JP2532962B2 - Color video camera - Google Patents
Color video cameraInfo
- Publication number
- JP2532962B2 JP2532962B2 JP2058652A JP5865290A JP2532962B2 JP 2532962 B2 JP2532962 B2 JP 2532962B2 JP 2058652 A JP2058652 A JP 2058652A JP 5865290 A JP5865290 A JP 5865290A JP 2532962 B2 JP2532962 B2 JP 2532962B2
- Authority
- JP
- Japan
- Prior art keywords
- color
- evaluation value
- color evaluation
- screen
- gain control
- 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.)
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- Processing Of Color Television Signals (AREA)
Description
【発明の詳細な説明】 (イ) 産業上の利用分野 本発明は,撮像素子から得られる撮像映像信号を基
に、白バランスの制御を行うカラービデオカメラの自動
白バランス調整装置に関する。The present invention relates to an automatic white balance adjusting device for a color video camera that controls white balance based on an image pickup video signal obtained from an image pickup device.
(ロ) 従来の技術 カラービデオカメラに於いては、光源による光の波長
分布の違いを補正するために、白バランスの制御を行う
必要がある。(B) Conventional Technology In a color video camera, it is necessary to control the white balance in order to correct the difference in the wavelength distribution of light depending on the light source.
この制御は、赤(以下R)、青(以下B)、緑(以下
G)の三原色信号の比が1:1:1となるように、各色信号
の利得を調整することで行われる。一般には、例えば特
開昭62−35792号公報(H04N9/73)に示される様に、画
面の色差信号R−Y、B−Yの積分値が零になるように
利得を調節する方式が用いられている。This control is performed by adjusting the gain of each color signal so that the ratio of the three primary color signals of red (hereinafter R), blue (hereinafter B), and green (hereinafter G) is 1: 1: 1. Generally, for example, as shown in JP-A-62-35792 (H04N9 / 73), a method of adjusting the gain so that the integrated value of the color difference signals RY and BY of the screen becomes zero is used. Has been.
第10図は、この方式を用いた白バランス回路のブロッ
ク図である。FIG. 10 is a block diagram of a white balance circuit using this method.
レンズ(1)を通過した光は、撮像素子(CCD)
(2)で光電変換された後、色分離回路(3で、R、
G、Bの3原色信号として取り出され、Gの色信号は直
接、R及びBの色信号はR増幅回路(4)、B増幅回路
(5)を経て、カラープロセス及びマトリクス回路
(6)に入力され、輝度信号Y、赤及び青それぞれの色
差信号R−Y、B−Yが作られて、ビデオ回路へ送られ
る。The light that has passed through the lens (1) is the image sensor (CCD).
After photoelectric conversion in (2), the color separation circuit (3, R,
The three primary color signals of G and B are taken out, and the G color signal is directly input to the R and B color signals through the R amplification circuit (4) and the B amplification circuit (5), and then to the color process and matrix circuit (6). The luminance signal Y, the color difference signals RY and BY for red and blue, respectively, are created and sent to the video circuit.
同時に、二つの色差信号は、それぞれ積分回路(17)
(18)で、十分に長い時間、積分されその結果が零にな
るように利得制御回路(13)(14)がR、B各々の利得
可変な増幅回路(4)、(5)の利得を調節する。At the same time, the two color difference signals are respectively integrated by an integrating circuit (17).
At (18), the gain control circuits (13) and (14) adjust the gains of the variable gain amplifier circuits (4) and (5) for R and B respectively so that they are integrated for a sufficiently long time and the result becomes zero. Adjust.
(ハ) 発明が解決しようとする課題 前述の方式では、一般被写体を撮影した場合、画面全
体の色差信号を平均化した値は、完全白色画を撮影した
場合と等価となり、光源の色温度が変化すると、画面全
体の色情報が色温度変化の分布範囲内でのみ変化すると
いう経験則を前提としている。(C) Problems to be Solved by the Invention In the above-mentioned method, when a general subject is photographed, the averaged color difference signals of the entire screen are equivalent to those when a perfect white image is photographed, and the color temperature of the light source is It is based on the empirical rule that the color information of the entire screen changes only when it changes, within the distribution range of the change in color temperature.
ところで、一般の撮影状態で、光源の色温度分布範囲
外の色情報信号を有する有彩色の被写体、例えば緑や黄
色やマゼンダの被写体が画面の多くの部分を占める状況
は比較的よく経験するものであり、この様な場合に上述
の方式を採用すると、これらの色を打ち消す方向に利得
が変化し、不自然な画質になるという問題が生じる。By the way, in a general shooting condition, a situation in which a chromatic subject having a color information signal outside the color temperature distribution range of the light source, for example, a subject of green, yellow, or magenta occupies a large part of the screen is relatively well experienced. Therefore, if the above-mentioned method is adopted in such a case, there is a problem that the gain changes in the direction of canceling out these colors, resulting in an unnatural image quality.
