JPS57208768A - Digitizing system for video signal - Google Patents

Digitizing system for video signal

Info

Publication number
JPS57208768A
JPS57208768A JP9384181A JP9384181A JPS57208768A JP S57208768 A JPS57208768 A JP S57208768A JP 9384181 A JP9384181 A JP 9384181A JP 9384181 A JP9384181 A JP 9384181A JP S57208768 A JPS57208768 A JP S57208768A
Authority
JP
Japan
Prior art keywords
signal
register
converter
gain
video signal
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.)
Granted
Application number
JP9384181A
Other languages
Japanese (ja)
Other versions
JPS6335149B2 (en
Inventor
Tetsuzo Tanimoto
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.)
Hitachi Ltd
Original Assignee
Hitachi 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 Hitachi Ltd filed Critical Hitachi Ltd
Priority to JP9384181A priority Critical patent/JPS57208768A/en
Publication of JPS57208768A publication Critical patent/JPS57208768A/en
Publication of JPS6335149B2 publication Critical patent/JPS6335149B2/ja
Granted 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

Abstract

PURPOSE:To obtain information of broad range with high accuracy, by subtracting a minimum value of a picture signal after A/D conversion from a video signal, and inputting this signal to an amplifier which uses the ratio of the difference between the maximum and minimum values of the signal to the input range of the A/D converter, as a gain set input. CONSTITUTION:A calibration start signal 11 clears a register 8, makes an output of a D/A converter 10 zero, 1 is set to a register 9 and makes the gain of a programmable gain amplifier 5 to 1. A timing circuit 12 is started with the signal 11, a transfer clock from a clock generator 2 is timed and gives an instruction of the start of conversion to an A/D converter 6 and stores all the picture elements to a computer 7. After the end of storage, a maximum value V'max and a minimum value V'min are retrieved from the data, and the V'min is set to a register 8. The ratio G of the difference between the V'max and the V'min to the input range R of the A/D converter 6 is calcurated and set to a register 9. The V'min is subtracted from a Vi to exclude background component.
JP9384181A 1981-06-19 1981-06-19 Digitizing system for video signal Granted JPS57208768A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP9384181A JPS57208768A (en) 1981-06-19 1981-06-19 Digitizing system for video signal

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP9384181A JPS57208768A (en) 1981-06-19 1981-06-19 Digitizing system for video signal

Publications (2)

Publication Number Publication Date
JPS57208768A true JPS57208768A (en) 1982-12-21
JPS6335149B2 JPS6335149B2 (en) 1988-07-13

Family

ID=14093616

Family Applications (1)

Application Number Title Priority Date Filing Date
JP9384181A Granted JPS57208768A (en) 1981-06-19 1981-06-19 Digitizing system for video signal

Country Status (1)

Country Link
JP (1) JPS57208768A (en)

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59163953A (en) * 1983-03-08 1984-09-17 Canon Inc Picture processing device
JPS59171259A (en) * 1983-03-17 1984-09-27 Nec Corp Device for correcting contrast
JPS6090466A (en) * 1983-10-24 1985-05-21 Nippon Kogaku Kk <Nikon> Photoelectric convertor
JPS60220659A (en) * 1984-04-17 1985-11-05 Fuji Photo Film Co Ltd Density adjusting method of colored picture output device
JPS6129275A (en) * 1984-07-19 1986-02-10 Matsushita Electric Ind Co Ltd Method of correcting half tone picture
JPS61107872A (en) * 1984-10-31 1986-05-26 Usac Electronics Ind Co Ltd Background level follow-up circuit
JPS61144989A (en) * 1984-12-19 1986-07-02 Sony Corp High efficient coding device of television signal
JPS61144990A (en) * 1984-12-19 1986-07-02 Sony Corp High efficient coding device of television signal
JPS61147689A (en) * 1984-12-21 1986-07-05 Sony Corp Highly efficient tv signal encoding device
JPS61147691A (en) * 1984-12-21 1986-07-05 Sony Corp Highly efficiency tv signal encoding device
JPS61147690A (en) * 1984-12-21 1986-07-05 Sony Corp Highly efficient code decoding device
JPS61214893A (en) * 1985-03-21 1986-09-24 Canon Inc Color picture processing method
JPS61224663A (en) * 1985-03-25 1986-10-06 ジヨンソン・アンド・ジヨンソン・ウルトラサウンド・インコーポレイテツド Contrast control for copy image
JPS6271390A (en) * 1985-05-10 1987-04-02 Matsushita Electric Ind Co Ltd Intermediate-level setting circuit for video
JPS62142469A (en) * 1985-12-17 1987-06-25 Matsushita Graphic Commun Syst Inc Method of normalizing density region in original read processing
JPH01175469A (en) * 1987-12-29 1989-07-11 Kyocera Corp Charge accumulation controller for image sensor
US5196948A (en) * 1989-07-07 1993-03-23 Konica Corporation Image density reading apparatus capable of selecting a desired amplification level for the density

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS53145525A (en) * 1977-05-25 1978-12-18 Oki Electric Ind Co Ltd Optical character reader
JPS5416918A (en) * 1977-07-07 1979-02-07 Mitsubishi Electric Corp Background density compensating circuit

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS53145525A (en) * 1977-05-25 1978-12-18 Oki Electric Ind Co Ltd Optical character reader
JPS5416918A (en) * 1977-07-07 1979-02-07 Mitsubishi Electric Corp Background density compensating circuit

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59163953A (en) * 1983-03-08 1984-09-17 Canon Inc Picture processing device
JPS59171259A (en) * 1983-03-17 1984-09-27 Nec Corp Device for correcting contrast
JPS6090466A (en) * 1983-10-24 1985-05-21 Nippon Kogaku Kk <Nikon> Photoelectric convertor
JPS60220659A (en) * 1984-04-17 1985-11-05 Fuji Photo Film Co Ltd Density adjusting method of colored picture output device
JPS6129275A (en) * 1984-07-19 1986-02-10 Matsushita Electric Ind Co Ltd Method of correcting half tone picture
JPS61107872A (en) * 1984-10-31 1986-05-26 Usac Electronics Ind Co Ltd Background level follow-up circuit
JPS61144989A (en) * 1984-12-19 1986-07-02 Sony Corp High efficient coding device of television signal
JPS61144990A (en) * 1984-12-19 1986-07-02 Sony Corp High efficient coding device of television signal
JPS61147689A (en) * 1984-12-21 1986-07-05 Sony Corp Highly efficient tv signal encoding device
JPS61147691A (en) * 1984-12-21 1986-07-05 Sony Corp Highly efficiency tv signal encoding device
JPS61147690A (en) * 1984-12-21 1986-07-05 Sony Corp Highly efficient code decoding device
JPS61214893A (en) * 1985-03-21 1986-09-24 Canon Inc Color picture processing method
JPS61224663A (en) * 1985-03-25 1986-10-06 ジヨンソン・アンド・ジヨンソン・ウルトラサウンド・インコーポレイテツド Contrast control for copy image
JPS6271390A (en) * 1985-05-10 1987-04-02 Matsushita Electric Ind Co Ltd Intermediate-level setting circuit for video
JPS62142469A (en) * 1985-12-17 1987-06-25 Matsushita Graphic Commun Syst Inc Method of normalizing density region in original read processing
JPH01175469A (en) * 1987-12-29 1989-07-11 Kyocera Corp Charge accumulation controller for image sensor
US5196948A (en) * 1989-07-07 1993-03-23 Konica Corporation Image density reading apparatus capable of selecting a desired amplification level for the density

Also Published As

Publication number Publication date
JPS6335149B2 (en) 1988-07-13

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