GB1506530A - Transmitting video signals - Google Patents
Transmitting video signalsInfo
- 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
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.
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)
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)
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 |
-
1974
- 1974-11-15 DE DE2454232A patent/DE2454232C2/en not_active Expired
-
1975
- 1975-11-03 GB GB45665/75A patent/GB1506530A/en not_active Expired
Cited By (5)
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 |