JPS612487A - Automatic white balance adjusting method of color video camera - Google Patents
Automatic white balance adjusting method of color video cameraInfo
- Publication number
- JPS612487A JPS612487A JP59122703A JP12270384A JPS612487A JP S612487 A JPS612487 A JP S612487A JP 59122703 A JP59122703 A JP 59122703A JP 12270384 A JP12270384 A JP 12270384A JP S612487 A JPS612487 A JP S612487A
- Authority
- JP
- Japan
- Prior art keywords
- white balance
- red
- signal
- light
- blue
- 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
Links
Landscapes
- Color Television Image Signal Generators (AREA)
- Processing Of Color Television Signals (AREA)
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
本発明はカラービデオカメラ、カラーステイルビデオカ
メラ(電子カメラ)の自動白バランス調整方法に関する
。DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an automatic white balance adjustment method for color video cameras and color stale video cameras (electronic cameras).
背景技術とその問題点
一般にカラービデオカメラ、カラーステイルカメラに於
いては例えば被写体周辺光によりカラー映像信号の白バ
ランスが異なるので、この白ノ(ランス調整を行うこと
が要請されている。BACKGROUND ART AND PROBLEMS Generally, in color video cameras and color still cameras, the white balance of the color video signal varies depending on, for example, the surrounding light of the subject, so it is required to perform white balance adjustment.
従来このカラービデオカメラ、カラーステイルビデオカ
メラの自動白バランス調整方法として、第1図フローチ
ャー1m示す如く、所定の受光素子に依り被写体周辺光
の例えば赤色成分信号Rと青色成分信号Bとを検出し、
これより色温度情報を得、この色温度情報により、白バ
ランスの為の制御信号を演算し、この制御信号により白
バランスの調整を行い、これを順次繰返して自動白バラ
ンス調整を行っていた。Conventionally, as an automatic white balance adjustment method for a color video camera or a color stay video camera, as shown in the flowchart 1m of FIG. death,
Color temperature information is obtained from this, a control signal for white balance is calculated using this color temperature information, white balance is adjusted using this control signal, and this is sequentially repeated to perform automatic white balance adjustment.
この場合被写体周辺光の明るさが例えば100ルックス
以上に明るいときには受光素子の光の検出が良好であり
、被写体周辺光に応じて自動的に良好にこの白バランス
調整を行うことができる。然しなからとの被写体周辺光
の明るさが低照度例えば100ルツクス以下のときには
光の情報量が少なくなり例えば受光素子の直線性が悪く
なり、色温度情報の誤差が大きくなり、この白バランス
が不安定になってしまう不都合があった。In this case, when the brightness of the surrounding light of the object is, for example, 100 lux or more, the light detection of the light receiving element is good, and this white balance adjustment can be performed automatically and satisfactorily in accordance with the surrounding light of the object. However, when the brightness of the light surrounding the subject is low, for example 100 lux or less, the amount of light information decreases, for example, the linearity of the light receiving element deteriorates, the error in color temperature information becomes large, and this white balance becomes There was an inconvenience that it became unstable.
発明の目的
本発明は斯る点に鑑み上述の如きカラービデオカメラの
自動白バランス調整方法属於いて、低照度のときに白バ
ランスが不安定となるのを改善する様にしたものである
。OBJECTS OF THE INVENTION In view of the above, the present invention is directed to an automatic white balance adjustment method for a color video camera as described above, in which the white balance becomes unstable at low illuminance.
発明の概要
本発明は被写体周辺光の色温度情報に応じてカラー映像
信号の白バランスを調整する様にすると共にこの被写体
周辺光の明るさが所定値以下となったときにはこの色温
度情報が所定の値であるとしてこのカラー映像信号の白
バランスを調整する様にし、低照度のときにも白バラン
スが安定となる様にしたものである。Summary of the Invention The present invention adjusts the white balance of a color video signal according to the color temperature information of the light surrounding the subject, and when the brightness of the light surrounding the subject falls below a predetermined value, the color temperature information is adjusted to a predetermined value. The white balance of this color video signal is adjusted based on the value of , so that the white balance is stable even in low illuminance.
実施例
以下第2図及び第3図を参照しながら本発明カラービデ
オカメラの自動白バランス調整方法の一実施例を説明し
よう。Embodiment An embodiment of the automatic white balance adjustment method for a color video camera according to the present invention will be described below with reference to FIGS. 2 and 3.
