Gaze analysis method and apparatus

• US 9,984,289 B2
• Filed: 10/15/2015
• Issued: 05/29/2018
• Est. Priority Date: 07/29/2015
• Status: Active Grant

• Current Assignee: Institute For Information Industry
• Original Assignee: Institute For Information Industry
• Inventors: Lin, Ching-Wen, Tsai, Kuei-Chien
• Primary Examiner(s): Elahi, Shan E
• Application Number:
  US14/884,200
• Publication Number:
  US 20170032173A1
• Time in Patent Office: 957 Days
• Field of Search: 348 78
• CPC Class Codes: G06F 3/013 Eye tracking input arrangements G06F3/015 takes precedence
• CPC Class Codes: G06V 40/18 Eye characteristics, e.g. of the iris

Abstract

A gaze analysis method has following steps. When detecting at least one face in an image, according to a face angle and an eye angle, a gazing angle is calculated, and whether the gazing angle falls within a first range is determined, wherein the eye angle is obtained according to information of irises and scleras of left and right eyes. A differential value between a focusing distance and a spacing distance from the face to the object falls within a second range is determined if the gazing angle falls within the first range, and a detecting result whether the differential value falls within the second range is used to determine whether the object is gazed, wherein the focusing distance is determined according to the information of the irises and scleras of the left and right eyes.

Claims

1. A gaze analysis method, executed by a gaze analysis apparatus, the gaze analysis apparatus comprising an image capturing device, a face detecting device, a face angle calculating device, an eye angle calculating device, a gazing angle determining device, an object-being-gazed determination device, and a time counting device, the method comprising:

detecting at least one face in an image captured by the image capturing device through the face detecting device;

calculating a gazing angle of the face in the image according to a face angle and an eye angle of the face in the image through the eye angle calculating device, and determining whether the gazing angle falls within a first range through the gazing angle determining device, wherein the eye angle is obtained according to information of an iris and a sclera of a left eye and information of an iris and a sclera of a right eye through the eye angle calculating device;

determining a differential value between a focusing distance and a spacing distance falls within a second range if the gazing angle falls within the first range, and determining whether the object is gazed according to a detecting result whether the differential value falls within the second range through the object-being-gazed determination device, wherein the focusing distance is determined according to the information of the iris and the sclera of the left eye and the information of the iris and the sclera of the right eye through the object-being-gazed determination device;

calculating a continuous or accumulation time which the differential value falls within the second range, so as to obtain a gazing time through the time counting device; and

determining whether the gazing time is larger than a specific value through the time counting device;

wherein when the gazing time is larger than the specific value, the indication device is used for executing a corresponding command.

2. The gaze analysis method according to claim 1, wherein positions of a mouth and the two eyes within the face in the image are obtained, and at least one head shape model is referred to obtain the face angle.

3. The gaze analysis method according to claim 1, wherein the eye angle is determined according to a ratio relation of lengths of the two irises and the two scleras associated with the left and right eyes.

4. The gaze analysis method according to claim 3, the eye angle is determined according to a ratio of a first differential length over a total length of the left eye and the right eye and a ratio of a second differential length over the total length of the left eye and the right eye and a ratio, wherein the first differential length is a differential between left and right portions of the sclera within the left eye, and the first differential length is a differential between left and right portions of the sclera within the right eye.

5. The gaze analysis method according to claim 1, wherein a left eye angle which a center point of an eye ball of the left eye is towards a focusing point is determined according to a ratio which a left portion of the sclera of the left eye occupies within all of the sclera of the left eye, a right eye angle which a center point of an eye ball of the right eye is towards the focusing point is determined according to a ratio which a right portion of the sclera of the right eye occupies within all of the sclera of the right eye, and the focusing distance is determined according to the left eye angle, the right eye angle, and a distance between the two center points of the eye balls of the right and left eyes.

6. The gaze analysis method according to claim 5, wherein by using a cosine theorem, a first distance from the eye ball of left eye to the focusing point and a second distance from the eye ball of right eye to the focusing point are obtained according to according to the left eye angle, the right eye angle, and the distance between the two center points of the eye balls of the right and left eyes, and by using a parallelogram law, the focusing distance is determined according to the first distance, the second distance, and the distance between the two center points of the eye balls of the right and left eyes.

