Patent Application
20180037165
The present invention relates to an image processing device and an electronic mirror system, which are provided in a vehicle.
In recent years, there has been a vehicle provided with a device, which captures an image behind the vehicle and displays the captured image so that a following vehicle or the like can be confirmed.
PTL 1 discloses, as an example of such a device as described above, a rear confirmation device which, when an opening/closing storage-type rear seat display provided on a ceiling of a vehicle is in an open state, prevents a part of the rear seat display from being reflected on an inside rear-view mirror provided in a front portion of the vehicle.
In this rear confirmation device, a magic mirror is used for a mirror surface of the inside rear-view mirror, and a liquid crystal display that displays a rearward image captured by a camera is disposed on a back surface of the magic mirror. Then, when the rear seat display is opened at an angle at which it is partially reflected on the inside rear-view mirror, the rearward image captured by the camera disposed on a rear end portion of a vehicle cabin is displayed on the liquid crystal display, and the rearward image is made visible through the magic mirror.
It is an object of the present invention to provide an image processing device and an electronic mirror system, which make it easy for a driver to grasp a sense of distance, and present more information to the driver who confirms the rear, thus making it possible to contribute to safe driving.
An image processing device of the present invention is an image processing device that performs image processing on a rearward image of a vehicle and outputs an image to a display; the rearward image is captured by an imaging unit; the image is obtained as a result of the image processing. The image processing device includes an object sensor and a compressor. The object sensor senses that an object has come near the vehicle by sensing that the object is within a predetermined range behind the vehicle. When the object sensor senses that the object has come near the vehicle by sensing that the object is within the predetermined range behind the vehicle, the compressor creates a compressed image obtained by compressing a part of a display target range in the rearward image. When the object having come near is sensed, the display target range is changed to a second display target range obtained by moving down a lower end of a first display target range; the first display target range is the display target range when the object is out of the predetermined range. The compressor compresses a part of the rearward image in a vertical direction; the rearward image is present within the second display target range.
An image processing device of the present invention includes the image processing device, the display, the imaging unit, and a distance measuring sensor that outputs a signal indicating a distance between the vehicle and the object; the object sensor senses that the object has come near the vehicle by sensing that the object is within the predetermined range behind the vehicle based on the signal output from the distance measuring sensor.
In accordance with the present invention, it is made easy for the driver to grasp the sense of distance, and more information is presented to the driver who confirms the rear, and thus a contribution can be made to the safe driving.
Prior to describing exemplary embodiments of the present invention, problems found in a conventional device will now briefly be described herein. In the above-mentioned conventional technology of PTL 1, the camera is installed at the rear end of the vehicle cabin away from the inside rear-view mirror, and accordingly, a following vehicle is displayed largely when an image captured by the camera is simply displayed on the liquid crystal display, and the driver may sometimes feel that it is difficult to grasp the sense of distance.
Moreover, when the following vehicle approaches a subject vehicle too closely, then a direction indicator of the following vehicle becomes unseeable. It is also desired that this problem be solved, and that more information be presented to the driver so that the driver can drive more safely.
Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. Note that the respective exemplary embodiments, which will be described below, are merely examples, and the present invention is not limited by these exemplary embodiments.
Moreover, installed on the rear of rear seat 4 are: imaging unit 5 which captures an image of the rear of vehicle 1; and distance measuring sensor 6, which detects a distance from vehicle 1 to an object such as a following vehicle that approaches the rear of vehicle 1, and outputs a signal indicating the distance. Note that, in the following description, it is assumed that the object that approaches the rear of vehicle 1 is the following vehicle.
Moreover, at an attaching position of an inside rear-view mirror in front of front seat 3, image display device 8 is attached to attachment portion 7 so that an attachment angle of image display device 8 can be adjustable. Image display device 8 is a device which displays a rearward image of vehicle 1 or the like, which is captured by imaging unit 5. Note that image display device 8 performs wired communication or wireless communication with imaging unit 5 and distance measuring sensor 6. Image display device 8, imaging unit 5 and distance measuring sensor 6 constitute an electronic mirror system.
Light control filter 83 is a device which can variably control its transmittance and reflectance by applying a voltage, and is capable of realizing at least two states which are a light reflection state and a light transmission state. Such a light control filter is described in detail, for example, in Unexamined Japanese Patent Publication No. 2012-181389.
When display 82 is turned to the OFF state by an operation of operating portion 84, image display device 8 brings light control filter 83 into a light reflection state with a reflectance of 50% or more (preferably a reflectance of 80% or more). In this state, light control filter 83 plays a role as a mirror. In this way, a driver can confirm the rear by an image reflected on light control filter 83.