第2図に於いて、 (IR)及び(1B)は夫々カラー
ビデオカメラ又はカラーステイルビデオカメラ色光受光
素子及び青色光受光素子を示し、この赤色光受光素子(
IR)及び青色光受光素子(IB)の出力信号を対数圧
縮回路(2)に供給し、この対数圧縮回路(2)の出力
信号をアナログ信号をデジタル信号に変換するA−D変
換器(3)を介してマイコン(4)に供給する。この場
合この赤色光受光素子(IR)の出力信号をRとし、青
色先受□光素子(IB)の出力るので、これよりマイコ
ン(4)に於いて色温度情報を得ることができる。又マ
イコン(4)に於いてはこの赤色光受光素子(IR)及
び青色光受光素子(IB)の出力信号等により被写体周
辺の明るさを検出することができる。In FIG. 2, (IR) and (1B) respectively indicate a color light receiving element and a blue light receiving element of a color video camera or a color still video camera, and this red light receiving element (
IR) and the blue light receiving element (IB) to a logarithmic compression circuit (2), and an A-D converter (3) that converts the output signal of the logarithmic compression circuit (2) from an analog signal to a digital signal. ) is supplied to the microcomputer (4). In this case, the output signal of the red light receiving element (IR) is set to R and is output from the blue first receiving light element (IB), so that the microcomputer (4) can obtain color temperature information from this signal. Further, the microcomputer (4) can detect the brightness around the subject based on the output signals of the red light receiving element (IR) and the blue light receiving element (IB).
又このマイコン(4)に於いては予め色温度情報に対応
し【白バランス制御信号が決定される如くなされている
。本例に於いてはカラー映像信号の赤、緑及び青信号の
うち緑信号を一定レベルとし、赤信号及び青信号の夫々
のレベルを制御して白バランスを調整する如くする。In addition, this microcomputer (4) is configured so that a white balance control signal is determined in advance in response to color temperature information. In this example, the green signal of the red, green, and blue signals of the color video signal is kept at a constant level, and the white balance is adjusted by controlling the respective levels of the red signal and the blue signal.
このマイコン(4)に得られるデジタルの赤信号制御信
号及び青信号制御信号をデジタル信号をアナログ信号に
変換するD−A変換回路(5)に供給し、このD−A変
換回路(5)の2つの出力端子(5R)及び(5B)
k夫々得られるアナログの赤信号制御信号及び青信号制
御信号を夫々赤信号Rの利得を制御する赤信号系に設け
られた赤信号利得制御回路(6R)及び青信号Bの利得
を制御する青信号系に設けられた青信号利得制御回路(
6B) K夫々利得制御信号として供給する第2図に於
いて(7R)、(7G)及び(7B)は撮像素子よりの
カラー映像信号の夫々赤、緑及び青信号の入力端子を示
し、(8R) 、 (8G)及び(8B)は夫々この赤
、緑及び青信号の出力端子を示す。The digital red light control signal and green light control signal obtained by this microcomputer (4) are supplied to a D-A conversion circuit (5) that converts the digital signal into an analog signal, and the two of this D-A conversion circuit (5) Two output terminals (5R) and (5B)
The analog red signal control signal and blue signal control signal obtained from each k are sent to the red signal gain control circuit (6R) provided in the red signal system that controls the gain of the red signal R and the green signal system that controls the gain of the green signal B, respectively. A green signal gain control circuit provided (
6B) In FIG. 2, (7R), (7G), and (7B) indicate the input terminals of the red, green, and blue signals of the color video signal from the image sensor, respectively, and (8R) is supplied as a gain control signal. ), (8G) and (8B) indicate the output terminals of the red, green and blue signals, respectively.
本例に於いては第3図に示すフローチャートの如く作動
する。即ちスタート時点で被写体周辺光の明るさを測光
し、これが低照度例えば100ルツクス以下のときはマ
イコン(4)に於いて色温度が例えば3200 K K
対応する赤信号制御信号及び青信号制御信号を設定し、
これにより赤及び青信号利得制御回路(6R)及び(6
B)の利得を制御し、これにより出力端子(8R) 、
(8G) 、 (8B)に安定した白バランスのカラ
ー映像信号を得る様にし、以後、この被写体周辺光の明
るさが例えば100ルックス以上の照度になるまで、こ
の状態が保持され、この被写体周辺光の照度が例えば1
00 A/ラックス上となったときは、被写体周辺光の
測光、この赤色成分信号Rと青色成分信号Bとにより色
温度情報を得る為の演算、この演算値より白バランスの
為の赤及び青信号制御信号の設定、この設定制御信号に
より赤及び青信号利得制御回路(6R)及び(6B)の
制御のルーチンが繰り返され、被写体周辺光に応じた自
動白バランス調整が行なわれる。In this example, the operation is as shown in the flowchart shown in FIG. That is, at the start, the brightness of the surrounding light of the subject is measured, and when this is low illuminance, for example, 100 lux or less, the color temperature is set to 3200K in the microcomputer (4).
