DEFECT DETECTING DEVICE, DEFECT DETECTING METHOD, IMAGE SENSOR DEVICE, IMAGE SENSOR MODULE, DEFECT DETECTING PROGRAM, AND COMPUTER-READABLE RECORDING MEDIUM

• US 20080205747A1
• Filed: 12/26/2007
• Published: 08/28/2008
• Est. Priority Date: 12/28/2006
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: KUCHII, Toshimasa
• Granted Patent: US 8,391,585 B2
• Time in Patent Office: Days
• US Class Current: 382/149
• CPC Class Codes: G06T 2207/10024 Color image
• CPC Class Codes: G06T 2207/20021 Dividing image into blocks, subimages or windows
• CPC Class Codes: G06T 5/002 Denoising; Smoothing noise processing or correction adapted to be used in an image pickup device containing and electronic image sensor H04N23/81, H04N25/60 - H04N25/67
• CPC Class Codes: G06T 5/005 Retouching; Inpainting; Scratch removal detecting, correction, reducing or removing defects, e.g. non-responsive pixels of solid state image sensors H04N25/68, scratch removal for cinematographic films scanned by electronic image sensor H04N5/253
• CPC Class Codes: G06T 5/20 using local operators
• CPC Class Codes: G06T 5/70 Denoising; Smoothing
• CPC Class Codes: G06T 5/77 Retouching; Inpainting; Scratch removal
• CPC Class Codes: G06T 7/0004 Industrial image inspection
• CPC Class Codes: G06T 7/13 Edge detection

Abstract

A defect detecting device 1 includes a pixel value correcting section 16, a block-division processing section 17, and a defective/non-defective determining section 19. The pixel value correcting section 16 corrects a pixel value of an inspection-target image, on which detection of a defective area is to be carried out, in such a manner that the defective area of the inspection-target image is emphasized with respect to the other areas of the inspection-target image. The block-division processing section 17 divides, into plural blocks, the inspection-target image with pixel values having been corrected, and obtains a block addition value, which is a value obtained by adding pixel values of pixels present in a block, or a block mean value, which is a value obtained by dividing the block addition value by the number of pixels present in the block. The defective/non-defective determining section 19 determines whether the defective area is present or not, by carrying out statistical processing of a statistic processing section 18 to determine whether an outlier of the block addition value or an outlier of the block mean value is present or not. The foregoing realizes a defect detecting device and a defect detecting method, by which defective areas of image-sensor images are emphasized to enable accurate detection of the defective areas.

Claims

1. A defect detecting device that detects, from a digital image, a defective area where a pixel value changes more unevenly than a pixel value in an area surrounding the defective area does, the defect detecting device comprising:

a pixel value correcting section that corrects a pixel value of an inspection-target image, on which detection of the defective area is to be carried out, in such a manner that a pixel value corresponding to an area that is to be detected as the defective area is emphasized with respect to a pixel value of an area other than the defective area; and

a block-division processing section that divides the inspection-target image into plural blocks and obtains a block addition value, which is a value obtained by adding pixel values of pixels present in a block, or a block mean value, which is a value obtained by dividing the block addition value by the number of pixels in the block,

the block addition value or the block mean value being supplied to a defective-area presence determining section that determines whether the defective area is present or not, by carrying out statistical processing to determine whether an outlier of the block addition value or an outlier of the block mean value is present or not.

2. The device of claim 1, wherein

the block-division processing section divides the inspection-target image having undergone correction of the pixel value, which correction is carried out in the pixel value correcting section.

3. The device of claim 1, wherein:

the pixel value correcting section corrects a pixel value of a block thus formed as a result of division carried out in the block-division processing section; and

the block-division processing section obtains the block addition value or the block mean value of each block having undergone correction of the pixel value, which correction is carried out in the pixel value correcting section.

4. The device of claim 1, wherein the pixel value correcting section corrects the pixel value of the inspection-target image on which the block-division processing section has carried out processing to divide the inspection-target image into plural blocks and to obtain the block addition value or the block mean value of the inspection-target image.

5. The device of claim 1, wherein the pixel value correcting section is realized by applying, to the inspection-target image, a filter that causes a change in a pixel value of an area of the inspection-target image in such a manner that the higher the pixel value of the area is, the greater the change becomes.

