JP7767702B2 - Display control device and display control program - Google Patents

Description

The present invention relates to a display control device and a display control program that controls the display of an in-vehicle display device.

Patent Document 1 discloses a vehicle periphery display device and a vehicle periphery display program that display an image that combines an image of the vehicle with a captured image of the vehicle's surroundings. This vehicle periphery display device and vehicle periphery display program utilizes the vehicle's movement to generate and display an image of the area directly below the current bottom of the vehicle from past images captured by an onboard camera that captures the surroundings of the vehicle.

Japanese Patent Application Laid-Open No. 2004-336613

In this type of technology, the vehicle's position or movement amount is estimated using driving state information acquired from on-board sensors such as wheel speed sensors in order to generate and display an image of the area directly below the current bottom of the vehicle. This generates estimation errors dependent on factors such as sensor error and slippage between the wheels and the ground. As these estimation errors accumulate over time, the displayed image of the area directly below the current bottom of the vehicle may deviate from reality, causing discomfort to the user or leading to concerns that the user may misidentify the location of a target object such as a wheel chock. The present invention was made in light of the circumstances exemplified above. Specifically, the present invention provides technology that effectively reduces deviations from reality and the resulting discomfort experienced by the user when displaying an image of the area directly below the current bottom of the vehicle.

The display control device (5) for controlling the display of the in-vehicle display device (2) according to claim 1 comprises:
a historical image acquisition unit (532) that acquires the historical images from a historical image storage unit (54) that stores, in chronological order, photographed images including a first area image corresponding to a first area (R1) around the host vehicle equipped with the on-vehicle display device and a second area image corresponding to a second area (R2) outside the first area in the vehicle width direction as historical images;
an image matching processing unit (533) that matches a current image corresponding to a currently captured image of the surroundings of the vehicle with the second area image in the history image acquired by the history image acquisition unit;
a display processing unit (534) that displays, on the in-vehicle display device, the first area image included in the history image that has been identified as matching the current image through matching in the image matching processing unit, as an underfloor image that is an image of a portion directly below the bottom of the vehicle;
Equipped with
The image matching processing unit matches the current image with the second region image in the history image using template matching .
The display control program according to claim 5 is a program executed by a display control device (5) that controls display of an in-vehicle display device (2),
The process executed by the display control device is
a historical image acquisition process for acquiring the historical images from a historical image storage unit (54) that stores, in chronological order, photographed images including a first area image corresponding to a first area (R1) around the host vehicle equipped with the on-vehicle display device and a second area image corresponding to a second area (R2) outside the first area in the vehicle width direction as historical images;
an image matching process for matching a current image corresponding to a currently captured image of the surroundings of the host vehicle with the second area image in the history image acquired by the history image acquisition process;
a display process for displaying, on the in-vehicle display device, the first area image included in the history image identified as matching the current image through the comparison in the image comparison process, as an underfloor image that is an image of a portion directly below the bottom of the vehicle;
Including,
The image matching process is a process of matching the current image with the second region image in the history image using template matching .

Note that in each section of the application documents, each element may be assigned a reference symbol in parentheses. In such cases, the reference symbol merely indicates an example of the correspondence between the element and the specific configuration described in the embodiment described below. Therefore, the present invention is not limited in any way by the reference symbol.

1 is a block diagram showing a schematic configuration of an in-vehicle system including a display control device according to an embodiment of the present invention; 2 is a plan view showing a state in which a host vehicle equipped with the in-vehicle system shown in FIG. 1 is traveling forward. FIG. 2 is a schematic diagram showing an example of an underfloor image displayed by the vehicle-mounted display device shown in FIG. 1 ; FIG. 10 is a schematic diagram showing an example of a display of an underfloor image in a comparative example. 2 is a flowchart showing a specific example of a display control program executed by the display control device shown in FIG. 1 .

(Embodiment)
Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that if a description of various modifications applicable to one embodiment is inserted in the middle of a series of descriptions relating to the embodiment, it may hinder understanding of the embodiment. Therefore, the modifications will be described together after the series of descriptions relating to the embodiment, rather than in the middle of the series of descriptions relating to the embodiment.

(composition)
Fig. 1 shows a schematic functional block configuration of an in-vehicle system 1 mounted on a host vehicle C shown in Fig. 2. As shown in Fig. 2, the host vehicle C is a so-called four-wheeled passenger car, having a box-shaped body CB, with one wheel CT provided at each of the four corners of the body CB. Below, the schematic configuration of the in-vehicle system 1 will be described with reference to Figs. 1 and 2. As shown in Fig. 1, the in-vehicle system 1 includes an in-vehicle display device 2, a peripheral camera 3, an in-vehicle communication bus 4, and a display control device 5.

