KR20080095205A - Smart sunglass using camera - Google Patents

Abstract

A smart sunglass using camera is provided to help a user to see a landscape around a light source clearly and reduce glariness by making a glare region on the sunglass translucent selectively and the other area transparent. A cameras(cam1, cam2) pick up an image of sunglass, an image processor calculates the position of a glare light source(LS) based on the photographed image by the cameras. A controller controls the transparency of a filter on which a straight line, between the light source calculated by the image processor and an eye or image sensors, is crossed. A filter changes the transparency of a special region according to a signal from the controller.

Description

Smart Sunglasses Using Cameras {SMART SUNGLASS USING CAMERA}

The present invention relates to sunglass for preventing glare. Sunglass not only means sunglasses that people wear like glasses, but also filters attached to digital cameras, cctv cameras, or traditional film cameras using image sensors. The conventional sunglass has a disadvantage that the entire field of view is dark because the light transmittance of the lens is fixed. Recent research is developing smart sunglass technology that can electrically adjust the light transmittance of the lens. For example, research has been conducted on the functions of being transparent indoors and slightly opaque outdoors. In addition, when the welding spark is detected during the welding operation, the light transmittance is lowered. However, when the driver wears this conventional smart sunglass at night, the entire lens is translucent, so the headlights of the vehicle approaching from the other side are less glare, but the scenery around the headlights is darker, which is as if the eyes are closed. There is a risk of traffic accidents. In addition, when photographing a vehicle facing at night with a surveillance camera attached to the vehicle, there is a problem that the license plate of the vehicle is blurred due to the glare of the headlight of the vehicle and thus the number cannot be recognized. At this time, if the translucent filter is attached to prevent glare, the entire screen becomes dark.

An object of the present invention is to overcome the limitations of the conventional sunglass or camera filter as described above, to provide a sunglass that is selectively translucent only in the dazzling portion of the field of view and the other region can maintain a transparent state.

According to the sunglass device using the camera according to the present invention, unlike the conventional sunglass, not only the glare of the dazzling light source but also the landscape around the light source can be clearly seen, so if a night driver wears the sunglass of the present invention, the risk of a traffic accident Can be reduced. It can also be used to protect the eyes of welders exposed to strong flashes or soldiers engaged in night combat.

The present invention includes a camera unit including a camera to photograph the front, an image processor for detecting a dazzling light source by analyzing an image taken by the camera unit, calculating a relative position from the camera to a dazzling light source, and the dazzling light source calculated by the image processor. And a control unit for selectively translucently adjusting the filter area through which the gaze between the pupil or the image sensor passes. In this case, the control unit may be a microcontroller and the lens may be a transmissive LCD display with a polarization filter attached thereto. That is, the controller can make the desired area opaque or translucent by applying an appropriate electrical signal to the LCD display. The transparent LCD display here is just one embodiment that can be realized with current technology. Currently, polymer lenses that can electrically change transparency or color are also being studied. The lens of the sunglass of the present invention can be used as long as it can electrically adjust transparency or color.

Example 1

1 is a perspective view showing the appearance of the sunglass according to the present invention and Figure 2 is a plan view showing a person wearing it from above. At both ends of the sunglass, two stereo cameras (cam1, cam2) are attached side by side like binoculars, so you can take a picture of the front facing your eyes. The captured stereo images may be analyzed by the image processor to detect the three-dimensional position of the bright light source LS. This is a known technique in the field of triangulation and stereo vision. That is, the three-dimensional position of the light source is calculated by obtaining a corresponding relationship between each light source in the two images and analyzing the difference (disparity) of the position in the image of the corresponding light source. When the positions of the intersection points of the straight lines L1 and L2 from the two cameras thus obtained are obtained, the points become three-dimensional coordinates of the light source LS. In more detail, the image analyzer may be an image processing program executed in a microcomputer or a digital signal processor (DSP). Since the relative positions of the sunglass and the pupil are fixed, it is possible to know which point (C1, C2) of the lens of the sunglass passes through the straight line between the pupil and the light source. The controller unit adjusts the transmittance of light of the portions C1 and C2 of the lens through which the straight line between the light source and the pupil passes and makes the portions translucent or opaque so that the sunglass wearer can reduce the glare of the light from the light source. At this time, the rest of the lens is transparent so that other scenery around the light source can be seen clearly.

