JPH0385888A - Color detecting circuit - Google Patents
Color detecting circuitInfo
- Publication number
- JPH0385888A JPH0385888A JP22145389A JP22145389A JPH0385888A JP H0385888 A JPH0385888 A JP H0385888A JP 22145389 A JP22145389 A JP 22145389A JP 22145389 A JP22145389 A JP 22145389A JP H0385888 A JPH0385888 A JP H0385888A
- Authority
- JP
- Japan
- Prior art keywords
- color
- output
- level
- circuit
- 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
Links
- 238000001514 detection method Methods 0.000 claims abstract description 53
- 230000002401 inhibitory effect Effects 0.000 abstract description 3
- 238000010586 diagram Methods 0.000 description 6
- 230000000694 effects Effects 0.000 description 5
- 239000011159 matrix material Substances 0.000 description 3
- 239000003086 colorant Substances 0.000 description 2
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- 230000003321 amplification Effects 0.000 description 1
- 239000003990 capacitor Substances 0.000 description 1
- 238000000295 emission spectrum Methods 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 230000005764 inhibitory process Effects 0.000 description 1
- 230000007257 malfunction Effects 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
Landscapes
- Processing Of Color Television Signals (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、テレビジョン受信機などの画像処理回路の色
補正系に適用して好適な色検出回路に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a color detection circuit suitable for application to a color correction system of an image processing circuit such as a television receiver.
画像処理では色の補正がしばしば必要となる場合がある
。Image processing often requires color correction.
例えばテレビジョン受像機等においては、設定された復
調軸の位相、利得の関係やブラウン管の各蛍光体の発光
スペクトラムの違い等の理由より、ある特定の色が出に
くくなる場合などである。For example, in a television receiver or the like, it may be difficult to produce a certain color due to the relationship between the phase and gain of the set demodulation axis, or differences in the emission spectrum of each phosphor in a cathode ray tube.
上述の不具合の解決を目的として、特開昭６１５２０９
３号公報に記載のように、特定の領域の色相のみの補正
が可能な色補正回路が提案されている。以下、これを第
６図により説明する。同図において、所定の色信号、例
えばＲ−Ｙは加算器１に供給されると共に、抽出手段と
してのスライス回路２に供給されてその負成分（−（Ｒ
−Ｙ））が抽出される。抽出された負成分（−（Ｒ−Ｙ
））は利得可変形増幅Ｄ３で増幅された後、加算器１に
供給される。一方、Ｒ−Ｙ以外の色信号、例えばＢ−Ｙ
は、抽出手段としてのスライス回路７でＢ−Ｙ信号の負
成分の信号レベルが抽出される。In order to solve the above-mentioned problems, Japanese Patent Application Laid-Open No. 615209
As described in Japanese Patent No. 3, a color correction circuit capable of correcting only the hue of a specific area has been proposed. This will be explained below with reference to FIG. In the figure, a predetermined color signal, for example, R
-Y)) is extracted. Extracted negative component (-(RY
)) is amplified by the variable gain amplifier D3 and then supplied to the adder 1. On the other hand, color signals other than R-Y, such as B-Y
The signal level of the negative component of the BY signal is extracted by the slice circuit 7 serving as an extraction means.
この信号レベルに応じて利得制御を行なう利得制御回路
６を介して、前記利得可変形増幅器の利得を制御する構
成となっている。The configuration is such that the gain of the variable gain amplifier is controlled via a gain control circuit 6 that performs gain control according to this signal level.
すなわち、同図においては、肌色が正しく調整した場合
に、黄緑がかった色になる緑色を、より緑に近い色に補
正するための回路構成となっている。かかる回路構成に
おいては、緑が黄緑っぽいということから、Ｒ−Ｙの負
（−）方向の成分のみを増幅し、その際、他の色への影
響を少なくするためにＢ−Ｙの負成分の信号レベルに応
じてＲ−Ｙの負成分の増幅率を制御するので、第３象限
の色相のなかのある範囲（第７図に斜線で示す範囲）の
色相だけ色相を変化させることができる。That is, in the figure, the circuit configuration is for correcting the green color, which becomes yellowish-greenish when the skin color is correctly adjusted, to a color closer to green. In this circuit configuration, since green has a yellowish-greenish color, only the negative (-) direction component of R-Y is amplified, and in this case, in order to reduce the influence on other colors, B-Y is amplified. Since the amplification factor of the negative component of R-Y is controlled according to the signal level of the negative component, the hue can be changed by only a certain range of hues in the third quadrant (the shaded range in Figure 7). I can do it.
