Vehicle image processing device

Abstract

To reduce a physiological burden on the eyes of an operator of a vehicle equipped with an electronic mirror.SOLUTION: An image processing device for vehicle 100 comprises: an input unit into which a periphery image obtained by imaging the surrounding of a vehicle is inputted; a superimposition unit 14 which generates a display image by superimposing a focusing assist image onto the periphery image, the focusing assist image expressing a focusing assist graphic in which a plurality of white block areas are periodically aligned; and a display unit 12 which displays the display image.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an image processing device for a vehicle. [Background technology]

[0002] Patent Document 1 describes an in-vehicle image processing device that processes an image signal output from an imaging device that captures an image of the rear side of a vehicle and displays the processed image on a display device. This in-vehicle image processing device has a driving state information acquisition unit that acquires driving state information of the vehicle, and an image processing unit that processes the image signal from the imaging device based on the driving state information so that at least a part of the image displayed on the display device is blurred. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-125894 A Summary of the Invention [Problem to be solved by the invention]

[0004] Unlike optical mirrors, the display device of an electronic mirror is installed inside the vehicle cabin. The difference in the visual distance between the front of the vehicle and the display device of the electronic mirror inside the vehicle cabin is larger than the difference in the visual distance between the front of the vehicle and the optical mirror outside the vehicle cabin, so the driver of a vehicle equipped with an electronic mirror places a large physiological strain on the eyes.

[0005] An object of the present invention is to reduce the physiological strain on the eyes of a driver of a vehicle equipped with an electronic mirror. [Means for solving the problem]

[0006] In order to achieve the above object, the vehicle image processing device according to the present invention includes an input unit to which an ambient image capturing the surroundings of a vehicle is input, a synthesis unit to generate an image for display by synthesizing a focus adjustment assistance image, in which a focus adjustment assistance figure formed of a periodic arrangement of a plurality of white block areas is represented, with the ambient image, and a display unit to display the image for display. The period of the arrangement corresponds to a range of visual angles of 0.5 degrees to 1.5 degrees when the visual distance to the display unit is 1 meter, and the luminance of the white block area is 1.2 or 0.8 times the pixel luminance of the ambient image. The focus adjustment assistance figure includes a first block group formed by arranging a plurality of the white block areas along the horizontal direction of the focus adjustment assistance image near the top side of the focus adjustment assistance image, a second block group formed by arranging a plurality of the white block areas along the horizontal direction of the focus adjustment assistance image near the bottom side of the focus adjustment assistance image, and a left end of the first block group and a right end of the first block group. 2 between the left end of the first block group, or between the right end of the first block group and 2 and a third block group, in which a plurality of the white block regions are arranged along the vertical direction of the focus adjustment assisting image between the right end of the block group and the right end of the first block group. Each of the plurality of white block regions is square, and the length of each side is equal to the distance between two adjacent white block regions. Effect of the Invention

[0007] According to the present invention, it is possible to reduce the physiological strain on the eyes of a driver of a vehicle equipped with an electronic mirror. [Brief description of the drawings]

[0008] [Figure 1] FIG. 4 is an explanatory diagram showing the viewing distance of an optical mirror. [Diagram 2] FIG. 2 is an explanatory diagram showing the viewing distance of a display device of an electronic mirror. [Diagram 3] FIG. 1 is a block diagram of an image processing device. [Figure 4] FIG. 13 is an explanatory diagram showing an example of an adjustment support image. [Diagram 5]13 is an explanatory diagram showing a display image obtained by superimposing an adjustment assistance image on a camera image. FIG. [Figure 6] FIG. 13 is an explanatory diagram showing another example of the accommodation support image. [Figure 7] FIG. 13 is an explanatory diagram showing yet another example of the adjustment support image. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the present invention will be described based on the illustrated embodiment, however, the present invention is not limited to the embodiment described below.

[0010] In order to visually check the rear and sides of the vehicle while in a normal driving position, the reflected image from a mirror (rear-view mirror) is used. Meanwhile, electronic mirrors that combine a camera and a display device are being developed with the aim of reducing the air resistance of the vehicle body, dynamically changing the field of view, and improving safety by combining night vision technology and object detection technology.

