JP2019122010A - Rear image display device for vehicle - Google Patents

Abstract

To provide a rear image device for a vehicle that can separately draw right and left head lamps of a rear vehicle included in a vehicle rear image and can easily identify a distance from an own vehicle to the rear vehicle.SOLUTION: A rear image display device 1 for a vehicle comprises a rear camera 10R for photographing a vehicle rear area where a gain is set so as to allow separate drawing of right and left head lamps of a rear vehicle when the right and left head lamps are turned on, a front camera 10F for photographing a vehicle front area illuminated by right and left head lamps of an own vehicle, a partial image extraction part 30 for extracting a partial image by cutting a part of the front area image obtained from photographing by the front camera 10F, a composite image generation part 60 for generating a composite image by overlapping the partial image extracted by the partial image extraction part 30 with the rear area image obtained from photographing by the rear camera 10R, and a display part 70 for displaying the composite image generated by the composite image generation part 60.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vehicle rear image display device mounted on a vehicle and imaging and displaying a rear side.

  Conventionally, when a camera mounted on a vehicle captures an image of the front of the vehicle and pixels in a saturated state in which the pixel value of each pixel included in the obtained image reaches a saturation level are adjacently a predetermined number of pixels or more There is known an on-vehicle camera control device that changes the pixel value and brightness characteristic when the camera captures an image in the direction in which the high luminance portion is suppressed (see, for example, Patent Document 1). By performing such processing, when a high brightness portion such as a headlight of an oncoming vehicle, a tail lamp of a preceding vehicle, or a brake lamp is present in an image captured by a camera, brightness is used as a pixel value / brightness characteristic of the camera. Since the sensitivity of the change in pixel value to the brightness is lowered and the change ratio of the pixel value is changed to a smaller value as the brightness level is higher, the brightness of the entire image is suppressed while the brightness of the entire image is suppressed. It is possible to detect various contrasts.

Unexamined-Japanese-Patent No. 2006-339994

  By the way, recently, a camera is installed at the rear of the vehicle, and a method of converting the rearview mirror into an electronic mirror is put into practical use by drawing the rear image of the vehicle taken by this camera on the LCD panel arranged at the rearview mirror. is there. When displaying a vehicle rear image using such a method, the illumination on the nearby road is low during night driving, and the rear view becomes extremely poor due to halation by the headlights of the following vehicles. On the other hand, in order to correspond to PLS (Point Light Source) in the CMS (Camera Monitoring System) standard, it is necessary to divide and draw the two following vehicle headlights located 250 m behind as two light sources.

  In order to respond to such a request, it is conceivable to use the method of Patent Document 1 described above. However, there has been a problem that the processing load is increased if it is attempted to control the various optical elements of the camera each time to change the pixel value and brightness characteristics in accordance with the brightness of the headlights of the following vehicle. On the other hand, even if the left and right headlights of the following vehicle can be drawn separately, if the distance from the own vehicle to the following vehicle is dark, the left and right headlights of the following vehicle suddenly appear in the dark As a result, there is a problem that it is difficult to grasp the distance from the host vehicle to the following vehicle.

  The present invention has been made in view of such a point, and an object thereof is to draw separately the left and right headlights of the following vehicle included in the vehicle rear image and to draw the distance from the own vehicle to the following vehicle An object of the present invention is to provide a rear image display apparatus for a vehicle which can easily grasp the interval.

  In order to solve the problems described above, the vehicle rear image display device of the present invention is set to a gain that can separate and draw the left and right headlights when the left and right headlights of the following vehicle are turned on. A first imaging means for imaging the rear of the vehicle, a second imaging means for imaging the front of the vehicle illuminated by the left and right headlights of the vehicle, and a front image obtained by imaging by the second imaging means The partial image extracted by the partial image extraction unit is superimposed on the partial image extraction unit that extracts the partial image by cutting out a part, and the backward image obtained by the imaging by the first imaging unit to generate a composite image And image display means for displaying the synthesized image synthesized by the image synthesis means.

  By performing the gain adjustment of the first imaging means, the left and right headlights of the following vehicle included in the rear image can be divided and drawn, and a partial image obtained by cutting out a part of the front image is used as the rear image. The processing load can be reduced because only the superposition is performed.