しかしながら、上記従来技術には次のような問題がある
。However, the above conventional technology has the following problems.
まず、第１に、第６図の構成においては、Ｒ−Ｙの振幅
およびＢ−Ｙの振幅に比例して色補正を行なうため、前
記振幅が小さい、すなわち色飽和度の低い色においても
色補正行ない、また１色飽和度の低い色の場合、色成分
よりも残留キャリアや色ノイズ等のノイズ成分の方が支
配的となるため、色補正によりノイズが強調されてしま
うという問題があった。First, in the configuration shown in FIG. 6, color correction is performed in proportion to the amplitude of R-Y and the amplitude of B-Y. When correction is performed, and in the case of a color with low saturation, noise components such as residual carrier and color noise become more dominant than color components, so there is a problem that noise is emphasized by color correction. .
第２に、第６図の構成において、増幅器３の出力信号は
、特定色検出信号となっており、この信号を加算器１に
供給したり、供給しないと切換えることにより、色補正
をＯＮ、ＯＦＦすることができる。しかし、増幅器３に
出力オフセントが存在する場合、色補正のＯＮ、ＯＦＦ
によりＲ−Ｙ出力の直流電位が変動し、画像のホワイト
バランスが変動してしまうという問題がある。この問題
に対しては、出力オフセットを吸収する調整を行なうこ
とで対処可能であるが、調整が必要となる問題があった
。Second, in the configuration shown in FIG. 6, the output signal of the amplifier 3 is a specific color detection signal, and by switching between supplying this signal to the adder 1 and not supplying it, the color correction can be turned on and off. Can be turned off. However, if there is an output offset in amplifier 3, the color correction is turned on and off.
This causes a problem in that the DC potential of the RY output fluctuates, and the white balance of the image fluctuates. This problem can be dealt with by making adjustments to absorb the output offset, but there is a problem in that adjustments are required.
本発明の目的は、かかる問題点を解消し、低飽和度の色
の場合においてノイズを強調せず、また特定色検出信号
に出力オフセットがあっても色補正のＯＮ、ＯＦＦによ
りホワイトバランスが変動しない色検出回路を提供する
ことにある。It is an object of the present invention to solve such problems, to avoid emphasizing noise in the case of low-saturation colors, and to change the white balance by turning color correction ON and OFF even if there is an output offset in the specific color detection signal. The objective is to provide a color detection circuit that does not require color detection.
上記目的を達成するために、本発明は、特定色の色の検
出を行なう色検出手段と、所定の色信号の信号レベルが
所定レベル以上のときその信号の信号レベルに応じた出
力を発生するレベル検出手段と、前記色検出手段の出力
を、該レベル検出手段の出力で制御する制御手段とを設
ける。In order to achieve the above object, the present invention provides a color detection means for detecting a specific color, and a means for generating an output according to the signal level of a predetermined color signal when the signal level of the predetermined color signal is equal to or higher than a predetermined level. Level detection means and control means for controlling the output of the color detection means with the output of the level detection means are provided.
該所定の色信珍は、任意の復調軸を得る手段により得ら
れる色信号とする。The predetermined color signal is a color signal obtained by means for obtaining an arbitrary demodulation axis.
色信号のレベル検出手段の出力信号で色検出手段の出力
を制御するため、色信号が小さい場合、色検出手段の出
力を禁止することができる。それによって、小信号に含
まれるノイズ成分を強調してしまうという弊害を解消で
きる。また、色検出手段の出力に出力オフセットが存在
する場合、色相補正動作の０Ｎ１０ Ｆ Ｆにより、ホ
ワイトバランスが変動してしまう。これについても前記
色検出手段の出力を禁止する動作により誤動作すること
がない。Since the output of the color detection means is controlled by the output signal of the color signal level detection means, the output of the color detection means can be inhibited when the color signal is small. This eliminates the problem of emphasizing noise components contained in small signals. Further, if an output offset exists in the output of the color detection means, the white balance will fluctuate due to the hue correction operation 0N10FF. In this case as well, there will be no malfunction due to the operation of inhibiting the output of the color detection means.