(ニ) 課題を解決するための手段 本発明は、撮像映像信号中の色情報信号を基に白バラ
ンス調整を行う白バランス調整装置であり撮像画面内で
色情報信号が一定の色温度変化の分布範囲内にないとき
に、該色情報信号を該色温度分布範囲内のものに修正す
ることを特徴とし、更に具体的には、画面を複数の領域
に分割して、各領域毎に色信号の量を色評価値として検
出し、色温度分布範囲外の評価値を持つ領域があれば、
これらの領域での色評価値を色温度分布範囲に修正し、
また全画面の色情報を基に算出された利得制御量が色温
度分布方向のものでなければ、これを色温度分布方向に
修正し、更にその方向に応じて利得制御量を重み付け
し、このようにして得られた利得制御量によって各色信
号の利得を制御する (ホ) 作用 本発明は、上述の如く構成したので、撮像画面中に色
温度分布範囲外の色情報を有する被写体が含まれる場合
でも、この被写体の色を著しく打ち消す方向に白バラン
スがずれることが防止される (ヘ) 実 施 例 以下、図面に従い本発明の実施例について説明する。(D) Means for Solving the Problems The present invention is a white balance adjustment device for performing white balance adjustment based on a color information signal in an imaged video signal, and a color information signal of a constant color temperature change within an image pickup screen is provided. When the color information signal is not within the distribution range, the color information signal is corrected to be within the color temperature distribution range. More specifically, the screen is divided into a plurality of areas, and the color information is divided for each area. The amount of signal is detected as a color evaluation value, and if there is an area with an evaluation value outside the color temperature distribution range,
Correct the color evaluation values in these areas to the color temperature distribution range,
If the gain control amount calculated based on the color information of the entire screen is not in the color temperature distribution direction, the gain control amount is corrected in the color temperature distribution direction, and the gain control amount is weighted according to the direction. The gain of each color signal is controlled by the gain control amount obtained in this way. (E) Operation Since the present invention is configured as described above, the image pickup screen includes a subject having color information outside the color temperature distribution range. Even in this case, it is possible to prevent the white balance from being shifted in the direction in which the color of the subject is significantly canceled. (F) Example Hereinafter, an example of the present invention will be described with reference to the drawings.
第1図は本実施例による自動白バランス調整回路と回
路ブロックである。FIG. 1 shows an automatic white balance adjusting circuit and a circuit block according to this embodiment.
レンズ(1)を通過した光は、CCD(2)上に結像さ
れて光電変換された後、色分離回路(3にて、R、G、
Bの3原色信号として取り出される。これら3原色信号
の中のR及びB信号は、夫々R及びB増幅回路(4)
(5)を経て、G信号と共にカメラプロセス及びマトリ
クス(6)に入力され、これらを基に輝度信号(Y)及
び赤、青夫々の色差信号(R−Y)、(B−Y)が作成
されて、ビデオ回路(7)に供給され周知の処理が施さ
れる。また、(R−Y)(B−Y)の各信号は、同時に
選択回路(21)にも供給される。The light passing through the lens (1) is imaged on the CCD (2) and photoelectrically converted, and then the color separation circuit (3, R, G,
The B primary color signals are extracted. The R and B signals in these three primary color signals are R and B amplifier circuits (4), respectively.
It is input to the camera process and the matrix (6) together with the G signal through (5), and the luminance signal (Y) and the color difference signals (RY) and (BY) of red and blue are created based on these. Then, it is supplied to the video circuit (7) and subjected to well-known processing. Further, the respective signals (RY) and (BY) are simultaneously supplied to the selection circuit (21).
選択回路(21)はタイミング回路(25)からの選択信
号(S1)により色差信号(R−Y)(B−Y)の2つの
信号を1フィールド毎に順次切り換えるもので、(R−
Y)→(B−Y)→(R−Y)…と1フィールド毎に後
段のA/D変換器(22)に出力される。尚、選択信号(S
1)は後述の如く同期分離回路(24)から得られる垂直
同期信号に基づいて作成される。The selection circuit (21) sequentially switches two signals of the color difference signals (RY) and (BY) for each field by the selection signal (S1) from the timing circuit (25).
Y) → (B−Y) → (R−Y) ... Each field is output to the A / D converter (22) in the subsequent stage. The selection signal (S
1) is created based on the vertical sync signal obtained from the sync separation circuit (24) as described later.
