JPS55140372A - Luminance signal processing unit - Google Patents

Luminance signal processing unit

Info

Publication number
JPS55140372A
JPS55140372A JP4844679A JP4844679A JPS55140372A JP S55140372 A JPS55140372 A JP S55140372A JP 4844679 A JP4844679 A JP 4844679A JP 4844679 A JP4844679 A JP 4844679A JP S55140372 A JPS55140372 A JP S55140372A
Authority
JP
Japan
Prior art keywords
signal
amplifier
luminance
outputs
level
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
JP4844679A
Other languages
Japanese (ja)
Inventor
Tetsuo Tomimoto
Yoshitomi Nagaoka
Yoshiteru Matsuda
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.)
Panasonic Holdings Corp
Original Assignee
Matsushita Electric Industrial 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 Matsushita Electric Industrial Co Ltd filed Critical Matsushita Electric Industrial Co Ltd
Priority to JP4844679A priority Critical patent/JPS55140372A/en
Publication of JPS55140372A publication Critical patent/JPS55140372A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/14—Picture signal circuitry for video frequency region

Landscapes

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

Abstract

PURPOSE:To improve the gradation characteristic of reproduced pictures considerably by detecting the distribution state of the luminance signal level to control linearity of the luminance signal transmission system. CONSTITUTION:This unit is constituted by nonlinear amplifier 1 and luminance distribution detection unit 2. In unit 2, components of a comparatively high luminance level of the input luminance signal, components of a low level, and the average level obtained by smoothing them are detected by white picture detector 7, black picture detector 9 and average luminance detector 8 respectively, and the signal corresponding to detection results is supplied to control signal generator 3. Generator 3 consisting of three differential amplifiers 10-12 outputs the difference signal between detectors 7 and 8 from amplifier 10 and outputs the difference signal between detectors 8 and 9 from amplifier 11 and supplies the difference signal between amplifiers 10 and 11 from amplifier 12 to variable mixer 6 to control nonlinearity of amplifier 1. Then, amplifier 1 outputs signal A of gamma correcting circuit 4 for a comparatively dark input picture and the signal of gamma correcting circuit 5 for a bright picture from mixer 6. Thus, the gradation characteristic of reproduced pictures is improved considerably.
JP4844679A 1979-04-18 1979-04-18 Luminance signal processing unit Pending JPS55140372A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP4844679A JPS55140372A (en) 1979-04-18 1979-04-18 Luminance signal processing unit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP4844679A JPS55140372A (en) 1979-04-18 1979-04-18 Luminance signal processing unit

Publications (1)

Publication Number Publication Date
JPS55140372A true JPS55140372A (en) 1980-11-01

Family

ID=12803566

Family Applications (1)

Application Number Title Priority Date Filing Date
JP4844679A Pending JPS55140372A (en) 1979-04-18 1979-04-18 Luminance signal processing unit

Country Status (1)

Country Link
JP (1) JPS55140372A (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59189378U (en) * 1983-06-01 1984-12-15 日立電子株式会社 tv jiyoung camera
JPS6413858U (en) * 1987-06-08 1989-01-24
JPH02206282A (en) * 1989-02-06 1990-08-16 Canon Inc Gamma correcting device
JPH0440170A (en) * 1990-06-05 1992-02-10 Matsushita Electric Ind Co Ltd Black level corrector for video signal
US5296941A (en) * 1991-12-20 1994-03-22 Matsushita Electric Industrial Co, Ltd. Gradation compensation apparatus of video image
JP2015233323A (en) * 2011-03-15 2015-12-24 ドルビー ラボラトリーズ ライセンシング コーポレイション Method and apparatus for image data transformation

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59189378U (en) * 1983-06-01 1984-12-15 日立電子株式会社 tv jiyoung camera
JPS6413858U (en) * 1987-06-08 1989-01-24
JPH02206282A (en) * 1989-02-06 1990-08-16 Canon Inc Gamma correcting device
JPH0440170A (en) * 1990-06-05 1992-02-10 Matsushita Electric Ind Co Ltd Black level corrector for video signal
US5296941A (en) * 1991-12-20 1994-03-22 Matsushita Electric Industrial Co, Ltd. Gradation compensation apparatus of video image
JP2015233323A (en) * 2011-03-15 2015-12-24 ドルビー ラボラトリーズ ライセンシング コーポレイション Method and apparatus for image data transformation
CN105516541A (en) * 2011-03-15 2016-04-20 杜比实验室特许公司 Method and apparatus for image data transformation
US9916809B2 (en) 2011-03-15 2018-03-13 Dolby Laboratories Licensing Corporation Method and apparatus for image data transformation
CN105516541B (en) * 2011-03-15 2018-10-26 杜比实验室特许公司 Method and apparatus for image data transformation
US10255879B2 (en) 2011-03-15 2019-04-09 Dolby Laboratories Licensing Corporation Method and apparatus for image data transformation

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