JP2009260470A - Defective pixel correction method and apparatus for imaging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a defective pixel correction method for an imaging device by which a defective pixel correction can easily and accurately be executed without any trouble. <P>SOLUTION: In the defective pixel correction method, when the pixel data of the pixel 2-n of the second row and the n-th column are defective, only the pixel data of the pixel 1-n of the first row and the same column as the defective pixel 2-n of the second row are acquired at the time t1. At the timing of the next time t2, after moving in a row direction by a moving amount x, the pixel data of second row pixels 2-1, 2-2, 2-3, ..., 2-(n-1), 2-(n+1), ..., 2-(m-2), 2-(m-1) and 2-(m) are acquired, and by performing complement so as to replace the pixel data of the defective pixel 2-n with the pixel data of the pixel 1-n acquired at the time t1 and gathering the pixel data, m pieces of the pixel data 2-1, 2-2, 2-3, ..., 2-(n-1), 2-n, 2-(n+1), ..., 2-(m-2), 2-(m-1) and 2-(m) of the second row without omission as a pixel row are outputted. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a defective pixel correction method and apparatus for an imaging apparatus applied to an inspection apparatus such as a scanner or various devices.

  Conventionally, as this type of defective pixel correction device, for example, difference data between pixel data of a target pixel and estimated pixel data calculated from pixel data of peripheral pixels of the target pixel is a threshold value modulated by the estimated pixel data. A function for comparing the pixel data of the target pixel and the estimated pixel data calculated from the pixel data of the peripheral pixels as the corrected pixel data as a comparison result of the comparator. What has (refer patent document 1).

  By the way, when performing defective pixel correction processing in a line sensor which is an example of an imaging device, assuming a line sensor having a one-row configuration in which a predetermined number of pixels are arranged in the column direction, the pixel in the n-th column has a defect. Assuming that accurate pixel data cannot be obtained, the average value of the (n−1) th column pixel data and the (n + 1) th column pixel data arranged on both sides is generally calculated. The average value is output as corrected pixel data in the nth column.

By the way, to determine which pixel has a defect, the pixel level is calibrated by measuring the pixel data of the white level (when the light source emits light) and the black level (when light is blocked) before starting the normal scanning (scanning). It can be easily judged. In addition, if a defective pixel determined in advance at the time of shipping inspection of the line sensor is stored in a memory such as a ROM, it can also be determined by reading the stored information.
Japanese Patent Laid-Open No. 2004-320128 (Summary, FIG. 2)

  In the case of defective pixel correction in the defective pixel correction device according to Patent Document 1 described above, the correction pixel data for the pixel data of the target pixel is calculated from the peripheral pixel data, not the pixel data of the target pixel, based on the comparison result of the comparator. When the estimated pixel data is output, unlike the actual data, it becomes data corrected from the surrounding pixels, so if applied to an inspection device that requires high resolution, missing data in the corrected pixel data cannot be allowed. Therefore, there is a problem that accurate inspection cannot be performed. In such a case, it is sufficient to further improve the resolution of the correction pixel data. However, in practice, the data processing becomes complicated and the circuit becomes large-scale, which makes implementation difficult.

Further, in the case of defective pixel correction processing of the line sensor, pixels arranged on both sides of the defective pixel used as correction pixel data are aligned in the column direction (horizontal direction alignment), and in the moving direction (scanning direction) of the line sensor or subject. Since it is different from the corresponding row direction (vertical direction), it is necessary to shift these members by the pixel interval in the row direction, and it is necessary to average the two obtained pixel data, thereby correcting defective pixels. There is a problem that it is troublesome and cannot be easily executed (particularly, in the case of a configuration in which a plurality of pixel configurations of the line sensor exist in the row direction, it is not always a rational method depending on the position of the defective pixel).
Therefore, a technical problem of the present invention is to provide a defective pixel correction method and apparatus for an image pickup apparatus that can be easily and accurately performed without taking time and effort for correcting defective pixels.

The first invention for solving the above technical problem is:
A defective pixel correction method for an image pickup apparatus in which a plurality of pixel rows in which a predetermined number of pixels are arranged in a column direction are arranged in a row direction,
The same column portion (for example, the second row to the nth column in FIG. 1) adjacent to the row and column position where the defective pixel exists (for example, the first row to the nth column pixel 1-n in FIG. 1). This is a defective pixel correction method for an imaging apparatus, wherein any one of the pixel data of the eye pixel 2-n) is read and replaced with the pixel data of the defective pixel and complemented.
According to this defective pixel correction method, when a defective pixel exists in a certain row and column position, pixel data in the same column portion of another row adjacent to the row is read and used as it is for complementation. Can be corrected, and pixel data having no omission as a pixel row can be acquired.
That is, according to the present invention, it is possible to provide a defective pixel correction method for an imaging apparatus that can be easily and accurately performed without taking time and effort for correcting defective pixels.

The second invention is
A defective pixel correction method for an image pickup apparatus in which a plurality of pixel rows in which a predetermined number of pixels are arranged in a column direction are arranged in a row direction,
In a row and column position where a defective pixel exists (for example, a pixel j-n in the j-th row to the n-th column in FIG. 5) At least one of the pixel data at the same row in the adjacent column [for example, pixel (j-1) -n in the (j−1) th row to the nth column in FIG. 5, the (j + 1) th row to the nth column] Pixel (j + 1) -n, j-th row- (n-1) th column pixel j- (n-1), j-th row- (n + 1) th column pixel j- (n + 1)] A defective pixel correction method for an image pickup apparatus, wherein the pixel data is complemented and complemented.

  According to this defective pixel correction method, when there is a defective pixel at a certain row and column position, the pixel data of the same row in another row adjacent to the row or the pixel data in the same row in another column adjacent to the column In addition to correcting at least one of the pixel data, the defective pixel can be corrected more accurately, and if the pixel data at the same row or row is corrected one or more times, the defective pixel can be corrected continuously. Pixel data that can be corrected and has no omission in all pixels can be acquired.

The third invention is
Pixel data of pixels in the same column in the pixel after the defective pixel is complemented [for example, pixels 1-1 and 2-1, pixels 1-2 and 2-2, pixels 1-3 and 2-3 in FIG. ..., pixels 1- (n-1) and 2- (n-1), pixels 1- (n + 1) and 2- (n + 1), ..., pixels 1- (m-2) and 2- ( m-2), pixels 1- (m-1) and 2- (m-1), and two pixel data of pixels 1- (m) and 2- (m)] are averaged or added. This is a defective pixel correction method for an imaging apparatus.
According to this defective pixel correction method, the SN of each pixel data can be improved.

