DE3809303A1 - Circuit arrangement for setting colour saturation - Google Patents
Circuit arrangement for setting colour saturationInfo
- Publication number
- DE3809303A1 DE3809303A1 DE3809303A DE3809303A DE3809303A1 DE 3809303 A1 DE3809303 A1 DE 3809303A1 DE 3809303 A DE3809303 A DE 3809303A DE 3809303 A DE3809303 A DE 3809303A DE 3809303 A1 DE3809303 A1 DE 3809303A1
- Authority
- DE
- Germany
- Prior art keywords
- saturation
- signals
- circuit arrangement
- amplifier
- control stage
- 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.)
- Withdrawn
Links
- 230000001419 dependent effect Effects 0.000 claims abstract 2
- 241000023320 Luma <angiosperm> Species 0.000 claims description 6
- OSWPMRLSEDHDFF-UHFFFAOYSA-N methyl salicylate Chemical group COC(=O)C1=CC=CC=C1O OSWPMRLSEDHDFF-UHFFFAOYSA-N 0.000 claims description 6
- 230000003321 amplification Effects 0.000 claims description 2
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 2
- 230000007423 decrease Effects 0.000 description 2
- 230000035945 sensitivity Effects 0.000 description 1
- 238000009331 sowing Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N9/00—Details of colour television systems
- H04N9/64—Circuits for processing colour signals
- H04N9/68—Circuits for processing colour signals for controlling the amplitude of colour signals, e.g. automatic chroma control circuits
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N9/00—Details of colour television systems
- H04N9/77—Circuits for processing the brightness signal and the chrominance signal relative to each other, e.g. adjusting the phase of the brightness signal relative to the colour signal, correcting differential gain or differential phase
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Processing Of Color Television Signals (AREA)
Abstract
Description
Die in den Ansprüchen gekennzeichnete Erfindung beschäf tigt sich mit dem Problem, daß das in Farbfernsehgeräten auftretende Farbrauschen, das z.B. von verrauschten Video signalquellen stammt, sich dann besonders störend auf dem Bildschirm bemerkbar macht, wenn dunkle Bildinhalte wiedergegeben werden.The invention characterized in the claims deals with the problem that this is in color televisions occurring color noise, e.g. of noisy video signal sources, is particularly annoying notices the screen when dark image content are reproduced.
Die Aufgabe der Erfindung besteht darin, eine Schaltungs anordnung anzugeben, mit der der betrachterseitige sub jektive Eindruck des Farbrauschens bei dunklen Bildinhal ten reduziert werden kann. Zur Lösung dieser Aufgabe liegt der Erfindung der Gedanke zugrunde, die Farbsät tigung bei dunklen Signalen gegenüber der bei hellen Signalen zu reduzieren, da die Farbempfindlichkeit des menschlichen Auges bei sinkender Helligkeit abnimmt.The object of the invention is a circuit to specify the arrangement with which the viewer's sub jective impression of color noise in dark picture content ten can be reduced. To solve this task the invention is based on the idea of color sowing dark signals compared to light ones Reduce signals because of the color sensitivity of the human eye decreases as the brightness decreases.
Die Erfindung wird nun anhand der Figur der Zeichnung näher erläutert, die ein stark schematisiertes Blockschalt bild eines Ausführungsbeispiels zeigt.The invention is now based on the figure of the drawing which explains a highly schematic block circuit Picture of an embodiment shows.
Das Lumasignal y und die Chromasignale r, b werden bei der Erfindung als im Farbfernsehempfänger aus dem von der Antenne empfangenen Signal bereits separiert voraus gesetzt, was auf irgend eine der üblichen Arten - analog oder digital - erfolgen kann. Das Lumasignal y ist der Sättigungssteuerstufe ss zugeführt, bei der die Amplitude von deren Ausgangssignal nach einer vorgebbaren Funktion von der Amplitude des Lumasignal y abhängt. Diese Abhängig keit kann z.B. eine rein lineare sein; der Fachmann kann jedoch auch geeignet erscheinende andere Abhängigkeiten im Unter- oder Überproportionalbereich wählen. The luma signal y and the chroma signals r , b are already assumed in the invention as being separated in the color television receiver from the signal received by the antenna, which can be done in any of the usual ways - analog or digital. The luma signal y is fed to the saturation control stage ss , in which the amplitude of its output signal depends on the amplitude of the luma signal y according to a predefinable function. This dependency can be, for example, a purely linear one; however, the person skilled in the art can also choose other dependencies in the under- or over-proportional range that appear suitable.