Example 2

In the first embodiment, the filter GL of the smart sunglass according to the present invention is positioned in front of the human eyes ey1 and ey2. However, in the present embodiment, the camera camc is positioned at the position of the human eye as shown in FIG. Describe the configuration. In FIG. 3, two cameras cam1 and cam2 are cameras for calculating a three-dimensional position of a light source and the other cameras are cameras for outputting an image without glare. Cameras using conventional image sensors include an AGC (auto gain control) circuit to automatically adjust the brightness of the entire screen. However, such a circuit only adjusts the brightness of the entire screen, but does not have the ability to selectively darken any dazzling area. However, if the smart sunglass filter GL according to the present invention is attached to the front of the camera (camc) as shown in FIG. 3, the entire image taken by the camc camera can be kept bright while removing the dazzling portion.

Example 3

In Example 2, the two cameras cam1 and cam2 detect the three-dimensional position of the light source LS, and the glare is removed. However, in the present embodiment, the camera is photographed without glare with only one camera camc. The same structure is demonstrated. In Fig. 4, a filter GL that can adjust the transmittance is attached to the lens Lz in the image sensor IS inside the camera camc. At this time, the filter GL is preferably attached close to the image sensor IS because the calculation becomes simpler. That is, the light of the external dazzling light source LS passes through the lens Lz of the camera camc, passes through the filter GL, and reaches the image sensor IS. When photographing every odd-numbered frame image of a video photographed by a camera, the filter GL is kept in a transparent state and photographed, and the image is transferred to an image processor to calculate the position of the light source LS. The equation of the straight line L1 can be found from the position of the bright point Bp in the captured image. When photographing every even-numbered frame, the area C1 of the filter GL passing through the position of the light source LS calculated in the previous frame and the line L1 passing through the lens Lz is translucently photographed. To output the image. That is, if only the even frame image is output without the odd frame image, the image with the glare removed is output.

Such a camera can be used for traffic accident recording in front of night vision cameras or robots or vehicles that must operate in glare-rich environments. In addition, the output image of the camera of the present embodiment can also be used by outputting to a head mount display (HMD) as shown in FIG. Fig. 5 is a plan view of the spectacle type HMD with cameras camc1 and camc2 attached to the outside of the spectacle lens, respectively. In this case, the output image of the first camera camc1 is output to the left lens portion of hmd and is input to the left eye ey1, and the output image of the remaining second camera camc2 is output to the right lens portion of hmd and the right eye ( sy2). Such a device can be worn by a glare welder or a night driver to reduce eye strain.

Example 4

In the first embodiment, the relative position between the pupil and the smart sunglass is fixed, but the configuration of the case where the relative position is not fixed in the present embodiment will be described. For example, a night driver who is uncomfortable wearing sunglass may implement the smart sunglass function on the windshield GL of the vehicle as shown in FIG. 6. In this case, stereo cameras (cam1, cam2) are installed on the left and right sides of the windshield of the car, and the 3rd and 4th stereo cameras (cam3, cam4) are mounted in front of the driver to photograph the dazzling light source outside the vehicle. Detects the eye's position. At this time, the third and fourth cameras are preferably attached to the roof of the car on the driver's seat so as not to obstruct the driver's view. The image captured by the first and second cameras is analyzed by the image processor to determine the three-dimensional position of the dazzling light source LS, and the images of the third and fourth cameras are analyzed to determine the three-dimensional position of the driver's eyes. Detecting the human eye in the captured image is a known technique in the field of image processing called face recognition. The glare of the driver can be eliminated by making the area C1 through which the straight line between the light source LS and the eyes ey1 and ey2 thus found passes through the windshield of the vehicle. At this time, by attaching the polarizing film and the LCD to the windshield of the car it can be electrically controlled the degree of light transmission.

