JP2002176587A - Picture input device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a picture input device which minimizes the occurrence of a defective pixel to let out more normal pixels. SOLUTION: A two-dimensional sensor which can switch the pixel letting-out direction to two directions is provided, and this two-dimensional sensor examines positions of defective pixels and selects the direction in which more pixels in the normal level can be obtained, and switches the direction to let out pixels.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image input device, and more particularly, to an image input device having a two-dimensional sensor.

[0002]

2. Description of the Related Art A conventional image input device (for example, an image scanner, a CCD camera, a digital camera, etc.) is shown in FIG.
As shown in FIG. 3, a photoelectric conversion unit 5 for taking in an image from the outside
01, a timing generator 502 for controlling the operation of the photoelectric conversion unit, a pixel defect detection unit 503 for detecting a pixel for which a normal-level output cannot be obtained from the captured image data (hereinafter referred to as a defective pixel), and using peripheral pixels. It comprises a defective pixel correction unit 504 for correcting defective pixels, an image storage memory 505 for storing corrected image data, and the like.

[0005] A timing generator 502 is connected to the photoelectric conversion unit 501, and the photoelectric conversion unit 501 operates to take in image data under the control of the timing generator 502. The photoelectric conversion unit 501 includes:
The pixel defect detection unit 503 is connected, and the captured image data is detected as a defective pixel by a method of comparing with the peripheral pixels.

[0004] A defective pixel correction unit 504 is connected to the pixel defect detection unit 503, and correction is performed using pixels around the defective pixel. Further, an image storage memory 505 is connected to the defective pixel correction unit 504, and stores the corrected pixel data.

At this time, in a two-dimensional sensor used for an image input device, as the number of pixels increases, a large number of defective pixels are included. The main causes of the generation of such defective pixels include those caused by the failure of the photoelectric conversion element for each pixel and those caused by the failure of the CCD for vertical transfer.

If such defective pixels are present in an extremely large number, problems may occur when the acquired image is enlarged and displayed or when the acquired image is recognized. For this reason, such a defective pixel is normally corrected using normal pixels existing around the defective pixel. For example, if the photoelectric conversion element for each pixel is defective, only that pixel is processed as a pixel defect.

[0007]

However, when there is a defect in the vertical transfer CCD, there is a problem that a plurality of defective pixels are generated because one pixel is defective. That is, if there is a defect in the vertical transfer CCD, FIG.
As shown in FIG. 4, when normal pixel data is vertically transferred and passes through a pixel defect position, the normal pixel data is destroyed and a new defective pixel is generated. As described above, when there is a defect in the CCD for vertical transfer, there is a problem that defective pixels are generated one after another due to defective one pixel.

Accordingly, it is an object of the present invention to provide a new and improved image input apparatus capable of discharging more normal pixels while minimizing the generation of defective pixels.

[0009]

According to a first aspect of the present invention, there is provided an image input apparatus having a two-dimensional sensor, wherein the two-dimensional sensor is configured to set a pixel discharge direction in two directions, up and down. A pixel discharge direction switching means capable of switching to a normal output, a pixel determination means for determining whether or not the pixel is a pixel capable of obtaining a normal level output, and a position of a defective pixel for which a normal level output is not obtained. An image input apparatus comprising: a defective pixel position investigating unit; and a pixel discharging direction determining unit that determines a pixel discharging direction in which more normal level pixels are obtained according to the position of the defective pixel. Is done.

In the invention described in this section, the image is discharged far from the defect position of the vertical transfer CCD.
The number of defective pixels can be reduced as compared with the conventional case where an image is discharged.

According to a second aspect of the present invention, there is provided an image input apparatus having a two-dimensional sensor, wherein the two-dimensional sensor divides image data into two upper and lower regions and outputs the image data simultaneously. Data division output means, pixel discharge direction switching means capable of switching the pixel discharge direction in the upper and lower two directions for each of the two upper and lower areas, and determine whether the pixel is a pixel capable of obtaining a normal level output Pixel determining means; defective pixel position investigating means for examining the position of a defective pixel for which an output of a normal level cannot be obtained for each of the two upper and lower regions; An image input device is provided, comprising: a pixel discharge direction determining means for determining a pixel discharge direction in which more normal level pixels are obtained for every two regions.