A/D変換器(22)は、所定のサンプリング周期で選択
回路(21)にて選択された信号(R−Y)(B−Y)の
何れかをサンプリングしてディジタル値に変換し、この
値を積分器(23)に出力する。ところで、タイミング回
路(25)はカメラプロセス及びマトリクス回路(6)か
ら垂直、水平同期信号及びCCD(2)を駆動する固定の
発振器出力に基づいて、撮像画面を第2図に示す8×8
の64個の同一面積の長方形の領域(A11)、(A12)、
(A13)…、即ち(Aij)(但し、i、j=1〜8の整
数)に分割して、各領域毎にこれらの領域内の選択回路
(21)出力を時分割で取り出すための切換信号(S2)を
積分器(23)に出力する。The A / D converter (22) samples one of the signals (RY) and (BY) selected by the selection circuit (21) at a predetermined sampling period and converts it into a digital value. The value is output to the integrator (23). By the way, the timing circuit (25) shows an image pickup screen as shown in FIG.
64 rectangular areas of the same area (A11), (A12),
(A13), that is, (Aij) (where i and j are integers from 1 to 8), and switching for extracting the output of the selection circuit (21) in these areas in time division for each area The signal (S2) is output to the integrator (23).
積分器(23)は切換信号(S2)を受けて、選択回路
(21)出力のA/D変換値を領域毎に1フィールド期間に
わたって加算し、即ち64個の領域毎にディジタル積分
し、この1フィールド分の積分が完了すると、この積分
値を色評価値としてメモリ(26)に保持する。この結
果、ある任意のフィールドで64個の領域内に対応する色
差信号(R−Y)の領域毎のディジタル積分値が64個の
色評価値(rij)として得られ、同様に次のフィールド
では色差信号(B−Y)の色評価値(bij)が得られ
る。こうして、色差信号(R−Y)(B−Y)の2フィ
ールドの積算が終了した時点で、色評価値(rij)(bi
j)がメモリ(26)に保持されることになる。これ以
降、上述と同様の動作が繰り返され、色評価値(rij)
(bij)と順次更新される。The integrator (23) receives the switching signal (S2), adds the A / D converted value of the output of the selection circuit (21) over one field period for each region, that is, digitally integrates for every 64 regions, When the integration for one field is completed, the integrated value is held in the memory (26) as a color evaluation value. As a result, a digital integrated value for each area of the color difference signal (RY) corresponding to 64 areas in a given field is obtained as 64 color evaluation values (rij), and similarly in the next field. The color evaluation value (bij) of the color difference signal (BY) is obtained. Thus, when the integration of the two fields of the color difference signals (RY) (BY) is completed, the color evaluation value (rij) (bi
j) will be retained in the memory (26). After that, the same operation as above is repeated, and the color evaluation value (rij)
(Bij) is updated sequentially.
第11図に、この積分器(23)の内部構造を更に詳細に
示す。各A/D変換値は、切換回路(61)に供給される。
この切換回路(61)は切換信号(S2)を受けて、各A/D
変換値を領域毎に用意された加算器(Pij)の中で該当
サンプリング点が存在する領域用の加算器に供給する役
割を有する。即ち、ある任意のA/D変換値のサンプリン
グ点が、領域(A11)内に含まれているならば、このデ
ータを領域(A11)用の加算器(P11)に供給する。尚、
以下、同様に加算器(Pij)は領域(Aij)用に設定され
全部で64個の加算器が用意されている。各加算器の後段
には、保持回路(Qij)がそれぞれ配設され、各加算値
は各保持回路に一旦保持される各保持回路の保持データ
は、再び加算器に入力されて、つぎのA/D変換値と加算
される。また、各保持回路は、1フィールド毎にリセッ
トされ、このリセット直前の保持データのみがメモリ
(26)に供給される。従って、1組の加算器及び保持回
路にて1個のディジタル積分回路が構成され合計64個の
積分回路が積分器(23)を構成することになり、1フィ
ールド毎に各保持回路から64個の領域毎に各色差信号の
ディジタル積分値がメモリ(26)に入力される。FIG. 11 shows the internal structure of the integrator (23) in more detail. Each A / D converted value is supplied to the switching circuit (61).
This switching circuit (61) receives the switching signal (S2) and receives each A / D signal.
It has a role of supplying the converted value to the adder for the area where the corresponding sampling point exists among the adders (Pij) prepared for each area. That is, if a sampling point of an arbitrary A / D converted value is included in the area (A11), this data is supplied to the adder (P11) for the area (A11). still,
Hereinafter, similarly, the adder (Pij) is set for the area (Aij), and a total of 64 adders are prepared. A holding circuit (Qij) is provided after each adder, and each added value is temporarily held in each holding circuit. The held data in each holding circuit is input to the adder again, and the next A / D Converted value is added. Further, each holding circuit is reset for each field, and only the held data immediately before this reset is supplied to the memory (26). Therefore, one digital integrator circuit is configured by one set of adder and holding circuit, and a total of 64 integrator circuits constitute the integrator (23), and 64 in each holding circuit for each field. The digital integrated value of each color difference signal is input to the memory (26) for each area.
