IMAGE RECOGNITION DEVICE, FOCUS ADJUSTMENT DEVICE, IMAGING APPARATUS, IMAGE RECOGNITION METHOD AND FOCUS ADJUSTMENT METHOD

• US 20090010492A1
• Filed: 06/18/2008
• Published: 01/08/2009
• Est. Priority Date: 07/03/2007
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: MURAMATSU, Keiko
• Granted Patent: US 8,325,977 B2
• Time in Patent Office: Days
• US Class Current: 382/103
• CPC Class Codes: G02B 7/34 using different areas in a pupil plane
• CPC Class Codes: G06T 7/248 involving reference images or patches

Abstract

An image recognition device includes a detection unit which is configured to detect a first difference between partial information of at least a part of the first image information and the reference information and to detect a second difference between partial information of at least a part of the second image information and the reference information. A recognition unit is configured to recognize a first area corresponding to the reference image in the first image information. A calculation unit is configured to calculate a determination value based on a reference area in the second image information corresponding to the first area by weighting the second difference. The recognition unit is configured to recognize a second area corresponding to the reference image in the second image information based on at least one of the second difference and the determination value.

Claims

1. An image recognition device comprising:

an imaging unit configured to acquire first image information and second image information;

a holding unit configured to hold reference information that functions as a reference image;

a detection unit connected to the holding unit and configured to detect a first difference between partial information of at least a part of the first image information and the reference information and to detect a second difference between partial information of at least a part of the second image information and the reference information;

a recognition unit connected to the holding unit and configured to recognize a first area corresponding to the reference image in the first image information; and

a calculation unit connected to the detection unit and configured to calculate a determination value based on a reference area in the second image information corresponding to the first area by weighting the second difference, the recognition unit being configured to recognize a second area corresponding to the reference image in the second image information based on at least one of the second difference and the determination value.

2. The image recognition device according to claim 1, wherein the detection unit is configured to detect the second difference from each of a plurality of the partial information of the second information, the calculation unit is configured to weight the second difference so that the determination value becomes relatively smaller as the partial information based on which the second difference is detected is closer to the reference area, and the recognition unit is configured to recognize the partial information having a smallest determination value as the second area.

3. The image recognition device according to claim 1, wherein the detection unit is configured to detect the second difference from each of a plurality of the partial information of the second image information, and wherein the calculation unit is configured to calculate the determination value by multiplying the second difference by a coefficient corresponding to a distance between the reference area and the partial information based on which the second difference is detected.

4. The image recognition device according to claim 3, wherein the calculation unit is configured to calculate the determination value so that the determination value increases as the distance increases, and wherein the recognition unit is configured to recognize the partial information having a smallest determination value as the second area.

5. The image recognition device according to claim 1, wherein the detection unit is configured to detect the first difference from each of a plurality of the partial information of the first image information, and wherein the recognition unit is configured to recognize an area of the partial information in which a smallest first difference is detected as corresponding to the reference image.

6. The image recognition device according to claim 1, wherein the calculation unit is configured to calculate the determination value according to a distance between a center of the second image information and the partial information based on which the second difference is detected.

7. The image recognition device according to claim 6, wherein the detection unit is configured to detect the second difference from each of a plurality of the partial information of the second information, the calculation unit is configured to calculate the determination value to decrease as the partial information based on which the second difference is detected approaches the center, and the recognition unit is configured to recognize the partial information having a smallest determination value as the second area.

8. The image recognition device according to claim 1, wherein the detection unit is configured to detect a plurality of second differences in the second image information within a predetermined range from the reference area.

9. The image recognition device according to claim 1, wherein the calculation unit is configured to calculate the determination value by multiplying the second difference by a magnification according to a state of the second difference.

10. The image recognition device according to claim 1, wherein the detection unit is configured to detect the first difference and the second difference using color information and luminance information.