In the invention described in this section, the image data is divided into two regions, and the pixels are discharged in the direction in which the defective pixels do not pass through each region as much as possible, so that the number of defective pixels can be further reduced. . For example, vertical transfer CCD
If the defect position is close to the pixel ejection division point, the pixels in the upper region are ejected upward, and the pixels in the lower region are ejected downward. The number of pixels can be reduced.

According to a third aspect of the present invention, there is provided an image input apparatus including a two-dimensional sensor, wherein the two-dimensional sensor divides image data into four areas, that is, up, down, left, and right, and outputs the divided areas at the same time. Image data division and output means, pixel discharge direction switching means capable of switching the pixel discharge direction up and down two directions for each of the four regions, and determine whether the pixel is a pixel capable of obtaining a normal level output. A pixel judging means for judging, a defective pixel position investigating means for investigating a position of a defective pixel for which an output of a normal level is not obtained for each of the four upper, lower, left, and right regions; A pixel discharge direction determining means for determining a pixel discharge direction in which more normal level pixels can be obtained for each of the four regions. It is.

In the invention described in this section, the image data is divided into four regions, and pixels are discharged in a direction in which the defective pixels do not pass through each region as much as possible, so that the number of defective pixels can be reduced. For example, when the defect position of the vertical transfer CCD is close to the pixel ejection division point, pixels are ejected by selecting an upward direction or a downward direction for each area, so that defective pixels can be effectively reduced.

According to a fourth aspect of the present invention, there is provided an image input apparatus including a two-dimensional sensor, wherein the two-dimensional sensor is capable of switching a pixel discharge direction between upper and lower directions. Direction switching means, pixel determining means for determining whether the pixel is a normal pixel from which a normal level output can be obtained, and normal level output can be obtained for an image output from one of the vertical directions. A defective pixel position investigating unit for inspecting the position of a defective pixel, and judging that the pixel corresponding to the defective pixel position of the image discharged from the one direction is a normal pixel in the image data output from the other direction. In this case, there is provided pixel replacement means for replacing a normal pixel of the image data output from the other direction with a defective pixel of the image data output from the one direction. Image input device is provided, characterized and.

According to the invention described in this section, the same image is photographed twice and is discharged from the CCD in two directions, and defective pixels of image data output from one direction are defective pixels of image data output from the other direction. Since the image is output after being replaced by a normal pixel corresponding to the pixel, the number of defective pixels can be significantly reduced as compared with the case of normally discharging an image.

[0017]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
In the following description and the accompanying drawings, components having the same functions and configurations are denoted by the same reference numerals, and redundant description will be omitted.

(First Embodiment) A first embodiment will be described with reference to FIG. FIG. 1 is a block diagram showing the configuration of the image input device according to the present embodiment.

First, as shown in FIG.
Reference numeral 00 denotes a photoelectric conversion unit 101 that takes in an image from the outside, and a timing generator 10 that controls the operation of the photoelectric conversion unit.
2, a multiplexer 107 for switching image data discharged and output from the photoelectric conversion unit 101 in two directions, a pixel defect detection unit 103 for detecting a defective pixel from the captured image data, and a defective pixel for correcting a defective pixel using peripheral pixels It comprises a correction unit 104, an image storage memory 105 for storing image data in which defective pixels have been corrected, a pixel rearrangement processing unit 106 for inverting image data, and the like.

A timing generator 102 is connected to the photoelectric conversion unit 101, and the photoelectric conversion unit 101 is operated under the control of the timing generator 102 to capture image data. Further, a multiplexer 107 is connected to the photoelectric conversion unit 101, and can switch image data that is discharged and output from the photoelectric conversion unit 101 in two directions.