Meanwhile, when display 82 is turned to the ON state by an operation of operating portion 84, image display device 8 brings light control filter 83 into a light transmission state with a transmittance of 50% or more (preferably a transmittance of 80% or more). In this state, light control filter 83 transmits an image displayed on display 82. At this time, the driver can confirm the rear by a rearward image of vehicle 1 displayed on display 82.
Note that a half mirror may be used in place of light control filter 83. When display 82 is in the ON state, the driver can confirm the rearward image, which is displayed on display 82, through the half mirror. Meanwhile, when display 82 is in the OFF state, the driver can confirm the rear by an image reflected on the half mirror. Moreover, the present invention may be applied to an electronic mirror system in which neither the light control filter nor the half mirror is provided and display 82 is always set to the ON state at the time of confirming the rear.
Image processing device 85 is a device which performs image processing on the rearward image of vehicle 1 captured by imaging unit 5, and outputs an image obtained as a result of the image processing to display 82. Next, a description will be made of an example of a configuration of this image processing device 85.
Image processing device 85 includes object sensor 85a, vanishing point calculator 85b, image clipper 85c, compressor 85d, drawing unit 85e, and controller 85f.
Based on a signal which indicates a detection result of the distance and is output from distance measuring sensor 6, object sensor 85a senses that the following vehicle has come near vehicle 1 by sensing that the following vehicle is within a predetermined range behind vehicle 1.
When following vehicle 9 approaches vehicle 1 and a distance between vehicle 1 and following vehicle 9 becomes shorter than D, then following vehicle 9 will not remain within a capturing range (an angle of view is 50° in an example of
In order to solve such a problem, image processing device 85 performs predetermined image processing for the rearward image of vehicle 1 which is captured by imaging unit 5.
Note that, though distance measuring sensor 6 is installed at a position of imaging unit 5 in
Hereinafter, vanishing point calculator 85b, image clipper 85c, compressor 85d and drawing unit 85e will be described with reference to
Vanishing point calculator 85b shown in
Image clipper 85c clips a part of the rearward image captured by imaging unit 5, and creates a clipped image. The rearward image captured by imaging unit 5 includes an image of a wider range than first display target range a shown in
Moreover, when it is sensed by object sensor 85a that following vehicle 9 has come near vehicle 1 by sensing that following vehicle 9 is within the predetermined range behind vehicle 1, image clipper 85c determines whether or not vanishing point 10 is located below predetermined range b in an upper portion of a display target range when following vehicle 9 is out of the predetermined range (first display target range a shown in
A vertical length of predetermined range b is set, for example, to ⅕ of a vertical length of first display target range a. In this case, if a resolution of display 82 is 900 pixels in width and 250 pixels in height, then the vertical length of predetermined range b has a length corresponding to 50 pixels. Note that this length may be set arbitrarily.
When vanishing point 10 is located below predetermined range b (in the example shown in
When vanishing point 10 is not located below predetermined range b, then from the rearward image captured by imaging unit 5, image clipper 85c clips an image of a display target range obtained by moving down only the lower end of first display target range a.
Hereinafter, the display target range obtained by moving down the upper end and lower end of first display target range a or the display target range obtained by moving down only the lower end of first display target range a will be referred to as second display target range e.
In the example of
Specifically, in the case of moving down the upper end of the display target range, image clipper 85c moves the upper end within a range where vanishing point 10 is not excluded from second display target range e.
Moreover, a vertical length of range c in
In this way, for example, when following vehicle 9 has come near vehicle 1, an image including a wider range of a lower portion of following vehicle 9 than when following vehicle 9 has not come near vehicle 1 can be obtained, and information about a direction indicator and the like of following vehicle 9 can be presented to the driver.
When it is sensed by object sensor 85a that following vehicle 9 has come near vehicle 1 by sensing that following vehicle 9 is within the predetermined range behind vehicle 1, compressor 85d shown in
For example, compressor 85d creates, as the compressed image, an image (an image shown in
For example, compressor 85d compresses lower portion f of the rearward image by using a bilinear method or a bicubic method. In this way, a size of vehicle 1 is reduced in the vertical direction, and accordingly, the information about the direction indicator and the like of following vehicle 9, which was not displayed before the compression, can be presented to the driver effectively.
Hence, it becomes easy for the driver to grasp the sense of distance between following vehicle 9 and a subject vehicle. Moreover, since a part of second display target range e is compressed, an uncompressed area remains in the compressed image. Hence, the driver can be prevented from erroneously recognizing a distance between following vehicle 9. In particular, in this exemplary embodiment, since lower portion f of second display target range e is compressed, a region including a vanishing point remains uncompressed. Hence, the above-described erroneous recognition of the distance can be prevented more effectively.
