Image processing apparatus performing pixel similarity judgment and image processing program

• US 20050069218A1
• Filed: 12/27/2002
• Published: 03/31/2005
• Est. Priority Date: 12/28/2001
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Chen, Zhe-Hong
• Granted Patent: US 7,346,210 B2
• Time in Patent Office: Days
• US Class Current: 382/274
• CPC Class Codes: G06T 7/00 Image analysis

Abstract

An image processing device according to the present invention includes a similarity factor calculating portion locally comparing pixels that compose an image so as to calculate a similarity factor of the pixels in a predetermined direction, and includes an analyzing portion analyzing the structure of the image in accordance with the similarity factor calculated by the similarity factor calculating portion. In particular, the similarity factor calculating portion selects and changes pixels to be compared in accordance with color shift of the image to calculate the similarity factor. As a result, a similarity factor can be calculated with suppressing influence of color shift.

Claims

1. An image processing device, comprising:

a similarity factor calculating portion locally comparing pixels that compose an image so as to calculate a similarity factor of the pixels in a predetermined direction; and

an analyzing portion analyzing structure of the image in accordance with the similarity factor calculated by the similarity factor calculating portion, wherein

the similarity factor calculating portion calculates the similarity factor of the pixels in accordance with positions of the pixels in the image.

2. The image processing device as set forth in claim 1, wherein:

the similarity factor includes a value determined by performing a weighted addition of “

a similarity factor element in same colors obtained by comparing pixels of same colors” and

“

a similarity factor element in different colors obtained by comparing pixels of different colors”

; and

the similarity factor calculating portion changes a weighting coefficient for the weighted addition in accordance with the positions of the pixels whose similarity factor is to be calculated, and calculates the similarity factor thereof.

3. The image processing device as set forth in claim 2, wherein

the similarity factor calculating portion changes the weighting coefficient in accordance with distance from “

the center of the image”

to “

the pixels whose similarity factor is to be calculated”

.

4. The image processing device as set forth in claim 3, wherein

the similarity factor calculating portion changes the weighting coefficient so that weight of the similarity factor element in different colors is smaller at a peripheral part of the image than at the center part of the image.

5. The image processing device as set forth in claim 3, wherein

the similarity factor calculating portion divides the image into a plurality of regions and changes the weighting coefficient for each of the divided regions.

6. The image processing device as set forth in claim 2, wherein

the similarity factor calculating portion changes the weighting coefficient in accordance with a characteristic of color shift of an optical system for generating the image.

7. The image processing device as set forth in claim 1, wherein:

the similarity factor calculating portion calculates a similarity factor including a weighted addition value of “

a similarity factor element in same colors obtained by comparing pixels of same colors” and

“

a similarity factor element in different colors obtained by comparing pixels of different colors”

in a region containing the center of the image; and

the similarity factor calculating portion calculates a similarity factor that does not contain the similarity factor element in different colors, but contains the similarity factor element in same colors in a region other than that containing the center of the image.

8. The image processing device as set forth in claim 1, wherein

the similarity factor calculating portion changes relative location of “

a considered pixel whose similarity factor is to be calculated” and

“

a reference pixel that is referenced when calculating the similarity factor”

in accordance with position of the considered pixel.

9. The image processing device as set forth in claim 8, wherein

the similarity factor calculating portion changes the relative location in accordance with distance from the center of the image to the considered pixel.

10. The image processing device as set forth in claim 9, wherein

the similarity factor calculating portion divides the image into a plurality of regions and changes the relative location for each of the regions.

11. The image processing device as set forth in claim 8, wherein

the similarity factor calculating portion changes the relative location in accordance with a characteristic of color shift of an optical system for generating the image.

12. An image processing device, comprising:

a similarity factor calculating portion locally comparing pixels that compose an image so as to calculate a similarity factor of the pixels in a predetermined direction; and

a pixel value calculating portion referencing the pixels that compose the image so as to obtain a value of a new pixel, wherein

the similarity factor calculating portion calculates the similarity factor of the pixels in accordance with positions of the pixels in the image, and

the pixel value calculating portion changes relative location of “

a considered pixel from which the new value is to be calculated” and

“

a reference pixel that is referenced when calculating the new value”

in accordance with position of the considered pixel and the similarity factor, and calculates the new value of the considered pixel.

13. The image processing device as set forth in claim 12, wherein

the pixel value calculating portion changes the relative location predetermined in accordance with “

distance from the center of the image to the considered pixel”

, according to the similarity factor.

14. The image processing device as set forth in claim 13, wherein

the pixel value calculating portion divides the image into a plurality of regions and changes the relative location predetermined for each of the regions in accordance with the similarity factor.

15. The image processing device as set forth in claim 12, wherein

the pixel value calculating portion changes the relative location predetermined in accordance with “

a characteristic of color shift of an optical system for generating the image”

, according to the similarity factor.

16. The image processing device as set forth in claim 15, wherein:

when the new value contains an element composed of a value of a color that has color shift and the element is calculated, the pixel value calculating portion selects, as the reference pixel, a pixel in a local region selected in accordance with a direction of the color shift and an amount of the color shift; and

the pixel value calculating portion adds with weight the selected reference pixel in accordance with the similarity factor so as to calculate the new value.

17. An image processing program that causes a computer to perform functions of:

a similarity factor calculating portion locally comparing pixels that compose an image so as to calculate a similarity factor of the pixels in a predetermined direction; and

an analyzing portion analyzing structure of the image in accordance with the similarity factor calculated by the similarity factor calculating portion, wherein

the similarity factor calculating portion calculates the similarity factor of the pixels in accordance with positions of the pixels in the image.

18. An image processing program that causes a computer to perform functions of:

a similarity factor calculating portion locally comparing pixels that compose an image so as to calculate a similarity factor of the pixels in a predetermined direction; and

a pixel value calculating portion referencing the pixels that compose the image so as to obtain a value of a new pixel, wherein

the similarity factor calculating portion calculates the similarity factor of the pixels in accordance with positions of the pixels in the image, and

the pixel value calculating portion changes relative location of “

a considered pixel from which the new value is to be calculated” and

“

a reference pixel that is referenced when calculating the new value”

in accordance with position of the considered pixel and the similarity factor, and calculates the new value of the considered pixel.