JPH0730906A - Picture element defect correction device - Google Patents
Picture element defect correction deviceInfo
- Publication number
- JPH0730906A JPH0730906A JP5166849A JP16684993A JPH0730906A JP H0730906 A JPH0730906 A JP H0730906A JP 5166849 A JP5166849 A JP 5166849A JP 16684993 A JP16684993 A JP 16684993A JP H0730906 A JPH0730906 A JP H0730906A
- Authority
- JP
- Japan
- Prior art keywords
- pixel
- detection circuit
- correlation
- signal
- output
- Prior art date
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- Color Television Image Signal Generators (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明はＣＣＤ等の固体撮像素子
を用いた撮像装置において、固体撮像素子に存在する画
素欠陥を検出し補正する画素欠陥補正装置に関するもの
である。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pixel defect correcting apparatus for detecting and correcting a pixel defect existing in a solid-state image sensor in an image sensor using a solid-state image sensor such as CCD.
【０００２】[0002]
【従来の技術】一般にＣＣＤ等の半導体により形成され
た固体撮像素子においては、半導体の局部的な結晶欠陥
等により画質劣化を生じることが知られている。入射光
量に応じた撮像出力に常に一定のバイアス電圧が加算さ
れてしまう画像欠陥は、この画像欠陥信号がそのまま処
理されるとモニター画面上に高輝度の白い点として現れ
るので白キズと呼ばれている。また、光電感度の低いも
のは黒い点として現れるので黒キズと呼ばれている（以
後、画素欠陥をキズと称する）。2. Description of the Related Art Generally, it is known that in a solid-state image pickup device formed of a semiconductor such as CCD, image quality is deteriorated due to local crystal defects of the semiconductor. An image defect in which a constant bias voltage is always added to the imaging output according to the amount of incident light appears as a high-intensity white dot on the monitor screen if this image defect signal is processed as it is. There is. In addition, those having low photosensitivity appear as black dots and are called black scratches (hereinafter, pixel defects are called scratches).
【０００３】従来、上記のようなキズに対する検出に関
しては、例えば特開昭６１−２６１９７４号公報に示さ
れている。この方法は注目画素が周辺の画素に対して一
定量以上大きいまたは小さい出力を持つ画素をキズとし
て検出する方法であり、横方向および縦方向に隣接画素
間の差を取り、周辺の画素と異なる出力を持つ画素を検
出するものである。Conventionally, the detection of scratches as described above is disclosed in, for example, Japanese Patent Laid-Open No. 61-261974. This method is a method of detecting a pixel in which the pixel of interest has an output larger or smaller than a peripheral pixel by a certain amount or more as a flaw. The difference between adjacent pixels in the horizontal direction and the vertical direction is obtained, and the pixel is different from the peripheral pixels. It detects a pixel having an output.
【０００４】以下、ＣＣＤの水平方向における白キズの
検出の場合について説明を行うものとする。また、本発
明は、複数のＣＣＤを用いており、ここではそれに対応
し、３個のＣＣＤを用い、Ｒ，Ｇ，Ｂ光信号がこれら３
個のＣＣＤに入力される、いわゆる３板の場合におい
て、従来の画素欠陥補正装置をそのまま適用した場合に
ついて具体的に説明を行う。白キズは、周辺の画素に対
して、通常１画素のみ突出している。例えば、注目画素
とその前後の画素の関係は図９の（ａ）のＧ入力のよう
に表される。このため、注目画素とその隣接する前後の
画素と比較し、注目画素が一定レベル以上前後の画素よ
り大きい場合キズと見なすことができる。The case of detecting a white defect in the horizontal direction of the CCD will be described below. In addition, the present invention uses a plurality of CCDs, and correspondingly, three CCDs are used here, and R, G, and B optical signals are used for these three CCDs.
In the case of a so-called three-plate input to one CCD, a case where the conventional pixel defect correction device is applied as it is will be specifically described. The white flaw normally projects only one pixel with respect to the surrounding pixels. For example, the relationship between the pixel of interest and the pixels before and after it is represented as G input in FIG. Therefore, when the pixel of interest is compared with the adjacent pixels before and after it, the pixel of interest can be regarded as a flaw if it is larger than the pixels of a certain level or more.
【０００５】上記内容を実現するブロック図を図８に示
す。Ｒ，Ｇ，Ｂ光信号がそれぞれ入力されたＣＣＤの出
力信号は、補正回路１４，１５，１６を経由して出力さ
れると共に、検出回路１１，１２，１３に入力され、こ
れらの検出回路の出力により、対応する補正回路１４，
１５，１６を制御する。A block diagram for realizing the above contents is shown in FIG. The output signals of the CCD to which the R, G, and B optical signals are respectively input are output via the correction circuits 14, 15, and 16 and are input to the detection circuits 11, 12, and 13 to detect these detection circuits. Depending on the output, the corresponding correction circuit 14,
15 and 16 are controlled.