It is preferable that compressor 85d compress lower portion f of the rearward image so that a vertical length of lower portion f becomes two-thirds or more of the vertical length concerned before lower portion f is compressed. In this way, it can suppress a phenomenon that lower portion f of the rearward image becomes too small to be recognizable with ease.
Moreover, it is preferable that an area of an image in range h shown in
Drawing unit 85e superimposes boundary line 11 (refer to
Note that, though the boundary is indicated here by boundary line 11, the boundary may be indicated by another image such as an arrow in place of boundary line 11.
Controller 85f is connected to imaging unit 5, object sensor 85a, vanishing point calculator 85b, image clipper 85c, compressor 85d, drawing unit 85e, and display 82, and controls exchange of information between the respective units.
Next, a description will be made of an example of a processing procedure of image processing according to the first exemplary embodiment.
First, distance measuring sensor 6 detects the distance to following vehicle 9 (step S1). Then, object sensor 85a determines whether or not following vehicle 9 has come near vehicle 1 by sensing that vehicle 9 is within predetermined distance D behind vehicle 1, that is, whether or not the distance from vehicle 1 to following vehicle 9 is smaller than predetermined distance D (step S2).
When the distance from vehicle 1 to following vehicle 9 is not smaller than predetermined distance D (in the case of NO in step S2), image clipper 85c performs normal processing of clipping the image, which is captured by imaging unit 5, in first display target range a shown in
When the distance from vehicle 1 to following vehicle 9 is smaller than predetermined distance D (in the case of YES in step S2) in step S2, vanishing point calculator 85b calculates the position of vanishing point 10 of the image captured by imaging unit 5 (step S4).
Then, image clipper 85c determines whether or not vanishing point 10 is located below predetermined range b in the upper portion of first display target range a as shown in
When vanishing point 10 is located below predetermined range b (in the case of YES in step S5), image clipper 85c moves down the upper end of first display target range a so that vanishing point 10 is included in a predetermined range in the upper portion of the display target range (step S6). The upper end of second display target range e shown in
After the processing of step S6, or when vanishing point 10 is not located below predetermined range b (in the case of NO in step S5), image clipper 85c moves down the lower end of first display target range a so that the vertical length becomes longer than the vertical length of first display target range a shown in
Then, compressor 85d compresses the lower portion of the image in the display target range, which is obtained by moving down the upper end and lower end of first display target range a, or in the display target range, which is obtained by moving down only the lower end of first display target range a (step S8).
Thereafter, drawing unit 85e superimposes boundary line 11 (refer to
As described above, in accordance with the first exemplary embodiment, it is made easy for the driver to grasp the sense of distance, and more information is presented to the driver when the driver confirms the rear, and thus a contribution can be made to the safe driving.
In the above-mentioned first exemplary embodiment, from the rearward image captured by imaging unit 5, image clipper 85c clips the image of the display target range, which is obtained by moving down the upper end and lower end of first display target range a, or the image of the display target range, which is obtained by moving down only the lower end of first display target range a.
In the second exemplary embodiment, a description will be made of the case of setting a capturing direction of imaging unit 5 to the downward direction in order to move down the upper end and lower end of the display target range.
First, a description will be made of an example of a functional configuration of image processing device 85 according to the second exemplary embodiment.
Unlike image processing device 85 shown in
Specifically, direction controller 85g controls a motor or the like (not shown), which changes the capturing direction of imaging unit 5, and moves down the upper end and lower end of the display target range.
In this way, the upper end and lower end of first display target range a shown in
Note that a method for changing the display target range from first display target range a to second display target range e is not limited to the above-described method. First, the capturing direction of imaging unit 5 may be changed until the lower end of first display target range a becomes the lower end of range d, and then, the clipping range of the image in image clipper 85c may be set wider in the upward direction until the upper end of the display target range becomes the upper end of second display target range e. That is, the change of the display target range from first display target range a to second display target range e just needs to be performed by both of the change of the capturing direction of imaging unit 5 and the change of the clipping range of the image in image clipper 85c.
Next, a description will be made of an example of a processing procedure of image processing according to the second exemplary embodiment.
Here, processing in steps S11 to S15 and steps S17 to S19 is the same as the processing in steps S1 to S5 and steps S7 to S9, which are shown in
However, in this image processing, in step S16, direction controller 85g directs the capturing direction of imaging unit 5 downward in order to move down the upper end of first display target range a shown in
As described above, in accordance with the second exemplary embodiment, the capturing direction of imaging unit 5 is adjusted, and thus the display target range in the image captured by imaging unit 5 can be determined easily.
