KR20170091216A - Non-wearable gaze tracking system at distance by background lighting and reference point lighting - Google Patents

Abstract

The present invention relates to an infrared lighting configuration in a system for tracking the sight line of a user by using an infrared image. According to an embodiment of the present invention, a distant sight line tracking system is provided. The distant sight line tracking system comprises: a sight line tracker body; an optical camera which generates an image for tracking the face of a user; an infrared background lighting which is separated from the sight line tracker body, is positioned to be adjacent to the user, and irradiates the face of the user with an infrared ray; a datum lighting which irradiates the face of the user with an infrared ray with relatively less intensity than that of the infrared background lighting; an infrared camera which generates an infrared image of the face of the user including corneal reflection; and an infrared camera driving unit which adjusts the direction of the infrared camera to be directed to the tracked face of the user.

Description

[0001] The present invention relates to a non-wearable gaze tracking system using background illumination and reference point illumination,

The present invention relates to an infrared illumination configuration in a system for tracking a user's gaze using an infrared image.

Eye tracking technology to find the direction or position that the user is looking at can be divided into wearable and non-wearable types. In the case of non-wearable technology, it can be divided into near and far vision tracking systems depending on the distance between the user and the eyesight tracking system have. Most non-worn line-of-sight tracking technologies use one or more infrared lights and infrared cameras that know their location in advance. In the infrared image of the user's eye, the pupil is displayed in black with low brightness, and the iris surrounding the pupil has higher brightness, so pupil can be detected through boundary detection and circular fitting. In the cornea covering the pupil of the user, reflected light of infrared light is generated. The position of the reflected light is determined by the position of the infrared camera, the illumination, and the user's eye. Therefore, the gaze position of the user can be estimated by using the position of the center of the moving pupil according to the user's gaze position and the position of the reflected light that does not change according to the gaze.

In an environment where no external infrared light sources such as sunlight or incandescent lamps are present, a near-line tracking system can produce sufficient brightness for infrared imaging even with small-sized infrared illumination. However, the far-sight line tracking system must concentrate the illumination angle very narrowly or concentrate or use strong infrared light so that a sufficient amount of infrared light reaches a long distance. However, if the illumination angle of the illumination is narrowed, the range of the eye tracking can be narrowed because the infrared ray can not be irradiated when the user of the far distance moves to the upper, lower, left, and right sides. And the size of the whole eye tracking system and manufacturing cost are increased due to the enlargement of the power source unit and the heat dissipating unit.

In the present invention, in order to obtain an infrared image of sufficient brightness in a far-sight line tracking system using infrared light, a stronger infrared light should be used as a reference point light as the distance between the user and the far-sight line tracking system becomes longer, We are trying to solve the problem that the consumption is getting worse and the system becomes bigger.

According to an embodiment of the present invention, a far-sight line tracking system is provided. The long-distance line-of-sight tracking system includes a line-of-sight tracer main body, a wide-angle camera for generating an image for tracing a user's face, an infrared ray detector for detecting an infrared ray directed to the user's face, An infrared ray camera for generating an infrared ray image including the cornea reflection light by infrared ray photographing of the face of the user, and an infrared ray camera for generating an infrared ray image including the cornea reflection light, And an infrared camera driving unit for adjusting the direction of the infrared camera so as to face the user's face.

One embodiment of the present invention is composed of hardware suitable for each role by dividing the infrared illumination used for long-distance line-of-sight into the background illumination for securing the light amount of the whole image and the reference point illumination for generating the reflected light in the cornea and searching for the reference position .

According to the configuration of the present invention, the background illumination can be installed at a position which is not fixed relatively close to the user, unlike the reference point illumination in which the position is fixed. Therefore, compared with the case where the background illumination is installed at a fixed position with the camera, The manufacturing cost, size, power, and heat required for the display device can be reduced.

Hereinafter, the present invention will be described with reference to the embodiments shown in the accompanying drawings. For the sake of clarity, throughout the accompanying drawings, like elements have been assigned the same reference numerals. It is to be understood that the present invention is not limited to the embodiments illustrated in the accompanying drawings, but may be embodied in many other specific forms without departing from the spirit or essential characteristics thereof.
FIG. 1 is a block diagram illustrating an exemplary configuration of a long-distance line-of-sight tracking system according to an exemplary embodiment of the present invention. Referring to FIG.
2 is a view for explaining an application example of a long-distance line-of-sight tracking system according to an embodiment of the present invention.
3 is a diagram for explaining a line-of-sight tracking method.

While the present invention has been described in connection with certain exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and similarities. It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Hereinafter, the present invention will be described in detail with reference to the preferred embodiments of the present invention with reference to the accompanying drawings.

FIG. 1 is a block diagram exemplarily showing the configuration of a far-sight line tracking system according to an embodiment of the present invention. FIG. 2 is a view for explaining an application example of a far-sight line tracking system according to an embodiment of the present invention. And FIG. 3 is a view for explaining a line-of-sight tracking method.

1 to 3, the far-sight line tracking system includes a line-of-sight tracer main body 100, a wide-angle camera 111, an infrared camera driver 121, an infrared camera 122, a reference point light 131, (132). Meanwhile, the gaze tracker main body 100 includes a face tracking unit 110, a gaze tracking unit 120, and a lighting control unit 130.