The fourth invention is:
The pixel row has a color pixel configuration in which pixels in the first row are red, pixels in the second row are green, pixels in the third row are blue, and are sequentially arranged in the row direction.
The interpolation is performed in the row and column positions where defective pixels exist (for example, the first row-nth column R pixel 1-n, second row-nth column G pixel 2-n, third row in FIG. 2). The same column and the same color part (for example, the 4th row-nth column R pixel 4-n, the 5th row-nth column in FIG. 2) adjacent to the row-nth column B pixel 3-n). Only the pixel data of the G pixel 5-n of the eye and the B pixel 6-n of the sixth row-n-th column) are read out, or the other pixel adjacent to the row and column position where the defective pixel exists is read. Same row and same color location [for example, R pixel 1- (n-1) in the first row- (n-1) th column, R pixel 1- (n + 1) in the first row- (n + 1) th column in FIG. 2) , Second row- (n-1) th column G pixel 2- (n-1), second row- (n + 1) th column G pixel 2- (n + 1), third row-th (n) -1) B pixel in column 3- (n-1), 3rd row- (n + 1) An image pickup device for defective pixel correction method and performing reading the pixel data of the eye of the B pixel 3- (n + 1)].
According to this defective pixel correction method, it is possible to accurately correct a defective pixel with respect to a color pixel composed of three primary color pixels, and it is possible to obtain pixel data having no omission in all pixels.

The fifth invention is:
Same-color and same-color pixels in the pixel row after the defective pixel is complemented [for example, 1-1 and 4-1, 1-2 and 4 in the relationship of the first row R pixel and the fourth row R pixel in FIG. -2, 1-3 and 4-3, ..., 1- (n-1) and 4- (n-1), 1- (n + 1) and 4- (n + 1), ..., 1- ( m-2) and 4- (m-2), 1- (m-1) and 4- (m-1), 1-m and 4- (m) two pixel data, as well as the second row G 2-1 and 5-1, 2-2 and 5-2, 2-3 and 5-3, ..., 2- (n-1) and 5- (n -1), 2- (n + 1) and 5- (n + 1), ..., 2- (m-2) and 5- (m-2), 2- (m-1) and 5- (m-1) ), 2- (m) and 5- (m) pixel data, as well as the third row The relationship between the B pixel and the sixth row B pixel is 3-1 and 6-1, 3-2 and 6-2, 3-3 and 6-3, ..., 3- (n-1) and 6- ( n-1), 3- (n + 1) and 6- (n + 1), ..., 3- (m-2) and 6- (m-2), 3- (m-1) and 6- (m- 1), 3- (m) and 6- (m)] are averaged or added, and this is a defective pixel correction method for an imaging apparatus.
According to this defective pixel correction method, the SN of each pixel data can be improved for a color pixel composed of three primary color pixels.

The sixth invention is:
An imaging unit (for example, the camera 1 in FIG. 3) in which a plurality of pixel rows in which a predetermined number of pixels are arranged in the column direction are arranged in the row direction;
Subject moving means for moving a subject imaged by the imaging unit (for example, subject 2 in FIG. 3) in a row direction at a row interval of the predetermined number of pixels;
A data processing unit that reads out one of the pixel data in the same column of another row adjacent to the row where the defective pixel exists and the column position at the time of correcting the defective pixel of the imaging unit and replaces it with the pixel data of the defective pixel, and ,
It is the defective pixel correction apparatus for imaging devices characterized by comprising.

  According to such a configuration, the imaging unit (for example, the camera 1 in FIG. 3) is fixed, and the subject (for example, the subject 2 in FIG. 3) is moved by the subject moving unit so that the row interval between the pixels (for example, X in FIG. 3). The pixel data is read by the data processing unit in the same column position of another row adjacent to the row where the defective pixel exists and the row position in the column position, and is complemented by using it as it is. Thus, it is possible to correct defective pixels and to obtain pixel data having no omission as a pixel row, that is, to perform defective pixel correction easily and accurately.

The seventh invention
An imaging unit (for example, the camera 1 in FIG. 4) in which a plurality of pixel rows in which a predetermined number of pixels are arranged in the column direction are arranged in the row direction;
Scanning moving means for causing the imaging unit to scan in the row direction for each row of the predetermined number of pixels (for example, a movement amount x in the X direction in FIG. 4);
A data processing unit that reads out one of the pixel data in the same column of another row adjacent to the row where the defective pixel exists and the column position at the time of correcting the defective pixel of the imaging unit and replaces it with the pixel data of the defective pixel, and ,
It is the defective pixel correction apparatus for imaging devices characterized by comprising.
According to such a configuration, the subject (for example, the subject 2 in FIG. 4) is fixed, and the imaging unit (for example, the camera 1 in FIG. 4) is moved by the scanning movement unit for each pixel row (for example, X in FIG. 4). As in the case of the sixth aspect of the invention, the defective pixel correction can be easily and accurately executed by the data processing unit by moving the movement amount x) in the direction.

The eighth invention
An imaging unit (for example, the camera 10 in FIG. 6) in which a plurality of pixel rows in which a predetermined number of pixels are arranged in the column direction are arranged in the row direction;
The subject imaged by the imaging unit (for example, subject 2 in FIG. 6) in the row direction with the row spacing times and column spacing times (for example, movement amount ax in the X direction and Y direction in FIG. 6) of the predetermined number of pixels. Subject moving means for moving in the row direction;
Among the pixel data of the row where the defective pixel exists at the time of correcting the defective pixel of the imaging unit, the same column location of another row adjacent to the column position, and the row where the defective pixel exists and the same row location of the other column adjacent to the column position A data processing unit that reads and replaces at least one of the pixel data of defective pixels, and
It is the defective pixel correction apparatus for imaging devices characterized by comprising.