Das Ausgangssignal der Sättigungssteuerstufe ss ist im Ausführungsbeispiel der Figur dem Verstärker v zugeführt, dessen Verstärkungsfaktor dadurch gesteuert wird.The output signal of the saturation control stage ss is fed to the amplifier v in the exemplary embodiment of the figure, the gain factor of which is controlled thereby.
Im Ausführungsbeispiel der Figur sind die Farbdifferenz signale r, b dem Signaleingang des Verstärkers v über den Multiplexer mx zugeführt, und die verstärkungsge steuerten Farbdifferenzsignale r′, b′ sind aus dem Aus gangssignal des Verstärkers v mittels des Demultiplexers dx gebildet. Falls es zu aufwendig sein sollte, den Multi plexer mx und den Demultiplexer dx vorzusehen, ist es auch möglich, für jedes Farbdifferenzsignal einen eignen Verstärker v vorzusehen, der dann jeweils vom Ausgangs signal der Sättigungssteuerstufe ss in seinem Verstär kungsgrad gesteuert wird.In the embodiment of the figure, the color difference signals r , b are fed to the signal input of the amplifier v via the multiplexer mx , and the amplification-controlled color difference signals r ', b ' are formed from the output signal of the amplifier v by means of the demultiplexer dx . If it should be too expensive to provide the multiplexer mx and the demultiplexer dx , it is also possible to provide a separate amplifier v for each color difference signal, which is then controlled in each case by the output signal of the saturation control stage ss in its gain.
In der Figur ist ferner gestrichelt eine Weiterbildung der Erfindung gezeigt, es kann nämlich zwischen dem Aus gang der Sättigungssteuerstufe ss und dem Steuereingang des Verstärkers v die vom Rauschen der Chromasignale r, b nach einer vorgebbaren Funktion im Sinne der Rausch verminderung gesteuerte Stufe s eingefügt werden, deren Steuersignal mittels des Rauschdetektors rd aus mindestens einem Farbdifferenzsignal gebildet wird.In the figure, a further development of the invention is shown in dashed lines, namely it can be inserted between the output of the saturation control stage ss and the control input of the amplifier v, the level s controlled by the noise of the chroma signals r , b according to a predefinable function in the sense of noise reduction whose control signal is formed by means of the noise detector rd from at least one color difference signal.
Die Erfindung eignet sich sowohl für analoge Chromasignale und ein analoges Luminanzsignal als auch für entsprechend digitalisierte Signale, wie sie in den sogenannten digi talen Fernsehempfängern verarbeitet werden. Für den Fall digitaler Signale ist es besonders vorteilhaft, den Ver stärker v als Multiplizierer auszubilden und als Sätti gungssteuerstufe ss eine ROM-Tabelle, also einen Festwert speicher, in dem die beabsichtigte Funktion abgelegt ist, einzusetzen.The invention is suitable both for analog chroma signals and an analog luminance signal and for correspondingly digitized signals, such as are processed in the so-called digital television receivers. In the case of digital signals, it is particularly advantageous to design the amplifier v as a multiplier and to use a ROM table, ie a fixed value memory, in which the intended function is stored, as the saturation control stage ss .