That is, the photoelectric conversion unit 101 can selectively output image data in two directions as shown in FIG. Here, the position of the defective pixel in the image data including the obtained defective pixel is recognized, and the distance a to the discharge position in the discharge direction A and the distance b to the discharge position in the discharge direction B are obtained. At this time, when the discharge distance a> the discharge distance b, the discharge direction of the pixel is set to the direction A, and when the discharge distance a <the discharge distance b, the discharge direction is set to the direction B. Is operated to reduce the number of defective pixels during subsequent image acquisition.

Further, the multiplexer 107 is connected to the pixel defect detection unit 103 and the pixel defect detection unit 1
In 03, a defective pixel in the captured image data is detected by a method of comparing with a peripheral pixel or the like. A defective pixel correction unit 104 is connected to the pixel defect detection unit 103, and the defective pixel correction unit 104 performs correction using pixels around the defective pixel.

Further, the defective pixel correction section 104 is connected to an image storage memory 105 and stores corrected pixel data. At this time, for example, if the discharge direction A is a normal pixel discharge direction, discharging pixels in the discharge direction B results in an image that is inverted in the vertical direction.
Therefore, the image data is inverted upside down and output by the pixel rearrangement processing unit 103.

The image output in this manner will be described with reference to FIG. When pixels are discharged in the image input apparatus according to the present embodiment, as shown in FIG. 3A, an image is discharged in a direction far from the defective pixel position of the vertical transfer CCD. The number of defective pixels can be reduced as compared with the case where pixels are discharged in a direction closer to the defect position shown in FIG.

In this embodiment, a vertical transfer CCD is used.
Since the image is discharged in a direction far from the defective pixel position, the number of defective pixels can be reduced as compared with the case where the image is discharged in a direction close to the defective position.

(Second Embodiment) Next, a second embodiment will be described with reference to FIG. FIG. 4 is a block diagram illustrating a configuration of the image input device according to the present embodiment. The image input device according to the present embodiment is different from the first embodiment in that image data output from the photoelectric conversion unit is divided into upper and lower parts and output simultaneously.

First, as shown in FIG. 4, the image input apparatus according to the present embodiment includes a photoelectric conversion unit 201 for taking in an image from outside, a timing generator 202 for controlling the operation of the photoelectric conversion unit, Pixel defect detection units 203 and 208 for detecting pixels, and defective pixel correction units 204 and 20 for correcting defective pixels using peripheral pixels
9. Image storage memory 2 for storing corrected image data
05, Pixel rearrangement processing unit 2 for inverting image data
06 and the like.

The image input device according to the present embodiment has a first
Unlike the embodiment, the image data output from the photoelectric conversion unit is divided into upper and lower parts and output simultaneously. For this reason,
Each of the pixel defect detection unit and the defective pixel correction unit is configured to have two circuits. Therefore, unlike the first embodiment, a multiplexer is not required.

In the image input apparatus having the above configuration, the photoelectric conversion unit 20 is controlled by the timing generator 202.
1 is divided into upper areas (A areas) and lower areas (B
In this case, the image data is divided into upper and lower parts so that the image data is divided into upper and lower parts. Next, the upper image data of the upper and lower divided image data is sent to the pixel defect detector 203 which detects defective pixels in the upper region. On the other hand, the lower image data is sent to a pixel defect detector 208 that detects defective pixels in the lower region. Each defective pixel detector 2
In steps 03 and 208, a defective pixel is detected by a method such as comparing the image data of each area with peripheral pixels. further,
In the defective pixel correction units 204 and 209, the correction is performed using the peripheral pixels of the defective pixel and stored in the image storage memory 205.

At this time, as shown in FIG. 5, the position of the defective pixel in the acquired image data is determined by two upper and lower areas (A area,
B region). At this time, for the defective pixel recognized in the area A, the distance a from the upper end of the image data is
1. A distance a2 from the division line and a distance a3 from the lower end of the image data are obtained. On the other hand, for the defective pixel recognized in the area B, the distance b1 from the lower end of the image data, the distance b2 from the division line, and the distance b3 from the upper end of the image data are obtained.