7. The gaze analysis method according to claim 1, wherein the spacing distance is calculated according to an area of the face in the image.

8. The gaze analysis method according to claim 1, further comprising:

detecting whether the face in the image.

9. The gaze analysis method according to claim 8, wherein a Markov modeling face detection manner is used to detect whether the face in the image.

10. The gaze analysis method according to claim 1, wherein the face angle comprises a horizontal rotation angle.

11. The gaze analysis method according to claim 10, wherein the face angle comprises an elevation angle.

12. A gaze analysis apparatus, comprising:

an image capturing device, used to capture an image;

a face detecting device, electrically connected to the image capturing device, used to perform face detection on the image to detect at least one face in the image;

a face angle calculating device, electrically connected to the face detecting device, when the face in the image is detected, used to calculate a face angle;

an eye angle calculating device, electrically connected to the face angle calculating device, when the face in the image is detected, used to calculate an eye angle according to information of an iris and a sclera of a left eye and information of an iris and a sclera of a right eye in the image;

a gazing angle determining device, electrically connected to the eye angle calculating device, when the face in the image is detected, used to calculate a gazing angle according to a face angle and an eye angle, and determine whether the gazing angle falls within a first range;

an object-being-gazed determination device, electrically connected to the gazing angle determining device, used to determine a differential value between a focusing distance and a spacing distance falls within a second range if the gazing angle falls within the first range, and determining whether the object is gazed according to a detecting result whether the differential value falls within the second range, wherein the focusing distance is obtained according to the information of the iris and the sclera of the left eye and the information of the iris and the sclera of the right eye;

a time counting device, electrically connected to the object-being-gazed determination device, used to calculate a continuous or accumulation time which the differential value falls within the second range, so as to obtain a gazing time, and determine whether the gazing time is larger than a specific value; and

an indication device, electrically connected to the time counting device when the gazing time is larger than the specific value, used to execute a corresponding command.

13. The gaze analysis apparatus according to claim 12, wherein the face detecting device obtains positions of a mouth and the two eyes within the face in the image, and refers at least one head shape model to obtain the face angle.

14. The gaze analysis apparatus according to claim 12, wherein the eye angle calculating device determines the eye angle according to a ratio relation of lengths of the two irises and the two scleras associated with the left and right eyes.

15. The gaze analysis apparatus according to claim 14, wherein the eye angle is determined according to a ratio of a first differential length over a total length of the left eye and the right eye and a ratio of a second differential length over the total length of the left eye and the right eye and a ratio, wherein the first differential length is a differential between left and right portions of the sclera within the left eye, and the first differential length is a differential between left and right portions of the sclera within the right eye.

16. The gaze analysis apparatus according to claim 12, wherein the object-being-gazed determination device determines a left eye angle which a center point of an eye ball of the left eye is towards a focusing point according to a ratio which a left portion of the sclera of the left eye occupies within all of the sclera of the left eye, determines a right eye angle which a center point of an eye ball of the right eye is towards the focusing point according to a ratio which a right portion of the sclera of the right eye occupies within all of the sclera of the right eye, and determines the focusing distance according to the left eye angle, the right eye angle, and a distance between the two center points of the eye balls of the right and left eyes.

17. The gaze analysis apparatus according to claim 16, wherein by using a cosine theorem, the object-being-gazed determination device obtains a first distance from the eye ball of left eye to the focusing point and a second distance from the eye ball of right eye to the focusing point according to according to the left eye angle, the right eye angle, and the distance between the two center points of the eye balls of the right and left eyes, and by using a parallelogram law, the object-being-gazed determination device obtains the focusing distance according to the first distance, the second distance, and the distance between the two center points of the eye balls of the right and left eyes.

18. The gaze analysis apparatus according to claim 12, wherein the object-being-gazed determination device calculates the spacing distance according to an area of the face in the image.