尚、A/D変換器(22)に入力される色差信号(R−
Y)(B−Y)の基準レベル即ち零レベルは、完全に白
色の無彩色の画面が得られるときの値に予め設定されて
おり、従って、A/D変換器(22)による個々のA/D変換デ
ータには、正だけでなく負の値も存在し、完全白色面の
撮影時には、各色評価値はいずれも零になる。It should be noted that the color difference signal (R- input to the A / D converter (22)
The reference level of Y) (B-Y), that is, the zero level, is preset to a value when a completely white achromatic screen is obtained, and therefore, the individual A by the A / D converter (22). The / D conversion data includes not only positive values but also negative values, and when shooting a completely white surface, each color evaluation value becomes zero.
この様にして得られた最新の色評価値(rij(bij)
は、後段の色評価値修正回路(27)に供給される。The latest color evaluation value (rij (bij) obtained in this way
Is supplied to the color evaluation value correction circuit (27) in the subsequent stage.
色評価値修正回路(27)は、各領域の色評価値が第3
図の斜線に示す適正な色温度分布範囲内にあるか否かを
判断して、範囲内にない場合には該当の色評価値に、第
4図に示すような色温度分布方向に直交する方向への修
正を加えて出力する ここで、具体的な修正方法について説明する。まず、
一般に光源の色温度変化と各色差信号の関係について考
えると、白い被写体を照射している光源の色温度が変化
した場合の色差信号は、第12図の光源色温度軸の様に変
化する。The color evaluation value correction circuit (27) determines that the color evaluation value of each area is the third.
It is determined whether the color temperature distribution is within the proper color temperature distribution range shown by the diagonal lines in the figure. If it is not within the range, the color evaluation value is orthogonal to the color temperature distribution direction as shown in FIG. Output after adding correction to the direction Here, a specific correction method will be described. First,
Generally, considering the relationship between the color temperature change of the light source and each color difference signal, the color difference signal when the color temperature of the light source illuminating the white subject changes changes like the light source color temperature axis of FIG.
そこで、横軸(X軸)に(B−Y)の色評価値(ri
j)を、縦軸(Y軸)に(R−Y)の色評価値(bij)を
とり、前記光源色温度軸を近似すると第3図及び第4図
の(L1)の様に、傾き(a)の直線(式で示すとY=aX
…)で表現できる。尚、この直線(L1)の延在方向は
色温度分布方向となる。Therefore, the color evaluation value (ri) of (BY) is plotted on the horizontal axis (X axis).
j) is the color evaluation value (bij) of (RY) on the vertical axis (Y axis), and when the light source color temperature axis is approximated, as shown in (L1) of FIG. 3 and FIG. The straight line of (a) (Y = aX
...). The extending direction of this straight line (L1) is the color temperature distribution direction.
この直線(L1)を中心に、白バランスに不都合が生じ
ない、即ち、許容できる適正な色温度分布範囲として、
斜線の範囲が設定できる。この範囲とは、具体的には、
直線(L1)をY軸正及び負方向にシフト量(d)(c)
(d<c)だけシフトさせた2本の直線(L2)(L3)で
囲まれた領域である。ここで、直線(L2)(L3)はそれ
ぞれ次式で示される。With this straight line (L1) as the center, there is no inconvenience in white balance, that is, as an allowable and appropriate color temperature distribution range,
The range of diagonal lines can be set. This range is, specifically,
Shift amount of straight line (L1) in the positive and negative directions of Y axis (d) (c)
It is a region surrounded by two straight lines (L2) and (L3) shifted by (d <c). Here, the straight lines (L2) and (L3) are respectively expressed by the following equations.
L2:Y=aX+d … L3:Y=aX−c … 色評価値修正回路(27)では、これら2本の直線(L
2)(L3)が描かれた座標軸を用いて修正動作が為され
る。メモリ(26)から各領域毎に入力される色評価値
(bij)(rij)を(bij,rij)として前記座標軸上にプ
ロットする。そして、このプロット点が適正な色温度分
布範囲内にあるか否かの判断が為され、範囲内にあれば
何ら加工をせずに、そのまま新しい色評価値(HBij)
(HRij)として出力される 例えば、領域(A11)についてのプロット点M11(b11,
r11)が、第4図の位置にあれば色温度分布範囲内にな
るので、HB11=b11、HR11=r11として出力される。L2: Y = aX + d ... L3: Y = aX-c ... In the color evaluation value correction circuit (27), these two straight lines (L
2) Corrective action is performed using the coordinate axis with (L3) drawn. The color evaluation values (bij) (rij) input from the memory (26) for each area are plotted on the coordinate axes as (bij, rij). Then, it is judged whether or not this plot point is within the proper color temperature distribution range, and if it is within the range, the new color evaluation value (HBij) is used without any processing.
Output as (HRij) For example, plot point M11 (b11,
If r11) is in the position shown in FIG. 4, it is within the color temperature distribution range, so that HB11 = b11 and HR11 = r11 are output.