  According to such a configuration, the imaging unit (for example, the camera 10 in FIG. 6) is fixed, and the subject (for example, the subject 2 in FIG. 6) is moved by the subject moving unit to the row interval times and the column interval times (for example, the subject intervals). 6, when there is a defective pixel in a certain row and column position by the data processing unit so that the pixel is moved by the movement amount ax) in the X direction and the Y direction in FIG. 6, In order to complement on the basis of reading at least one of the pixel data at the same row in the other column adjacent to the column, it is possible to correct the defective pixel more accurately, and also correct the pixel data at the same column or the same row. Is performed once or more, it is possible to correct even consecutive defective pixels, and it is possible to acquire pixel data having no omission in all pixels, that is, to perform defective pixel correction simply and accurately.

The ninth invention
An imaging unit (for example, the camera 10 in FIG. 7) in which a plurality of pixels arranged in the column direction are arranged in the row direction;
Scanning movement means for scanning the imaging unit in a row direction and a column direction for each row multiple and column multiple of the predetermined number of pixels (for example, a movement amount ax in the X direction and the Y direction in FIG. 7);
Among the pixel data of the row where the defective pixel exists at the time of correcting the defective pixel of the imaging unit, the same column location of another row adjacent to the column position, and the row where the defective pixel exists and the same row location of the other column adjacent to the column position A data processing unit that reads and replaces at least one of the pixel data of defective pixels, and
It is the defective pixel correction apparatus for imaging devices characterized by comprising.
According to such a configuration, the subject (for example, the subject 2 in FIG. 7) is fixed, and the scanning unit moves the imaging unit (for example, the camera 10 in FIG. 7) for each row multiple and column multiple (for example, for each pixel). As in the case of the eighth invention, the defective pixel correction is simply and accurately executed by the data processing unit by moving in the row direction and the column direction in the movement amounts ax) in the X direction and the Y direction in FIG. can do.

The tenth invention is
The data processing unit includes pixel data of pixels in the same column in the pixel after the defective pixel is complemented [for example, pixels 1-1 and 2-1, pixels 1-2 and 2-2 in FIG. 3 and 2-3, ..., pixels 1- (n-1) and 2- (n-1), pixels 1- (n + 1) and 2- (n + 1), ..., pixel 1- (m- 2) and 2- (m-2), pixels 1- (m-1) and 2- (m-1), and pixels 1- (m) and 2- (m). It is a defective pixel correction device for an imaging device characterized by adding.
According to such a configuration, the SN of each pixel data can be improved.

The eleventh invention is
The pixel row has a color pixel configuration in which the pixels in the first row are red, the pixels in the second row are green, and the pixels in the third row are sequentially arranged in the row direction.
The data processing unit performs the complementation on the row and column positions where defective pixels exist (for example, the first row-nth column R pixel 1-n, the second row-nth column G pixel in FIG. 2). 2-n, third row-n-th column B pixel 3-n) and the same-color and same-color location in another row (for example, the fourth row-n-th column R pixel 4-n, n-th column in FIG. 2) 5th row-nth column G pixel 5-n, 6th row-nth column B pixel 6-n) is read out, or the row and column position where the defective pixel exists 2 in the same row and the same color in the other columns [for example, R pixel 1- (n-1) in the first row- (n-1) th column, R in the first row- (n + 1) th column in FIG. Pixel 1- (n + 1), second row- (n-1) th column G pixel 2- (n-1), second row- (n + 1) th column G pixel 2- (n + 1), second B pixel 3- (n-1) in the 3rd row to the (n-1) th column, Three lines - a first (n + 1) th column of B pixel 3- (n + 1)] imaging device for defective pixel correction apparatus characterized by performing reads the pixel data of the.
According to such a configuration, it is possible to accurately correct a defective pixel with respect to a color pixel composed of three primary color pixels, and it is possible to acquire pixel data having no omission in all pixels.

The twelfth invention is
The data processing unit is configured such that pixels in the same column and same color in the pixel row after the defective pixel is complemented [for example, 1-1 and 4-1 in the relationship between the first row R pixel and the fourth row R pixel in FIG. 1-2 and 4-2, 1-3 and 4-3, ..., 1- (n-1) and 4- (n-1), 1- (n + 1) and 4- (n + 1),. Two pixel data of 1- (m-2) and 4- (m-2), 1- (m-1) and 4- (m-1), 1-m and 4- (m), Similarly, in the relationship between the second row G pixel and the fifth row G pixel, 2-1 and 5-1, 2-2 and 5-2, 2-3 and 5-3, ..., 2- (n-1 ) And 5- (n-1), 2- (n + 1) and 5- (n + 1), ..., 2- (m-2) and 5- (m-2), 2- (m-1) and Two pixels 5- (m-1), 2- (m) and 5- (m) Similarly, in the relationship between the third row B pixel and the sixth row B pixel, the data 3-1 and 6-1, 3-2 and 6-2, 3-3 and 6-3, ..., 3- (n -1) and 6- (n-1), 3- (n + 1) and 6- (n + 1), ..., 3- (m-2) and 6- (m-2), 3- (m-1 ) And 6- (m−1), 3- (m), and 6- (m)] are averaged or added.
According to such a configuration, the SN of each pixel data can be improved for a color pixel composed of three primary color pixels.

Hereinafter, embodiments of a defective pixel correction method and apparatus for an imaging apparatus according to the present invention will be described with reference to the drawings. However, the above-described well-known technique can be applied to determine which pixel has a defect.
(Embodiment 1)
FIG. 1 is a schematic diagram for explaining a defective pixel correction method for a line sensor, which is a monochrome imaging apparatus according to Embodiment 1 of the present invention. This line sensor has a pixel configuration in which a predetermined number m of pixels are arranged in the column direction and two pixel rows are arranged in the row direction. Specifically, the pixel in the first row (first pixel) Pixel rows) are arranged from the first column to the m-th column, and the pixels in the second row (second pixel rows) are also arranged from the first column to the m-th column.
Referring to FIG. 1, the pixels in the first row to the n-th column indicated by hatching (here, m> n, hereinafter referred to as 1-n), or the first pixel indicated by hatching. It is assumed that the pixel data of the pixel in the 2nd row and the nth column (hereinafter referred to as 2-n) is defective.