第工図は本発明による色検出回路の実施例を示１０６は
レベル検出回路、１０７は利得制御回路である。同図に
おいて、端子１〜３に供給されたＲ−Ｙ−２３−Ｙの色
信号５Ｒ−ＳＢ（その振幅レベルはＥＲ−ＥＢ）は、色
検出回路１ｏに入力され、特定色を検出し、端子１．０
８に色検出出方信号ＳＡ（その振幅レベルはＥＡ）が得
られる。この例では、検出する特定色を第７図に斜線で
示す色層、すなわち緑色とする。次に、レベル検出回路
１０６はＳＧを入力とし、その正成分レベルが所定レベ
ル以上のときその信号レベルに応じた出力を発生し、そ
の出力で利得制御回路１０７を介し１色検出回路１０の
出力を制御する。The first drawing shows an embodiment of the color detection circuit according to the present invention, and 106 is a level detection circuit, and 107 is a gain control circuit. In the figure, a color signal 5R-SB of RY-23-Y (its amplitude level is ER-EB) supplied to terminals 1 to 3 is input to a color detection circuit 1o, which detects a specific color. terminal 1.0
8, a color detection output signal SA (its amplitude level is EA) is obtained. In this example, the specific color to be detected is the shaded color layer in FIG. 7, that is, green. Next, the level detection circuit 106 receives SG as an input, and when the positive component level thereof is equal to or higher than a predetermined level, it generates an output corresponding to the signal level. control.
利得制御特性の一例を第２図に示す。同図におイテ横軸
ハレベル検出回路１０６の入力レベルＥＧを示し、縦軸
は色検出回路１０の出力レベルＥＣを示す。利得制御し
ない従来の場合、ＥＡレベルはＥＧレベルに比例して増
加する。これは同図に点線で示す。この発明により利得
制御をした場合の特性を実線で示す。すなわち、ＥＧレ
ベルがＥ、１のレベルとなるまで、色検出出力信号を禁
止し、Ｒ８のレベルを越えると、徐々に禁止を解除する
。この特性により、ＥＮ程度のノイズが入力された場合
２色検出出力にノイズは伝送されず。An example of gain control characteristics is shown in FIG. In the figure, the horizontal axis shows the input level EG of the high level detection circuit 106, and the vertical axis shows the output level EC of the color detection circuit 10. In the conventional case without gain control, the EA level increases in proportion to the EG level. This is shown by the dotted line in the figure. The solid line shows the characteristics when the gain is controlled according to the present invention. That is, the color detection output signal is inhibited until the EG level reaches the level E,1, and when it exceeds the level R8, the inhibition is gradually released. Due to this characteristic, if noise of EN level is input, the noise will not be transmitted to the two-color detection output.
ノイズを強調することはない。すなわち、ＥＮの不感帯
を設けたことになる。Noise is not emphasized. In other words, a dead zone for EN is provided.
次に、色検出回路の出力に、出力オフセットが存在する
場合の動作を第３図に示す。同図の横軸。Next, FIG. 3 shows the operation when an output offset exists in the output of the color detection circuit. Horizontal axis of the same figure.
縦軸は第２図と同一である。従来の場合、出力オフセッ
ト■８が存在すると同図のようにＥＧレベルがＯ以下に
おいても色検出出力ＥＡがｖ２だけ生じるため、ホワイ
トバランスが変動してしまうが、この発明により利得制
御により出力を禁止することにより、実線で示す特性と
なる。これにより、ホワイトバランス変動をなくせる。The vertical axis is the same as in FIG. In the conventional case, when the output offset ■8 exists, the color detection output EA is generated by v2 even when the EG level is O or less as shown in the same figure, resulting in fluctuations in white balance, but with this invention, the output can be adjusted by gain control. By prohibiting this, the characteristics shown by the solid line will be obtained. This eliminates white balance fluctuations.
第４図に第１図の具体的回路の一例を示す。FIG. 4 shows an example of the specific circuit shown in FIG. 1.