  Further, the above-mentioned image combining means is configured to use, as a rear image, a plurality of partial images extracted by the partial image extraction means from each of the plurality of front images obtained by imaging by the second imaging means as the vehicle moves. It is desirable to overlap it. Thereby, in the rear image, the part from the host vehicle to the following vehicle can be drawn using a partial image corresponding to the road surface illuminated by the headlights of the host vehicle, and the separated left and right headlights of the following vehicle In addition, displaying such a road surface makes it easy to grasp the distance between the host vehicle and the following vehicle.

  Further, it is preferable that the partial image extracted by the partial image extraction unit described above from the front image includes a range wider than the width of the travel lane of the host vehicle. As a result, it is possible to display a rear image that reproduces the width of the actual lane (road), and it is possible to perform display without a sense of discomfort.

  Further, the above-mentioned image combining means sets a running locus corresponding to the running state of the vehicle on the rear image, and performs image combining by arranging a plurality of partial images in order of imaging time along the running locus. Is desirable. In particular, it is desirable that the traveling state described above includes the direction, speed, and snake angle of the host vehicle. Thus, the road shape in the rear image can be changed in accordance with the traveling state of the host vehicle, and the discomfort due to the use of the composite image can be further reduced.

  Moreover, as for the display means mentioned above, it is desirable to display a synthesized image on a part of room mirror. As a result, it is possible to display the rear image and the composite image that are actually seen side by side, and by comparing these images, it is easier to grasp the distance from the host vehicle to the following vehicle.

It is a figure showing composition of a back image display for vehicles of one embodiment. It is a flowchart which shows the operation | movement procedure of the image synthesis performed when isolate | separating the headlights of the following vehicle in a back image at the time of night travel. It is a figure which shows the specific example which extracts a partial image from a front image. It is a figure which shows the set traveling locus. It is explanatory drawing which arranges a partial image along the traveling locus shown in FIG. It is a figure which shows the example of a display of a synthetic | combination image.

  Hereinafter, a rear image display apparatus for a vehicle according to an embodiment to which the present invention is applied will be described with reference to the drawings.

  FIG. 1 is a diagram showing the configuration of a rear image display apparatus for a vehicle according to an embodiment. As shown in FIG. 1, the vehicle rear image display device 1 of the present embodiment includes a front camera 10F, a rear camera 10R, a front image storage unit 20F, a rear image storage unit 20R, a partial image extraction unit 30, and a superimposed image storage unit. 40, a traveling state detection unit 50, an image combining unit 60, and a display unit 70.

  The front camera 10F images the front of the host vehicle. The imaging range is a range including the road surface on which the illumination is applied when the headlight of the host vehicle is turned on, and at least includes the range of the road surface wider than the width of the traveling lane.

  When it is assumed that a physical rearview mirror is provided, the rear camera 10R captures an image of the rear of the host vehicle so that the area seen by the rearview mirror as viewed from the driver of the vehicle is included in the imaging range. Further, in the present embodiment, when the left and right headlights of the following vehicle traveling behind the host vehicle are turned on, the gain of the rear camera 10R is set so that the left and right headlights can be separated and rendered. ing.

  An image (forward image) obtained by imaging with the front camera 10F is stored in the front image storage unit 20F. Further, an image (rear image) obtained by imaging with the rear camera 10R is stored in the rear image storage unit 20R.

  The partial image extraction unit 30 extracts a partial image by cutting out a part of the front image captured by the front camera 10F and stored in the front image storage unit 20F. When front images are taken at predetermined time intervals by the front camera 10F, partial images are sequentially extracted from the respective front images and stored in the superimposed image storage unit 40.

  The traveling state detection unit 50 detects at least the direction, speed, and snake angle of the host vehicle as the traveling state. For example, the orientation of the host vehicle can be detected by using a GPS device or an acceleration sensor. Also, the speed of the vehicle can be detected by measuring the output interval of the vehicle speed pulse. Furthermore, the snake angle can be detected by measuring the operating angle of the steering wheel with a sensor. As a specific method of detection, other methods may be used.

  The image combining unit 60 sets the traveling locus of the own vehicle corresponding to the traveling state of the own vehicle detected by the traveling state detection unit 50 on the rear image read out from the rear image storage unit 20R. By arranging a plurality of partial images stored at different imaging times along the traveling locus, the plurality of partial images are superimposed on the rear image to generate a composite image. The traveling locus set here corresponds to the shape of the road seen behind the host vehicle. For example, when it is detected by the traveling state detection unit 50 that the steering wheel is turned to the right while traveling at a certain traveling speed A road locus curving to the right with a radius of curvature corresponding to the traveling speed is set. In addition, on the rear image, a traveling locus shape after performing viewpoint conversion focusing on the viewpoint position of the driver with respect to such a curved shape is obtained.

