GB1506530A - Transmitting video signals - Google Patents

Transmitting video signals

Info

Publication number
GB1506530A
GB1506530A GB45665/75A GB4566575A GB1506530A GB 1506530 A GB1506530 A GB 1506530A GB 45665/75 A GB45665/75 A GB 45665/75A GB 4566575 A GB4566575 A GB 4566575A GB 1506530 A GB1506530 A GB 1506530A
Authority
GB
United Kingdom
Prior art keywords
level
threshold level
characteristic
video signal
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.)
Expired
Application number
GB45665/75A
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.)
Robert Bosch GmbH
Original Assignee
Robert Bosch GmbH
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 Robert Bosch GmbH filed Critical Robert Bosch GmbH
Publication of GB1506530A publication Critical patent/GB1506530A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B14/00—Transmission systems not characterised by the medium used for transmission
    • H04B14/02—Transmission systems not characterised by the medium used for transmission characterised by the use of pulse modulation
    • H04B14/04—Transmission systems not characterised by the medium used for transmission characterised by the use of pulse modulation using pulse code modulation
    • H04B14/046—Systems or methods for reducing noise or bandwidth
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
    • H04N19/102—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the element, parameter or selection affected or controlled by the adaptive coding
    • H04N19/124—Quantisation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/50—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using predictive coding

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Multimedia (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Compression, Expansion, Code Conversion, And Decoders (AREA)
  • Compression Or Coding Systems Of Tv Signals (AREA)
  • Analogue/Digital Conversion (AREA)

Abstract

1506530 Video signal encoding; digital transmission ROBERT BOSCH GmbH 3 Nov 1975 [15 Nov 1974] 45665/75 Headings H4F and H4P Delta-encoded video signals are fed to a quantizer which is changed for a predetermined time from a first quantization characteristic to a second when the video signal exceeds a preset threshold level. The signal exceeds this level when it represents a substantial change in contrast, e.g. the edge of an object in the scanned field. In order to reduce the noise that would otherwise appear in the picture as a consequence of jitter from one characteristic to the other when noise accompanying the video signal causes the signal to jitter about the threshold level, the characteristics have a common switching level, equal to the threshold level, at which the quantizer output changes from a first value to a second value, the first values and the second values respectively being the same for both characteristics. The output is therefore the same for a signal level closely above, or alternatively closely below, the threshold level irrespective of which characteristic is operative.
GB45665/75A 1974-11-15 1975-11-03 Transmitting video signals Expired GB1506530A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE2454232A DE2454232C2 (en) 1974-11-15 1974-11-15 System for coding video signals using the so-called difference signal method

Publications (1)

Publication Number Publication Date
GB1506530A true GB1506530A (en) 1978-04-05

Family

ID=5930927

Family Applications (1)

Application Number Title Priority Date Filing Date
GB45665/75A Expired GB1506530A (en) 1974-11-15 1975-11-03 Transmitting video signals

Country Status (2)

Country Link
DE (1) DE2454232C2 (en)
GB (1) GB1506530A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1435694A2 (en) * 2002-12-24 2004-07-07 Fujitsu Limited Spread spectrum clock generation circuit jitter generation circuit and semiconductor device

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2740945C3 (en) * 1977-09-10 1982-02-11 Licentia Patent-Verwaltungs-Gmbh, 6000 Frankfurt Method for the transmission of image signals with the aid of differential pulse code modulation (DPCM) and a controlled quantizer
GB8703354D0 (en) * 1987-02-13 1987-03-18 British Telecomm Coder

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1435694A2 (en) * 2002-12-24 2004-07-07 Fujitsu Limited Spread spectrum clock generation circuit jitter generation circuit and semiconductor device
EP1435694A3 (en) * 2002-12-24 2004-09-29 Fujitsu Limited Spread spectrum clock generation circuit jitter generation circuit and semiconductor device
US6975148B2 (en) 2002-12-24 2005-12-13 Fujitsu Limited Spread spectrum clock generation circuit, jitter generation circuit and semiconductor device
EP1672800A3 (en) * 2002-12-24 2006-07-05 Fujitsu Limited Jitter generation circuit
US7095260B2 (en) 2002-12-24 2006-08-22 Fujitsu Limited Spread spectrum clock generation circuit, jitter generation circuit and semiconductor device

Also Published As

Publication number Publication date
DE2454232C2 (en) 1982-11-18
DE2454232A1 (en) 1976-05-20

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Legal Events

Date Code Title Description
PS Patent sealed
746 Register noted 'licences of right' (sect. 46/1977)
PCNP Patent ceased through non-payment of renewal fee