JP2014021543A - Visual field support device and program for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the possibility that a driver of an own vehicle is dazzled by light of a light-emitting body around a road, in a technology to obtain a photographic image from an on-vehicle camera that photographs surroundings of the vehicle and display a mask on the obtained photographic image in a transparent manner.SOLUTION: A visual field support device obtains a photographic image from an on-vehicle camera 1 (Step 130), sets a transmittance to be smaller according as a representative value of brightness within a predetermined detection range in an image for display based on the photographic image is smaller (Step 145), overlaps a mask of the transmittance on a mask region in the image for display (Step 150), and displays the image for display with the mask overlapped in a transparent manner on a display 3 (Step 160).

Description

  The present invention relates to a vehicular visual field support device and a vehicular visual field support program.

  Conventionally, Patent Document 1 discloses a technique for acquiring a captured image from an in-vehicle camera that captures the periphery of a vehicle and displaying a mask transparently on the acquired captured image. In the technique described in Patent Document 1, the risk prediction region is emphasized by transparently superimposing a mask outside the risk prediction region, and the transmittance is changed according to the risk level of the risk prediction region, the vehicle speed of the host vehicle, and the like. I am letting.

2011-240331 gazette

  However, if the transmittance is changed based on the risk in the danger prediction area and the vehicle speed of the host vehicle as in Patent Document 1, the driver of the host vehicle is dazzled by the lighting device attached to the buildings around the road. I can't prevent that.

  In view of the above points, the present invention acquires a captured image from an in-vehicle camera that captures the surroundings of a vehicle, and in a technique for transparently displaying a mask on the acquired captured image, a light emitter around a road (for example, attached to a building) The object is to reduce the possibility that the driver of the host vehicle will be dazzled by the light of the lighting device.

  In order to achieve the above object, the invention described in claim 1 is characterized in that an acquisition means (130) for acquiring a captured image from an in-vehicle camera (1) that captures the periphery of a vehicle, and a predetermined detection area ( L1-L3) transmittance setting means (145, 147) for setting a smaller transmittance as the representative luminance value is smaller, and the transmission in the mask area in the display image (10) based on the acquired photographed image. A vehicle comprising: a superimposing means (150) for superimposing a rate mask (GM); and a display control means (160) for causing the display (3) to display the display image on which the mask is transparently superimposed. It is a visual field support device.

  In this way, by setting the smaller transmittance as the representative value of the luminance in the predetermined detection area in the captured image is smaller, the surroundings are dark as a whole, and the driver of the host vehicle is dazzled by the light emitters around the road In the case where there is a high possibility, the transmittance of the mask is reduced and the luminance of the light emitter is suppressed, so that the possibility that the driver of the host vehicle is dazzled is reduced.

  In addition, the code | symbol in the bracket | parenthesis in the said and the claim shows the correspondence of the term described in the claim, and the concrete thing etc. which illustrate the said term described in embodiment mentioned later. .

It is a lineblock diagram of the vision support system for vehicles concerning the embodiment of the present invention. It is a flowchart of the process which ECU performs. It is a figure which illustrates gradation mask GM superimposed on picture 10 for display. It is a flowchart which shows the detail of a gradation mask specification production | generation process. It is a graph which shows the relationship between the brightness | luminance B and the minimum transmittance | permeability. It is a figure which shows the change of the display image 10 before and behind superimposition of a gradation mask.

  Hereinafter, an embodiment of the present invention will be described. The vehicle vision support system according to the present embodiment is mounted on a vehicle, and includes an in-vehicle camera 1, an ECU 2 (corresponding to an example of a vehicle vision support device), and a display 3, as shown in FIG.

  The in-vehicle camera 1 is fixedly mounted in the vicinity of the rear end of the vehicle. Specifically, the vehicle-mounted camera 1 has a predetermined range behind the vehicle (for example, a range in which the driver can see with a normal room mirror). Images are taken repeatedly (for example, at a cycle of 1/30 seconds), and video signals of the captured images in the predetermined range obtained as a result of the shooting are sequentially output to the ECU 2.