  First, a case where the pixel data of the pixel 1-n in the first row-nth column is defective will be described. In such a case, in the defective pixel correction method according to the first embodiment, the 1-n pixel data at a certain time t1 is not used as pixel data because it is defective, and the defective pixel in the first row at the timing of time t1. 1st row pixels other than 1-n 1-1, 1-2, 1-3,..., 1- (n-1), 1- (n + 1), ..., 1- (m-2) , 1- (m−1), 1- (m) pixel data, and at the timing of the next time t2, the amount of movement x (pixels in the row direction larger than the pixel center interval y in the column direction in FIG. 1) After moving in the row direction by the center interval x), only the pixel data of the pixel 2-n in the second row that is the same column as the defective pixel 1-n in the first row is acquired, and the pixel data of the pixel 2-n is obtained. Complementing the pixel data of the defective pixel 1-n to complement the pixel data acquired at the timing at time t1 , M pixel data 1-1, 1-2, 1-3,..., 1- (n-1), 1-n, 1- (n + 1) in the first row without any missing pixel rows. , ..., 1- (m-2), 1- (m-1), 1- (m) are output.

  However, here, the first row pixels 1-1, 1-2, 1-3,..., 1- (n-1), 1- (n + 1),. m-2), 1- (m-1), and 1- (m) pixel data are acquired, then pixel data of the pixel 2-n in the second row is acquired at time t2, and time t1, t2 Since the pixel data is rearranged by the time difference of the first row pixels 1-1, 1-2, 1-3,..., 1- (n-1), acquired at the timing of time t1, It is necessary to temporarily hold and store pixel data of 1- (n + 1),..., 1- (m-2), 1- (m-1), 1- (m).

  Next, a case where the pixel data of the pixel 2-n in the second row-nth column is defective will be described. In such a case, in the defective pixel correction method according to the first embodiment, the pixel reading method is changed, and the pixel data of the pixel 1-n in the first row that is the same column as the defective pixel 2-n in the second row at the timing of time t1. Only at the timing of the next time t2, after moving in the row direction by the movement amount x, the second row pixels 2-1, 2-2, 2-3,..., 2- (n−1) ), 2- (n + 1),..., 2- (m−2), 2- (m−1), and 2- (m) pixel data, and the pixel 1 acquired at the timing at time t1. The pixel data is complemented by replacing the pixel data of -n with the pixel data of the defective pixel 2-n, and the pixel data is matched, so that m pixel data 2-1 and 2-2 in the second row without any missing pixel rows are obtained. , 2-3, ..., 2- (n-1), 2-n, 2- (n + 1), ..., 2- (m-2), 2- ( -1), and it outputs a 2-(m). In this case, the amount of stored data can be reduced compared to the previous pattern.

  As a result, even if either the pixel 1-n or the pixel 2-n is defective, the first row pixels 1-1, 1-2, 1-3,. (N-1), 1- (n + 1),..., 1- (m-2), 1- (m-1), 1- (m) pixel data are acquired, and the timing of the next time t2 Then, the second row pixels 2-1, 2-2, 2-3,..., 2- (n-1), 2-n, 2- (n + 1),. By acquiring the pixel data of 2- (m-2), 2- (m-1), and 2- (m), the first row and the second row obtained by the defective pixel correction method according to the first embodiment are obtained. Pixels in a common column without any defect as a pixel row, that is, pixels 1-1 and 2-1, pixels 1-2 and 2-2, pixels 1-3 and 2-3,. (N-1) and 2- n-1), pixels 1- (n + 1) and 2- (n + 1), ..., pixels 1- (m-2) and 2- (m-2), pixels 1- (m-1) and 2- If the two pixel data of (m-1), pixels 1- (m) and 2- (m) are averaged (or may be added), the SN ratio of the pixel data can be significantly improved. .

That is, in the case of the defective pixel correction method according to the first embodiment, one of the pixel data in the same column in another row adjacent to the row and column position where the defective pixel exists is read and replaced with the pixel data of the defective pixel. This is complemented (the pixel configuration of the line sensor is different, and can be similarly applied to defective pixel correction of a pixel configuration in which, for example, three or more pixel rows including a predetermined number m of pixels are arranged in the row direction). Almost no time is required, and it is possible to acquire all pixel data having no missing pixel rows. In other words, when a defective pixel exists in a certain row and column position, pixel data in the same column portion of another row adjacent to the row is read and used as it is for complementation, so that the defective pixel can be corrected accurately. Therefore, according to the defective pixel correction method according to the first embodiment, the defective pixel correction does not take time and can be performed easily and accurately.
As the moving means in the defective pixel correction method according to the first embodiment, the line sensor is fixed and the subject is moved, and the subject is fixed and the line sensor is moved. May be.

  The defective pixel correction apparatus to which the defective pixel correction method according to the first embodiment is applied includes an imaging unit in which a plurality of pixel rows in which a predetermined number of pixels are arranged in the column direction are arranged in the row direction, and an imaging unit. Subject moving means for moving the subject to be imaged in the row direction at the row interval of each pixel, and pixel data in the same column position in the other row adjacent to the row where the defective pixel exists at the time of correcting the defective pixel of the imaging unit and the column position A data processing unit that reads out and replaces the defective pixel data with pixel data of a defective pixel (comprising a pixel data storage and holding function as in the case of the following embodiments) A configuration including the above can be taken as an example. In the case of this defective pixel correction device, the image processing unit is fixed, and the subject is moved by the subject moving means in the row direction with the row interval of each pixel (for example, the movement amount x in FIG. 1). Since pixel data in the same column of another row adjacent to the row and column position where the pixel exists is read and used as it is, the defective pixel correction can be performed easily and accurately.

In another example, instead of the subject moving means, scanning moving means for scanning the imaging unit in the row direction for each row of pixels is provided. In the case of this defective pixel correction apparatus, if the subject is fixed and the imaging unit is moved for each pixel row by the scanning movement means, the defective pixel correction can be easily and accurately executed by the data processing unit. it can.
Incidentally, the technique for moving the subject or the line sensor by the pixel center interval x in the row direction can be applied to the defective pixel correction method and apparatus according to the first embodiment, and will not be described in detail here. Further, in the manufacturing process of the line sensor, for example, a case where the pixels 1-n and 2-n in the row are simultaneously defective (or the same applies to the pixels in the column) may actually occur. In that case, since it is handled as a defective product (NG), the defective pixel correction in such a case is regarded as unexpected.

(Embodiment 2)
FIG. 2 is a schematic diagram for explaining a defective pixel correction method for a line sensor that is a color imaging apparatus according to the second embodiment of the present invention. The pixel configuration of this line sensor is a three primary color (hereinafter referred to as RGB) color in which a predetermined number m of red (red), green (green), and blue (blue) pixels are sequentially arranged in the column direction. Specifically, two pixels are arranged in the row direction. Specifically, the R pixel row is the first row and the fourth row, the G pixel row is the second row and the fifth row, and the B pixel. Rows are arranged as the third row and the sixth row.

