JPS57116479A - Image processing circuit - Google Patents

Image processing circuit

Info

Publication number
JPS57116479A
JPS57116479A JP56002836A JP283681A JPS57116479A JP S57116479 A JPS57116479 A JP S57116479A JP 56002836 A JP56002836 A JP 56002836A JP 283681 A JP283681 A JP 283681A JP S57116479 A JPS57116479 A JP S57116479A
Authority
JP
Japan
Prior art keywords
image
frequency component
counter
threshold value
circuit
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
JP56002836A
Other languages
Japanese (ja)
Inventor
Koichi Ejiri
Morizumi Kurose
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 JP56002836A priority Critical patent/JPS57116479A/en
Publication of JPS57116479A publication Critical patent/JPS57116479A/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
    • H04N1/409—Edge or detail enhancement; Noise or error suppression

Landscapes

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

Abstract

PURPOSE:To obtain an image of high quality by preventing the generation of the moire of a mesh-point image and a dithered image by extracting the high-frequency component of an image signal and by inputting only a clock for picture- element transfer to a counter for addressing when the high-frequency component exceeds some threshold value. CONSTITUTION:An image density signal S(i,j) from an image sensor 1 is inputted to a comparator 3 and a filter 10, which extracts a high-frequency component from the image signal. A discriminating circuit 11 compares the value of this extracted high-frequency component with some threshold value and, when the high-frequency component exceeds some threshold value, puts a random access generating circuit 12 in operation to generate random pulses. The random pulses are delayed by a delay circuit 13 and ORed with clock pulses by an OR circuit 14, whose outputs are inputted to a counter 4. Then, the counter 4 reads image information from a dither matrix 5 to a DA converter 6, and the comparator 3 outputs image signals (oi) and (j) to prevent the generation of a moire.
JP56002836A 1981-01-12 1981-01-12 Image processing circuit Pending JPS57116479A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP56002836A JPS57116479A (en) 1981-01-12 1981-01-12 Image processing circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP56002836A JPS57116479A (en) 1981-01-12 1981-01-12 Image processing circuit

Publications (1)

Publication Number Publication Date
JPS57116479A true JPS57116479A (en) 1982-07-20

Family

ID=11540494

Family Applications (1)

Application Number Title Priority Date Filing Date
JP56002836A Pending JPS57116479A (en) 1981-01-12 1981-01-12 Image processing circuit

Country Status (1)

Country Link
JP (1) JPS57116479A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06195471A (en) * 1985-06-19 1994-07-15 Pixar Method for point sampling of image data, method for formation of video image frame and apparatus for display of image

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06195471A (en) * 1985-06-19 1994-07-15 Pixar Method for point sampling of image data, method for formation of video image frame and apparatus for display of image

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