Living Eye Judging Method and Living Eye Judging Device

• US 20090161923A1
• Filed: 02/23/2009
• Published: 06/25/2009
• Est. Priority Date: 07/04/2003
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Corporation of America (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Kondo, Kenji, Azuma, Takeo
• Granted Patent: US 7,801,336 B2
• Time in Patent Office: Days
• US Class Current: 382/117
• CPC Class Codes: A61B 3/112 for measuring diameter of pupils
• CPC Class Codes: A61B 3/12 for looking at the eye fundus, e.g. ophthalmoscopes A61B3/13 takes precedence
• CPC Class Codes: G06T 2207/30041 Eye; Retina; Ophthalmic
• CPC Class Codes: G06V 40/18 Eye characteristics, e.g. of the iris

Abstract

An eye (EY) of a person to be shot is illuminated coaxially with the optical axis of a camera (11), and then, is shot. At this time, a retinal reflex is caused and the luminance in the pupil region becomes high if the eye (EY) is a living eye. A living eye judgment section (17) judges whether an eye included in the image is a living eye is performed based on the luminance in the pupil region of the image captured by the camera (11).

Claims

1. A living eye judging method comprising:

a first step of obtaining an image captured by shooting a subject with illumination coaxial with an optical axis of a camera; and

a second step of judging whether an eye included in the image is a living eye or not, utilizing that retinal reflex is caused by coaxial incident illumination if the eye is a living eye, based on luminance in a pupil region of the eye in the image.

2. The method of claim 1,

wherein in the first step, a plurality of images sequential in time are obtained, and

in the second step, whether the eye is a living eye or not is judged based on time variation in a predetermined index for luminance in the pupil region obtained from the plurality of images.

3. The method of claim 2,

wherein the predetermined index is an average value of luminance in the pupil region.

4. The method of claim 2,

wherein the predetermined index is a ratio of luminance of the pupil region to the iris region.

5. The method of claim 2,

wherein the predetermined index is a total sum of luminance values of each pixel in the pupil region.

6. The method of claim 5,

wherein the total sum of the luminance values is normalized by an area of the iris region.

7. A living eye judging device comprising:

a camera for shooting a subject;

an illumination section for illuminating the subject coaxially with an optical axis of the camera; and

a living eye judgment section that receives an image captured by the camera with illumination by the illumination section and performs judgment as to whether an eye included in the image is a living eye or not, utilizing that retinal reflex is caused by coaxial incident illumination if the eye is a living eye, based on luminance in a pupil region of the eye in the image.

8. A living eye judging device comprising:

a camera for shooting a subject;

a first illumination section for illuminating the subject coaxially with an optical axis of the camera;

a second illumination section for illuminating the subject on an optical axis different from the optical axis of the camera; and

a living eye judgment section that receives a first image captured by the camera with illumination by the first illumination section and a second image captured by the camera with illumination by the second illumination section and performs judgment as to whether an eye included in the first and second images is a living eye or not based on luminance in pupil regions of the eye in the first and second images,

wherein the living eye judgment section performs;

obtaining a first luminance difference, which is a difference in luminance between the pupil region and an iris region in the first image, and a second difference, which is a difference in luminance between the pupil region and an iris region in the second image; and

judging the eye as a living eye when an absolute value of a difference between the first luminance difference and the second luminance difference is larger than a predetermined threshold value.

9. A living eye judging device comprising:

a camera for shooting a subject;

a first illumination section for illuminating the subject coaxially with an optical axis of the camera;

a second illumination section for illuminating the subject on an optical axis different from the optical axis of the camera; and

a living eye judgment section that receives a first image captured by the camera with illumination by the first illumination section and a second image captured by the camera with illumination by the second illumination section and performs judgment as to whether an eye included in the first and second images is a living eye or not based on luminance in pupil regions of the eye in the first and second images,

wherein the living eye judgment section performs;

obtaining a first luminance ratio, which is a ratio in luminance of the pupil region to an iris region in the first image, and a second luminance ratio, which is a ratio in luminance of the pupil region to an iris region in the second image; and

judging the eye as a living eye when a ratio of the first luminance ratio to the second luminance ratio is larger than a predetermined threshold value.