Set the corresponding red light control signal and green light control signal,
This allows the red and blue signal gain control circuit (6R) and (6R)
B) gain is controlled, thereby output terminal (8R),
(8G) and (8B) to obtain a color video signal with a stable white balance. From then on, this state is maintained until the brightness of the surrounding light of this subject reaches, for example, 100 lux or more. For example, if the illuminance of the light is 1
When the value is above 00 A/lux, photometry of the surrounding light of the subject is performed, calculation is performed to obtain color temperature information using this red component signal R and blue component signal B, and red and blue signals for white balance are calculated from these calculated values. Setting the control signal, and using this setting control signal, the routine of controlling the red and blue signal gain control circuits (6R) and (6B) is repeated, and automatic white balance adjustment is performed according to the surrounding light of the subject.
途中で被写体周辺光の胛皮が一定照度以下例えば100
ルツクス以下となったときKは、このマイコン(4)に
於いてはこの一定照度以下となる前の白バランスの設定
制御信号に保持され、これが一定照度以上になるまで保
持され、安定した白バランスが得られる如くなされる。In the middle of the shot, the light surrounding the subject is below a certain level of illuminance, for example 100.
When the illuminance becomes below the certain level, K is held in the microcomputer (4) at the white balance setting control signal before the illuminance became below the certain level, and this is held until the illuminance exceeds the certain level to maintain a stable white balance. It will be done so that it can be obtained.
再びこの一定照度以上となったときには士述の如く被写
体周辺光に応じた自動白バランス調整が行なわれる。When the illuminance exceeds this certain level again, automatic white balance adjustment is performed according to the surrounding light of the subject as described above.
斯る本例に於いては被写体周辺光の照度が低照度のとき
は所定の一定照度例えば100ルツクスとして白バラン
スの制御信号を設定するので、低照度時に白バランスが
不規則に変化したり色ずれを越したりする白バランスが
不安定となることはない。従って本例に依れば低照度時
も安定な画像を得ることができる。又、本例に依ればス
タート時に低照度のときは色温度が例えば3200Kに
対応する白バランスの制御信号に設定しているので、夜
景の撮影が可能である。又本例に於いては撮影中にビデ
オカメラのレンズや受光素子を誤って手等で急に覆って
しまっても、その直前の白バランスの設定制御信号が保
持されるので、このときも白バランスの安定な画像が得
られるカラー映像信号を得ることができる。In this example, when the illuminance of the surrounding light of the subject is low, the white balance control signal is set to a predetermined constant illuminance, for example, 100 lux, so the white balance may change irregularly or the color may change at low illuminance. The white balance will not become unstable due to exceeding the deviation. Therefore, according to this example, a stable image can be obtained even at low illuminance. Furthermore, according to this example, when the illuminance is low at the start, the white balance control signal is set to correspond to a color temperature of, for example, 3200K, so night scenes can be photographed. In addition, in this example, even if you suddenly cover the video camera lens or light receiving element with your hand or other object during shooting, the previous white balance setting control signal is retained, so even in this case, the white balance setting control signal will be retained. It is possible to obtain a color video signal that provides an image with stable balance.
尚本発明は土述実施例に限ることなく本発明の要旨を逸
脱することなくその他種々の構成が取り得ることは勿論
である。It goes without saying that the present invention is not limited to the embodiments described above, and that various other configurations can be taken without departing from the gist of the present invention.
発明の効果
本発明に依れば被写体周辺光が一定照度以上のときは被
写体周辺光に応じた自動白バランス調整が行なわれると
共にこの照度が一定照度以下となったとなったときには
所定の色温度情報に対応した白バランスの設定制御信号
に依りカラー映像信号の白バランスを調整するので安定
した白バランスのカラー映像信号が得られる利益がある
。Effects of the Invention According to the present invention, when the ambient light around the subject is above a certain level of illuminance, automatic white balance adjustment is performed according to the surrounding light of the subject, and when this illuminance becomes below the certain level of illuminance, predetermined color temperature information is adjusted. Since the white balance of the color video signal is adjusted according to the white balance setting control signal corresponding to the white balance, there is an advantage that a color video signal with a stable white balance can be obtained.