As described above, the above values are obtained for all the defective pixels existing in the area A and the area B of the image data. The pixel discharge direction of the defective pixel for which the above value is obtained is determined according to the conditions shown in FIG. 6, and the pixel is discharged in a predetermined direction by the operation of the timing generator 202.

That is, in the present embodiment, each area has a two-dimensional sensor capable of outputting in two directions in the vertical direction. Can be determined. As a result, the generation of defective pixels can be reduced more effectively than in the first embodiment.

At this time, assuming that the discharge direction A is the normal pixel discharge direction, when the pixels are discharged in the discharge direction B, the image is upside down. For this reason, the pixel rearrangement processing unit 206 outputs the image data after inverting the image data upside down.

FIG. 7 shows the output image data at this time. In the image input device according to the present embodiment, as shown in FIG. 7A, when a defective pixel of the vertical transfer CCD exists at a position near the division point, the defective pixel is prevented from passing through the defective pixel. Each of the pixels in the upper region discharges the pixel in the upper direction, and the lower pixel discharges the pixel in the lower direction. As a result, as shown in FIG. 7B, the number of defective pixels can be reduced as compared with the case where images are discharged in the same direction.

In the present embodiment, the image data is divided into two regions, and pixels are discharged in the direction in which defective pixels do not pass through each region as much as possible. The number of defective pixels can be reduced

Third Embodiment Next, a third embodiment will be described with reference to FIGS. Note that FIG.
1 is a block diagram illustrating a configuration of an image input device according to the present embodiment.

The image input device according to the present embodiment
In the embodiment of FIG.
Image data is input by dividing the area. Also, four circuits are provided so that a pixel defect detection unit and a defective pixel correction unit correspond to each image area.

First, as shown in FIG. 8, under the control of the timing generator 302, the photoelectric conversion unit 301 is operated with the output divided into four parts in the upper, lower, left and right directions, and the image data divided into four parts in the upper, lower, left and right directions is taken in. Next, the image data divided into four is sent to the pixel defect detection unit 303 for detecting the defective pixel in the area A, and the image data in the area A shown in FIG. Pixel detector 31
0, the image data in the C area is sent to a defective pixel detection unit 308 that detects a defective pixel in the C area, and the image data in the D area is output to a defective pixel detection unit 3 that detects a defective pixel in the D area.
11 is sent. Each defective pixel detector 303, 308, 3
In steps 10 and 311, a defective pixel in each area is detected by a method of comparing with a peripheral pixel or the like, and then sent to the defective pixel correction units 304, 312, 309, and 313 for each area, and a defect is detected using the peripheral pixel. After the pixels are corrected, they are stored in the image storage memory 305.

Here, as shown in FIG. 9, the position of the defective pixel in the acquired image data is examined, and the defective pixel in the area A is located at a distance a1 from the upper end and a distance a2 from the division line.
And the distance a3 from the lower end. For the defective pixel in the area B, a distance b1 from the lower end, a distance b2 from the division line, and a distance b3 from the upper end are obtained. For the defective pixel in the area C, a distance c1 from the upper end, a distance c2 from the division line, and a distance c3 from the lower end are obtained. For the defective pixel in the D area, a distance d1 from the lower end, a distance d2 from the division line, and a distance d3 from the upper end are obtained. These values are obtained for all defective pixels in each area.

Thereafter, the pixel discharge direction for each area is determined according to the conditions shown in FIG. 10, and the pixels are discharged in a predetermined direction by the operation of the timing generator 302.

That is, the present embodiment has a two-dimensional sensor capable of outputting to each of the four regions in the upper, lower, left and right regions, and in each region, the discharge direction of the pixels so that the normal pixels do not pass through the defective pixels as much as possible. Is determined. As a result, the second
As compared with the embodiment, the generation of defective pixels can be reduced more effectively.

At this time, assuming that the discharge directions A and C are normal pixel discharge directions, when pixels are discharged in the discharge directions B and D, the image is inverted up and down. Therefore, the pixel rearrangement processing unit 306 outputs the image data after inverting the image data upside down.