以下、この第４図を説明する６レベル検出回路１０６は
Ｑ１〜Ｑ４とＲ１，Ｒ２と電流源工１と基ｆ９ｇ電圧ｇ
ｖｒにより構成している。利得制御回路１０７は、Ｑ５
．Ｑ６とＲ３−Ｒ６と電流源工２により構成している。Hereinafter, the 6-level detection circuit 106 to explain this FIG.
It is composed of VR. The gain control circuit 107
．． It is composed of Q6, R3-R6, and current source 2.
第１、図に対応する部分には同一符号をつけている。こ
の例では色検出回路１０は緑色の検出を行ない、検出出
力信号ＳＡは検出電流とする。First, parts corresponding to those in the figure are given the same reference numerals. In this example, the color detection circuit 10 detects green color, and the detection output signal SA is a detection current.
かかる構成の色検出回路による動作は、検出色相である
緑色の色振幅をＱｌ、Ｑ２で構成する差動対により検出
し、Ｑｌのコレクタ電流として出力し、Ｑ３．Ｑ４で構
成する電流ミラー回路により、Ｒ２を負荷抵抗として検
出出力ＶＧを得る。The color detection circuit having such a configuration detects the color amplitude of green, which is the detected hue, by a differential pair consisting of Ql and Q2, outputs it as a collector current of Ql, and outputs it as a collector current of Q3. A detection output VG is obtained by a current mirror circuit constituted by Q4, with R2 as a load resistance.
このＶＧをＱ５．Ｑ６で構成する差動対によりＱ５のコ
レクタ電流を制御する。ここで０５のコレクタ電流は１
色検出回路の動作電流源としているため、緑色の正振幅
が設定レベルより小さい場合はＶＧが低電圧でありＱ５
をＯＮできないため、色検出回路出力の出力電流を禁止
することになり、また、緑色の正振幅が設定レベルより
大きい場合はＱ５がＯＮＬ、Ｑ５のコレクタ電流は工２
となり色検出回路１０が通常動作する。This VG is Q5. The collector current of Q5 is controlled by the differential pair made up of Q6. Here, the collector current of 05 is 1
Since it is used as the operating current source for the color detection circuit, if the positive amplitude of green is smaller than the set level, VG is a low voltage and Q5
cannot be turned ON, the output current of the color detection circuit output is prohibited, and if the positive amplitude of green is larger than the set level, Q5 is ONL, and the collector current of Q5 is
The color detection circuit 10 then operates normally.
第５図は本発明による色検出回路の他の実施例を示すブ
ロック図であって、１０９は任意の復調軸を得る手段と
なるマトリクス回路であり、第１図に対応する部分には
同一符号をつけている。この例では色検出回路の検出色
を中間色の肌色等とした場合を示す。FIG. 5 is a block diagram showing another embodiment of the color detection circuit according to the present invention, in which reference numeral 109 is a matrix circuit serving as means for obtaining an arbitrary demodulation axis, and parts corresponding to FIG. 1 are denoted by the same reference numerals. is attached. In this example, a case is shown in which the color detected by the color detection circuit is a neutral skin color or the like.
中間色の場合、レベル検出回路１０６の入力信号は検出
する色相の復調軸をもつ色信号とする必要がある。した
がって、色信号５Ｒ−５Ｂの任意の信号をマトリクス回
路１０９に入力し、必要な中間色の復調軸を得、その信
号をレベル検出回路へ供給することにより中間色におい
ても第２図。In the case of an intermediate color, the input signal to the level detection circuit 106 needs to be a color signal having a demodulation axis of the hue to be detected. Therefore, by inputting any of the color signals 5R-5B to the matrix circuit 109 to obtain the demodulation axis of the necessary intermediate color, and supplying the signal to the level detection circuit, the same as shown in FIG. 2 can be obtained even for the intermediate color.
第３図と同一の効果を得ることができる。The same effect as in FIG. 3 can be obtained.
以上説明したように、本発明によれば小振幅の色信号に
対して色検出出力を禁止するため、小振幅色信号に重畳
したノイズ成分を抑圧できるので色補正したときノイズ
成分を強調することがないという効果がある。As explained above, according to the present invention, since the color detection output is prohibited for small amplitude color signals, the noise component superimposed on the small amplitude color signal can be suppressed, so that the noise component can be emphasized when performing color correction. The effect is that there is no
また、色検出回路の出力に出力オフセットが存７Ｆする
場合においても、上記出力を禁止する動作によりホワイ
トバランスが変動することがないという効果がある。Further, even if an output offset exists in the output of the color detection circuit, the above operation of inhibiting the output has the effect that the white balance does not fluctuate.