【０００６】検出回路の一例のブロック図を図１１に示
す。入力された信号は複数のフリップフロップ（以下Ｆ
Ｆと略す）２１，２２を通り、順次送られてきた注目画
素値とその前後の画素値、ｙn-1，ｙn，ｙn+1を得る。
これ以後、信号を、ｒ，ｇ，ｂをｙで代表し表記する。
これらの信号に対して、加算器２３，２４、比較回路２
５，２６、ＡＮＤ回路２７により下記の演算を行ってい
る。A block diagram of an example of the detection circuit is shown in FIG. The input signal is a plurality of flip-flops (hereinafter F
The pixel value of interest and the pixel values before and after it, which are sequentially sent, are passed through 21 and 22 (abbreviated as F), y n-1 , y n , and y n + 1 .
Hereinafter, the signal will be represented by representing r, g, and b by y.
For these signals, the adders 23 and 24, the comparison circuit 2
5, 26 and the AND circuit 27 perform the following calculation.
【０００７】 ｙn-1−ｙn＞ａ1 ｙn+1−ｙn＞ａ2 ａ1，ａ2は、ｙnのｙn-1，ｙn+1に対する突出量のしき
い値であり、ここではａ1＝ａ2＝ａ（＞０）として考え
る。[0007] y n-1 -y n> a 1 y n + 1 -y n> a 2 a 1, a 2 is the amount of projection of the threshold for y n-1, y n + 1 of the y n Therefore, it is assumed here that a 1 = a 2 = a (> 0).
【０００８】以上により、注目する画素の値がその周辺
の画素の値に対して一定レベル以上突出している場合は
キズとみなし「１」を出力し、それ以外の場合「０」を
出力する。補正回路は、その検出出力により制御され
る。As described above, when the value of the pixel of interest is more than a certain level above the values of the surrounding pixels, it is regarded as a flaw and "1" is output, otherwise "0" is output. The correction circuit is controlled by its detection output.
【０００９】画素欠陥の補正に関しては、特開昭６２−
８６６６号公報にいくつかの方法が示されている。例え
ば、１画素もしくは２画素前の画素で置換する方法、前
後の画素値の平均で置換する方法、または同様に垂直方
向で考え、１つ上の画素で置換する方法、上下の画素値
の平均で置換する方法などがある。Regarding the correction of pixel defects, Japanese Patent Laid-Open No. 62-
Several methods are shown in the 8666 publication. For example, a method of substituting one pixel or two pixels before, a method of substituting the average of previous and next pixel values, or a method of thinking in the vertical direction and substituting by one pixel above, an average of upper and lower pixel values There is a method of replacing with.
【００１０】補正回路の一例のブロック図は図１２に示
す。ここでは、補正回路は前後の画素値の平均で置換す
るものとし、動作は以下の通りである。入力された信号
はＦＦ４１，４２を通り、中央の注目画素の値とその前
後の画素値を抽出する。注目画素の前後の画素値からこ
れらの平均値を求め補正信号としている。検出回路の検
出信号に従い、通常は中央の注目画素の値を、キズと判
定した場合は補正信号を出力する。A block diagram of an example of the correction circuit is shown in FIG. Here, the correction circuit replaces the average of the pixel values before and after, and the operation is as follows. The input signal passes through the FFs 41 and 42 to extract the value of the pixel of interest in the center and the pixel values before and after it. An average value of these pixel values before and after the pixel of interest is calculated and used as a correction signal. According to the detection signal of the detection circuit, the value of the pixel of interest in the center is normally output, and when it is determined that there is a flaw, a correction signal is output.
【００１１】以上より、Ｒ，Ｇ，Ｂの各経路において、
周辺の画素の値に対して一定レベル以上突出している画
素に対してはキズとして検出でき、目立たないよう補正
することができる。From the above, in each route of R, G, B,
Pixels that project by a certain level or more with respect to the values of surrounding pixels can be detected as flaws, and can be corrected so as not to be noticeable.
【００１２】従来の画素欠陥補正装置における第１の信
号波形例を図９に示す。図９の（ａ）にＧのキズが補正
される様子を示す。FIG. 9 shows a first signal waveform example in the conventional pixel defect correcting device. FIG. 9A shows how the flaw of G is corrected.
【００１３】以上の画素欠陥補正の動作は、３個のＣＣ
Ｄが、例えば、Ｇに対しＲ，Ｂが半画素ずれているよう
な画素ずらしを行っていても同様な回路で行うことがで
きる。The above pixel defect correction operation is performed by using three CCs.
A similar circuit can be used even if the pixel shift is performed such that D is shifted from G by R and B by half a pixel.
【００１４】従来の画素欠陥補正装置ににおける第２の
信号波形例を図１０に示す。図１０の（ａ）にＧのキズ
が補正される様子を示す。FIG. 10 shows a second signal waveform example in the conventional pixel defect correction device. FIG. 10A shows how the G flaw is corrected.