[0011] 1, another vehicle 2 is located to the right rear of a host vehicle 1a equipped with an optical mirror (right door mirror) M. The viewing distance when the driver of the host vehicle 1a visually recognizes the other vehicle 2 through the optical mirror M is equal to a distance D1 to a virtual image 2a of the other vehicle 2 by the optical mirror M.

[0012] An electronic mirror system is installed in the host vehicle 1b shown in Fig. 2. This electronic mirror system includes a camera 11 provided outside the vehicle cabin, and a display 12 provided inside the vehicle cabin (around the driver's seat) on which an image captured by the camera (right door camera) 11 is displayed. Another vehicle 2 is located to the right rear of the host vehicle 1b. The viewing distance when the driver of the host vehicle 1b views the other vehicle 2 through the display 12 is equal to the distance D2 to the display. This distance D2 is around 1 meter, which is shorter than the distance D1 in Fig. 1.

[0013] The difference between the viewing distance (almost infinity) when viewing the area ahead of the vehicle 1a and the distance D1 is larger than the difference between the viewing distance when viewing the area ahead of the vehicle 1b and the distance D2. This places a heavy burden on the driver of a vehicle equipped with an electronic mirror system in terms of eye focus adjustment.

[0014] The human eye adjusts the thickness of the crystalline lens and the convergence angle of both eyes with respect to the gaze point, using the degree of blur of the image formed on the retina and a pictorial sense of distance as clues. In view of this, in the following embodiment, a focus adjustment assisting figure that makes it easier to perceive the blur of the image on the retina and expresses a pictorial sense of depth on the display is superimposed on the camera image, and the camera image and the focus adjustment assisting figure are displayed on the display. This supports the focus adjustment function of the eye.

[0015] Specifically, a focus adjustment assistance figure combining the following three elements is superimposed on the camera image. (1) Use of geometric shapes that match the spatial frequency-contrast sensitivity characteristics of the human eye The human eye does not always focus accurately on a visual object, and there is a certain degree of accommodation error. This accommodation error is determined according to the spatial frequency of the image of the visual object. For this reason, a block group in which a plurality of block areas, each having a certain size, are periodically arranged, which produces a rectangular wave-like brightness change that is fine to some extent and makes it easy to identify edge blurring, is suitable for assisting focus adjustment (focusing). From the spatial frequency characteristics of the human eye, it is desirable for the arrangement period of the block areas to be 0.5 degrees to 1.5 degrees in terms of visual angle. This corresponds to an arrangement period of about 10 millimeters to 25 millimeters for a display placed at a viewing distance of about 1 meter.

[0016] (2) Low contrast When the difference between light and dark on the screen is large (high contrast), the boundary between light and dark is clearly visible even if the image is slightly out of focus, so the human eye stops accommodating. For this reason, there is a certain relationship between the focus adjustment error of the eye and the contrast of the image to be viewed. Using this relationship, a multiplication or addition process is performed so that the brightness of each pixel in the display area where the white accommodation assistance figure is displayed is approximately 1.2 times the brightness of the corresponding pixel in the camera image, and a focus accommodation assistance figure is drawn semi-transparently on the original camera image.

[0017] (3) A design that makes the display panel easier to recognize The camera image displayed on the display is a real landscape, so it has a painterly perspective. The human eye uses the subjective perspective felt from the image as a clue for adjusting the focus, so when an image appears to be far away, the eye tries to adjust as if it were looking at something far away. As a focus adjustment support figure for this purpose, it is preferable to prepare a plurality of block groups each consisting of a plurality of block areas spaced apart and arranged in one direction so as to make it easier to sense the panel surface of the display and to eliminate the sense of perspective, and to combine these at right angles with the spacing between adjacent block areas being constant within the image.

[0018] 3 shows an electronic mirror system 100 mounted on the vehicle 1b. In addition to the camera 11 and display 12 described above, the electronic mirror system 100 also includes a focus adjustment assistance image generating unit 13 and an image synthesis unit 14. The camera 11 and the focus adjustment assistance image generating unit 13 are connected to an input unit of the image synthesis unit 14, and an output unit of the image synthesis unit 14 is connected to the display 12.