The wide-angle camera 111 is installed at a position capable of photographing a wide-angle environment at a long distance, and is shown attached to the front of the gaze tracker main body 100 in FIG. 2. However, the present invention is not limited thereto. The face tracking unit 110 finds the face position of the user from the image photographed by the wide-angle camera 111 using, for example, Adaboost. When a plurality of users are detected, the face tracking unit 110 can find the face position of a specific user by comparing the feature points with the face images registered in advance in the user database. Information on the detected face position of the user is provided to the gaze tracking unit 120 for gaze tracking.

(Hereinafter, referred to as an infrared ray image 300) is required for accurate eye tracking, the infrared ray camera 122 is linearly or rotationally moved by the infrared ray camera driving unit 121, Aim. The infrared camera 122 and the infrared camera driving unit 121 are installed at positions where the infrared ray image 300 can be photographed and are attached to the top surface of the gaze tracker body 100 in FIG. .

If the user's face position information is provided after the initial operation or the user moves to provide new face position information after the initial operation, the gaze tracking unit 120 searches the face tracking unit 110 according to the face position information provided by the face tracking unit 110 The infrared camera driver 121 is adjusted so that the infrared camera 122 faces the face of a specific user. In this way, the user's gaze can be continuously tracked.

In another embodiment, the infrared camera driving unit 121 may be directly controlled by the face tracking unit 110. [ That is, the face tracking unit 110 continuously tracks the face position information, and controls the infrared camera driver 121 whenever the face position information is changed so that the infrared camera 122 faces the face of a specific user .

The illumination control unit 130 controls turning on / off of the reference point illumination 131. [ In addition, the illumination control unit 130 may control the turning on / off of the infrared background illumination 132. When the number of the reference point illumination 131 and / or the infrared background illumination 132 is two or more, the illumination control unit 130 may turn on each of the plurality of reference point lights 131 and / or the plurality of infrared background lights 132 / Off < / RTI > Meanwhile, the illumination control unit 130 may control the intensity of the infrared rays irradiated by controlling the power supplied to the reference point illumination 131 and / or the infrared background illumination 132. [

The reference point illumination 131 generates the cornea reflected light 310 that can be detected by the infrared camera 122. For this purpose, the positional relationship between the reference point illumination 131 and the infrared camera 122 must be fixed. For example, the reference point illumination 131 may be fixed to the gaze tracker body 100 or attached to the edge of the display 200 or the like. 3, since most of the light amount necessary for generating the cornea reflection light 310 that can be recognized in the infrared ray image 300 shown in FIG. 3 is secured by the infrared background illumination 132, the reference point illumination 131 considers power and heat generation And can have a relatively low amount of light compared to the infrared background illumination 132. [ The reference point illumination 131 directly irradiates the infrared light to the eye of the user so as to form the point-shaped cornea reflection light 310 of an identifiable size in the infrared image 300 during eye-gaze tracking. Since the pupil has very low brightness irrespective of the amount of light of the infrared backlight 132 illuminated to the user, the reference point illuminator 131 can generate an identifiable cornea reflection light in the user's pupil cornea with low output power.

The one or more infrared background lights 132 are positioned adjacent to the user and illuminate infrared rays near the user's face. The infrared background illumination 132 can illuminate the infrared camera 122 with a sufficient amount of light to obtain a clear image between the pupil and iris, iris and sclera without noise. Here, when the reflected light of the infrared backlight 132 is generated in the user's pupil, it is possible to brighten a part of the pupil displayed in the form of a black circle, thereby making it difficult to detect the pupil contour line and distinguish the center position. It is difficult to find the reference point of the line of sight. Unlike other parts of the skin or eyes, the pupil part rarely reflects light other than the specular reflection on the surface. Accordingly, the infrared backlight 132 may further include a diffuser 133 for spreading the direction of the light to various degrees on the front surface of the infrared backlight 132 to which the infrared light is irradiated. The diffuser 133 can suppress the generation of the reflected light by the infrared background illumination 132 by reducing the amount of infrared rays that are directly projected by the user's eyes. In addition, the infrared backlight 132 may include a light emitting device and a reflection plate arranged so that the infrared light is irradiated for a long length in order to widen the irradiation range and to make the shape of the reflected light different from the reference reflected light that represents the point.

It will be understood by those skilled in the art that the foregoing description of the present invention is for illustrative purposes only and that those of ordinary skill in the art can readily understand that various changes and modifications may be made without departing from the spirit or essential characteristics of the present invention. will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

It is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. .

Claims (1)

Eye tracker main body;
A wide angle camera for generating an image for tracking a user's face;
An infrared backlight spaced apart from the gaze tracker main body and positioned adjacent to the user, the infrared background illuminating the user's face with infrared light;
A reference point illumination for irradiating an infrared ray of a relatively small intensity relative to the infrared background illumination toward the face of the user;
An infrared camera for infrared imaging the face of the user to generate an infrared image including cornea reflection light; And
And an infrared camera driving unit for adjusting the direction of the infrared camera so as to face the traced user's face.

Images