【００１５】[0015]
【発明が解決しようとする問題点】しかしながら、上記
の方法によれば、点光源のような信号に対しては、信号
であるにも関わらず突出していることからキズと誤って
判定する。例えば、周囲が暗い中で１点のみ明るい図９
の（ｂ）のような信号が入力された場合、その中心の信
号はキズと誤って判定され、誤補正されてしまう。これ
により、図９の（ｂ）の左に示す出力のように、本来あ
るべき信号がなくなってしまう。このように点光源のよ
うな信号がある場合には画質を劣化させ、良好な画像を
得ることができないという問題があった。However, according to the above-mentioned method, a signal such as a point light source is erroneously determined as a flaw because it is projected even though it is a signal. For example, in the dark surroundings, only one point is bright.
When a signal such as (b) is input, the center signal is erroneously determined as a flaw and is erroneously corrected. As a result, there should be no signals as they should be, such as the output shown on the left side of FIG. 9B. As described above, when there is a signal such as a point light source, there is a problem that the image quality is deteriorated and a good image cannot be obtained.
【００１６】また、３個のＣＣＤが、例えば、Ｇに対し
Ｒ，Ｂが半画素ずれているような画素ずらしを行ってい
ても同様な問題を生じる。例えば、周囲が暗い中で１点
のみ明るい図１０の（ｂ）のような信号が入力された場
合、その中心の信号はキズと誤って判定され、誤補正さ
れてしまう。これにより、図１０の（ｂ）の左に示す出
力のように、本来あるべき信号がなくなってしまう。The same problem arises even if the three CCDs perform pixel shifting such that R and B are displaced by half a pixel with respect to G, for example. For example, when a signal such as that shown in FIG. 10B in which only one point is bright in the dark surroundings is input, the signal at the center is erroneously determined as a flaw and is erroneously corrected. As a result, there should be no signal as it should be, such as the output shown on the left side of FIG.
【００１７】このように、点光源のような信号がある場
合には画質を劣化させ、良好な画像を得ることができな
いという問題があった。As described above, when there is a signal such as a point light source, there is a problem that the image quality is deteriorated and a good image cannot be obtained.
【００１８】本発明はこのような従来の問題点を解決す
るものであり、簡単な構成で信号とキズを精度良く判別
し、キズについてのみ補正を行い、点光源のような信号
を含む画像においても、本来の画質を劣化させることな
く、良好な画像を得ることができる画素欠陥補正装置を
提供するものである。The present invention solves the above-mentioned conventional problems. In an image including a signal such as a point light source, a signal and a flaw are accurately discriminated with a simple structure and only the flaw is corrected. Also, the present invention provides a pixel defect correction device capable of obtaining a good image without deteriorating the original image quality.
【００１９】[0019]
【課題を解決するための手段】本発明の画素欠陥補正装
置は、複数の固体撮像素子と、これら固体撮像素子より
出力された前記固体撮像素子の画素の値より突出を検出
する検出回路と、これらの検出回路の出力の相関を検出
する相関検出回路と、この相関検出回路の出力信号によ
り制御される補正回路とからなる。A pixel defect correction apparatus according to the present invention comprises a plurality of solid-state image pickup devices, and a detection circuit for detecting protrusion from the pixel values of the solid-state image pickup devices output from the solid-state image pickup devices. It comprises a correlation detection circuit for detecting the correlation of the outputs of these detection circuits, and a correction circuit controlled by the output signal of this correlation detection circuit.
【００２０】また、本発明の画素欠陥補正装置は、第１
の固体撮像素子に対し第２の固体撮像素子が半画素ずれ
た位置に配置された複数の固体撮像素子と、第１の固体
撮像素子の第１の画素およびその前後の画素の値より突
出を検出する第１の検出回路と、第１の固体撮像素子の
第１の画素の半画素前後の第２の固体撮像素子の第２，
第３の画素の値およびその前後の画素の値より第２，第
３の画素の値の突出を検出する第２の検出回路と、第
１，第２の検出回路の出力の相関を検出する相関検出回
路と、この相関検出回路の出力信号により制御される補
正回路とからなる。The pixel defect correcting device of the present invention is the first
Of the plurality of solid-state image pickup elements in which the second solid-state image pickup element is displaced by a half pixel from the solid-state image pickup element, and the values of the first pixel of the first solid-state image pickup element and the pixels before and after it. A first detection circuit for detecting, and a second solid-state image sensor including a second solid-state image sensor before and after a half pixel of the first pixel of the first solid-state image sensor.
The correlation between the outputs of the first and second detection circuits and the second detection circuit that detects the protrusion of the values of the second and third pixels from the value of the third pixel and the values of the pixels before and after it is detected. It is composed of a correlation detection circuit and a correction circuit controlled by an output signal of the correlation detection circuit.
【００２１】[0021]
【作用】本発明によれば、点光源のような信号において
も従来のように誤検出、誤補正を行わず、信号とキズを
区別し、キズを精度良く検出できるため、キズについて
のみ補正を行い、本来の画質を劣化させることなく、良
好な画像を得ることができる。According to the present invention, even if a signal such as a point light source is not erroneously detected or erroneously corrected as in the prior art, the signal and the flaw can be distinguished and the flaw can be accurately detected. Therefore, only the flaw is corrected. By doing so, a good image can be obtained without deteriorating the original image quality.