  The display unit 70 displays the combined image generated by the image combining unit 60. For example, the display unit 70 is configured by a liquid crystal display device, and is embedded in a part of the rearview mirror.

  The above camera 10R is the first imaging means, the front camera 10F is the second imaging means, the partial image extraction unit 30, the superimposed image storage unit 40 is the partial image extraction means, and the image combining unit 60 is the image combining means The display unit 70 corresponds to the display means.

  The vehicle rear image display device 1 of the present embodiment has such a configuration, and the operation thereof will be described next.

  In the present embodiment, it is considered that halation may occur due to illumination lights of left and right headlights of the following vehicle captured by the rear camera 10R at night traveling, and these left and right headlights may not be separated. In order to separate the headlights, the gain (sensitivity) of the rear camera 10R is lowered to prevent the pixel value from being saturated. Further, after this, a process of combining a partial image cut out from the front image taken by the front camera 10F with the rear image taken by the camera 10R is performed.

  Therefore, as the timing for performing such processing, (1) when the high brightness area corresponding to the left and right headlights of the following vehicle is extracted and it is detected that the high brightness area can not be separated into two left and right (2) When a sensor (not shown) detects that the surroundings of the host vehicle have become dark, (3) When the headlights of the host vehicle are turned on, etc. can be considered.

  FIG. 2 is a flow chart showing an operation procedure of image synthesis performed when separating the left and right headlights of the following vehicle in the rear image when traveling at night. This operation procedure is repeated at predetermined time intervals.

  First, each imaging range is imaged by the front camera 10F and the rear camera 10R (step 100). Since nighttime traveling is assumed, the headlight of the host vehicle is turned on, and a predetermined range including the road surface ahead of the host vehicle is bright, and this bright road surface is imaged by the front camera 10F. Also, since the rear camera 10R for imaging the rear of the vehicle has a low gain, even if the following vehicle with its headlights turned on enters the field of view (imaging range), the rear image corresponds to the left and right headlights Regions can be separated. A front image obtained by imaging with the front camera 10F is stored in the front image storage unit 20F. A rear image obtained by imaging with the rear camera 10R is stored in the rear image storage unit 20R.

  Next, the partial image extraction unit 30 reads out the front image stored in the previous image storage unit 20F, cuts out a part of it, and extracts a partial image (step 102). The partial images extracted in this manner are sequentially stored in the superimposed image storage unit 40.

  FIG. 3 is a diagram showing a specific example of extracting a partial image from a front image. In FIG. 3, P indicates a region from which a partial image is cut out. This area P is a horizontally long area ahead of the host vehicle by a predetermined distance (for example, 3 m), and has a width that is greater than the width of the lane in which the host vehicle is traveling.

  Next, the traveling state detection unit 50 detects the traveling state of the host vehicle, specifically, the direction, speed, and snake angle of the host vehicle (step 104).

  Next, the image combining unit 60 reads the rear image from the rear image storage unit 20R, and sets the traveling locus of the vehicle corresponding to the detected traveling state on the rear image (step 106). Further, the image combining unit 60 reads out a plurality of partial images stored in the superimposed image storage unit 40 at different imaging times, and arranges the partial images along the traveling locus to superimpose the plurality of partial images on the rear image. Then, a composite image is generated (step 108). The composite image generated in this manner is displayed on the display unit 70 (step 110).

  FIG. 4 is a diagram showing a set traveling locus. In FIG. 4, T1 and T2 are traveling trajectories set corresponding to the traveling state of the host vehicle. These two travel trajectories T1 and T2 correspond to, for example, the left and right tire marks of the host vehicle, but use two travel trajectories wider or narrower than the interval (width) of the left and right tires, One travel regulation may be used.

  FIG. 5 is an explanatory view of arranging the partial images along the traveling trajectories T1 and T2 shown in FIG. In FIG. 5, S1, S2, S3, S4,... Indicate a plurality of partial images extracted from forward images different in imaging time. S1 is a partial image extracted from the forward image with the latest imaging time, and the imaging time becomes old in the order of S2, S3 and S4. The width of each partial image S1, S2,... Is appropriately reduced (a certain enlargement) in the lateral direction in accordance with the distance between the traveling loci T1, T2.