  Referring to FIG. 2, the R pixel, which is a pixel in the first row to the n-th column indicated by hatching (here, m> n, and hereinafter referred to as 1-n), Pixel data of a G pixel that is a pixel in the second row to the nth column (hereinafter referred to as 2-n) and a B pixel that is a pixel in the third row to the nth column (hereinafter referred to as 3-n) Is a defect, or a pixel in the 4th row to the nth column (hereinafter referred to as 4-n) indicated by a broken line, and a pixel in the 5th row to the nth column (hereinafter referred to as 4-n). It is assumed that the pixel data of the G pixel, which is denoted as 5-n), and the B pixel, which is the pixel in the sixth row-nth column (hereinafter denoted as 6-n), is defective.

  First, when the R pixel 1-n in the first row-n-th column, the G pixel 2-n in the second row-n-th column, and the B pixel 3-n in the third row-n-th column are defective. Will be explained. In such a case, in the defective pixel correction method according to the second embodiment, the pixel data of the R pixel 1-n, the G pixel 2-n, and the B pixel 3-n at a certain time t1 are not used as defects, but at the time t1. 1st row R pixels 1-1, 1-2, 1-3,..., 1- (n-1), 1- (n + 1),. -(M-2), 1- (m-1), 1- (m) pixel data, second row G pixels 2-1, 2-2, 2-3 other than the defective G pixel 2-n, .., 2- (n-1), 2- (n + 1), ..., 2- (m-2), 2- (m-1), 2- (m) pixel data, defective B pixel 3 Third row B pixels 3-1, 3-2, 3-3 other than -n, 3- (n-1), 3- (n + 1), ..., 3- (m-2) , 3- (m-1), 3- (m) pixel data is acquired and After moving in the row direction by the amount of movement 3x (showing three times the pixel center interval x in the row direction larger than the pixel center interval y in the column direction in FIG. 2) at the timing of t2, the fourth row R pixel 4- Only the pixel data of n, the pixel data of the fifth row G pixel 5-n, and the pixel data of the sixth row B pixel 6-n are obtained, and these pixel data are obtained as the defective R pixel 1-n and defective G pixel 2 respectively. -N, by complementing the pixel data of the defective B pixel 3-n and combining the RGB pixel data acquired at the timing at time t1, m Rs in the first row with no missing pixel rows Pixels 1-1, 1-2, 1-3, ..., 1- (n-1), 1-n, 1- (n + 1), ..., 1- (m-2), 1- ( m-1), 1- (m) pixel data, m G pixels 2-1, 2-2, 2-3,. -(N-1), 2-n, 2- (n + 1), ..., 2- (m-2), 2- (m-1), 2- (m) image data, and the like Three rows of m B pixels 3-1, 3-2, 3-3, ..., 3- (n-1), 3-n, 3- (n + 1), ..., 3- (m -2), 3- (m-1), 3- (m) image data is output.

  However, here, the first row R pixels 1-1, 1-2, 1-3,..., 1- (n-1), 1- (n + 1),. (M-2), 1- (m-1), 1- (m) pixel data, second row G pixels 2-1, 2-2, 2-3, ..., 2- (n-1 ), 2- (n + 1),..., 2- (m-2), 2- (m-1), 2- (m) pixel data, third row B pixel 3-1, 3-2, 3-3, ..., 3- (n-1), 3- (n + 1), ..., 3- (m-2), 3- (m-1), 3- (m) pixel data , The pixel data of the fourth row R pixel 4-n, the pixel data of the fifth row G pixel 5-n, and the pixel data of the sixth row B pixel 6-n are obtained at the timing of time t2. Since the pixel data is rearranged according to the time difference between t1 and t2, 1st row R pixels 1-1, 1-2, 1-3,..., 1- (n-1), 1- (n + 1),. 2), 1- (m-1), 1- (m) pixel data, second row G pixels 2-1, 2-2, 2-3, ..., 2- (n-1), 2 -(N + 1), ..., 2- (m-2), 2- (m-1), 2- (m) pixel data, third row B pixel 3-1, 3-2, 3-3 , ..., 3- (n-1), 3- (n + 1), ..., 3- (m-2), 3- (m-1), 3- (m) pixel data are temporarily stored. I need to remember.

  Next, a case where the pixel data of the fourth row R pixel 4-n, the pixel data of the fifth row G pixel 5-n, and the pixel data of the sixth row B pixel 6-n are defective will be described. In such a case, in the defective pixel correction method according to the second embodiment, the pixel reading method is changed, and at the timing of time t1, the R pixel 1 in the first row in the same row as the defective R pixel 4-n in the fourth row. n pixel data, pixel data of the second row G pixel 2-n that is the same column as the defective G pixel 5-n in the fifth row, and third pixel that is the same column as the B pixel 6-n that is defective in the sixth row Only the pixel data of the B pixel 3-n in the row is acquired, and at the timing of the next time t2, the fourth row R pixel 4-1, 4-2, 4-3 is moved in the row direction by the moving amount 3x. , ..., 4- (n-1), 4- (n + 1), ..., 4- (m-2), 4- (m-1), 4- (m) pixel data, fifth Row G pixels 5-1, 5-2, 5-3, ..., 5- (n-1), 5- (n + 1), ..., 5- (m-2), 5- (m- 1), pixel value of 5- (m) And 6th row B pixels 6-1, 6-2, 6-3, ..., 6- (n-1), 6- (n + 1), ..., 6- (m-2), Pixel data of 6- (m-1) and 6- (m) are acquired, and pixel data of the R pixel 1-n, G pixel 2-n, and B pixel 3-n acquired at the timing at time t1 are obtained. By complementing the pixel data of the defective pixel R pixel 4-n, G pixel 5-n, and B pixel 6-n to match the pixel data, the fourth row with no missing pixel rows R pixels 4-1, 4-2, 4-3, ..., 4- (n-1), 4-n, 4- (n + 1), ..., 4- (m-2), 4 -(M-1), 4- (m) image data, similar 5th row m G pixels 5-1, 5-2, 5-3, ..., 5- (n-1), 5-n, 5- (n + 1), ..., 5- (m-2 , 5- (m−1), 5- (m), and the sixth row m B pixels 6-1, 6-2, 6-3,..., 6- (n− 1), 6-n, 6- (n + 1), ..., 6- (m-2), 6- (m-1), 6- (m) image data is output. In this case, the amount of stored data can be reduced compared to the previous pattern.

