Image processing apparatus and image processing method

• US 9,351,650 B2
• Filed: 02/18/2014
• Issued: 05/31/2016
• Est. Priority Date: 02/28/2013
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Uji, Akihito, Imamura, Hiroshi
• Primary Examiner(s): Dinh, Jack
• Application Number:
  US14/182,677
• Publication Number:
  US 20140240668A1
• Time in Patent Office: 833 Days
• Field of Search: 351/206, 351/246
• US Class Current: 1/1
• CPC Class Codes: A61B 3/1025 for confocal scanning
• CPC Class Codes: A61B 3/1241 specially adapted for observation of ocular blood flow, e.g. by fluorescein angiography
• CPC Class Codes: A61B 3/14 Arrangements specially adapted for eye photography apparatus or arrangements for taking photographs per se G03B
• CPC Class Codes: A61B 5/0261 using optical means, e.g. infrared light
• CPC Class Codes: G06V 20/69 Microscopic objects, e.g. biological cells or cellular parts

Abstract

An image processing apparatus obtains an image of an eye area, determines a measurement target among multiple vascular branches based on information regarding multiple vascular branches that include multiple vascular bifurcations in the obtained image, and measures the size of a blood cell aggregate in the determined measurement target.

Claims

1. An image processing apparatus comprising:

an image obtaining unit configured to obtain an image of an eye area;

an information obtaining unit configured to obtain information regarding a plurality of vascular branches that include a plurality of vascular bifurcations in the obtained image;

a determining unit configured to determine a measurement target from the plurality of vascular branches based on the obtained information; and

a measuring unit configured to measure the size of a blood cell aggregate in the determined measurement target.

2. The apparatus according to claim 1, wherein the information obtaining unit obtains at least one value out of a length and a diameter of the plurality of vascular branches as the information regarding the plurality of vascular branches, and

wherein the determining unit determines the measurement target from the plurality of vascular branches based on the obtained value.

3. The apparatus according to claim 2, further comprising:

a vascular branch specifying unit configured to specify the plurality of vascular branches using a region that includes two neighboring vascular bifurcations out of the plurality of vascular bifurcations and a blood vessel between the two vascular bifurcations as one vascular branch,

wherein the information obtaining unit obtains at least one out of the lengths and the vascular diameters of the specified plurality of vascular branches.

4. The apparatus according to claim 2, wherein the determining unit determines a vascular branch among the plurality of vascular branches whose vascular diameter is within a predetermined range as the measurement target.

5. The apparatus according to claim 2, wherein the image obtaining unit obtains a moving image of the eye area as the image, and

wherein the measuring unit measures change in the size of the blood cell aggregate based on the obtained value.

6. The apparatus according to claim 5, further comprising:

a vascular region specifying unit configured to specify a vascular region from the obtained moving image based on change in luminance values in the obtained moving image; and

a vascular bifurcation specifying unit configured to specify the plurality of vascular bifurcations from the specified vascular region.

7. The apparatus according to claim 6, further comprising:

a region-of-interest specifying unit configured to specify a region of interest from the obtained moving image based on the specified vascular region and a parafoveal region in the eye area,

wherein the vascular bifurcation specifying unit specifies the plurality of vascular bifurcations from the specified region of interest,

wherein the information obtaining unit furthermore obtains information regarding a luminance value in the specified region of interest, and

wherein the determining unit determines the measurement target from the specified plurality of vascular branches based on the obtained value and the information regarding the luminance value.

8. The apparatus according to claim 7, wherein the obtained information regarding the luminance value is the difference between luminance values or the distribution of luminance values in the specified region of interest.

9. The apparatus according to claim 6, further comprising:

a vascular region specifying unit configured to specify an avascular region border from the obtained image based on the parafoveal region of the eye area,

wherein the vascular bifurcation specifying unit specifies the plurality of vascular bifurcations from the specified avascular region border.

10. The apparatus according to claim 1, further comprising:

a blood cell aggregate specifying unit configured to specify the blood cell aggregate based on a luminance value that is at or above a threshold value in the determined measurement target,

wherein the measuring unit measures the length of the specified blood cell aggregate as the size.

11. The apparatus according to claim 1, further comprising:

a display control unit configured to cause a display mode to be displayed on a display unit, the display mode indicating at least one of the measured size and a deviation from a statistical value for the size.

12. The apparatus according to claim 11, wherein the display control unit causes the display mode and a normal value range to be displayed on the display unit.

13. An image processing method comprising:

a step of obtaining an image of an eye area;

a step of obtaining information regarding a plurality of vascular branches that include a plurality of vascular bifurcations in the obtained image;

a step of determining a measurement target from the plurality of vascular branches based on the obtained information; and

a step of measuring the size of a blood cell aggregate in the determined measurement target.

14. The method according to claim 13, wherein in the step of obtaining information, at least one value out of the length and the vascular diameter of the plurality of vascular branches is obtained as the information regarding the plurality of vascular branches, and

wherein in the step of determining, the measurement target is determined from the plurality of vascular branches based on the obtained value.

15. The method according to claim 14, further comprising:

a step of specifying the plurality of vascular branches using a region that includes two neighboring vascular bifurcations out of the plurality of vascular bifurcations and a blood vessel between the two vascular bifurcations as one vascular branch,

wherein in the step of obtaining information, at least one value out of the lengths and the vascular diameters of the specified plurality of vascular branches is obtained.

16. The method according to claim 14, wherein in the step of obtaining the image, a moving image of the eye area is obtained as the image, and

wherein in the step of measuring, change in the size of the blood cell aggregate is measured based on the obtained value.

17. A non-transitory computer-readable storage medium storing a program for causing a computer to execute a method comprising:

obtaining an image of an eye area;

obtaining information regarding a plurality of vascular branches that include a plurality of vascular bifurcations in the obtained image;

determining a measurement target from the plurality of vascular branches based on the obtained information; and

measuring the size of a blood cell aggregate in the determined measurement target.