At this time, the output image data is
Shown in In the image input device according to the present embodiment,
As shown in FIG. 11A, the defect position of the vertical transfer CCD is determined for each of the four regions, and when the defective pixel existing in each of the four regions is located at a position close to the pixel discharge division point. In the above, each pixel in the upper region discharges a pixel upward so as not to pass through a defective pixel, and a certain lower pixel discharges a pixel downward. As a result, as shown in FIG. 11 (b), compared to the case where images are ejected in the same direction,
The number of defective pixels can be reduced.

In the present embodiment, the image data is divided into four regions, and pixels are discharged in the direction in which defective pixels do not pass through each region as much as possible. The number of defective pixels can be reduced.

(Fourth Embodiment) Next, a fourth embodiment will be described with reference to FIG. Note that FIG.
FIG. 4 is an explanatory diagram for describing an image input method according to the embodiment. Note that the configuration of the image input apparatus of the present embodiment is the same as that of the first embodiment, and a description thereof will be omitted.

Hereinafter, the operation of the image input apparatus according to this embodiment will be described with reference to FIGS. 3, 4, and 12.

First, as shown in FIG. 3, under the control of the timing generator 102, the photoelectric conversion unit 101 is operated to capture image data. Next, the captured image data is output from the photoelectric conversion unit 101 so that the discharge direction is the A direction, and a defective pixel is detected by a pixel defect detection unit that detects a defective pixel by a method of comparing with a peripheral pixel. Next, the defective pixel correction unit corrects the defective pixel using the peripheral pixels, and stores the image data in the image storage memory 105.
To be stored.

Furthermore, in the present embodiment, unlike the first embodiment, the photoelectric conversion unit 101 takes in the image data again and outputs the image data from the photoelectric conversion unit 101 so that the discharge direction becomes the B direction. After that, the image data output in the B direction is stored in another area of the image storage memory 105 in the same manner as described above.

Further, the position of the defective pixel is examined in the image data in the ejection direction A among the two acquired image data. At this time, if the position of the defective pixel in the discharge direction A and the pixel at the same position in the image data in the discharge direction B are normal pixels, the defective pixel is stored in the pixel reordering unit 106 as a replaceable pixel. . After such processing is performed for all defective pixels in the image data in the discharge direction A, the replaceable defective pixels are replaced by the pixel rearranging unit 106 with the image data in which the image data in the discharge direction B has been replaced with the normal pixels. Is output.

At this time, the output image data is
Shown in The image input device according to the present embodiment has the configuration shown in FIG.
(A) As shown in FIG.
The discharge is performed in one discharge direction, and the defective pixel is replaced with one normal pixel and output. As a result, FIG.
As shown in (b), the number of defective pixels can be significantly reduced as compared with the case where image data is discharged only once in the same direction.

In the present embodiment, the same image is photographed twice and discharged from the CCD in two directions, and defective pixels of image data output from one direction are defective pixels of image data output from the other direction. Is output after being replaced by normal pixels corresponding to the normal pixel, so that the number of defective pixels can be significantly reduced as compared with the case of normally discharging an image.

Although the preferred embodiment according to the present invention has been described above, the present invention is not limited to this configuration.
Those skilled in the art can envisage various modified examples and modified examples within the scope of the technical idea described in the claims, and those modified examples and modified examples are also included in the technical scope of the present invention. It is understood to be included in.

[0053]

Since the position of the defective pixel is recognized and the pixel is discharged so as not to pass through the defective pixel as much as possible, the number of defective pixels can be reduced effectively.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an image input device according to a first embodiment.

FIG. 2 is an explanatory diagram for explaining a relationship between a position of a defective pixel and a discharge direction of the pixel in the image input device according to the first embodiment;

FIG. 3 is an explanatory diagram for explaining an image output by the image input device according to the first embodiment;

FIG. 4 is a block diagram illustrating a configuration of an image input device according to a second embodiment;

FIG. 5 is an explanatory diagram for explaining a relationship between a position of a defective pixel and a discharge direction of the pixel in the image input device according to the second embodiment.