  The ECU 2 is repeatedly input with the captured image from the in-vehicle camera 1 and is repeatedly input with vehicle speed information and shift range information from the vehicle. The ECU 2 then superimposes the gradation mask on the captured image input from the in-vehicle camera 1 and inputs the video signal of the captured image after superimposition to the display 3. ECU2 may be a microcomputer provided with CPU, RAM, ROM, and I / O, for example.

  The display 3 is a device that displays a captured image represented by the video signal input from the ECU 2, and a position where the displayed captured image can be viewed by a driver in the vehicle (for example, the position of the room mirror, the dashboard) (Center, door mirror position, etc.).

  Hereinafter, the operation of the vehicular visual field support system having such a configuration will be described. When the power is turned on and the ECU 2 is activated, the ECU 2 executes the processing shown in FIG.

  The ECU 2 first activates the vehicle-mounted camera 1 at step 110. Accordingly, the in-vehicle camera 1 repeatedly captures a predetermined range behind the vehicle, and sequentially outputs a video signal of a captured image in the predetermined range obtained as a result of the imaging to the ECU 2.

  Subsequently, the ECU 2 starts to repeatedly execute the processing of steps 120 to 160. In step 120, vehicle speed information and shift position information are acquired from the vehicle as vehicle information.

  Subsequently, in step 130, the video signal of the latest photographed image is acquired from the in-vehicle camera 1. Various corrections are performed on the captured image represented by the video signal, and the corrected captured image is used as a display image.

  Examples of the correction include trimming that cuts and discards the top, bottom, left, and right ends of the captured image, and distortion correction that corrects distortion. The corrected display image corresponds to an example of a display image based on the captured image.

  Subsequently, in step 140, a specification of a mask image (hereinafter referred to as a gradation mask) is generated. In subsequent step 150, a gradation mask according to the generated specification is created, and the created gradation mask is used as a mask in the display image. Transparently overlaps the target range.

  Here, the gradation mask GM will be described with reference to FIG. As illustrated in FIG. 3, in step 150, the ECU 2 sets the entire range from the predetermined mask lower end line ML to the mask upper end line MU in the display image 10 as a mask area, and a gradation mask having the same shape as the mask area. A GM is created, and the created gradation mask GM is transparently superimposed on the entire mask area.

  The position of the mask upper end line MU coincides with the upper end of the display image. The position of the mask bottom line ML is one of the specifications of the gradation mask, and is generated in step 140.

  Note that “transparently superimpose” means that a portion of the image for display that is covered by the gradation mask GM (an image other than the gradation mask GM) is also superimposed so that the gradation mask GM can be seen through. That means.

  The transmittance of the gradation mask GM is 100% (that is, total transmission) at the position of the mask lower end line ML, and monotonously decreases from the mask lower end line ML to the mask upper end line MU (for example, the primary distance from the mask upper end line). And the minimum transmittance becomes the position at the position of the mask upper end line MU. The minimum transmittance is one of the gradation mask specifications and is generated in step 140.

  The reason why the transmittance is 100% (total transmission) at the position of the mask lower end line ML is to smoothly change the display color from the end of the mask region to the portion adjacent to the mask region. If, for example, the transmittance is 80% at the position of the mask lower end line ML, a line appears between the mask region and the portion adjacent to the mask region.

  The gradation mask GM itself is a black or gray single color image having no pattern. The color is black or gray (so-called achromatic color). When using a chromatic color such as red or blue, the color of a signboard or the like that is transmitted and displayed in the mask area is greatly different from the original color. This is because the driver may feel uncomfortable.

  Subsequently, in step 160, the video signal of the display image on which the gradation mask is transparently superimposed is input to the display 3. Thereby, the display 3 displays the display image on the driver.