また、プロット点が色温度分布範囲外で直線(L2)よ
り上側の領域に位置するときには、このプロット点から
直線(L1)に垂線を描き、この垂線と直線(L2)との交
点の座標が新しい色評価値(HBij)(HRij)として出力
される。When the plot point is located in the area above the straight line (L2) outside the color temperature distribution range, draw a perpendicular line from this plot point to the straight line (L1) and the coordinates of the intersection of this perpendicular line and the straight line (L2) are It is output as a new color evaluation value (HBij) (HRij).
例えば、領域(A12)についてのプロット点M12(B12,
R12)が第4図の位置にあれば、 Y=(−1/a)・(X−B12)+R12 … で示される垂線(LH)を描き、この垂線(LHと直線(L
2)との交点(T1)を式、より求め、この交点の座
標(X1,Y1)が新しい色評価値(HB12)(HR12)とされ
る。即ちHB12=X1、HR12=Y1として出力される。For example, plot point M12 (B12,
If R12) is in the position shown in Fig. 4, draw a perpendicular line (LH) indicated by Y = (-1 / a) · (X-B12) + R12…, and draw this perpendicular line (LH and straight line (LH
The intersection (T1) with 2) is obtained from the formula, and the coordinates (X1, Y1) of this intersection are used as new color evaluation values (HB12) (HR12). That is, HB12 = X1 and HR12 = Y1 are output.
尚、具体的には、 HB12=(b12+ar12−ad)/(a2+1) HR12=a・(b12+ar12−ad)/(a2+1)+d となる。Specifically, HB12 = (b12 + ar12−ad) / (a 2 +1) HR12 = a · (b12 + ar12−ad) / (a 2 +1) + d.
また、プロット点が色温度分布範囲外で直線(L3)よ
り下側の領域に位置するときには、このプロット点から
直線(L1)に垂線を描き、この垂線と直線(L3)との交
点の座標が、新しい色評価値(HBij)(HRij)として出
力される。When the plot point is located in the area below the straight line (L3) outside the color temperature distribution range, draw a perpendicular line from this plot point to the straight line (L1) and the coordinates of the intersection of this perpendicular line and the straight line (L3). Is output as a new color evaluation value (HBij) (HRij).
例えば、領域(A13)についてのプロット点M13(B13,
R13)が、第4図の位置にあれば、 Y=(−1/a)・(X−B13)+R13 … で示される垂線(LL)を描き、この垂線(LL)と直線
(L3)との交点(T2)を式より求め、この交点の座
標(X2,Y2)が新しい色評価値(HB13)(HR13)とされ
る。即ち、HB13=X2、HR13=Y2として出力される。For example, plot point M13 (B13,
If R13) is in the position shown in Fig. 4, draw a perpendicular line (LL) indicated by Y = (-1 / a) · (X-B13) + R13 ..., and draw this perpendicular line (LL) and straight line (L3). The intersection point (T2) of is calculated from the formula, and the coordinates (X2, Y2) of this intersection point are used as new color evaluation values (HB13) (HR13). That is, HB13 = X2 and HR13 = Y2 are output.
尚、具体的には、 HB13=(b13+ar13+ac)/(a2+1) HR13=a・(b13+ar13+ac)/(a2+1)−c となる。Specifically, HB13 = (b13 + ar13 + ac) / (a 2 +1) HR13 = a · (b13 + ar13 + ac) / (a 2 +1) -c.
色評価値修正回路(27)から出力される無修正あるい
は、修正後の新しい色評価値(HBij)及び(HBij)は、
画面評価回路(28)に送られ次式に基づいて各色差
信号の画面全体の色評価値(Vr)(Vb)として算出され
る。The uncorrected or corrected new color evaluation values (HBij) and (HBij) output from the color evaluation value correction circuit (27) are
It is sent to the screen evaluation circuit (28) and is calculated as a color evaluation value (Vr) (Vb) of the entire screen of each color difference signal based on the following equation.
この式は、色評価値修正回路(27)を経た64個の
各領域の色評価値(HRij)(HBij)の全ての総和を領域
数で割算して、1個の領域についての平均値を画面色評
価値(Vr)(Vb)として算出することを意味する。 This formula divides the total sum of all 64 color evaluation values (HRij) (HBij) of each area that passed through the color evaluation value correction circuit (27) by the number of areas, and calculates the average value for one area. Is calculated as the screen color evaluation value (Vr) (Vb).
利得制御回路(29)(30)は、画面全体の色評価値で
ある画面色評価値(Vr)(Vb)が共に零となる様に利得
制御信号(Gr)(Gb)を出力する。The gain control circuits (29) (30) output gain control signals (Gr) (Gb) so that the screen color evaluation values (Vr) (Vb), which are the color evaluation values of the entire screen, become zero.
