Image processing apparatus, alignment method and storage medium

Patent metadata

Field	Value
Publication number	US-10789721-B2
Application number	US-201816122234-A
Country	US
Kind code	B2
Filing date	Sep 5, 2018
Priority date	Sep 7, 2017
Publication date	Sep 29, 2020
Grant date	Sep 29, 2020

Abstract

An image processing apparatus includes first alignment means configured to perform an alignment in a horizontal direction on a plurality of two-dimensional tomographic images based on measurement light controlled to scan an identical position of an eye according to a first method, and second alignment means configured to perform an alignment in a depth direction on the plurality of two-dimensional tomographic images according to a second method that is different from the first method.

First claim

What is claimed is:

1. An image processing apparatus comprising:
a first alignment unit configured to perform an alignment in a direction intersecting with a depth direction of an eye on a plurality of two-dimensional tomographic images using information regarding to a positional deviation amount obtained by comparing projected images in the depth direction obtained using information regarding to the plurality of the two-dimensional tomographic images, the plurality of two-dimensional tomographic images being obtained based on measurement light controlled to scan an identical position of the eye; and
a second alignment unit configured to perform an alignment in the depth direction on the plurality of two-dimensional tomographic images.

2. The image processing apparatus according to claim 1 , wherein the second alignment unit performs the alignment in the depth direction on the plurality of two-dimensional tomographic images using information regarding to a positional deviation amount obtained by comparing layer boundaries obtained using information regarding to the plurality of two-dimensional tomographic images.

3. The image processing apparatus according to claim 2 , wherein the second alignment unit performs the alignment in the depth direction on the plurality of two-dimensional tomographic images based on a positional deviation amount of layer boundaries obtained from a plurality of regions dividing the two-dimensional tomographic image in the direction intersecting with the depth direction.

4. The image processing apparatus according to claim 3 , wherein the second alignment unit selects a predetermined number of positional deviation amounts from positional deviation amounts of the layer boundaries in the plurality of regions such that a value indicating a variation of the positional deviation amount in a predetermined number of combinations is at a minimum, and performs the alignment in the depth direction on the plurality of two-dimensional tomographic images based on a representative value of the selected positional deviation amounts.

5. The image processing apparatus according to claim 4 ,
wherein the value indicating a variation includes a variance or a standard deviation; and
wherein the value includes an average value or a median value.

6. The image processing apparatus according to claim 1 , further comprising:
an image selection unit configured to select a reference image being a reference for an alignment from the plurality of two-dimensional tomographic images,
wherein the image selection unit selects the reference image based on at least one of (a) a result of a comparison between projected images in the depth direction obtained from the plurality of two-dimensional tomographic images and (b) a result of a comparison between layer boundaries obtained from the plurality of two-dimensional tomographic images.

7. The image processing apparatus according to claim 6 ,
wherein the result of the comparison between projected images in the depth direction obtained from the plurality of two-dimensional tomographic images includes a similarity between the projected images; and
wherein the result of the comparison between layer boundaries obtained from the plurality of two-dimensional tomographic images includes a positional deviation amount of the layer boundaries.

8. The image processing apparatus according to claim 7 , wherein the image selection unit selects the reference image based on, in a case where one two-dimensional tomographic image and a plurality of other two-dimensional tomographic images are compared in the plurality of two-dimensional tomographic images, one of a number of two-dimensional tomographic images having a predetermined threshold or higher value of similarity and having a predetermined threshold or lower positional deviation amounts of the layer boundaries and a number of two-dimensional tomographic images having a predetermined or higher number of regions dividing each of the two-dimensional tomographic images in the direction intersecting with the depth direction, the regions having a predetermined threshold or lower positional deviation amounts of the layer boundaries.

9. The image processing apparatus according to claim 6 , further comprising:
a third alignment unit configured to perform an alignment on the plurality of two-dimensional tomographic images having undergone the alignment by the first alignment unit and the second alignment unit with reference to the reference image; and
an image selection unit configured to select a reference image for the alignment to be performed by the third alignment unit from the plurality of two-dimensional tomographic images.

10. The image processing apparatus according to claim 9 , further comprising a generation unit configured to generate an averaged image by averaging the plurality of two-dimensional tomographic images having undergone an alignment by the third alignment unit.

11. The image processing apparatus according to claim 9 , wherein an OCTA (Optical Coherence Tomography Angiography) image is generated from the plurality of two-dimensional tomographic images having undergone an alignment by the third alignment unit.

12. An alignment method comprising:
performing an alignment in a direction intersecting with a depth direction of an eye on a plurality of two-dimensional tomographic images using information regarding to a positional deviation amount obtained by comparing projecting images in the depth direction obtained using information regarding to the plurality of two-dimensional tomographic images, the plurality of two-dimensional tomographic images being obtained based on measurement light controlled to scan an identical position of the eye; and
performing an alignment in the depth direction on the plurality of two-dimensional tomographic images.

13. A non-transitory computer-readable storage medium storing a program for causing a computer to execute the method according to claim 12 .

14. An image processing apparatus comprising:
a first alignment unit configured to perform an alignment in a direction intersecting with a depth direction of an eye on a plurality of two-dimensional tomographic images, the plurality of two-dimensional tomographic images being obtained based on measurement light controlled to scan an identical position of the eye;
a second alignment unit configured to perform an alignment in the depth direction on the plurality of two-dimensional tomographic images; and
an image selection unit configured to select a reference image being a reference for an alignment from the plurality of two-dimensional tomographic images using at least one of (a) a result of a comparison between projected images in the depth direction obtained using information regarding to the plurality of two-dimensional tomographic images and (b) a result of a comparison between layer boundaries obtained information regarding to the plurality of two-dimensional tomographic images.

15. The image processing apparatus according to claim 14 , wherein the first alignment unit performs the alignment in the direction intersecting with the depth direction on the plurality of two-dimensional tomographic images using information regarding to a positional deviation amount obtained by comparing projected images in the depth direction obtained using information regarding to the plurality of two-dimensional tomographic images.

16. An alignment method comprising:
performing an alignment in a direction intersecting with a depth direction of an eye on a plurality of two-dimensional tomographic images, the plurality of two-dimensional tom

Assignees

• Canon Kk

Inventors

• Iwase Yoshihiko
• Sagano Osamu
• Sato Makoto
• Uchida Hiroki

Classifications

• A61B3/102 Primary

  for optical coherence tomography [OCT] · CPC title

• G06T7/337 Primary

  involving reference images or patches · CPC title

• G06T7/0012

  Biomedical image inspection · CPC title

• G06T2207/10101

  Optical tomography; Optical coherence tomography [OCT] · CPC title

• G06T2207/30041

  Eye; Retina; Ophthalmic · CPC title