  As a result, the first row R pixel 1-n, second row G pixel 2-n, third row B pixel 3-n, or fourth row R pixel 4-n, fifth row G pixel 5-n, Even if any of the 6-row B pixels 6-n is defective, the first-row R pixels 1-1, 1-2, 1-3,..., 1- (n-1) at the timing of time t1. ), 1- (n + 1),..., 1- (m-2), 1- (m-1), 1-m pixel data, second row G pixels 2-1, 2-2, 2- 3, ..., 2- (n-1), 2- (n + 1), ..., 2- (m-2), 2- (m-1), 2-m pixel data, third row B pixels 3-1, 3-2, 3-3, ..., 3- (n-1), 3- (n + 1), ..., 3- (m-2), 3- (m-1 ), 3-m pixel data is acquired, and at the timing of the next time t2, after moving by the moving amount 3x, the fourth row R image Elements 4-1, 4-2, 4-3, ..., 4- (n-1), 4-n, 4- (n + 1), ..., 4- (m-2), 4- ( m-1), 4- (m) pixel data, 5th row G pixel 5-1, 5-2, 5-3,..., 5- (n-1), 5-n, 5- ( n + 1),..., 5- (m-2), 5- (m-1), 5- (m) pixel data, 6th row B pixel 6-1, 6-2, 6-3,. .., 6- (n-1), 6-n, 6- (n + 1),..., 6- (m-2), 6- (m-1), 6- (m) pixel data By obtaining the defect pixel correction method according to the second embodiment, there is a defect in any of the common pixel R pixel, the second row, and the fifth row that are not defective in any of the first row and the fourth row. Two pixel data of G pixel in the common column with no common, and B pixel in the common column with no defect in any of the third and sixth rows Are averaged (or may be added), the SN of RGB pixel data can be improved.

  Incidentally, for the two pixel data here, in the relationship between the first row R pixel and the fourth row R pixel, 1-1 and 4-1, 1-2 and 4-2, 1-3 and 4-3, ..., 1- (n-1) and 4- (n-1), 1- (n + 1) and 4- (n + 1), ..., 1- (m-2) and 4- (m-2) ), 1- (m−1) and 4- (m−1), 1-m and 4- (m), similarly, 2 in the relationship between the second row G pixel and the fifth row G pixel. -1 and 5-1, 2-2 and 5-2, 2-3 and 5-3, ..., 2- (n-1) and 5- (n-1), 2- (n + 1) and 5 -(N + 1), ..., 2- (m-2) and 5- (m-2), 2- (m-1) and 5- (m-1), 2- (m) and 5- ( m) of the two pixel data, similarly 3 in the relationship between the third row B pixel and the sixth row B pixel. -1 and 6-1, 3-2 and 6-2, 3-3 and 6-3, ..., 3- (n-1) and 6- (n-1), 3- (n + 1) and 6 -(N + 1), ..., 3- (m-2) and 6- (m-2), 3- (m-1) and 6- (m-1), 3- (m) and 6- ( m).

That is, in the case of the defective pixel correction method according to the second embodiment, the defective pixel correction method according to the first embodiment is applied to the color pixel configuration, and the complementary row is another row adjacent to the row where the defective pixel exists and the column position. In this case, defective pixels can be accurately corrected, and pixel data having no omission in all pixels can be obtained. Further, the SN of each pixel data can be improved by averaging or adding the pixel data of the same color and same color pixels in a plurality of row pixels after the defective pixels are complemented.
By the way, also in the case of the defective pixel correction method according to the second embodiment, in order to improve the resolution, instead of moving in the row direction by the moving amount 3x for the three pixel intervals, the moving direction x by the one pixel interval is used in the row direction. If defective pixel correction similar to that described above is performed, all pixel data having high resolution and no omission can be acquired.

  When the pixel data of the first row R pixel 1-n, the second row G pixel 2-n, and the third row B pixel 3-n are defective, the first row R pixel 1 is the same as the normal movement operation. -N, after acquiring all of the pixel data except the pixel data of the second row G pixel 2-n and the third row B pixel 3-n and moving in the row direction by the movement amount 3x or the movement amount x, the imaging device Alternatively, the subject is moved in the column direction by the movement amount y, and the first row R pixel 1- (n-1), the second row G pixel 2- (n-1), and the third row B pixel 3- (n-1). ) Or the pixel data of the first row R pixel 1- (n + 1), the second row G pixel 2- (n + 1), and the third row B pixel 3- (n + 1), and the defective pixels 1-n, 2-n, It is also possible to acquire all pixel data having no defect by scanning only one line in order to supplement 3-n pixel data. However, the defective pixel correction in this case is to read out pixel data of the same row and the same color in another row adjacent to the row and column position where the defective pixel exists, and details thereof will be described in the third embodiment below. .

  As for the moving means in the defective pixel correction method according to the second embodiment, for example, as shown in FIG. 3, a camera (line sensor) 1 as an imaging device is fixed and the subject 2 is moved in the X direction (row direction). A case where the object 2 is moved by an amount x and a case where the subject 2 is fixed and the camera (line sensor) 1 as an imaging device is similarly moved in the X direction (row direction) by an amount x as shown in FIG. Yes, either one may be adopted.

  The defective pixel correction apparatus to which the defective pixel correction method according to the second embodiment is applied has the same basic configuration and function as those of the apparatus described in the first embodiment. The difference is that the pixels in the first row are red, the pixels in the second row are green, the pixels in the third row are blue, and the pixels are sequentially arranged in the row direction. In addition, for the data processing unit, complementation is performed by reading out only pixel data of the same color and the same color in another row adjacent to the row where the defective pixel exists and the column position, and the same column in the pixel row after the defective pixel is complemented The difference is that pixel data of the same color pixels is averaged or added.

In the case of this defective pixel correction apparatus, defective pixels can be accurately corrected for color pixels (RGB pixels), pixel data having no omission in all pixels can be acquired, and the SN of each pixel data is improved. be able to.
Incidentally, also in the manufacturing process of the line sensor, for example, the first row R pixel 1-n, second row G pixel 2-n, third row B pixel 3-n, and fourth row R pixel 4- In the case where n, the fifth row G pixel 5-n, and the sixth row B pixel 6-n are defective at the same time (or the same applies to the pixels arranged in a column), this may actually occur. Is treated as a defective product (NG), and in such a case, the defective pixel correction is regarded as unexpected.

