JP2011138558A5

JP2011138558A5 -

Info

Publication number: JP2011138558A5
Application number: JP2011088669A
Authority: JP
Filing date: 2011-04-12
Publication date: 2012-01-19
Anticipated expiration: 2027-07-04

Claims

An eye position detection system including an original image acquisition unit including a face image and a calculation unit, wherein the calculation unit includes:
A function for creating a grayscale scan target image from an original image, a face image size frame is scanned on the scan target image, and a frame region whose peripheral portion is lighter than the center portion in the frame function to be detected, the ability to set the detected frame area as a detection target area of the eye position, creating a position detection image grayscale eye plurality hierarchy Lightness is changed for each detection target area of the position of each eye In the image for detecting the position of eyes in multiple layers, the cluster of pixels that gradually appear in the eye position detection image as the brightness gradually changes from the grayscale image faded out at high brightness to the grayscale image at low brightness. A function for detecting an area, a function for selecting a pair of detected pixel areas appearing in pairs as eye position candidates, and an output for all eye position detection images for all eye position candidates. Detection system the position of the eye to have a function to specify the position of the eyes from the eye position candidates based on frequency.

As a function for the arithmetic unit to create an image to be scanned,
When the original image has 256 gradations, an image with 0% fade-in has all pixels having a pixel value of 255, and an image with fade-in x% (where x> 0) has a pixel value of 2 in the original image. Pixels less than .55x have a pixel value of the original image, and pixels with a pixel value of 2.55x or more have a uniform pixel value of 255, an image with a fade-in of 25-35% of the original image The eye position detection system according to claim 1, which has a function of forming.

As a function that the arithmetic unit detects a frame region in which the peripheral part has low brightness compared to the central part in the frame of the face image size,
The eye position detection system according to claim 1 or 2, wherein a frame of a face image size is divided into nine 3 × 3 regions, and the frame regions are detected based on the following criteria (1) to (3).
(1) The existence ratio of areas with pixel values of 254 or less is higher in the surrounding 8 areas than in the central area.
(2) The existence ratio of the region having a pixel value of 254 or less is higher in the upper central region than in the central region.
(3) The existence ratio of the region having a pixel value of 254 or less is higher in the central left region or the central right region than in the central region.

The arithmetic unit has a function of accumulating, counting, ranking, and specifying the position of the eye over the gray scale eye position detection images of all levels of gray scale, and determining the position of the eye. The function to be identified is the position of the eye position candidate with the maximum count as the eye position, provided that the following conditions (a) to (d):
  (a) When the second position candidate for the ranking is higher than the first position candidate for the ranking
  (b) When the distance between the center of the eye position candidate of the 2nd ranked eye is longer than the distance between the centers of the position candidate of the 1st ranked eye
  (c) When the regions corresponding to the left and right pupils of the second-ranked eye position candidate are outside the positions corresponding to the left and right pupils of the first-ranked eye position candidate
  (d) The vertical distance between the first position candidate of the ranking and the second position candidate of the ranking is about the distance between the eyes and the eyebrows, and the first position candidate of the ranking is ranked first. When the position is above the second position candidate
If all of the conditions (a) to (c) are satisfied, or if the condition (d) is satisfied, the position of the eye position candidate with the second largest number of counts is set as the eye position. The eye position detection system according to any one of claims 1 to 3.

A method for detecting an eye position from an original image including a face image,
A. Create a grayscale scan target image from the original image,
Scanning a face image size frame on the scan target image and detecting an area in which the peripheral portion has low brightness as compared to the central portion in the frame as a detection target region of the eye position;
B. Lightness creates a position detection image grayscale eye plurality hierarchy vary from the detection target area of the eye position,
Detects clustered areas of pixels that gradually appear in the eye position detection image as the brightness gradually changes from a grayscale image that fades out at high brightness to a low-lightness grayscale image in multiple-level eye position detection images And
Select the detected pixel cluster area that appeared as a pair as the eye position candidate,
Identifying the eye position from the eye position candidates based on the appearance frequency over all eye position detection images of each eye position candidate;
A method for detecting the position of an eye.

6. The method of detecting an eye position according to claim 5 , wherein in step A, the original image is subjected to brightness correction to create a scanning target image.

The eye according to claim 5 or 6 , wherein in step A, a rectangular frame having one side that is twice to three times the maximum value of the eye spacing of individual face images included in the original image is set as the frame of the face image size. Position detection method.

In step A, when the original image has 256 gradations, an image with 0% fade-in has all pixels having a pixel value of 255 and an image with fade-in x% (where x> 0) A pixel having a pixel value of less than 2.55x has a pixel value of the original image, and a pixel having a pixel value of 2.55x or more has a uniform pixel value of 255. The method for detecting an eye position according to any one of claims 5 to 7 , wherein an image having a fade-in of 25 to 35% is formed.

In step A, the face image size frame for scanning the image to be scanned is divided into 3 × 3 9 areas, and the position of the eye is detected based on the following criteria (1) to (3). detection method for the eye position according to any one of claims 5-8 for detecting a target region.
(1) The existence ratio of areas with pixel values of 254 or less is higher in the surrounding 8 areas than in the central area.
(2) The existence ratio of the region having a pixel value of 254 or less is higher in the upper central region than in the central region.
(3) The existence ratio of the region having a pixel value of 254 or less is higher in the central left region or the central right region than in the central region.

In step B, the frequency of appearance of eye position candidates over the gray scale eye position detection images of all layers is accumulated, counted, ranked, and the position of the eye position candidate with the maximum count is set as the eye position, , The following conditions (a) to (d),
  (a) When the second position candidate for the ranking is higher than the first position candidate for the ranking
  (b) When the distance between the center of the eye position candidate of the 2nd ranked eye is longer than the distance between the centers of the position candidate of the 1st ranked eye
  (c) When the regions corresponding to the left and right pupils of the second-ranked eye position candidate are outside the positions corresponding to the left and right pupils of the first-ranked eye position candidate
  (d) The vertical distance between the first position candidate of the ranking and the second position candidate of the ranking is about the distance between the eyes and the eyebrows, and the first position candidate of the ranking is ranked first. When the position is above the second position candidate
If all of the conditions (a) to (c) are satisfied, or if the condition (d) is satisfied, the position of the eye position candidate with the second largest number of counts is set as the eye position. The method for detecting an eye position according to any one of claims 5 to 9.