【００２２】[0022]
【実施例】以下、本発明の第１の実施例について図面を
参照して説明する。本発明の第１の実施例のブロック図
を図１に示す。Ｒ，Ｇ，Ｂ光信号がそれぞれ入力された
ＣＣＤ１，２，３の出力信号は、補正回路１４，１５，
１６を経由して出力されると共に、検出回路１１，１
２，１３に入力され、これらの検出回路の出力により、
対応する補正回路を制御する。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings. A block diagram of the first embodiment of the present invention is shown in FIG. The output signals of the CCDs 1, 2, 3 to which the R, G, B optical signals are respectively input are corrected by the correction circuits 14, 15,
16 and the detection circuits 11 and 1
2, 13 and the output of these detection circuits,
Control the corresponding correction circuit.
【００２３】検出回路の一例は図１１に示したブロック
図と同じである。すなわち、入力された信号は複数のフ
リップフロップ（以下ＦＦと略す）２１，２２を通り、
順次送られてきた注目画素値とその前後の画素値、ｙ
n-1、ｙn、 ｙn+1を得る。これ以後、信号を、ｒ，ｇ，
ｂをｙで代表し表記する。これらの信号に対して、加算
器２３，２４、比較回路２５，２６、ＡＮＤ回路２７に
より下記の演算を行っている。An example of the detection circuit is the same as the block diagram shown in FIG. That is, the input signal passes through a plurality of flip-flops (hereinafter abbreviated as FF) 21 and 22,
The pixel value of interest sent in sequence and the pixel values before and after it, y
Obtain n-1 , y n , and y n + 1 . After this, the signals are changed to r, g,
b is represented by y. The following operations are performed on these signals by the adders 23 and 24, the comparison circuits 25 and 26, and the AND circuit 27.
【００２４】 ｙn-1−ｙn＞ａ1 ｙn+1−ｙn＞ａ2 ａ1，ａ2はｙnのｙn-1，ｙn+1に対する突出量のしきい
値であり、ここでは、ａ1＝ａ2＝ａ（＞０）として考え
る。[0024] y n-1 -y n> a 1 y n + 1 -y n> a 2 a 1, a 2 is an amount of protrusion of the threshold for y n-1, y n + 1 of the y n , Here, it is considered that a 1 = a 2 = a (> 0).
【００２５】以上により、注目する画素の値がその周辺
の画素の値に対して一定レベル以上突出している場合は
キズとみなし「１」を出力し、それ以外の場合「０」を
出力する。As described above, when the value of the pixel of interest is more than a certain level above the values of the surrounding pixels, it is regarded as a flaw and "1" is output, and otherwise "0" is output.
【００２６】相関検出回路の一例の回路図を図２に示
す。この回路の動作をＧの経路を中心にして述べる。こ
の相関検出回路のＧ出力は、Ｇ入力が「１」で、かつ
Ｒ，Ｂの両方が「０」の場合には、Ｇと他の信号と相関
がないとみなし、キズの可能性が高いと判断し、「１」
を出力する。また、Ｇ入力が「１」でも、かつＲ，Ｂの
両方または一方が「１」の場合には、Ｇと他の信号と相
関があるとみなし、点光源の可能性が高いと判断し、
「０」を出力する。A circuit diagram of an example of the correlation detection circuit is shown in FIG. The operation of this circuit will be described centering on the G path. When the G input is "1" and both R and B are "0", the G output of the correlation detection circuit is considered to have no correlation with G and other signals, and is likely to be damaged. Judge that, "1"
Is output. Further, when the G input is "1" and both or one of R and B is "1", it is considered that there is a correlation with G and other signals, and it is determined that the possibility of the point light source is high.
Outputs "0".
【００２７】補正回路の一例のブロック図は図１２に示
す。補正回路は、相関検出出力により制御される。補正
動作は従来例と同様、キズと判定された場合、前後の画
素値の平均で置換するものとする。すなわち、入力され
た信号はＦＦ３１，３２を通り、中央の注目画素の値と
その前後の画素値を抽出し、注目画素の前後の画素値か
らこれらの平均値を求め補正信号としている。相関検出
回路１７の検出信号に従い、通常は中央の注目画素の値
を、キズと判定した場合は補正信号を出力する。A block diagram of an example of the correction circuit is shown in FIG. The correction circuit is controlled by the correlation detection output. As in the case of the conventional example, the correction operation replaces with the average of the pixel values before and after when it is determined that there is a flaw. That is, the input signal passes through the FFs 31 and 32 to extract the value of the pixel of interest in the center and the pixel values before and after it, and obtains the average value of these pixel values before and after the pixel of interest as a correction signal. According to the detection signal of the correlation detection circuit 17, the value of the pixel of interest in the center is normally output, and when it is determined that there is a flaw, a correction signal is output.