  Here, the specification generation processing of the gradation mask in step 140 will be described in detail. In the gradation mask specification generation process, as shown in FIG. 4, first, in step 141, the ECU 2 sets the position of the mask lower end line ML based on the vehicle speed acquired in the immediately preceding step 120.

  First, the default position of the mask lower end line ML is determined in advance and recorded in the ROM or the like of the ECU 2.

  This default position may be set, for example, so as to be parallel to the horizontal line shown in the display image and at the same height as the horizontal line when the host vehicle is on a horizontal road surface. The position of the horizontal line in the display image is corrected when creating the display image from the specifications of the in-vehicle camera 1, the mounting position of the in-vehicle camera 1 on the vehicle, the mounting angle of the in-vehicle camera 1 on the vehicle, and the captured image. Can be specified in advance when the ECU 2 is attached to the vehicle.

  The default position may be set to be parallel to the horizontal line displayed in the display image and higher than the horizontal line when the host vehicle is on a horizontal road surface, for example.

  For example, the position in the display image that corresponds to the target position of 6 meters above the ground (the height of a general traffic light) at a point 100 meters away from the vehicle-mounted camera 1 in front of the vehicle is determined by the vehicle-mounted camera 1. If the specifications, the mounting position of the vehicle-mounted camera 1 on the vehicle, the mounting angle of the vehicle-mounted camera 1 on the vehicle, and the content of correction when creating the display image from the captured image are determined, the ECU 2 is mounted on the vehicle. Sometimes it can be specified in advance. Therefore, the position in the display image where the target position is reflected may be set in advance as the default position of the mask lower end line ML.

  The position of the mask lower end line ML is set to a position offset upward from the default position in the display image, and the offset amount increases as the vehicle speed decreases. That is, as the vehicle speed decreases, the position of the mask lower end line ML is increased.

  For example, when the vehicle speed is 50 km / h or more, the offset amount is set to zero. When the vehicle speed is from 50 km / h to 0 km, the offset amount is increased as the vehicle speed decreases with a linear function of the vehicle speed, and when the vehicle speed is 0 km / h, The offset amount may be such that the mask lower end line ML coincides with the mask upper end line MU.

  The reason why the mask area is narrowed as the vehicle speed is low is that, as the vehicle speed is low, it is more necessary to see the back side firmly. Also, the lower the vehicle speed, the smaller the inter-vehicle distance, and the lower the inter-vehicle distance, the higher the upper end position of the other vehicle (following vehicle) in the display image.

  Subsequently, in step 143, the luminance in the detection area is acquired, and a representative value B of the luminance is calculated. The detection area is a partial area in the mask area. For example, as shown in FIG. 3, three luminance detection lines L1 to L3 having a width of one pixel are set in the mask area, and all areas in the luminance detection lines L1 to L3 are set as detection areas. The representative value B of the luminance is a representative value based on the luminance distribution of all the pixels in the detection region, and may adopt an average value, a mode value, or a median value. May be.

  Subsequently, at step 145, the minimum transmittance (transmittance at the mask upper end line MU) is set based on the luminance representative value B calculated at the immediately preceding step 143.

  Specifically, the smaller the luminance representative value B, the smaller the minimum transmittance MU (makes it difficult to transmit). For example, as shown in FIG. 5, the minimum transmittance may be set as a linear function of the luminance representative value B.

  The reason why the gradation mask GM is superimposed is to prevent the driver of the host vehicle from being dazzled by a light emitter around the road (for example, a lighting device attached to a building).

  In other words, the driver feels dazzling around the road when the surroundings are dark, for example, at night. Under the bright daytime sky, even if the illuminants around the road shine brightly, it is unlikely that the driver will be dazzled by it.

  Therefore, in this embodiment, in order to prevent dazzling particularly when the surroundings are dark as a whole, the minimum transmittance MU is reduced (makes it difficult to transmit) as the luminance representative value B is smaller (the luminance is smaller as a whole).