前述の修正方法以外にも、第5図に示すように適正な
色温度分布範囲外に位置するプロット点について、原点
方向への修正を加える方法も採用できる。即ち、前記垂
線に代えて各プロット点と原点とを直線(L4)または
(L5)で結び、これらの直線と直線(L1)または(L2)
との交点(T3)または(T4)の座標のX成分及びY成分
が新しい色評価値(HBij)(HRij)として出力する方法
がある。In addition to the above-mentioned correction method, a method of correcting the plot points located outside the proper color temperature distribution range in the direction of the origin as shown in FIG. 5 can also be adopted. That is, instead of the perpendicular line, each plot point and the origin are connected by a straight line (L4) or (L5), and these straight lines are connected to the straight line (L1) or (L2).
There is a method of outputting the X component and Y component of the coordinates of the intersection (T3) or (T4) with and as new color evaluation values (HBij) (HRij).
例えば、前述の領域(A12)についてのプロット点M12
(b12,R12)を考えると、直線(L4)はY=(r12/b12)
・Xとなり、この式と式より交点(T3)の座標は、 (d/(r12/b12−a), d・r12/(r12−a・b12)) となり、 HB12=d/(r12/b12−a) HR12=d・r12/(r12−a・b12) となる。For example, the plot point M12 for the area (A12) described above.
Considering (b12, R12), the straight line (L4) is Y = (r12 / b12)
・ It becomes X, and the coordinates of the intersection point (T3) from this formula are (d / (r12 / b12-a), d ・ r12 / (r12-a ・ b12)), and HB12 = d / (r12 / b12 -A) HR12 = d.r12 / (r12-a.b12).
また、前述の実施例では、個々の領域の色評価値が、
全て適正な色温度分布範囲内におさまる様に色評価値自
体に修正を加えたが、これに代えて、第13図のように利
得制御回路(29)(30)から出力された利得制御信号
(Gr)及び(Gbが、色温度分布範囲内におさまる様にこ
れらの利得制御信号自体を修正することも可能である。
この第13図では、色評価値修正回路(27)を除去し、色
評価値に対しては何ら修正を施さず、即ち、HRij=ri
j、HBij=bijとし、その代わりに利得制御回路(29)
(30)の後段に、利得制御信号修正回路(31)を挿入し
たことを特徴とする。Further, in the above-described embodiment, the color evaluation value of each area is
The color evaluation values themselves have been modified so that they are all within the proper color temperature distribution range. Instead of this, the gain control signals output from the gain control circuits (29) (30) as shown in FIG. It is also possible to modify these gain control signals themselves so that (Gr) and (Gb) fall within the color temperature distribution range.
In FIG. 13, the color evaluation value correction circuit (27) is removed and no correction is made to the color evaluation value, that is, HRij = ri.
j, HBij = bij, instead gain control circuit (29)
A gain control signal correction circuit (31) is inserted after the (30).
この時の利得制御信号修正回路(31)での修正方法
は、前述の色評価値の修正時と同様である即ち、利得制
御信号(Gr)及び(Gb)と適正な色温度分布範囲との関
係は、第6図のようになり、近似直線(L1')をY軸に
シフトさせた2本の直線にて囲まれた領域となるため、
利得制御信号(Gr)及び(Gb)にてこの座標軸上にプロ
ットされた点が、第7図のM3、M4の様に色温度分布範囲
外であれば、直線(L1')に垂線を描き、近接している
側の直線との交点を求め、得られた交点の座標を修正後
の利得制御信号(G'r及び(G'b)として出力し、これに
よりR及びB増幅回路(4)(5)の利得制御を為す。The correction method in the gain control signal correction circuit (31) at this time is the same as that in the above-described color evaluation value correction, that is, the gain control signals (Gr) and (Gb) and the appropriate color temperature distribution range are set. The relationship is as shown in Fig. 6, and since it is the area surrounded by two straight lines that are shifted from the approximate straight line (L1 ') to the Y axis,
If the points plotted on this coordinate axis by the gain control signals (Gr) and (Gb) are outside the color temperature distribution range as shown in M3 and M4 in Fig. 7, draw a straight line on the straight line (L1 '). , An intersection with a straight line on the side of proximity is obtained, and the coordinates of the obtained intersection are output as a corrected gain control signal (G'r and (G'b), whereby the R and B amplifier circuits (4 ) Performs gain control of (5).
また、別の修正方法として、第8図のようにプロット
された点から原点に直線を描き、これらの直線と近接し
ている側の直線との交点を求め、得られた交点の座標を
修正後の利得制御信号(G'r及び(G'b)とすることも可
能である。As another correction method, draw straight lines from the points plotted as shown in Fig. 8 to the origin, find the intersections of these straight lines and the adjacent straight lines, and correct the coordinates of the obtained intersections. The latter gain control signals (G'r and (G'b)) are also possible.