【００２８】本発明の第１の実施例における信号波形を
図３に示す。以上の回路における、キズの場合と点光源
の場合のＲ，Ｇ，Ｂの入力と出力の関係を示す。以上の
回路における、キズの場合と点光源の場合のＲ，Ｇ，Ｂ
の入力と出力の関係を示す。この例のようにＧにキズが
ある場合、Ｇのみ突出し、補正される。通常の白の点光
源の場合は、Ｒ，Ｇ，Ｂ間に相関があるため信号と判断
され、誤って補正されず、本来の信号が出力される。A signal waveform in the first embodiment of the present invention is shown in FIG. The relationship between the input and output of R, G, and B in the case of a scratch and the case of a point light source in the above circuit is shown. In the above circuit, R, G, B in case of scratch and in case of point light source
Shows the relationship between the input and output of. If G has a flaw as in this example, only G is projected and corrected. In the case of an ordinary white point light source, there is a correlation among R, G, and B, so that it is judged as a signal and is not corrected by mistake, and the original signal is output.
【００２９】以下、本発明の第２の実施例について図面
を参照して説明する。本発明の第２の実施例のブロック
図を図４に示す。この図は、簡単のため、Ｇ，Ｒの２経
路について検出および補正する場合について図示してあ
る。以下、この２経路について検出および補正する場合
について述べる。A second embodiment of the present invention will be described below with reference to the drawings. A block diagram of the second embodiment of the present invention is shown in FIG. For simplification, this figure shows a case where two paths G and R are detected and corrected. The case of detecting and correcting these two paths will be described below.
【００３０】ここで、ＧのＣＣＤ１に対しＲ，ＢのＣＣ
Ｄ２，３は半画素ずれた位置に配置されている。Here, for the CCD 1 for G, the CC for R, B
D2 and D3 are arranged at positions shifted by half a pixel.
【００３１】Ｇ，Ｒの光信号が入力されたＣＣＤ１，２
の出力信号は、補正回路１４，１５を経由して出力され
ると共に、検出回路１１と検出回路６１，検出回路６２
と検出回路１２に入力される。ここでは、検出回路１１
と検出回路６２、検出回路６１と検出回路１２は同一回
路である。CCDs 1 and 2 to which G and R optical signals are input
Is output via the correction circuits 14 and 15, and the detection circuit 11 and the detection circuit 61 and the detection circuit 62 are output.
Is input to the detection circuit 12. Here, the detection circuit 11
The detection circuit 62 and the detection circuit 61 and the detection circuit 12 are the same circuit.
【００３２】検出回路１１と検出回路１２の出力が相関
検出回路１８に入力され、相関検出回路１８の出力によ
りＧ経路の補正回路１４が制御される。The outputs of the detection circuits 11 and 12 are input to the correlation detection circuit 18, and the output of the correlation detection circuit 18 controls the correction circuit 14 for the G path.
【００３３】検出回路６１と検出回路６２の出力が相関
検出回路１９に入力され、相関検出回路１９の出力によ
りＲ経路の補正回路１５が制御される。The outputs of the detection circuits 61 and 62 are input to the correlation detection circuit 19, and the output of the correlation detection circuit 19 controls the correction circuit 15 of the R path.
【００３４】以下、Ｇ信号について検出および補正する
場合について、つまり、検出回路１１と検出回路１２の
出力が相関検出回路１８に入力され、相関検出回路１８
によりＧ経路の補正回路１４が制御される場合について
述べることにする。Hereinafter, in the case of detecting and correcting the G signal, that is, the outputs of the detection circuits 11 and 12 are input to the correlation detection circuit 18, and the correlation detection circuit 18
A case will be described in which the G path correction circuit 14 is controlled by.
【００３５】検出回路の一例は図１１に示したブロック
図と同じである。この動作は第１の実施例において述べ
た内容と基本的には同じである。順次送られてきた注目
画素値とその前後の画素値ｇn-1，ｇn，ｇn+1に下記の
演算を行っている。An example of the detection circuit is the same as the block diagram shown in FIG. This operation is basically the same as the contents described in the first embodiment. Pixel value g n-1 sequentially sent the value of the pixel of interest has its front and rear, g n, and performs the calculation of the following to g n + 1.
【００３６】 ｇn-1−ｇn＞ａ ｇn+1−ｇn＞ａ ａはｇnのｇn-1，ｇn+1に対する突出量のしきい値であ
る。この演算によりｇnのｇn-1，ｇn+1に対する突出を
検出し、一定レベル以上突出している場合は「１」を出
力し、それ以外の場合「０」を出力する。[0036] g n-1 -g n> a g n + 1 -g n> a a is the amount of projection of the threshold for g n-1, g n + 1 of g n. Detecting a projected against g n-1, g n + 1 of g n This operation, if projecting a certain level or higher outputs "1", and outputs the otherwise "0".