[0019] The surrounding image of the vehicle 1b captured by the camera 11 is sent to an input section of the image synthesis unit 14. Furthermore, the focus adjustment assistance image generation unit 13 generates a focus adjustment assistance image in which a focus adjustment assistance figure is displayed, and sends the focus adjustment assistance image to the image synthesis unit 14. Hereinafter, the focus adjustment assistance figure and the focus adjustment assistance image will also be referred to as the assistance figure and the assistance image, respectively.

[0020] The digital mirror system 100 is a computer system. The image synthesis unit 14 has a processor, a memory, and a communication interface for communicating with the camera 11, the focus adjustment assistance image generation unit 13, and the display 12.

[0021] FIG. 4 shows a support image 5 in which a support figure is shown as an example. This support image 5 is rectangular and has the same size as the camera image. The support figure BF has a first block group B1, a second block group B2, and a third block group B3. The first block group B1 has a plurality of white block areas BL periodically arranged along the horizontal direction of the support image 5 near the upper side 51 of the support image 5. The second block group B2 has a plurality of white block areas BL periodically arranged along the horizontal direction of the support image 5 near the lower side 52 of the support image 5. The third block group B3 has a plurality of white block areas BL periodically arranged along the vertical direction of the support image 5 so as to connect the left end of the first block group B1 and the left end of the second block group B2 near the left side 53 of the support image 5. Thus, the support figure BF is generally approximately U-shaped.

[0022] Each white block area BL is a square, and the length of each side is equal to the distance between two adjacent block areas BL. In other words, the array period P of the block areas is twice the length of one side of each block area. This array period P is in the range of 0.5 to 1.5 degrees in terms of visual angle. When the viewing distance of the display 12 is 1 meter, the array period P is in the range of approximately 10 to 25 millimeters. In this way, the white block areas are arrayed with an array period that corresponds to the spatial frequency characteristics of the human eye.

[0023] The brightness of each pixel in the white block area BL is set to be about 1.2 times the brightness of the corresponding pixel in the camera image, and the white block area BL is displayed semi-transparently in the display image. In other words, the contrast between the white block area and other areas is about 20%. The reason for setting the contrast relatively low in this way is that if the contrast is relatively high, the human eye will stop adjusting even if the image is slightly out of focus.

[0024] In addition, the support figures are made up of a number of blocks arranged in one direction at intervals, and are combined at right angles to each other, so that the driver does not feel a sense of perspective. This makes it easier for the driver to sense the display panel surface.

[0025] Support image 5 showing support figure BF is generated by support image generation unit 13 and sent from support image generation unit 13 to image synthesis unit 14. Image synthesis unit 14 generates a display image by superimposing support image 5 on the camera image sent from camera 11. This display image is sent from image synthesis unit 14 to display 12 and displayed on display 12. An example of the display image is shown in FIG.

[0026] According to the above embodiment, the display image includes an assisting figure that assists in eye focus adjustment. Therefore, for the driver of a vehicle equipped with an electronic mirror system, the burden of eye focus adjustment caused by the change in viewing distance when viewing the in-vehicle display is reduced. In addition, since the assisting image is a still image, the process of superimposing the assisting image on the camera image as a mask image (addition or multiplication of luminance components) has a relatively low calculation load and is relatively easy to implement.

[0027] Support image 5 shown in Fig. 4 is superimposed on a camera image capturing the rear right side of the vehicle. The support image superimposed on the camera image capturing the rear left side of the vehicle can be generated symmetrically to support image 5 in Fig. 4. That is, the support figure in the support image superimposed on the camera image capturing the rear left side of the vehicle has a third block group (not shown) in addition to a first block group B1 and a second block group B2, similar to support figure BF. This third block group is composed of a plurality of blocks arranged in the vertical direction of the image between the right end of the first block group B1 and the right end of the second block group B2.