又本発明に依ればスタート時に低照度のときは色温度が
例えば3200Kに対応する白バランスの制御信号に設
定しているので夜景の撮影が可能である利益があるミス
本発明に於いては撮影中にビデオカメラのレンズや受光
素子を誤って手等で急に覆ってしまっても、その直前の
白バランスの設定制御信号が保持されるので、このとき
も白バランスの安定な画像の得られるカラー映像信号が
得られる利益がある。Also, according to the present invention, when the illuminance is low at the start, the white balance control signal is set to correspond to a color temperature of, for example, 3200K, so night scenes can be photographed. Even if you accidentally cover the video camera lens or photodetector with your hand or other object while shooting, the previous white balance setting control signal is retained, so you can still obtain images with stable white balance. There is an advantage that color video signals can be obtained.
第1図は従来のビデオカメラの自動白バランス調整方法
の例の説明に供する線図、第2図は本発明ビデオカメラ
の自動白バランス調整方法の一実施例の説明に供するブ
ロック図、第3図は第2図の説明に供する線図である。
(IR) Jび(IB)は夫々受光素子、(4)はマイ
コン(6R)及び(6B)は夫々赤及び青信号利得制御
回路、(7R)、(7G)及び(7B)は夫々赤、緑及
び青信号入力端子、(sR) 、 (sG)及び(8B
)は夫々赤、緑及び青信号出力端子である。FIG. 1 is a diagram for explaining an example of a conventional automatic white balance adjustment method for a video camera, FIG. 2 is a block diagram for explaining an example of an automatic white balance adjustment method for a video camera according to the present invention, and FIG. The figure is a diagram for explaining FIG. 2. (IR) J and (IB) are light receiving elements, (4) is a microcomputer (6R) and (6B) are red and blue signal gain control circuits, respectively, (7R), (7G) and (7B) are red and green respectively. and blue signal input terminals, (sR), (sG) and (8B
) are red, green and blue signal output terminals, respectively.
Claims (1)
バランスを調整する様にすると共に上記被写体周辺光の
明るさが所定値以下となつたときには上記色温度情報が
所定の値であるとして上記カラー映像信号の白バランス
を調整する様にしたことを特徴とするカラービデオカメ
ラの自動白バランス調整方法。The white balance of the color video signal is adjusted according to the color temperature information of the light surrounding the subject, and when the brightness of the light surrounding the subject falls below a predetermined value, the color temperature information is determined to be a predetermined value and the above-mentioned An automatic white balance adjustment method for a color video camera, characterized in that the white balance of a color video signal is adjusted.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP59122703A JPS612487A (en) | 1984-06-14 | 1984-06-14 | Automatic white balance adjusting method of color video camera |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP59122703A JPS612487A (en) | 1984-06-14 | 1984-06-14 | Automatic white balance adjusting method of color video camera |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS612487A true JPS612487A (en) | 1986-01-08 |
Family
ID=14842519
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP59122703A Pending JPS612487A (en) | 1984-06-14 | 1984-06-14 | Automatic white balance adjusting method of color video camera |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS612487A (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6361589A (en) * | 1986-09-02 | 1988-03-17 | Fuji Photo Film Co Ltd | Still video camera |
EP0263295A2 (en) * | 1986-09-09 | 1988-04-13 | Fuji Photo Film Co., Ltd. | Electronic still camera for compensating color temperature dependency of color video signals |
JPS63156491A (en) * | 1986-12-19 | 1988-06-29 | Mitsubishi Electric Corp | Color video camera |
US4879591A (en) * | 1986-01-31 | 1989-11-07 | Canon Kabushiki Kaisha | Image pickup apparatus compensating an image signal for variations in color temperature |
JP2011512112A (en) * | 2008-02-13 | 2011-04-14 | クゥアルコム・インコーポレイテッド | White balance calibration of digital camera devices |
-
1984
- 1984-06-14 JP JP59122703A patent/JPS612487A/en active Pending
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4879591A (en) * | 1986-01-31 | 1989-11-07 | Canon Kabushiki Kaisha | Image pickup apparatus compensating an image signal for variations in color temperature |
JPS6361589A (en) * | 1986-09-02 | 1988-03-17 | Fuji Photo Film Co Ltd | Still video camera |
EP0263295A2 (en) * | 1986-09-09 | 1988-04-13 | Fuji Photo Film Co., Ltd. | Electronic still camera for compensating color temperature dependency of color video signals |
US4774564A (en) * | 1986-09-09 | 1988-09-27 | Fuji Photo Film Co., Ltd. | Electronic still camera for compensating color temperature dependency of color video signals |
JPS63156491A (en) * | 1986-12-19 | 1988-06-29 | Mitsubishi Electric Corp | Color video camera |
JP2011512112A (en) * | 2008-02-13 | 2011-04-14 | クゥアルコム・インコーポレイテッド | White balance calibration of digital camera devices |
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