【００３７】検出回路の一例のブロック図を図５に示
す。検出回路１２は検出回路１１に対し、Ｇのキズを検
出するに当たって補助的な動作を行う。通常の白の点光
源で、中心がｇnの場合、光学ＬＰＦの影響で点光源が
広がりをもち、ｇnに加え、周辺の画素つまり、ｒ
n-0.5，ｒn-0.5に相当する部分にも光があたり、信号が
発生する。キズの場合は、ｇnのみ突出し、他の経路に
は突出は発生しない。このため検出回路１２により、周
辺の画素の値つまり、ｒn-0.5，ｒn-0.5の前後の画素の
値に対する突出を検出することにより、点光源かキズか
の判別ができる。A block diagram of an example of the detection circuit is shown in FIG. The detection circuit 12 performs an auxiliary operation for the detection circuit 11 in detecting a flaw of G. When a normal white point light source has a center of g n , the point light source has a spread due to the influence of the optical LPF, and in addition to g n , peripheral pixels, that is, r
The light also hits the portions corresponding to n - 0.5 and rn - 0.5 , and a signal is generated. For scratches, protrudes only g n, the other paths protruding does not occur. Therefore, the detection circuit 12 can detect whether the light source is a point light source or a flaw by detecting the protrusion of the peripheral pixel values, that is, the pixel values before and after r n - 0.5 and r n- 0.5. .
【００３８】検出回路１２の動作を以下に述べる。入力
された信号は複数のフリップフロップ７１〜７４を通
り、順次送られてきた注目画素値とその前後の画素値ｒ
n-1.5，ｒn-0.5，ｒn-0.5，ｒn+1.5を得る。これらの信
号に対して、加算器７５〜７７、比較回路７８，７９、
ＡＮＤ回路８０により下記の演算を行っている。The operation of the detection circuit 12 will be described below. The input signal passes through a plurality of flip-flops 71 to 74, and the pixel value of interest and the pixel values r before and after the pixel value of interest are sequentially transmitted.
n-1. 5, r n- 0 .5, r n- 0 .5, obtain r n + 1. 5. For these signals, adders 75 to 77, comparison circuits 78 and 79,
The AND circuit 80 performs the following calculation.
【００３９】 （ｒn-0.5＋ｒn-0.5）/2＝ｒn' ｒn'−ｒn-1.5 ＞ｂ1 ｒn'−ｒn+1.5 ＞ｂ2 ｂ1，ｂ2はｒn'のｒn-1.5，ｒn+1.5に対する突出量のし
きい値であり、ここではｂ1＝ｂ2＝ｂ（＞０）として考
える。[0039] (r n- 0 .5 + r n- 0 .5) / 2 = r n 'r n' -r n-1. 5> b 1 r n '-r n + 1. 5> b 2 b 1, b 2 is r n-1. 5, r n + 1. threshold amount of projection for 5 r n ', where b 1 = b 2 = considered as b (> 0).
【００４０】以上により、注目する画素の値がその周辺
の画素の値に対して一定レベル以上突出している場合は
キズとみなし「１」を出力し、それ以外の場合「０」を
出力する。As described above, when the value of the pixel of interest is more than a certain level above the values of the surrounding pixels, it is considered as a flaw and "1" is output, otherwise "0" is output.
【００４１】検出回路１１と検出回路１２が相関検出回
路１８に入力される。相関検出回路１８の一例を図６に
示す。ここでは、相関検出回路１８、相関検出回路１９
は同一回路である。この相関検出回路１８の出力は、Ｇ
入力が「１」で、Ｒ入力が「０」の場合には、Ｇ入力と
Ｒ入力と相関がないとみなし、キズの可能性が高いと判
断し、「１」を出力する。また、Ｇ入力が「１」でも、
かつＲ，Ｂの両方または一方が「１」の場合には、Ｇと
他の信号と相関があるとみなし、点光源の可能性が高い
と判断し、「０」を出力する。The detection circuit 11 and the detection circuit 12 are input to the correlation detection circuit 18. An example of the correlation detection circuit 18 is shown in FIG. Here, the correlation detection circuit 18 and the correlation detection circuit 19
Are the same circuit. The output of this correlation detection circuit 18 is G
When the input is "1" and the R input is "0", it is considered that there is no correlation between the G input and the R input, it is determined that the possibility of a scratch is high, and "1" is output. Also, even if the G input is "1",
If both or one of R and B is "1", it is considered that there is a correlation with G and other signals, it is determined that the possibility of a point light source is high, and "0" is output.
【００４２】補正回路の一例は図１２のブロック図と同
じである。補正回路は、相関検出出力により制御され
る。補正動作は従来例と同様、キズと判定された場合、
前後の画素値の平均で置換するものとする。入力された
信号はＦＦ４１，４２を通り、中央の注目画素の値とそ
の前後の画素値を抽出し、注目画素の前後の画素値から
これらの平均値を求め補正信号としている。相関検出回
路の検出信号に従い、通常は中央の注目画素の値を、キ
ズと判定した場合は補正信号を出力する。An example of the correction circuit is the same as the block diagram of FIG. The correction circuit is controlled by the correlation detection output. The correction operation is similar to the conventional example, if it is determined as a scratch,
The average of the pixel values before and after is replaced. The input signal passes through the FFs 41 and 42, extracts the value of the pixel of interest in the center and the pixel values before and after it, and obtains the average value of these pixel values before and after the pixel of interest as a correction signal. In accordance with the detection signal of the correlation detection circuit, the value of the pixel of interest in the center is normally output, and when it is determined that there is a flaw, a correction signal is output.