また、上記ホワイトバランスの変動は出力オフセットを
調整により解消できるが、本発明によればｖＲ整を削除
することができるという効果がある。Further, although the above-mentioned white balance fluctuation can be eliminated by adjusting the output offset, the present invention has the advantage that the vR adjustment can be eliminated.
また、第４図に示す様に、本発明による色検出回路は容
量とコイルを用いない回路構成で実現可能であるため、
ｉｃ化が容易であり、ｊｃ化により性能の安定化、コス
ト低減化などが見込めるという効果もある。Furthermore, as shown in FIG. 4, the color detection circuit according to the present invention can be realized with a circuit configuration that does not use capacitors and coils.
It is easy to convert to IC, and it is possible to stabilize performance and reduce costs by converting to JC.
第１図は本発明による色検出回路の一実施例を示すブロ
ック図、第２図、第３図はこの実施例の動作説明図、第
４図は第１図の具体的回路構成を示す回路図、第５図は
本発明による色検出回路の他の実施例を示すブロック図
、第６図は従来の色補正回路の一例を示すブロック図、
第７図はこの従来例の回路によって補正される領域を示
す色相ベクトル図である。
１０は従来の色検出回路、１０６はレベル検出回路、１
０７は利得制御回路、１０９はマトリクス回路。
稟
１
図
ネ
牛
図
稟
図FIG. 1 is a block diagram showing an embodiment of the color detection circuit according to the present invention, FIGS. 2 and 3 are diagrams explaining the operation of this embodiment, and FIG. 4 is a circuit showing the specific circuit configuration of FIG. 1. 5 is a block diagram showing another embodiment of the color detection circuit according to the present invention, and FIG. 6 is a block diagram showing an example of a conventional color correction circuit.
FIG. 7 is a hue vector diagram showing the area corrected by this conventional circuit. 10 is a conventional color detection circuit, 106 is a level detection circuit, 1
07 is a gain control circuit, and 109 is a matrix circuit. 1. Figure 1. Cow figure.
Claims (1)
と、所定の色信号の信号レベルが所定レベル以上のとき
その信号レベルに応じた出力を発生するレベル検出手段
と、前記色検出手段の出力を該レベル検出手段の出力で
制御する制御手段とを設けたことを特徴とする色検出回
路。 ２、請求項１において、前記所定の色信号は、任意の復
調軸を得る手段により得られる色成分であることを特徴
とする色検出回路。[Claims] 1. Color detection means that receives a color signal as input and detects a specific color; and level detection means that generates an output according to the signal level of a predetermined color signal when the signal level is equal to or higher than a predetermined level. and a control means for controlling the output of the color detection means with the output of the level detection means. 2. The color detection circuit according to claim 1, wherein the predetermined color signal is a color component obtained by means for obtaining an arbitrary demodulation axis.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22145389A JP2574897B2 (en) | 1989-08-30 | 1989-08-30 | Color detection circuit and image device using the same |
| US07/564,165 US5134465A (en) | 1989-08-30 | 1990-08-08 | Color detecting circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22145389A JP2574897B2 (en) | 1989-08-30 | 1989-08-30 | Color detection circuit and image device using the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0385888A true JPH0385888A (en) | 1991-04-11 |
| JP2574897B2 JP2574897B2 (en) | 1997-01-22 |
Family
ID=16766965
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP22145389A Expired - Fee Related JP2574897B2 (en) | 1989-08-30 | 1989-08-30 | Color detection circuit and image device using the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2574897B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0638230A (en) * | 1992-07-20 | 1994-02-10 | Hitachi Gazou Joho Syst:Kk | Skin color correction and its device |
-
1989
- 1989-08-30 JP JP22145389A patent/JP2574897B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0638230A (en) * | 1992-07-20 | 1994-02-10 | Hitachi Gazou Joho Syst:Kk | Skin color correction and its device |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2574897B2 (en) | 1997-01-22 |
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