(Embodiment 3)
FIG. 5 is a schematic diagram for explaining a defective pixel correction method for an area sensor which is a multi-pixel imaging device according to Embodiment 3 of the present invention. The pixel configuration in this area sensor is configured by arranging k rows × m columns of pixels in which k pixel rows in which a predetermined number m pixels are arranged in the column direction are arranged in a row direction in a matrix.
Referring to FIG. 5, pixel data of a pixel in the j-th row to the n-th column indicated by hatching (here, k> j, and hereinafter referred to as j-n) is defective. A certain case is assumed.

  In such a case, in the defective pixel correction method according to the third embodiment, the pixel data of the pixel j-n at a certain time t1 is not used as a defect, and the defect among the pixels in k rows × m columns at the timing of the time t1. After acquiring k × m−1 pixel data other than the pixel j−n and moving in the X direction (row direction) by the movement amount ax or the movement amount −ax at the timing of the next time t2, the pixel Only pixel data of j- (n−a) or j− (n + 1) is acquired, and the pixel data acquired at the timing of time t1 is complemented so as to be replaced with the pixel data of the defective pixel j−n. By combining them, pixel data of k rows × m columns with no defects is output. Note that a is an integer that may be determined according to the position of the pixel to be acquired.

Similarly, the pixel data of the pixel j-n at a certain time t1 is not used as a defect, and k × m−1 other than the defective pixel j-n among the pixels in k rows × m columns at the timing of the time t1. After acquiring pixel data and moving by the movement amount ax or movement amount -ax in the Y direction (column direction) at the timing of the next time t2, the pixel (j-1) -n or (j + 1) -n By acquiring only pixel data and complementing the pixel data acquired at the timing of time t1 with pixel data of the defective pixel j-n to match the pixel data, there are k rows × m columns of pixels without defects. Output data.
If the correction in the row direction and the column direction, or both corrections are performed once or a plurality of times, it is possible to correct a continuous pixel defect. Even when the imaging device is a color pixel described in the second embodiment, it is possible to acquire pixel data having no defect in all the pixels by correcting the pixel data at the defective pixel position by a similar method.

  Furthermore, k × m−1 pixel data other than the pixel j−n are acquired from the k rows × m columns of pixel data at a timing of a certain time t1, and the X direction (row) is acquired at the timing of the next time t2. Direction) and Y direction (column direction) after moving by the movement amount x, when k × m−1 pixel data excluding pixel j−n from the pixel data of k rows × m columns is acquired, In the pixel data of k rows × m columns acquired at two timings, one pixel data of pixel j−n and two pixel data of k × m−1 pixel data can be acquired. Therefore, for these k × m−1 pixels, the SN of each pixel data can be improved by averaging (or adding) two pieces of pixel data.

That is, in the case of the defective pixel correction method according to the third embodiment, the row where the defective pixel exists, the same column location in the other row adjacent to the column position, and the row location where the defective pixel exists, the same row location in the other column adjacent to the column position. Is read out and replaced with pixel data of defective pixels to complement the pixel data of other pixels adjacent to the row and column position where the defective pixel exists as described briefly in the second embodiment. This includes the case of reading out pixel data at the same location.
Here, when a defective pixel exists in a certain row and column position, at least one of the pixel data of the same column in another row adjacent to the row or the pixel data in the same row in another column adjacent to the column is read out. In order to compensate for this, the defective pixel can be corrected more accurately, and if the pixel data at the same row or row is corrected once or more, it can be corrected even for consecutive defective pixels. Pixel data without any omission can be acquired.

Such effects are the same even when applied when the pixel configuration is the color pixel described in the second embodiment. Complementation in such a case is performed by reading out only the pixel data of the same column and the same color in another row adjacent to the row and column position where the defective pixel exists, or the other column adjacent to the row and column position where the defective pixel exists. It is based on reading out the pixel data of the same color and same color part, and if the pixel data of the same color and same color pixels in the pixel row after the defective pixel is complemented is averaged or added, even for the color pixel The SN of all pixel data can be improved.
As for the moving means in the defective pixel correction method according to the third embodiment, for example, as shown in FIG. 6, a camera (area sensor) 10 as an imaging device is fixed and the subject 2 is moved in the X direction (row direction) or Y When moving in the direction (column direction) with the movement amount ax, as shown in FIG. 7, the subject 2 is fixed and the camera (area sensor) 10 as the imaging device is similarly set in the X direction (row direction) or the Y direction. There are cases in which the movement is made in the (row direction) with the movement amount ax, and either of them may be adopted.

  The defective pixel correction apparatus to which the defective pixel correction method according to the third embodiment is applied includes an imaging unit including a plurality of pixel rows in which a predetermined number of pixels are arranged in the column direction and an imaging unit. Object moving means for moving the object to be imaged in the row direction and the column direction by multiplying the row interval and the column interval of each pixel, and adjacent to the row and column position where the defective pixel exists at the time of correcting the defective pixel of the imaging unit A data processing unit that reads out and replaces at least one of the pixel data of the same row in the other row and the row where the defective pixel exists in the same row adjacent to the column position and replaces it with the pixel data of the defective pixel; A configuration including the above can be taken as an example. In the case of this defective pixel correction apparatus, the imaging unit is fixed, and the subject is moved by the subject moving means at the row interval times and the column interval times of each pixel (for example, the movement amount ax in the X direction and Y direction in FIG. 6). Thus, at least one of the row where the defective pixel exists by the data processing unit, the same column location of the other row adjacent to the column position, and the row where the defective pixel exists, the pixel data of the same row location of the other column adjacent to the column position. In addition to correcting pixel data more accurately, the defective pixel can be corrected more accurately, and if defective pixel data is corrected at the same row or row at least once, it can be corrected even for consecutive defective pixels. It is possible to acquire pixel data having no missing pixels, that is, to execute defective pixel correction simply and accurately.