【００４３】本発明の第２の実施例における信号波形を
図７に示す。以上の回路における、キズの場合と点光源
の場合のＲ，Ｇ，Ｂの入力と出力の関係を示す。この例
のようにＧにキズがある場合、Ｇのみ突出し、補正され
る。通常の白の点光源の場合は、Ｒ，Ｇ，Ｂ間に相関が
あるため信号と判断され、誤って補正されず、本来の信
号が出力される。この例ではＧ，Ｒの２経路についての
回路となっているためＢ信号は直接出力には寄与してい
ない。FIG. 7 shows a signal waveform in the second embodiment of the present invention. The relationship between the input and output of R, G, and B in the case of a scratch and the case of a point light source in the above circuit is shown. If G has a flaw as in this example, only G is projected and corrected. In the case of an ordinary white point light source, there is a correlation among R, G, and B, so that it is judged as a signal and is not corrected by mistake, and the original signal is output. In this example, the B signal does not directly contribute to the output because the circuit has two paths G and R.
【００４４】以上、Ｇ，Ｒの２経路について検出および
補正する場合について述べたが、Ｂが加わっても、Ｇ，
Ｒについての処理と同様、Ｒ，Ｂ、Ｂ，Ｇについても同
様な処理を行うことで実現できる。また、検出に当たっ
ては、例えば、Ｇにおいては、Ｇの検出回路出力とＲ，
Ｂ両方の検出回路出力の計３出力より相関検出回路にお
いて相関をとる方式も考えられる。The case of detecting and correcting the two paths G and R has been described above. Even if B is added, G,
Similar to the processing for R, it can be realized by performing the same processing for R, B, B, and G. In the detection, for example, in G, the output of the G detection circuit and R,
A method in which correlation is obtained in the correlation detection circuit from a total of 3 outputs of both B detection circuits is also conceivable.
【００４５】以上の第１，第２の実施例については、白
キズについてのみの説明を行っているが、黒キズについ
ても、キズの方向が反対であることを考慮し、ａ1，ａ2
の符号、不等号の向きを変更することにより、同様に検
出が可能である。In the above first and second embodiments, only white scratches have been described, but with regard to black scratches as well, considering that the directions of the scratches are opposite, a 1 and a 2
Similarly, the detection can be performed by changing the sign of and the direction of the inequality sign.
【００４６】また、以上の実施例については、水平方向
についてのみの説明を行っているが、垂直方向について
も同様であり、水平方向、垂直方向の両方を組み合わせ
た処理も可能である。In the above embodiment, only the horizontal direction has been described, but the same applies to the vertical direction, and processing in which both the horizontal direction and the vertical direction are combined is also possible.
【００４７】[0047]
【発明の効果】以上の説明より明らかなように、本発明
によれば、点光源のような信号においても従来のように
誤検出、誤補正を行わず、信号とキズを区別し、キズを
精度良く検出できるため、キズについてのみ補正を行
い、本来の画質を劣化させることなく、良好な画像を得
ることができる。As is apparent from the above description, according to the present invention, even in the case of a signal such as a point light source, the signal and the flaw are distinguished from each other without the erroneous detection and correction as in the conventional case, and the flaw is detected. Since it can be detected with high accuracy, only a flaw is corrected, and a good image can be obtained without deteriorating the original image quality.
【図面の簡単な説明】[Brief description of drawings]
【図１】本発明の第１の実施例における画素欠陥補正装
置の構成を示すブロック図FIG. 1 is a block diagram showing a configuration of a pixel defect correction device according to a first embodiment of the present invention.
【図２】同第１の実施例における相関検出回路の内部構
成例を示すブロック図FIG. 2 is a block diagram showing an internal configuration example of a correlation detection circuit according to the first embodiment.
【図３】同第１の実施例の動作を説明するための信号波
形図FIG. 3 is a signal waveform diagram for explaining the operation of the first embodiment.
【図４】本発明の第２の実施例における画素欠陥補正装
置の構成を示すブロック図FIG. 4 is a block diagram showing a configuration of a pixel defect correction device according to a second embodiment of the present invention.
【図５】同第２の実施例における検出回路の内部構成例
を示すブロック図FIG. 5 is a block diagram showing an internal configuration example of a detection circuit according to the second embodiment.
【図６】同第２の実施例における相関検出回路の内部構
成例を示すブロック図FIG. 6 is a block diagram showing an internal configuration example of a correlation detection circuit according to the second embodiment.
【図７】同第２の実施例の動作を説明するための信号波
形図FIG. 7 is a signal waveform diagram for explaining the operation of the second embodiment.
【図８】従来の画素欠陥補正装置の構成を示すブロック
図FIG. 8 is a block diagram showing a configuration of a conventional pixel defect correction device.
【図９】従来の画素欠陥補正装置の動作を説明するため
の信号波形図FIG. 9 is a signal waveform diagram for explaining the operation of a conventional pixel defect correction device.
【図１０】従来の画素欠陥補正装置の動作を説明するた
めの信号波形図FIG. 10 is a signal waveform diagram for explaining the operation of a conventional pixel defect correction device.
【図１１】同従来例おける検出回路の内部構成例を示す
ブロック図FIG. 11 is a block diagram showing an internal configuration example of a detection circuit in the conventional example.