[0028] When the support figure is substantially U-shaped along the top, bottom, and left or right sides of the image, the driver may perceive the substantially U-shaped support figure as if it were a window frame, and may have the sensation of looking into the distance through the window frame. To avoid this, the support figure may be configured to be substantially cross-shaped (cross cursor-shaped) instead of substantially U-shaped. An example of this is shown in FIG. 6 as support image 7. The support figure BF2 in support image 7 has a first block group B21 and a second block group B22. The first block group B21 extends vertically through the center of support image 7 from the vicinity of the top side 71 of the image to the vicinity of the bottom side 72. The second block group B22 extends horizontally through the center of support image 7 from the vicinity of the left side 73 of the image to the vicinity of the right side 74 of the image.

[0029] When capturing a snowy road, the entire camera image may be extremely bright and the average brightness may be extremely high. In such a case, the brightness after the multiplication or addition of the brightness components in the superimposition process may reach the upper limit of the display. To avoid this, instead of the multiplication or addition of the brightness components, a division or subtraction process of the brightness components may be performed. FIG. 7 shows a rectangular support image 8. The support image 8 has a rectangular central region C located at the center. The center of the central region C and the support image 8 are the same, and the aspect ratio of the central region C is the same as that of the support image 8. The support figure in the support image 8 has a first block group B31, a second block group B32, a third block group B33, and a fourth block group B34. The first block group B31 has a plurality of white block regions BL periodically arranged along the vertical direction passing through the center of the support image 8 between the upper side 81 and the central region C. The second block group B32 has a plurality of white block regions BL periodically arranged along the vertical direction passing through the center of the support image 8 between the bottom side 82 and the central region C. The third block group B33 has a plurality of white block regions BL periodically arranged along the horizontal direction passing through the center of the support image 8 between the left side 83 and the central region C. The fourth block group B34 has a plurality of white block regions BL periodically arranged along the horizontal direction passing through the center of the support image 8 between the right side 84 and the central region C. A division process or subtraction process can be performed so that the brightness of each pixel in the white block region BL becomes about 0.8 times the brightness of the corresponding pixel in the camera image. In other words, the brightness of the support figure becomes lower than the brightness of the other regions.

[0030] An example of multiplication and addition / subtraction processing of luminance components is described below. If the pixel data of the white part of the white line to be overlaid is set to 1 and the black part of the background is set to 0, the calculation formula for the blending mode is as follows: (1) When changing the brightness by +20% Multiplication process: Pixel brightness of the image of the outside world captured by the camera x white line pixel data x 1.2 Addition / subtraction process: Pixel brightness of the external image captured by the camera + white line pixel data × (+0.2) (2) When changing the brightness by -20% Multiplication process: Pixel brightness of the image of the outside world captured by the camera x white line pixel data x 0.8 Addition / subtraction process: Pixel brightness of the external image captured by the camera + white line pixel data × (-0.2) As mentioned above, such multiplication processing and addition / subtraction processing are merely examples.

[0031] In the image synthesis unit 14, as shown below, alpha blending calculation using transparency α may be performed on the RGB values ​​of pixels at the same coordinates in the camera image and the support image. R 出力 =R 支援図形 ·α+R カメラ画像 (1-α) G 出力 =G 支援図形 ·α+G カメラ画像 (1-α) B 出力 =B 支援図形 ·α+B カメラ画像 (1-α)

[0032] However, R 支援図形 is the brightness of the red component of the corresponding pixel of the support figure, and R カメラ画像 is the brightness of the red component at the pixel in the camera image, and R 出力 is the luminance of the red component of the pixel in the image to be displayed. 支援図形 is the luminance of the green component of the corresponding pixel of the support figure, and G カメラ画像 is the brightness of the green component at the pixel in the camera image, and G 出力 is the luminance of the green component in the pixel of the image to be displayed. 支援図形 is the luminance of the blue component of the pixel in the support figure, and B カメラ画像 is the brightness of the blue component at the pixel in the camera image, and B 出力 is the luminance of the blue component at that pixel in the image for display.