10. The device of claim 1, wherein the block-division processing section divides the inspection-target image into plural blocks in such a manner that adjacent blocks overlap each other.

11. The device of claim 1, further comprising:

a point defect eliminating section that eliminates, from the inspection-target image, a point defect having a pixel value outstanding from a pixel value around the point defect;

a noise eliminating section that eliminates, by use of a filter, a noise component from the inspection-target image from which the point defect has been eliminated in the point defect eliminating section; and

an image compressing section that compresses the inspection-target image from which the noise component has been eliminated in the noise eliminating section.

12. An image sensor device, comprising a defect detecting device defined in claim 1.

15. An image sensor module, comprising a defect detecting device defined in claim 1.

6. A defect detecting device that detects, from a digital image, a defective area where a pixel value changes more unevenly than a pixel value of an area surrounding the defective area does, the defect detecting device comprising:

a block-division processing section that divides an inspection-target image, on which detection of the defective area is to be carried out, in a block shape predetermined according to a shape of the defective area, and obtains a block addition value, which is a value obtained by adding pixel values of pixels present in a block, or a block mean value, which is a value obtained by dividing the block addition value by the number of pixels present in the block,

the block addition value or the block mean value being supplied to a defective-area presence determining section that determines whether the defective area is present or not, by carrying out statistical processing to determine whether an outlier of the block addition value or an outlier of the block mean value is present or not.

7. The device of claim 6, wherein the block shape is vertically-long rectangular.

8. The device of claim 6, wherein the block shape is horizontally-long rectangular.

13. An image sensor device, comprising a defect detecting device defined in claim 6.

16. An image sensor module, comprising a defect detecting device defined in claim 6.

9. A defect detecting device that detects, from a digital image, a defective area where a pixel value changes more unevenly than a pixel value of an area surrounding the defective area does, the defect detecting device comprising:

an image creating section that creates a color-difference image based on an inspection-target image, on which detection of the defective area is to be carried out; and

a block-division processing section that divides the color-difference image, which is created in the image creating section, into plural blocks, and obtains a block addition value, which is a value obtained by adding pixel values of pixels present in a block, or a block mean value, which is a value obtained by dividing the block addition value by the number of pixels present in the block,

the block addition value or the block mean value being supplied to a defective-area presence determining section that determines whether the defective area is present or not, by carrying out statistical processing to determine whether an outlier of the block addition value or an outlier of the block mean value is present or not.

14. An image sensor device, comprising a defect detecting device defined in claim 9.

17. An image sensor module, comprising a defect detecting device defined in claim 9.

18. A defect detecting method of detecting, from a digital image, a defective area where a pixel value changes more unevenly than a pixel value of an area surrounding the defective area does, the method comprising:

correcting a pixel value of an inspection-target image, on which detection of the defective area is to be carried out, in such a manner that a pixel value corresponding to an area that is to be detected as the defective area is emphasized with respect to a pixel value of an area other than the defective area; and

dividing the inspection-target image into plural blocks and obtaining a block addition value, which is a value obtained by adding pixel values of pixels present in a block, or a block mean value, which is a value obtained by dividing the block addition value by the number of pixels present in the block,

the block addition value or the block mean value being supplied to a defective-area presence determining section that determines whether the defective area is present or not, by carrying out statistical processing to determine whether an outlier of the block addition value or an outlier of the block mean value is present or not.

20. A defect detecting program for causing a computer to execute the method defined in claim 18.

22. A computer-readable recording medium, storing the defect detecting program defined in claim 20.

19. A defect detecting method of detecting, from a digital image, a defective area where a pixel value changes more unevenly than a pixel value of an area surrounding the defective area does, the method comprising:

creating a color-difference image based on an inspection-target image, on which detection of the defective area is to be carried out; and

dividing the color-difference image, which is created in the step of creating a color-difference image, into plural blocks and obtaining a block addition value, which is a value obtained by adding pixel values of pixels present in a block, or a block mean value, which is a value obtained by dividing the block addition value by the number of pixels present in the block,

the block addition value or the block mean value being supplied to a defective-area presence determining section that determines whether the defective area is present or not, by carrying out statistical processing to determine whether an outlier of the block addition value or an outlier of the block mean value is present or not.

21. A defect detecting program for causing a computer to execute the method defined in claim 19.

23. A computer-readable recording medium, storing the defect detecting program defined in claim 21.