更に、第9図に示すように、第6図の座標軸を重み付
け量(D)決定用のテーブルとして利用する方法もあ
る。即ち、適正色温度分布範囲内でD=2(重み付け量
(D)は○で囲む)、適正色温度分布範囲を除く第2及
び第4象現でD=1、適正色温度分布範囲を除く第1及
び第3象現でD=0.5とし,各プロット点の位置に応じ
て重み付け量(D)を決定し、 Gr'=D・Gr Gb'=D・Gb として修正し、適正な色温度分布範囲内での色情報を重
視して、前述の垂線利用等の方法と略同一の効果を得る
こともできる。Furthermore, as shown in FIG. 9, there is also a method of using the coordinate axes of FIG. 6 as a table for determining the weighting amount (D). That is, within the proper color temperature distribution range, D = 2 (the weighting amount (D) is circled), and in the second and fourth quadrants excluding the proper color temperature distribution range, D = 1, excluding the proper color temperature distribution range. D = 0.5 in the first and third quadrants, determine the weighting amount (D) according to the position of each plot point, correct it as Gr '= D · Gr Gb' = D · Gb, and correct color temperature By placing importance on color information within the distribution range, it is possible to obtain substantially the same effect as the above-described method of using a normal line or the like.
尚、前述の色評価値修正と利得制御信号修正を、同時
に行うことも可能であることは言うまでもない。It goes without saying that the color evaluation value correction and the gain control signal correction described above can be performed simultaneously.
(ト) 発明の効果 上述の如く本発明によれば、白バランス調整には適さ
ない、色温度分布範囲以外の色を含む場面を撮影した場
合でも、白バランスがずれることなく、適切な白バラン
ス調整が実現できる。(G) Effect of the Invention As described above, according to the present invention, even when a scene including a color outside the color temperature distribution range that is not suitable for white balance adjustment is photographed, the white balance does not shift and an appropriate white balance is obtained. Adjustment can be realized.
第1図、第11図は本発明の一実施例の回路ブロック図、
第2図は画面分割の説明図、第3図は色温度分布範囲の
説明図、第4図・第5図は色評価値修正の説明図、第6
図は利得制御信号の関係図、第7図・第8図・第9図は
利得制御信号修正の説明図、第10図は従来例の回路ブロ
ック図で第12図は色差信号の関係図、第13図は他の実施
例の回路ブロック図である。 (23)……積分器、(27)……色評価値修正回路、(2
8)……画面評価回路、(29)(30)……利得制御回
路、(31)……利得制御信号修正回路1 and 11 are circuit block diagrams of one embodiment of the present invention,
FIG. 2 is an explanatory diagram of screen division, FIG. 3 is an explanatory diagram of a color temperature distribution range, FIGS. 4 and 5 are explanatory diagrams of color evaluation value correction, and FIG.
The figure is a relation diagram of the gain control signal, FIGS. 7, 8 and 9 are explanatory diagrams of correction of the gain control signal, FIG. 10 is a circuit block diagram of a conventional example, and FIG. 12 is a relation diagram of the color difference signal, FIG. 13 is a circuit block diagram of another embodiment. (23) …… Integrator, (27) …… Color evaluation value correction circuit, (2
8) …… Screen evaluation circuit, (29) (30) …… Gain control circuit, (31) …… Gain control signal correction circuit
Claims (2)
毎に色情報信号レベルを各色の色評価値として得る色評
価値検出手段と、 色評価値が色温度分布範囲内にある領域についての色評
価値はそのままに、且つ色温度分布範囲外にある領域に
ついての色評価値は色温度分布範囲内の値に修正して出
力する色評価値修正手段と、 該色評価値修正手段出力より画面全体についての色評価
値を算出する画面色評価値算出手段と、 該画面色評価値を基に各色信号の増幅利得を制御する利
得制御手段を備えるカラービデオカメラ。1. A color evaluation value detecting means for obtaining a color information signal level as a color evaluation value of each color for each of a plurality of areas set by dividing an imaging screen, and an area having a color evaluation value within a color temperature distribution range. The color evaluation value as is, and the color evaluation value for the area outside the color temperature distribution range is corrected to a value within the color temperature distribution range, and output. A color video camera comprising: a screen color evaluation value calculation means for calculating a color evaluation value for the entire screen from output; and a gain control means for controlling an amplification gain of each color signal based on the screen color evaluation value.
価値として得る色評価値検出手段と、 該色評価値より画面全体についての色評価値を算出する
画面色評価値算出手段と、 該画面色評価値を基に各色信号の増幅利得を制御する利
得制御信号を発する利得制御手段を備えるカラービデオ
カメラにおいて、 該利得制御信号が一定の色温度変化の分布範囲外の時
に、範囲内に比べ小さな重み付け量にて重み付けを行っ
て修正することを特徴とするカラービデオカメラ。2. A color evaluation value detection means for obtaining a color information signal level of an image pickup screen as a color evaluation value of each color, and a screen color evaluation value calculation means for calculating a color evaluation value for the entire screen from the color evaluation value. In a color video camera equipped with a gain control means for issuing a gain control signal for controlling the amplification gain of each color signal based on the screen color evaluation value, when the gain control signal is outside a certain color temperature change distribution range, A color video camera characterized by being weighted and corrected with a smaller weighting amount than that of.