In another example, instead of the subject moving means, the imaging unit is scanned in the row direction and the column direction for each row multiple and column multiple (for example, the movement amount ax in the X direction and Y direction in FIG. 7). Scanning movement means is provided. In the case of this defective pixel correction apparatus, if the subject is fixed and the imaging unit is moved for each pixel row by the scanning movement means, the defective pixel correction can be easily and accurately executed by the data processing unit. it can.
Incidentally, since the defective pixel correction method and apparatus according to the third embodiment targets an area sensor having a large number of pixel configurations as an imaging device, it is different from the case of the line sensor described in the first and second embodiments. Further, pixel correction is also assumed in the case where pixels in a row or row are continuously defective at the same time.

It is the schematic diagram shown in order to demonstrate the defective pixel correction method for line sensors which is the monochrome imaging device which concerns on Embodiment 1 of this invention. It is the schematic diagram shown in order to demonstrate the defective pixel correction method for line sensors which is a color imaging device which concerns on Embodiment 2 of this invention. FIG. 6 is a schematic diagram illustrating a relationship between a fixed imaging device and a moved subject as an example of a moving unit applied in the defective pixel correction method according to the second embodiment. FIG. 10 is a schematic diagram illustrating a relationship between a moving imaging apparatus and a fixed subject as another example of a moving unit applied in the defective pixel correction method according to the second embodiment. It is the schematic diagram shown in order to demonstrate the defective pixel correction method for area sensors which is a multi-pixel imaging device concerning Embodiment 3 of this invention. FIG. 10 is a schematic diagram illustrating a relationship between a fixed imaging device and a moved subject as an example of a moving unit applied in the defective pixel correction method according to the third embodiment. FIG. 10 is a schematic diagram illustrating a relationship between a moving imaging apparatus and a fixed subject as another example of a moving unit applied in the defective pixel correction method according to the third embodiment.

Explanation of symbols

1, 10 cameras, 2 subjects

Claims (12)

A defective pixel correction method for an image pickup apparatus in which a plurality of pixel rows in which a predetermined number of pixels are arranged in a column direction are arranged in a row direction,
A defective pixel correction method for an imaging apparatus, comprising: reading out one of pixel data in the same column in another row adjacent to a row and column position where a defective pixel exists, replacing the pixel data with pixel data of the defective pixel, and complementing the pixel data . A defective pixel correction method for an image pickup apparatus in which a plurality of pixel rows in which a predetermined number of pixels are arranged in a column direction are arranged in a row direction,
Read out at least one of the row where the defective pixel exists, the same column location in the other row adjacent to the column position, and the pixel data in the same row location in the other column adjacent to the row where the defective pixel exists. A defective pixel correction method for an imaging apparatus, wherein the pixel data is replaced with pixel data and complemented.   3. The defective pixel correction method for an imaging apparatus according to claim 1, wherein pixel data of pixels in the same column in the pixel after the defective pixel is complemented is averaged or added. The pixel row has a color pixel configuration in which pixels in the first row are red, pixels in the second row are green, pixels in the third row are blue, and are sequentially arranged in the row direction.
The interpolation is performed by reading out only pixel data in the same column of another row adjacent to the row and column position where the defective pixel exists, or the same row and same color portion of the other column adjacent to the row and column position where the defective pixel exists. The defective pixel correction method for an imaging apparatus according to claim 1, wherein the pixel data is read out and performed.   5. The defective pixel correction method for an imaging apparatus according to claim 4, wherein pixel data of pixels in the same column and the same color in the pixel row after the defective pixels are complemented are averaged or added. An imaging unit comprising a plurality of pixel rows arranged in a row direction, each having a predetermined number of pixels arranged in a column direction;
Subject moving means for moving a subject imaged by the imaging unit in a row direction at a row interval of the predetermined number of pixels;
A data processing unit that reads out one of the pixel data in the same column of another row adjacent to the row where the defective pixel exists and the column position at the time of correcting the defective pixel of the imaging unit and replaces it with the pixel data of the defective pixel, and ,
A defective pixel correction device for an imaging apparatus, comprising: An imaging unit comprising a plurality of pixel rows arranged in a row direction, each having a predetermined number of pixels arranged in a column direction;
Scanning moving means for causing the imaging unit to scan in a row direction for each row of the predetermined number of pixels;
A data processing unit that reads out one of the pixel data in the same column of another row adjacent to the row where the defective pixel exists and the column position at the time of correcting the defective pixel of the imaging unit and replaces it with the pixel data of the defective pixel, and ,
A defective pixel correction device for an imaging apparatus, comprising: An imaging unit comprising a plurality of pixel rows arranged in a row direction, each having a predetermined number of pixels arranged in a column direction;
Subject moving means for moving a subject imaged by the imaging unit in a row direction and a column direction at a row interval times and a column interval times the predetermined number of pixels;
Among the pixel data of the row where the defective pixel exists at the time of correcting the defective pixel of the imaging unit, the same column location of another row adjacent to the column position, and the row where the defective pixel exists and the same row location of the other column adjacent to the column position A data processing unit that reads and replaces at least one of the pixel data of defective pixels, and
A defective pixel correction device for an imaging apparatus, comprising: An imaging unit comprising a plurality of pixel rows arranged in a row direction, each having a predetermined number of pixels arranged in a column direction;
Scanning moving means for scanning the imaging unit in a row direction and a column direction for each row multiple and column multiple of the predetermined number of pixels;
Among the pixel data of the row where the defective pixel exists at the time of correcting the defective pixel of the imaging unit, the same column location of another row adjacent to the column position, and the row where the defective pixel exists and the same row location of the other column adjacent to the column position A data processing unit that reads and replaces at least one of the pixel data of defective pixels, and
A defective pixel correction device for an imaging apparatus, comprising:   10. The imaging apparatus according to claim 6, wherein the data processing unit averages or adds pixel data of pixels in the same row in pixels after the defective pixels are complemented. 10. Defective pixel correction device. The pixel row has a color pixel configuration in which the pixels in the first row are red, the pixels in the second row are green, and the pixels in the third row are sequentially arranged in the row direction.
The data processing unit reads out only the pixel data of the same column in another row adjacent to the row and column position where the defective pixel exists, or is adjacent to the row and column position where the defective pixel exists. The defective pixel correction apparatus for an imaging apparatus according to any one of claims 6 to 9, wherein pixel data of the same row and same color part in another column is read out.   12. The defective pixel correction device for an imaging device according to claim 11, wherein the data processing unit averages or adds pixel data of the same color and same color pixels in the pixel row after the defective pixel is complemented.

Images