[0033] Regarding the embodiments described above, the following supplementary notes are disclosed. [Appendix 1] an input unit to which an image of the surroundings of the vehicle is input; a synthesis unit that generates a display image by synthesizing a focus adjustment assistance image, the focus adjustment assistance image including a focus adjustment assistance figure formed by periodically arranging a plurality of white block regions, with the surrounding image; a display unit for displaying the display image; An image processing device for a vehicle comprising: [Appendix 2] 2. The vehicle image processing device according to claim 1, wherein the period of the array corresponds to a range of visual angles of 0.5 degrees to 1.5 degrees when the visual distance to the display unit is 1 meter. [Appendix 3] 3. The vehicle image processing device according to claim 1, wherein the brightness of the white block area is 1.2 times or 0.8 times the pixel brightness of the camera image. [Appendix 4] The focus adjustment assist figure is a first block group including a plurality of the white block regions arranged along a horizontal direction of the focus adjustment assistance image in the vicinity of an upper side of the focus adjustment assistance image; a second block group in which a plurality of the white block regions are arranged along the horizontal direction of the focus adjustment assistance image in the vicinity of a bottom side of the focus adjustment assistance image; The left end of the first block group and the 2 between the left end of the first block group, or between the right end of the first block group and 2 a third block group in which a plurality of the white block regions are arranged along the vertical direction of the focus adjustment assisting image between the right end of the block group and the right end of the third block group; 4. The vehicle image processing device according to claim 1, further comprising: [Appendix 5] The focus adjustment assist figure is a first block group including a plurality of the white block regions arranged along a horizontal direction of the focus adjustment assistance image passing through a center of the focus adjustment assistance image; a second block group in which a plurality of the white block regions are arranged along a vertical direction of the focus adjustment assistance image passing through a center of the focus adjustment assistance image; 4. The vehicle image processing device according to claim 1, further comprising:

[0034] Although the embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and various modifications and changes can be made based on the technical concept of the present invention. [Explanation of symbols]

[0035] 100 Electronic mirror system 11 Camera 12 Display 13 Focus adjustment support image generation section 14 Image synthesis section 5 Focusing support image B1~B3 Block Group BL Block BF Support figure P period

Claims

1. an input unit to which an image of the surroundings of the vehicle is input; a synthesis unit that generates a display image by synthesizing a focus adjustment assistance image, in which a focus adjustment assistance figure is displayed, the focus adjustment assistance image being formed by periodically arranging a plurality of white block regions, with the surrounding image; a display unit for displaying the display image; Equipped with the period of the array corresponds to a range of visual angles of 0.5 degrees to 1.5 degrees when the viewing distance to the display unit is 1 meter; the luminance of the white block region is 1.2 times or 0.8 times the pixel luminance of the surrounding image; The focus adjustment assist figure is a first block group including a plurality of the white block regions arranged along a horizontal direction of the focus adjustment assistance image in the vicinity of an upper side of the focus adjustment assistance image; a second block group including a plurality of the white block regions arranged along a horizontal direction of the focus adjustment assistance image in the vicinity of a lower side of the focus adjustment assistance image; a third block group in which a plurality of the white block regions are arranged along the vertical direction of the focus adjustment assistance image between a left end of the first block group and a left end of the second block group, or between a right end of the first block group and a right end of the second block group; having Each of the plurality of white block regions is a square, and the length of each side is equal to the distance between two adjacent white block regions. Vehicle image processing device.

2. an input unit to which an image of the surroundings of the vehicle is input; a synthesis unit that generates a display image by synthesizing a focus adjustment assistance image, in which a focus adjustment assistance figure is displayed, the focus adjustment assistance image being formed by periodically arranging a plurality of white block regions, with the surrounding image; a display unit for displaying the display image; Equipped with the period of the array corresponds to a range of visual angles of 0.5 degrees to 1.5 degrees when the viewing distance to the display unit is 1 meter; the luminance of the white block region is 1.2 times or 0.8 times the pixel luminance of the surrounding image; The focus adjustment assist figure is a first block group including a plurality of the white block regions arranged along a horizontal direction of the focus adjustment assistance image passing through a center of the focus adjustment assistance image; a second block group in which a plurality of the white block regions are arranged along a vertical direction of the focus adjustment assistance image passing through a center of the focus adjustment assistance image; having Each of the plurality of white block regions is a square, and the length of each side is equal to the distance between two adjacent white block regions. Vehicle image processing device.

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