Eyelid opening/closing determination apparatus and drowsiness detection apparatus
A drowsiness detection apparatus includes a camera that images a face of a user, an opening/closing-degree calculation unit that calculates an eyelid opening/closing degree based on a face image acquired by the imaging, a face-angle detection unit that detects a face angle based on the face image, a distance calculation unit that calculates the distance between an eyelid and an eyebrow based on the face image, an opening/closing-degree correction unit that corrects the eyelid opening/closing degree based on the detected face angle and the calculated distance between the eyelid and eyebrow, and an eyelid-opening/closing determination unit that determines whether the eyelids are opened or closed by comparing the eyelid opening/closing degree with a predetermined threshold value.
1. An eyelid opening/closing determination apparatus comprising:
an imager for imaging a face of a user;
an opening/closing-degree calculator for calculating an eyelid opening/closing degree based on a face image acquired by the imager;
a face-angle detector for detecting a face angle based on the face image;
a distance calculator for calculating a distance between an eyelid and an eyebrow based on the face image;
an eyelid-opening/closing determiner for determining whether the eyelids are opened or closed by comparing the eyelid opening/closing degree with a predetermined threshold value; and
an opening/closing-degree corrector for correcting the eyelid opening/closing degree based on the face angle detected by the face-angle detector and the distance calculated by the distance calculator.
2. The eyelid opening/closing determination apparatus according to claim 1 , wherein the opening/closing-degree corrector corrects the eyelid opening/closing degree to a larger value when a face direction determined based on the face angle is downward from a first reference and the distance calculated by the distance calculator is less than a second reference.
3. The eyelid opening/closing determination apparatus according to claim 2 , wherein the opening/closing-degree corrector changes the second reference based on the face angle.
4. The eyelid opening/closing determination apparatus according to claim 3 , wherein the opening/closing-degree calculator calculates, as the eyelid opening/closing degree, a value of a width between an upper eyelid and a lower eyelid included in the face image.
5. A drowsiness detection apparatus comprising a drowsiness determiner for determining drowsiness of a user based on a determination result of the eyelid-opening/closing determination apparatus according to claim 4 .
6. A drowsiness detection apparatus comprising a drowsiness determiner for determining drowsiness of a user based on a determination result of the eyelid-opening/closing determination apparatus according to claim 3 .
7. The eyelid opening/closing determination apparatus according to claim 2 , wherein the opening/closing-degree calculator calculates, as the eyelid opening/closing degree, a value of a width between an upper eyelid and a lower eyelid included in the face image.
8. The eyelid opening/closing determination apparatus according to claim 1 , wherein the opening/closing-degree calculator calculates, as the eyelid opening/closing degree, a value of a width between an upper eyelid and a lower eyelid included in the face image.
9. A drowsiness detection apparatus comprising a drowsiness determiner for determining drowsiness of a user based on a determination result of the eyelid-opening/closing determination apparatus according to claim 8 .
10. A drowsiness detection apparatus comprising a drowsiness determiner for determining drowsiness of a user based on a determination result of the eyelid-opening/closing determination apparatus according to claim 1 .
11. An eyelid opening/closing determination method comprising:
imaging a face of a user;
calculating an eyelid opening/closing degree based on the face image;
detecting a face angle based on the face image;
calculating a distance between an eyelid and an eyebrow based on the face image;
determining whether the eyelids are opened or closed by comparing the eyelid opening/closing degree with a predetermined threshold value; and
correcting the eyelid opening/closing degree based on the detected face angle and the calculated distance.
12. The eyelid opening/closing determination method according to claim 11 , wherein the opening/closing-degree correcting step corrects the eyelid opening/closing degree to a larger value when a face direction determined based on the face angle is downward from a first reference and the calculated distance is less than a second reference.
13. The eyelid opening/closing determination method according to claim 12 , wherein the opening/closing-degree correcting step changes the second reference based on the face angle.
14. The eyelid opening/closing determination method according to claim 13 , wherein the opening/closing-degree calculating step calculates, as the eyelid opening/closing degree, a value of a width between an upper eyelid and a lower eyelid included in the face image.
15. A drowsiness detection method comprising determining drowsiness of a user based on a determination result of the eyelid-opening/closing determination method according to claim 14 .
16. A drowsiness detection method comprising determining drowsiness of a user based on a determination result of the eyelid-opening/closing determination method according to claim 13 .
17. The eyelid opening/closing determination method according to claim 12 , wherein the opening/closing-degree calculating step calculates, as the eyelid opening/closing degree, a value of a width between an upper eyelid and a lower eyelid included in the face image.
18. The eyelid opening/closing determination method according to claim 11 , wherein the opening/closing-degree calculating step calculates, as the eyelid opening/closing degree, a value of a width between an upper eyelid and a lower eyelid included in the face image.
19. A drowsiness detection method comprising determining drowsiness of a user based on a determination result of the eyelid-opening/closing determination method according to claim 18 .
20. A drowsiness detection method comprising determining drowsiness of a user based on a determination result of the eyelid-opening/closing determination method according to claim 11 .