In the above-mentioned first and second exemplary embodiments, compressor 85d compresses the lower portion of the image in the display target range; however, it may compress the upper portion of the image in the display target range. Accordingly, in the third exemplary embodiment, a description will be made of the case where compressor 85d compresses the upper portion of the image in the display target range.
Note that a functional configuration of image processing device 85 in this exemplary embodiment is the same as the functional configuration shown in
In this exemplary embodiment, in a similar way to the first exemplary embodiment, from the rearward image captured by imaging unit 5, image clipper 85c clips an image of a display target range (a range obtained by combining range c and range d, which are shown in
Also in this case, in a similar way to the case shown in
Here, a vertical length of range c in
Then, compressor 85d creates, as the compressed image, an image (an image shown in
Moreover, it is preferable that an area of an image in range k shown in
Next, a description will be made of an example of a processing procedure of image processing according to the third exemplary embodiment.
Here, processing in steps S21 to S27 and step S29 is the same as the processing in steps S1 to S7 and step S9, which are shown in
However, in this exemplary embodiment, in step S28, compressor 85d compresses the upper portion of the image in the display target range, which is obtained by moving down the upper end and lower end of first display target range a, or in the display target range, which is obtained by moving down only the lower end of first display target range a, as described with reference to
As described above, in accordance with the third exemplary embodiment, it is made easy for the driver to grasp the sense of distance, and more information is presented to the driver when the driver confirms the rear, and thus a contribution can be made to the safe driving. Moreover, the upper portion of the image in the display target range is compressed, and the lower portion of the image is not compressed, so that the image of the lower portion of the vehicle can be made easy to see.
In the above third exemplary embodiment, in a similar way to the first exemplary embodiment, from the rearward image captured by imaging unit 5, image clipper 85c clips the image of the display target range, which is obtained by moving down the upper end and lower end of first display target range a, or the image of the display target range, which is obtained by moving down only the lower end of first display target range a.
In the fourth exemplary embodiment, a description will be made of the case of setting the capturing direction of imaging unit 5 to the downward direction in order to move down the upper end and lower end of the display target range. Here, a functional configuration of image processing device 85 according to the fourth exemplary embodiment is the same as the functional configuration of image processing device 85 according to the second exemplary embodiment described with reference to
Specifically, direction controller 85g in this exemplary embodiment controls a motor or the like (not shown), which changes the capturing direction of imaging unit 5, and moves down the upper end and lower end of the display target range.
In this way, the upper end and lower end of first display target range a shown in
Note that a method for changing the display target range from first display target range a to second display target range e is not limited to the above-described method. First, the capturing direction of imaging unit 5 may be changed until the lower end of first display target range a becomes the lower end of range d, and then, the clipping range of the image in image clipper 85c may be set wider in the upward direction until the upper end of the display target range becomes the upper end of second display target range e. That is, the change of the display target range from first display target range a to second display target range e just needs to be performed by both of the change of the capturing direction of imaging unit 5 and the change of the clipping range of the image in image clipper 85c.
Next, a description will be made of an example of a processing procedure of image processing according to this fourth exemplary embodiment.
Here, processing in steps S31 to S37 and step S39 is the same as the processing in steps S11 to S17 and step S19, which are shown in
However, in this exemplary embodiment, in step S38, compressor 85d compresses the upper portion of the image in the display target range, which is obtained by moving down the upper end and lower end of first display target range a, or in the display target range, which is obtained by moving down only the lower end of first display target range a, as described with reference to
As described above, in accordance with the fourth exemplary embodiment, it is made easy for the driver to grasp the sense of distance, and more information is presented to the driver when the driver confirms the rear, and thus a contribution can be made to the safe driving. Moreover, the upper portion of the image in the display target range is compressed, and the lower portion of the image is not compressed, so that the image of the lower portion of the vehicle can be made easy to see.
Moreover, the capturing direction of imaging unit 5 is adjusted, so that the display target range in the image captured by imaging unit 5 can be determined easily.
Note that, in each of the first to fourth exemplary embodiments, compressor 85d compresses the lower portion or upper portion of the image in the display target range, which is obtained by moving down the upper end and lower end of the original display target range, or in the display target range, which is obtained by moving down only the lower end; however, may compress only a center portion of the display target range, and does not have to compress the lower portion or upper portion of the image.
The image processing device and the electronic mirror system according to the present invention are suitable for application to the image processing device, which performs the image processing for the rearward image of the vehicle, the rearward image being captured by the imaging unit, and outputs the image to the display, the image being obtained as a result of the image processing, and application to the electronic mirror system including the image processing device.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2015-073528 | Mar 2015 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2016/001423 | 3/14/2016 | WO | 00 |