【図１２】同従来例における補正回路の内部構成例を示
すブロック図FIG. 12 is a block diagram showing an internal configuration example of a correction circuit in the conventional example.
１〜３ ＣＣＤ １１〜１３ 検出回路 １４〜１６ 補正回路 １７ 相関検出回路 1 to 3 CCD 11 to 13 detection circuit 14 to 16 correction circuit 17 correlation detection circuit
Claims (2)
する複数の検出回路と、 これらの検出回路の出力の相関を検出する相関検出回路
と、 この相関検出回路の出力信号により制御される補正回路
とからなることを特徴とする画素欠陥補正装置。1. A plurality of solid-state image pickup devices, a plurality of detection circuits for detecting protrusions from pixel values of outputs of these solid-state image pickup devices, and a correlation detection circuit for detecting correlation of outputs of these detection circuits, A pixel defect correction device comprising a correction circuit controlled by an output signal of the correlation detection circuit.
像素子が半画素ずれた位置に配置された複数の固体撮像
素子と、 前記第１の固体撮像素子の第１の画素およびその前後の
画素の値より突出を検出する第１の検出回路と、 前記第１の固体撮像素子の第１の画素の半画素前後にあ
る前記第２の固体撮像素子の第２，第３の画素の値およ
びその前後の画素の値より第２，第３の画素の値の突出
を検出する第２の検出回路と、 第１，第２の検出回路の出力の相関を検出する相関検出
回路と、 前記相関検出回路の出力信号により制御される補正回路
とからなることを特徴とする画素欠陥補正装置。2. A plurality of solid-state imaging devices in which a second solid-state imaging device is arranged at a position shifted by a half pixel with respect to the first solid-state imaging device, a first pixel of the first solid-state imaging device, and the first solid-state imaging device. A first detection circuit for detecting a protrusion from the values of the pixels before and after, and second and third pixels of the second solid-state image sensor that are located before and after a half pixel of the first pixel of the first solid-state image sensor A second detection circuit that detects the protrusion of the values of the second and third pixels based on the value of and the values of the pixels before and after that, and a correlation detection circuit that detects the correlation between the outputs of the first and second detection circuits. And a correction circuit controlled by an output signal of the correlation detection circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5166849A JP2903956B2 (en) | 1993-07-06 | 1993-07-06 | Pixel defect correction device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5166849A JP2903956B2 (en) | 1993-07-06 | 1993-07-06 | Pixel defect correction device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0730906A true JPH0730906A (en) | 1995-01-31 |
| JP2903956B2 JP2903956B2 (en) | 1999-06-14 |
Family
ID=15838795
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5166849A Expired - Fee Related JP2903956B2 (en) | 1993-07-06 | 1993-07-06 | Pixel defect correction device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2903956B2 (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1178676A1 (en) * | 2000-07-31 | 2002-02-06 | Hitachi Kokusai Electric Inc. | Method and device for detecting defective pixels of a solid-state colour image-pickup apparatus |
| JP2003304548A (en) * | 2002-04-10 | 2003-10-24 | Canon Inc | Imaging apparatus |
| US7106371B1 (en) | 1998-09-08 | 2006-09-12 | Sharp Kabushiki Kaisha | Pixel defect detector for solid-state imaging device |
| JP2007174104A (en) * | 2005-12-20 | 2007-07-05 | Fujitsu Ltd | Image processing circuit and image processing method |
| JP2009027252A (en) * | 2007-07-17 | 2009-02-05 | Canon Inc | Image pickup device and imaging apparatus |
| JP2013258596A (en) * | 2012-06-13 | 2013-12-26 | Denso Corp | Image pick-up device |
-
1993
- 1993-07-06 JP JP5166849A patent/JP2903956B2/en not_active Expired - Fee Related
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7106371B1 (en) | 1998-09-08 | 2006-09-12 | Sharp Kabushiki Kaisha | Pixel defect detector for solid-state imaging device |
| EP1178676A1 (en) * | 2000-07-31 | 2002-02-06 | Hitachi Kokusai Electric Inc. | Method and device for detecting defective pixels of a solid-state colour image-pickup apparatus |
| US6950133B2 (en) | 2000-07-31 | 2005-09-27 | Hitachi Kokusai Electric Inc. | Method of detecting defective pixels of a solid-state image-pickup device and image-pickup apparatus using the same |
| JP2003304548A (en) * | 2002-04-10 | 2003-10-24 | Canon Inc | Imaging apparatus |
| JP2007174104A (en) * | 2005-12-20 | 2007-07-05 | Fujitsu Ltd | Image processing circuit and image processing method |
| US7978383B2 (en) | 2005-12-20 | 2011-07-12 | Fujitsu Semiconductor Limited | Image processing circuit and image processing method |
| JP2009027252A (en) * | 2007-07-17 | 2009-02-05 | Canon Inc | Image pickup device and imaging apparatus |
| JP2013258596A (en) * | 2012-06-13 | 2013-12-26 | Denso Corp | Image pick-up device |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2903956B2 (en) | 1999-06-14 |
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