Example 5

In Example 3, a glare area is removed by attaching a filter GL that can adjust transmittance on the image sensor IS. Such a filter may be implemented by an electronic shutter or an auto gain controller. Here, the electronic shutter adjusts the time for which the light is emitted to the image sensor, and the automatic gain adjuster adjusts the brightness of the screen to be close to the reference brightness. At this time, since the conventional electronic shutter operates at the same shutter speed for all pixels and the automatic gain adjuster operates at the same gain for all pixels, the entire screen becomes brighter or darker, but in this embodiment, the shutter speed is different for each pixel. It features an electronic shutter that operates with a digital gain and an automatic gain adjuster that operates with different gains for each pixel. In other words, the conventional electronic shutter obtains the average luminance of the entire screen and compares it with the reference luminance to make the screen brighter by slowing the shutter speed when it is darker than the reference luminance. Similarly, if the average luminance of the entire screen is darker than the reference luminance, the gain is increased to brighten the screen, and if it is brighter than the reference luminance, the gain is lowered to darken the screen. This method is introduced in the existing (Patent Application No. 10-2001-0063624 automatic brightness control device and automatic brightness control method of the image sensor). In this embodiment, the image of the odd frame is generated by processing the luminance control with the same shutter speed or gain for all pixels as in a camera using a conventional image sensor, and then the even frame image is detected after detecting a bright area in the image processor. In the bright area detected by the image processor from the previous odd frame image, the shutter area is amplified by increasing the shutter speed or lowering the gain. In other areas, the blind area is removed by lowering the shutter speed or increasing the gain. More specifically, the shutter speed is proportional to the brightness of each pixel in the odd frame image, and the gain is inversely adjusted.

At this time, the odd frame image is used as an input to the image processor and is not output to the actual user. Only the even frame image with the glare removed is output to the user.

The embodiments described above are only specific implementations of the technical idea in the present invention, and thus should not be construed as being limited to these embodiments in determining the technical scope of the present invention. The technical scope of the present invention will be reasonably determined by the method of interpretation of the claims.

1 is an external perspective view of a smart sunglass according to the present invention

Figure 2 is a plan view of the sungrass of Figure 1

3 is a plan view of the smart sunglass attached to the front of the camera

Figure 4 is an embodiment attached to the filter inside the camera

5 is a plan view of the smart sunglasses attached to the HMD

6 illustrates an embodiment in which the windshield of the vehicle functions as a filter

<Description of Major Symbols in Drawing>

CAM1, CAM2: Light source camera LS: Light source

L1, L2: straight line between camera and light source

C1, C2: the point where the straight line between the light source and the eye intersects the lens

GL: Filter that can control light transmittance in specific area

Camc, camc1, camc2: Camera Lz: Lens

IS: Image Sensor Bp: Bright Spot

Ey1, ey2: Eye cam3, cam4: Camera for eye shooting

Claims (4)

In the sunglass device using the camera, Camera unit for taking an image; An image processor for calculating a position of a dazzling light source from an image photographed by the camera unit; A controller for controlling transparency of the filter area where a straight line between the light source and the pupil or the image sensor calculated by the image processor intersects the filter; Smart sunglass device using a camera characterized in that it comprises a filter for changing the transparency or color of a specific area in response to the signal of the control unit The camera unit of claim 1 includes two or more cameras arranged side by side at intervals so as to photograph the same direction; The image processing unit is a smart sunglass device using a camera, characterized in that for analyzing the plurality of images simultaneously taken by a plurality of cameras of the camera unit to calculate the three-dimensional position of the dazzling light source In claim 1, the filter unit includes a filter installed between the lens of the camera of the camera unit and the image sensor The control unit keeps the filter transparent during the odd frame of the camera of the camera unit, and transmits the odd frame image captured by the camera of the camera unit to the image processing unit, and the even frame image is a specific area on the filter calculated by analyzing the previous frame image in the image processing unit. And a controller for translucently adjusting and outputting only the even-frame image with glare removed to the user. The image processing unit analyzes an odd frame image, calculates a position of a dazzling light source, and outputs an area of a filter through which a straight line passes between the light source and the image sensor to the controller. The smart sunglass apparatus using a camera according to any one of claims 1 to 3, wherein the filter unit is a transmissive LCD display in which a polarization film is attached to change transparency of a specific region by an electric signal.

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