  Note that the transmittance of the region from the mask upper end line MU to the mask lower end line ML changes (except for the mask lower end line ML itself) in accordance with the change in the minimum transmittance MU. That is, if the minimum transmittance MU decreases, the transmittance MU of almost the entire mask region decreases, and if the minimum transmittance MU increases, the transmittance MU of the entire mask region increases.

  Of course, it is possible to reduce the minimum transmittance MU when the surroundings of the daytime are bright as well as at night, but in this case, the upper part in the display image becomes dark due to the gradation mask GM, and this is seen. The driver may get the wrong impression, such as whether the sky is cloudy or raining, and the driver may feel uncomfortable without making a mistake. Further, since the whole is bright during the daytime when the brightness is high as a whole, the effect of anti-glare can be achieved to some extent only by making the gradation mask GM dark. On the other hand, at night when the brightness is low as a whole, even if the brightness is greatly reduced by the gradation mask GM, there is not much discomfort.

  Here, the reason why the detection area is within the mask area is that it is desirable to set the transmittance of the gradation mask GM according to the luminance of the place where the gradation mask GM is superimposed. If the detection area is set outside the mask area, for example, on the road surface, the brightness of the road is likely to fluctuate due to headlights, etc., and the transmittance of the gradation mask GM changes rapidly, resulting in driver discomfort. May be given.

  Subsequently, in step 147, the transmittance of the gradation mask GM is determined based on the shift position acquired in the immediately preceding step 120. At this time, the method for determining the transmittance differs depending on whether or not the shift position is reverse.

  When the shift position is not reverse, the minimum transmittance set in the immediately preceding step 145 is the transmittance of the mask lower end line ML, the transmittance of the mask upper end line MU is 100%, and the transmittance of the mask area in between is set as the mask. It is determined to monotonously decrease from the lower end line ML to the mask upper end line MU (for example, linearly decrease with respect to the distance from the mask lower end line ML).

  When the shift position is reverse, the transmittance of the entire gradation mask GM is set to 100% regardless of the setting contents in step 145. That is, the transmittance is set so as to produce the same effect as when the gradation mask GM is not superimposed. The reason for this is to make it easier to see the camera image by showing the entire display image showing the rear without superimposing the gradation mask GM when the vehicle moves backward.

  After step 147, the process proceeds to step 150 in FIG. 2, and a gradation mask GM is created in accordance with the specifications (transmittance and shape) of the gradation mask GM determined as described above, and the created gradation mask GM is used as a mask for a display image. Superimpose on the area.

  At this time, if the shift position is not reverse, as determined in step 147, the transmittance at the mask upper end line MU in the mask region becomes the above-described minimum transmittance (for example, 70%), and is transmitted from the mask upper end line to the mask lower end line. The superposition is performed by a well-known alpha blending process so that the rate increases and the transmittance becomes 100% at the mask lower end line ML. In step 160, the display image after the superimposition is displayed on the display 3.

  In FIG. 6, the display image 10 (left image) before the gradation mask GM is superimposed is compared with the display image 10 (right image) after the gradation mask GM is superimposed.

  As illustrated in this figure, in the display image on which the gradation mask GM is superimposed, since the brightness of the right upper light 20 is weakened, the possibility that the driver is dazzled by the light 20 is reduced.

  As described above, the ECU 2 sets a smaller transmittance as the representative value of the luminance in the predetermined detection area in the captured image is smaller. Thereby, when the surroundings are dark as a whole and there is a high possibility that the driver of the host vehicle will be dazzled by the light emitters around the road, the transmittance of the gradation mask GM is reduced and the luminance of the light emitters is suppressed. The possibility that the driver of the vehicle is dazzled is reduced.

  In the above-described embodiment, the ECU 2 functions as an example of an acquisition unit by executing step 130, functions as an example of a lower end setting unit by executing step 141, and executes steps 145 and 147. It functions as an example of a transmittance setting unit, functions as an example of a superimposing unit by executing step 150, and functions as an example of a display control unit by executing step 160.