FIG. 6 is an explanatory diagram for explaining a relationship between a position of a defective pixel and an ejection direction of a pixel in each area in the image input device according to the second embodiment;

FIG. 7 is an explanatory diagram for explaining an image output by an image input device according to a second embodiment;

FIG. 8 is a block diagram illustrating a configuration of an image input device according to a third embodiment.

FIG. 9 is an explanatory diagram for explaining a relationship between a position of a defective pixel and a discharge direction of the pixel in the image input device according to the third embodiment.

FIG. 10 is an explanatory diagram for explaining a relationship between a position of a defective pixel and an ejection direction of a pixel in each area in the image input device according to the third embodiment.

FIG. 11 is an explanatory diagram for explaining an image output by an image input device according to a third embodiment;

FIG. 12 is an explanatory diagram for explaining an image input method according to a fourth embodiment.

FIG. 13 is a block diagram illustrating a configuration of a conventional image input device.

FIG. 14 is an explanatory diagram for explaining a mechanism of generating a new defective pixel in a conventional image input device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 image input device 101 photoelectric conversion unit 102 timing generator 103 pixel defect detection unit 104 defective pixel correction unit 105 image storage memory 106 pixel rearrangement processing unit 107 multiplexer

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) H01L 21/339 H04N 1/40 101Z H04N 1/40

Claims (4)

[Claims] 1. An image input apparatus comprising a two-dimensional sensor, said two-dimensional sensor comprising: a pixel discharge direction switching means capable of switching a discharge direction of a pixel up and down two directions; Pixel determining means for determining whether the pixel is a defective pixel, defective pixel position checking means for checking the position of a defective pixel for which a normal level output cannot be obtained, and a normal level pixel according to the position of the defective pixel. And a pixel discharge direction determining means for determining a pixel discharge direction in which more pixels are obtained. 2. An image input apparatus comprising a two-dimensional sensor, wherein the two-dimensional sensor divides image data into two upper and lower regions and outputs the divided data at the same time;
A pixel discharge direction switching means capable of switching a pixel discharge direction between two upper and lower directions for each of the two upper and lower regions; a pixel determining means for determining whether the pixel is a pixel capable of obtaining a normal level output; Defective pixel position checking means for checking the position of a defective pixel for which a normal level output cannot be obtained for each of the upper and lower regions; and a normal level for each of the upper and lower regions according to the position of the defective pixel in the upper and lower regions. A pixel discharge direction determining means for determining a pixel discharge direction in which more pixels are obtained. 3. An image input device having a two-dimensional sensor, wherein the two-dimensional sensor converts image data into four, four and four directions.
Image data division and output means for dividing the image into areas and outputting the same at the same time; pixel discharge direction switching means for switching the pixel discharge direction between up and down two directions for each of the four vertical and horizontal areas; Pixel determining means for determining whether or not the pixel is a defective pixel; defective pixel position checking means for checking the position of a defective pixel for which a normal level output is not obtained for each of the four upper, lower, left, and right regions; A pixel discharge direction determining means for determining a pixel discharge direction in which more normal-level pixels are obtained for each of the four areas in the upper, lower, left and right directions according to the position of the defective pixel. 4. An image input apparatus comprising a two-dimensional sensor, said two-dimensional sensor comprising: a pixel discharge direction switching means capable of switching a pixel discharge direction up and down two directions; Pixel determining means for determining whether or not the pixel is a normal pixel to be detected; and defective pixel position checking means for checking a position of a defective pixel for which an output of a normal level cannot be obtained in an image output from one of the vertical directions. In the image data output from the other direction, when it is determined that the pixel corresponding to the defective pixel position of the image discharged from the one direction is a normal pixel, the image data output from the other direction is determined. An image input device, comprising: pixel replacement means for replacing a normal pixel with a defective pixel of the image data output from the one direction.