  FIG. 6 is a view showing a display example of a composite image. In FIG. 6, HL indicates the left headlight of the following vehicle, and HR indicates the right headlight of the following vehicle. Further, hatching represents darkness (a background portion where the contrast is not clear) included in the rear image. As shown in FIG. 6, in the composite image, the left and right headlights HL and HR of the following vehicle are drawn separately, and a state in which the road surface toward the following vehicle is brightly illuminated is drawn ing. In practice, since a partial image extracted from the front image is superimposed on the rear image, a shift of several meters occurs between the actual position at which the partial image is extracted and the drawing position, except for this point Since the image synthesis is performed using the image of the road surface actually captured, it is possible to generate a realistic composite image.

  As described above, in the vehicle rear image display device 1 of the present embodiment, by performing the gain adjustment of the rear camera 10R, the left and right headlights of the following vehicle included in the rear image can be divided and drawn. The composite image is generated only by superimposing the partial image obtained by cutting out a part of the front image on the rear image, and the processing load can be reduced.

  In addition, it is possible to draw from the own vehicle to the following vehicle in the rear image using a partial image corresponding to the road surface illuminated by the headlights of the own vehicle, with the separated left and right headlights of the following vehicle By displaying such a road surface, the distance between the host vehicle and the following vehicle can be easily grasped.

  In addition, by using a partial image including a range wider than the width of the travel lane of the host vehicle, it is possible to display a rear image that reproduces the width of the actual lane (road), and display without discomfort It becomes possible.

  In addition, a traveling locus corresponding to the traveling state of the host vehicle (for example, the direction, speed, and snake angle of the host vehicle) is set on the rear image, and a plurality of partial images are arranged in imaging time order along this traveling locus. Thus, the image synthesis is performed, and the road shape in the rear image can be changed in accordance with the traveling state of the host vehicle, and the discomfort caused by using the synthesized image can be further reduced.

  Further, by displaying the composite image on a part of the rearview mirror, it is possible to display the rear image and the composite image that are actually seen side by side, and by comparing these images, the distance between the own vehicle and the following vehicle Is easier to understand.

  The present invention is not limited to the above embodiment, and various modifications can be made within the scope of the present invention. For example, in the embodiment described above, the display unit 70 is provided at a part of the room mirror, but the display unit 70 may be provided at a position other than the room mirror.

  As described above, according to the present invention, by performing the gain adjustment of the first imaging means, it is possible to divide the left and right headlights of the following vehicle included in the rear image and draw the front headlights. The processing load can be reduced because only the partial image in which a part is cut out is superimposed on the rear image.

1 Vehicle Rear Image Display Device 10F Front Camera 10R Rear Camera 20F Front Image Storage Unit 20R Rear Image Storage Unit 30 Partial Image Extraction Unit 40 Superimposed Image Storage Unit 50 Running State Detection Unit 60 Image Synthesis Unit 70 Display Unit

Claims (6)

When the left and right headlights of the following vehicle are turned on, the left and right headlights are set separately to be drawable, and a first imaging means for imaging the rear of the vehicle
Second imaging means for imaging the front of the vehicle illuminated by the left and right headlights of the vehicle;
Partial image extraction means for extracting a partial image by cutting out a part of a front image obtained by imaging by the second imaging means;
An image synthesis unit that generates a composite image by superimposing the partial image extracted by the partial image extraction unit on a backward image obtained by imaging by the first imaging unit;
Display means for displaying the combined image combined by the image combining means;
A rear image display apparatus for a vehicle comprising:   The image combining unit is configured to generate the plurality of partial images extracted by the partial image extraction unit from each of the plurality of forward images obtained by imaging by the second imaging unit as the vehicle moves. The vehicle rear image display device according to claim 1, wherein the vehicle rear image is superimposed on the rear image.   The rear image display apparatus for a vehicle according to claim 1, wherein the partial image extracted by the partial image extraction unit includes a range wider than a width of a traveling lane of the host vehicle.   The image combining unit sets a traveling locus corresponding to the traveling state of the vehicle on the rear image, and performs image combination by arranging a plurality of the partial images in order of imaging time along the traveling locus. The rear image display apparatus for vehicles as described in any one of Claims 1-3 characterized by these.   The rear image display apparatus for a vehicle according to claim 4, wherein the traveling state includes the direction, the speed, and the snake angle of the host vehicle.   The rear display device for a vehicle according to any one of claims 1 to 5, wherein the display means displays the composite image on a part of a rearview mirror.

Images