Image processing method, image processing device, and program
An image processing method performed by a processor and including detecting positions of plural vortex veins in a fundus image of an examined eye, and computing a center of distribution of the plural detected vortex vein positions.
1. An image processing method performed by a processor, the image processing method comprising:
detecting positions of a plurality of vortex veins in a fundus image of an examined eye;
computing a center of distribution of the plurality of detected vortex vein positions;
wherein the center of distribution computation includes:
finding a vector from a start point to a position of the vortex vein for each of the plurality of vortex veins; and
finding a composite vector combining the plurality of vectors;
wherein the start point is a center point of an eyeball model; and
each of the plurality of vectors is a vector connecting the center point and a position of a vortex vein projected onto an eyeball surface of the eyeball model.
2. The image processing method of claim 1 , wherein the center of distribution computation further includes:
normalizing the composite vector; and
computing a point of intersection between the normalized composite vector and the eyeball surface as the center of distribution.
3. The image processing method of claim 1 , further comprising computing at least one feature value indicating a positional relationship between a position of an identified site on the examined eye and a position of the center of distribution.
4. The image processing method of claim 3 , wherein the at least one feature value is a distance between the center of distribution position and the identified site position.
5. The image processing method of claim 3 , wherein the at least one feature value is coordinates of the center of distribution on the eyeball surface of the eyeball model for a case in which a datum point is the identified site position projected onto the eyeball model.
6. The image processing method of claim 5 , wherein:
an arbitrary point on the eyeball surface is expressed by latitude and longitude;
coordinates of the datum point are zero latitude and zero longitude; and
coordinates of the center of distribution are determined by a latitude of the center of distribution and a longitude of the center of distribution.
7. The image processing method of claim 3 , wherein the identified site is an optic nerve head or a macula.
8. The image processing method of claim 3 , wherein:
the identified site includes:
a first identified site, and
a second identified site;
the first identified site and the second identified site are projected so as to be disposed at zero latitude on the eyeball surface of the eyeball model; and
the at least one feature value is coordinates of the center of distribution on the eyeball surface for a case in which the first identified site is a datum point.
9. The image processing method of claim 8 , wherein:
the first identified site is an optic nerve head; and
the second identified site is a macula.
10. An image processing device comprising a memory and a processor coupled to the memory, wherein the processor is configured to:
detect positions of a plurality of vortex veins in a fundus image of an examined eye; and
compute a center of distribution of the detected plurality of vortex vein positions.
11. A non-transitory storage medium storing a program that causes a computer to execute processing comprising:
detecting positions of a plurality of vortex veins in a fundus image of an examined eye;
computing a center of distribution of the detected plurality of vortex vein positions;
wherein the center of distribution computation includes:
finding a vector from a start point to a position of the vortex vein for each of the plurality of vortex veins; and
finding a composite vector combining the plurality of vectors;
wherein the start point is a center point of an eyeball model; and
each of the plurality of vectors is a vector connecting the center point and a position of a vortex vein projected onto an eyeball surface of the eyeball model.
12. An image processing method performed by a processor, the image processing method comprising:
detecting positions of a plurality of vortex veins and a position of an optic nerve head in a fundus image of an examined eye;
projecting the plurality of vortex veins and the optic nerve head onto an eyeball surface of an eyeball model;
generating a plurality of vectors from a center of the eyeball model to positions of the respective vortex veins on the eyeball surface; and
computing a composite vector combining the plurality of vectors.
13. The image processing method of claim 12 , wherein the composite vector is normalized.
14. The image processing method of claim 13 , wherein a position of a point of intersection between the normalized composite vector and the eyeball surface is detected as a center of distribution of the plurality of vortex veins.
15. The image processing method of claim 14 , further comprising computing a distance between a position of the center of distribution and the position of the optic nerve head.
16. An image processing device comprising a memory and a processor coupled to the memory, wherein the processor is configured to:
detect positions of a plurality of vortex veins and a position of an optic nerve head in a fundus image of an examined eye;
project the plurality of vortex veins and the optic nerve head onto an eyeball surface of an eyeball model;
generate a plurality of vectors from a center of the eyeball model to positions of the respective vortex veins on the eyeball surface; and
compute a composite vector combining the plurality of vectors.
17. A non-transitory storage medium storing a program causing a computer to execute processing comprising:
detecting positions of a plurality of vortex veins and a position of an optic nerve head in a fundus image of an examined eye;
projecting the plurality of vortex veins and the optic nerve head onto an eyeball surface of an eyeball model;
generating a plurality of vectors from a center of the eyeball model to positions of the respective vortex veins on the eyeball surface; and
computing a composite vector combining the plurality of vectors.