Priority Applications (13)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2058652A JP2532962B2 (en) | 1990-03-09 | 1990-03-09 | Color video camera |
US07/612,831 US5442408A (en) | 1989-11-17 | 1990-11-13 | White balance adjusting apparatus for automatically adjusting white balance in response to luminance information signal and color information signal obtained from image sensing device |
DE69027751T DE69027751T2 (en) | 1989-11-17 | 1990-11-16 | White balance adjustment device for automatic adjustment of the white balance depending on the luminance information signal and color information signal from an image recording device |
CA002030142A CA2030142C (en) | 1989-11-17 | 1990-11-16 | White balance adjusting apparatus for automatically adjusting white balance in response to color information signal obtained from image sensing device |
EP95119590A EP0711082B1 (en) | 1989-11-17 | 1990-11-16 | A white balance adjusting apparatus for automatically adjusting white balance in response to color information signal obtained from image sensing device |
EP95119589A EP0708569B1 (en) | 1989-11-17 | 1990-11-16 | A white balance adjusting apparatus for automatically adjusting white balance in response to color information signal obtained from image sensing device |
EP90121976A EP0433672B1 (en) | 1989-11-17 | 1990-11-16 | White balance adjusting apparatus for automatically adjusting white balance in response to colour information signal obtained from image sensing device |
ES90121976T ES2091784T3 (en) | 1989-11-17 | 1990-11-16 | WHITE BALANCE REGULATION CIRCUIT TO AUTOMATICALLY ADJUST THE WHITE BALANCE IN RESPONSE TO LIGHTING INFORMATION SIGNS AND COLOR INFORMATION SIGNALS FROM AN IMAGE CAPTURER. |
KR1019900018624A KR100196305B1 (en) | 1989-11-17 | 1990-11-16 | Automatic white balance adjusting apparatus for white balance adjusting on the basis of color information abtained from ccd |
DE69033743T DE69033743T2 (en) | 1989-11-17 | 1990-11-16 | White balance adjustment device for automatically adjusting the white balance depending on the color information signal from an image pickup device |
DE69033744T DE69033744T2 (en) | 1989-11-17 | 1990-11-16 | White balance adjustment device for automatic adjustment of the white balance in dependence on the color information signal from an image recording device |
US08/360,987 US5489939A (en) | 1989-11-17 | 1994-12-20 | White balance adjusting apparatus for automatically adjusting white balance in response to a color information signal obtained from an image sensing device |
US08/454,835 US5555022A (en) | 1989-11-17 | 1995-05-31 | White balance adjusting apparatus for automatically adjusting white balance in response to color information signal obtained from image sensing device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2058652A JP2532962B2 (en) | 1990-03-09 | 1990-03-09 | Color video camera |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH03259692A JPH03259692A (en) | 1991-11-19 |
JP2532962B2 true JP2532962B2 (en) | 1996-09-11 |
Family
ID=13090517
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP2058652A Expired - Fee Related JP2532962B2 (en) | 1989-11-17 | 1990-03-09 | Color video camera |
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JP (1) | JP2532962B2 (en) |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5760831A (en) * | 1992-08-28 | 1998-06-02 | Canon Kabushiki Kaisha | Image processing apparatus with white balance control |
JP3835517B2 (en) * | 2000-08-24 | 2006-10-18 | カシオ計算機株式会社 | White balance control device and white balance control method |
JP4329125B2 (en) | 2005-02-09 | 2009-09-09 | 富士フイルム株式会社 | White balance control method, white balance control device, and imaging device |
JP4889225B2 (en) * | 2005-02-15 | 2012-03-07 | 三洋電機株式会社 | Electronic camera |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH067656Y2 (en) * | 1986-03-31 | 1994-02-23 | シャープ株式会社 | Video camera auto white balance circuit |
JPS63115489A (en) * | 1986-10-31 | 1988-05-20 | Sharp Corp | White balance auto control circuit |
JPS63219291A (en) * | 1986-12-12 | 1988-09-12 | Hitachi Ltd | White balance controller |
JPH07105959B2 (en) * | 1987-05-15 | 1995-11-13 | キヤノン株式会社 | White balance adjuster |
JP2743393B2 (en) * | 1988-08-29 | 1998-04-22 | ソニー株式会社 | White balance adjustment circuit |
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1990
- 1990-03-09 JP JP2058652A patent/JP2532962B2/en not_active Expired - Fee Related
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