JPS57138268A - Image signal processing system - Google Patents

Image signal processing system

Info

Publication number
JPS57138268A
JPS57138268A JP56022924A JP2292481A JPS57138268A JP S57138268 A JPS57138268 A JP S57138268A JP 56022924 A JP56022924 A JP 56022924A JP 2292481 A JP2292481 A JP 2292481A JP S57138268 A JPS57138268 A JP S57138268A
Authority
JP
Japan
Prior art keywords
slice levels
original
image signal
analog
rom3
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
JP56022924A
Other languages
Japanese (ja)
Inventor
Eiji Kamijo
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.)
Ricoh Co Ltd
Original Assignee
Ricoh 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 Ricoh Co Ltd filed Critical Ricoh Co Ltd
Priority to JP56022924A priority Critical patent/JPS57138268A/en
Publication of JPS57138268A publication Critical patent/JPS57138268A/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
    • H04N1/405—Halftoning, i.e. converting the picture signal of a continuous-tone original into a corresponding signal showing only two levels

Landscapes

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

Abstract

PURPOSE:To reproduce a recorded image which has half tones with fidelity to an original by setting the intervals of slice levels corresponding to the reflectivity of the original. CONSTITUTION:The intervals of slice levels SL1'-SL4' are increased as the reflectivity of an original is increased and stored in an ROM3. An analog signal which corresponds to each picture element is outputted, synchronizing with a main scanning clock I, from a scanner, and this main scanning clock and subscanning clock J are counted by counters 1 and 2 respectively. On the basis of their count values K and L, the address of the ROM3 is specified to fetch the slice levels SL1'-SL4' which correspond to respective picture elements. For this purpose, they are converted by a D-A converter 4 into analog values N, so the analog image signal SA outputted from the scanner is converted into a binary numeral by a comparator 5 by using the slice levels SL1'-SL2', so that half tones are reproduced with fidelity on a reception side.
JP56022924A 1981-02-20 1981-02-20 Image signal processing system Pending JPS57138268A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP56022924A JPS57138268A (en) 1981-02-20 1981-02-20 Image signal processing system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP56022924A JPS57138268A (en) 1981-02-20 1981-02-20 Image signal processing system

Publications (1)

Publication Number Publication Date
JPS57138268A true JPS57138268A (en) 1982-08-26

Family

ID=12096181

Family Applications (1)

Application Number Title Priority Date Filing Date
JP56022924A Pending JPS57138268A (en) 1981-02-20 1981-02-20 Image signal processing system

Country Status (1)

Country Link
JP (1) JPS57138268A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS57160267A (en) * 1981-03-30 1982-10-02 Canon Inc Picture processor
JPS5944174A (en) * 1982-09-06 1984-03-12 Nippon Telegr & Teleph Corp <Ntt> Method for reproducing half tone
JPS60214678A (en) * 1984-04-10 1985-10-26 Fujitsu Ltd Transmitted picture reading controlling circuit

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5597770A (en) * 1979-01-19 1980-07-25 Matsushita Graphic Commun Syst Inc Half-tone reproduction system for facsimile or the like

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5597770A (en) * 1979-01-19 1980-07-25 Matsushita Graphic Commun Syst Inc Half-tone reproduction system for facsimile or the like

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS57160267A (en) * 1981-03-30 1982-10-02 Canon Inc Picture processor
JPS5944174A (en) * 1982-09-06 1984-03-12 Nippon Telegr & Teleph Corp <Ntt> Method for reproducing half tone
JPS60214678A (en) * 1984-04-10 1985-10-26 Fujitsu Ltd Transmitted picture reading controlling circuit

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