

Publication Number Publication Date
JPS56111373A true JPS56111373A (en) 1981-09-03

Family

ID=11858812

Family Applications (1)

Application Number Title Priority Date Filing Date
JP1435780A Pending JPS56111373A (en) 1980-02-08 1980-02-08 Picture scanning method

Country Status (1)

Country Link
JP (1) JPS56111373A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4605105A (en) * 1982-09-03 1986-08-12 Akebono Brake Industry Co., Ltd. Brake system

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4605105A (en) * 1982-09-03 1986-08-12 Akebono Brake Industry Co., Ltd. Brake system

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