Claims (4)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE3809303A DE3809303A1 (en) | 1988-03-19 | 1988-03-19 | Circuit arrangement for setting colour saturation |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE3809303A DE3809303A1 (en) | 1988-03-19 | 1988-03-19 | Circuit arrangement for setting colour saturation |
Publications (1)
Publication Number | Publication Date |
---|---|
DE3809303A1 true DE3809303A1 (en) | 1989-10-05 |
Family
ID=6350193
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
DE3809303A Withdrawn DE3809303A1 (en) | 1988-03-19 | 1988-03-19 | Circuit arrangement for setting colour saturation |
Country Status (1)
Country | Link |
---|---|
DE (1) | DE3809303A1 (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0386983A2 (en) * | 1989-03-07 | 1990-09-12 | Sony Corporation | Television image display apparatus |
EP0467602A2 (en) * | 1990-07-17 | 1992-01-22 | Matsushita Electric Industrial Co., Ltd. | Contrast corrector for video signal |
EP0551189A2 (en) * | 1992-01-09 | 1993-07-14 | Matsushita Electric Industrial Co., Ltd. | Video signal correction system |
WO1998020683A1 (en) * | 1996-11-06 | 1998-05-14 | Sgs-Thomson Microelectronics Asia Pacific (Pte) Ltd. | A method and apparatus for correcting colour difference signals |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3246055C2 (en) * | 1981-12-14 | 1986-07-17 | Rca Corp., New York, N.Y. | Circuit arrangement for automatic increase and color control for a video signal |
-
1988
- 1988-03-19 DE DE3809303A patent/DE3809303A1/en not_active Withdrawn
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3246055C2 (en) * | 1981-12-14 | 1986-07-17 | Rca Corp., New York, N.Y. | Circuit arrangement for automatic increase and color control for a video signal |
Cited By (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0386983A2 (en) * | 1989-03-07 | 1990-09-12 | Sony Corporation | Television image display apparatus |
EP0386983A3 (en) * | 1989-03-07 | 1991-10-09 | Sony Corporation | Television image display apparatus |
EP0467602A2 (en) * | 1990-07-17 | 1992-01-22 | Matsushita Electric Industrial Co., Ltd. | Contrast corrector for video signal |
EP0467602A3 (en) * | 1990-07-17 | 1993-04-28 | Matsushita Electric Industrial Co., Ltd | Contrast corrector for video signal |
US5255080A (en) * | 1990-07-17 | 1993-10-19 | Matsushita Electric Industrial Co., Ltd. | Contrast corrector for video signal |
EP0551189A2 (en) * | 1992-01-09 | 1993-07-14 | Matsushita Electric Industrial Co., Ltd. | Video signal correction system |
EP0551189A3 (en) * | 1992-01-09 | 1994-02-02 | Matsushita Electric Ind Co Ltd | |
US5351141A (en) * | 1992-01-09 | 1994-09-27 | Matsushita Electric Industrial Co., Ltd. | Video signal correction system |
WO1998020683A1 (en) * | 1996-11-06 | 1998-05-14 | Sgs-Thomson Microelectronics Asia Pacific (Pte) Ltd. | A method and apparatus for correcting colour difference signals |
US6137540A (en) * | 1996-11-06 | 2000-10-24 | Stmicroelectronics Asia Pacific Pte Limited | Method and apparatus for correcting color difference signals |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
DE69423541T2 (en) | Image contrast control through gamma control | |
DE4492446B4 (en) | Screen filtering boundary detection for an image composition | |
DE69123780T2 (en) | Device for processing image signals to improve edge steepness | |
DE4208943B4 (en) | Apparatus and method for stabilizing an image in an image system | |
DE69721972T2 (en) | SIGNAL SYSTEM IMPROVEMENT | |
DE69931308T2 (en) | Video signal processing circuit with optimum signal level for inverted gamma correction | |
DE69934439T2 (en) | Method and apparatus for dynamic contrast enhancement in video images | |
DE69118014T2 (en) | Noise reduction arrangements | |
DE69019391T2 (en) | Gamma correction device. | |
CH675919A5 (en) | ||
DE3587053T2 (en) | DEVICE FOR PROCESSING A VIDEO SIGNAL. | |
CH675777A5 (en) | ||
CH675640A5 (en) | ||
DE69738189T2 (en) | Device for mixing video signals | |
DE69310553T2 (en) | Device for correcting a video signal | |
DE3852866T2 (en) | Filter circuit for ghost cancellation. | |
DE2207536B2 (en) | Contrast compression circuit for a color television pickup system having a plurality of image pickup tubes | |
DE69123771T2 (en) | TV receiver with additional playback of characters | |
DE3202556A1 (en) | BROADBAND CHROMINANCE DEMODULATOR | |
DE3751200T2 (en) | Method for reducing noise in image signals of several gradations. | |
DE3246055C2 (en) | Circuit arrangement for automatic increase and color control for a video signal | |
DE68910948T2 (en) | Video image display device with a contrast control unit and method for adjusting the contrast of such a display device. | |
DE3809303A1 (en) | Circuit arrangement for setting colour saturation | |
DE69321016T2 (en) | Device for cutting off or limiting a color signal | |
DE3343262C2 (en) |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
OM8 | Search report available as to paragraph 43 lit. 1 sentence 1 patent law | ||
8139 | Disposal/non-payment of the annual fee |