(Other embodiments)
As mentioned above, although embodiment of this invention was described, the scope of the present invention is not limited only to the said embodiment, The various form which can implement | achieve the function of each invention specific matter of this invention is included. It is. For example, the following forms are also acceptable.

  (1) In the above embodiment, the gradation mask GM has a transmittance of 100% (total transmission) in the mask lower end line ML. However, if it does not matter that a line is visible between the mask area and a portion adjacent to the mask area, the transmittance of the gradation mask GM is other than 100% (for example, 80%) at the position of the mask bottom line ML. %).

  (2) In the above embodiment, the detection area is the luminance detection lines L1 to L3 in the mask area, but the detection area may be a pixel group selected at random in the mask area, The entire mask area may be used.

  Alternatively, when it is not a problem that the transmittance of the gradation mask GM changes rapidly, the detection region may be a region including a part inside the mask region and a part outside the mask region, or a region outside the mask region. It may be a region including only a part.

  (3) In the above-described embodiment, the color of the gradation mask GM is a black or gray achromatic color. However, if it is not a problem that the color of the signboard or the like in the display image is significantly different from the original color, the color of the gradation mask GM may be a chromatic color.

  (4) In the above embodiment, the image obtained as a result of correcting the captured image acquired from the in-vehicle camera 1 is used as the display image. However, the captured image acquired from the in-vehicle camera 1 is used as the display image as it is. Also good.

  (5) In the above embodiment, the gradation mask GM with non-uniform transmittance is illustrated as a mask to be superimposed on the mask area of the display image. However, a mask with uniform transmittance is superimposed. It may be.

  Even if it becomes like this, if the said uniform transmittance | permeability is made small so that the brightness | luminance representative value in detection area | region L1-L3 is small, the driver | operator of the own vehicle by the light of the light-emitting body around a road will become. The object of the present invention of reducing the possibility of being dazzled is achieved.

  (6) Moreover, in the said embodiment, although the vehicle-mounted camera 1 image | photographs the predetermined range of the back of a vehicle, the imaging | photography range of the vehicle-mounted camera 1 is not restricted to the back of a vehicle, Even in the front of a vehicle. It may be on the side.

1 In-vehicle camera 2 ECU
3 Display GM Gradation mask ML Mask lower end line MU Mask upper end line L1-L3 Luminance detection line

Claims (5)

An acquisition means (130) for acquiring a captured image from an on-vehicle camera (1) that captures the surroundings of the vehicle;
A transmittance setting means (145, 147) for setting a smaller transmittance as the representative value of luminance in the predetermined detection areas (L1 to L3) in the captured image is smaller;
Superimposing means (150) for superimposing the transmittance mask (GM) on the mask area in the display image (10) based on the acquired captured image;
And a display control means (160) for causing the display (3) to display the display image on which the mask is transparently superimposed. The transmittance setting means sets a minimum transmittance based on the representative value;
The mask area is an area above a predetermined mask lower end line (ML) in the display image,
The superimposing means displays the mask created so that the transmittance is the minimum transmittance at the mask upper end line (MU) of the mask region and the transmittance is increased from the mask upper end line to the mask lower end line. The vehicular field-of-view support device according to claim 1, wherein the vehicular field-of-view support device is superimposed on the mask region in the image for use.   The lower end line of the mask is set so as to be parallel to a horizontal line when the vehicle is on a horizontal road surface and located at the same height or higher than the horizontal line. Visibility support device for vehicles as described in 2. The mask area is an area above a predetermined mask lower end line (ML) in the display image,
The vehicular visibility support apparatus according to any one of claims 1 to 3, further comprising lower end setting means (141) for lowering the mask lower end line as the vehicle speed of the vehicle decreases. The vehicular visual field assistance device according to any one of claims 1 to 4, wherein the detection area is included in the mask area.