11. A focus adjustment device in the image recognition device according to claim 1, wherein the imaging unit is configured to acquire the first image information and the second image information through an optical system, the focus adjustment device comprising:

a focus detection unit configured to detect a focus state of the optical system at a plurality of detection areas provided in a screen by the optical system;

a selection unit connected to the focus detection unit and configured to select at least one detection area from the plurality of detection areas based on a position of a partial region recognized by the recognition unit and the focus state detected by the focus detection unit; and

a focus adjustment unit configured to perform focus adjustment of the optical system based on the focus state detected by the focus detection unit with respect to the at least one detection area selected by the selection unit.

12. The focus adjustment device according to claim 11, further comprising:

a specifying unit configured to specify at least one detection area from the plurality of detection areas, wherein the calculation unit is configured to calculate the determination value according to a distance between the detection area specified by the specifying unit and the partial information based on which the second difference is detected.

13. The focus adjustment device according to claim 12, wherein the calculation unit is configured to calculate the determination value to decrease as the distance decreases.

14. An imaging apparatus comprising the focus adjustment device according to claim 12.

15. An image recognition method comprising:

acquiring first image information and second image information;

holding reference information that functions as a reference image;

detecting a first difference between partial information of at least a part of the first image information and the reference information;

recognizing a first area corresponding to the reference image in the first image information;

detecting a second difference between partial information of at least a part of the second image information and the reference information;

weighting the second difference based on a reference area in the second image information corresponding to the first area to calculate a determination value; and

recognizing a second area corresponding to the reference image in the second image information based on at least one of the second difference and the determination value.

16. The image recognition method according to claim 15, wherein the second difference is detected from each of a plurality of the partial information of the second information, the second difference is weighted so that the determination value becomes relatively smaller as the partial information based on which the second difference is detected is closer to the reference area, and the partial information having a smallest determination value is recognized as the second area.

17. The image recognition method according to claim 15, wherein the second difference is detected from each of a plurality of the partial information of the second image information, and wherein the determination value is calculated by multiplying the second difference by a coefficient corresponding to a distance between the reference area and the partial information based on which the second difference is detected.

18. The image recognition method according to claim 17, wherein the determination value is calculated to increase as the distance increases, and wherein the partial information having a smallest determination value is recognized as the second area.

19. The image recognition method according to claim 15, wherein the first difference is detected from each of a plurality of the partial information of the first image information, and wherein an area of the partial information in which a smallest first difference is detected is recognized as corresponding to the reference image.

20. The image recognition method according to claim 15, wherein the determination value is calculated according to a distance between a center of the second image information and the partial information based on which the second difference is detected.

21. The image recognition method according to claim 20, wherein the second difference is detected from each of a plurality of the partial information of the second information, the determination value is calculated to decrease as the partial information based on which the second difference is detected approaches the center, and the partial information having a smallest determination value is recognized as the second area.

22. The image recognition method according to claim 15, wherein a plurality of second differences is detected in the second image information within a predetermined range from the reference area.

23. The image recognition method according to claim 15, wherein the determination value is calculated by multiplying the second difference by a magnification according to a state of the second difference.

24. A focus adjustment method in the image recognition method according to claim 15, wherein the first image information and the second image information are acquired through an optical system, the focus adjustment method comprising:

detecting a focus state of the optical system at a plurality of detection areas provided in a screen by the optical system;

selecting at least one detection area from a plurality of detection areas based on the second area and the focus state; and

performing focus adjustment of the optical system based on the focus state of the at least one detection area.

25. The focus adjustment method according to claim 24, further comprising:

specifying at least one detection area from the plurality of detection areas; and

calculating the determination value according to a distance between the specified detection area and the partial information based on which the second difference is detected.

26. The focus adjustment method according to claim 25, wherein the determination value is calculated to decrease as the distance decreases.

27. An image recognition device comprising:

imaging means for acquiring first image information and second image information;

holding means for holding reference information that functions as a reference image;

detection means for detecting a first difference between partial information of at least a part of the first image information and the reference information and to detect a second difference between partial information of at least a part of the second image information and the reference information;

recognition means for recognizing a first area corresponding to the reference image in the first image information; and

calculation means for calculating a determination value based on a reference area in the second image information corresponding to the first area by weighting the second difference, the recognition means being for recognizing a second area corresponding to the reference image in the second image information based on at least one of the second difference and the determination value.