The in-vehicle display device 2 is a flat or curved display device (i.e., for example, a CID device) mounted on the dashboard of the vehicle C, and is composed of a surface display device such as a liquid crystal display device or an organic EL display device. CID stands for center information display, and EL stands for electroluminescence. In this embodiment, the in-vehicle display device 2 is configured to be able to switch between displaying an image corresponding to an image of the surroundings of the vehicle C captured by the surrounding camera 3 and displaying other information, in response to operation by the occupant of the vehicle C.

The peripheral camera 3 is attached to the host vehicle C so as to capture images of the surroundings of the host vehicle C. Specifically, in this embodiment, the in-vehicle system 1 is equipped with a front camera 31, a rear camera 32, a left-side camera 33, and a right-side camera 34 as the peripheral cameras 3. The front camera 31 is configured to capture images of the area in front of the host vehicle C (i.e., the first forward area R1 shown in FIG. 2) and the area in front of the host vehicle C (i.e., the second forward area R2 shown in FIG. 2). As shown in FIG. 2, the first forward area R1, which corresponds to the "first area" of the present invention, is the area ahead of the host vehicle C while it is traveling forward, and is typically a predetermined width area on an extension of the vehicle center line CL of the host vehicle C. The "predetermined width" is, for example, αW, where W is the vehicle width dimension of the host vehicle C. α = 0.9 to 1.5, and typically α = 1. The second forward area R2, which corresponds to the "second area" of the present invention, is an area further outward in the vehicle width direction than the first forward area R1. The rear camera 32 is installed to capture images behind and to the rear of the vehicle C. The left side camera 33 is installed to capture images on the left side of the vehicle C. The right side camera 34 is installed to capture images on the right side of the vehicle C.

(Display control device)
The display control device 5 is connected to the peripheral camera 3 so as to be able to communicate signals with the peripheral camera 3, so as to receive, from the peripheral camera 3, image signals corresponding to images captured by the peripheral camera 3. The display control device 5 is also connected to the in-vehicle communication bus 4 so as to be able to communicate information or signals with the in-vehicle communication bus 4, so as to receive, via the bus 4, information or signals corresponding to the driving state and driving environment of the host vehicle C. The "driving state" includes, for example, quantities related to the driving operation state of the host vehicle C by an occupant or a driving automation system (i.e., an advanced driving assistance system or an autonomous driving system), such as accelerator opening, braking amount, shift position, and steering angle. The "driving state" also includes, for example, physical quantities related to the driving behavior of the host vehicle C, such as vehicle speed, longitudinal acceleration, lateral acceleration, and angular velocity. The "driving environment" includes, for example, physical quantities related to the natural environment, such as outside temperature and rainfall. The "driving environment" also includes, for example, the presence state of moving and stationary targets within a predetermined detection range around the host vehicle C. That is, the display control device 5 is connected via the in-vehicle communication bus 4 to well-known sensors necessary for vehicle driving control, such as an accelerator opening sensor, a steering angle sensor, a wheel speed sensor, an acceleration sensor, an angular velocity sensor, an outside air temperature sensor, a raindrop sensor, an ultrasonic sensor, and a radar sensor.

The display control device 5 is configured as a so-called HCU, which controls the display of the in-vehicle display device 2. HCU stands for HMI Control Unit. HMI stands for Human Machine Interface. In this embodiment, the display control device 5 is configured as a so-called in-vehicle microcomputer, equipped with a CPU, ROM, non-volatile rewritable memory, RAM, input/output interface, etc. CPU stands for Central Processing Unit and is also called a "processor." ROM stands for Read Only Memory. Non-volatile rewritable memory includes, for example, a hard disk, EEPROM, flash ROM, etc. EEPROM stands for Electronically Erasable and Programmable ROM. RAM stands for Random Access Memory. ROM, non-volatile rewritable memory, and RAM are so-called non-transient tangible storage media and are sometimes simply referred to as "memory." That is, the display control device 5 is configured to control the display of the in-vehicle display device 2 by having the CPU read and execute computer programs pre-stored in the ROM and/or non-volatile rewritable memory. In other words, the display control device 5 includes at least one processor and at least one memory, and is configured to perform predetermined display control by having the processor read and execute computer programs from the memory.

Specifically, the display control device 5 comprises an image signal input unit 51, a communication interface 52, an image processing unit 53, a history image storage unit 54, and an image signal output unit 55. The image signal input unit 51 is an input interface for image signals from the peripheral cameras 3 and is connected to the peripheral cameras 3 so as to be able to communicate signals. The communication interface 52 is an input interface for information or signals corresponding to the driving state and driving environment of the host vehicle C and is connected to the in-vehicle communication bus 4 so as to be able to communicate information or signals.

The image processing unit 53 performs various image processing operations on the image signals or image information acquired from the peripheral camera 3 and generates display image signals for display on the in-vehicle display device 2. Specifically, in this embodiment, the image processing unit 53 generates a historical image for displaying an image corresponding to an image captured by the front camera 31 or the rear camera 32 at a time prior to the present, and a current image for displaying an image corresponding to an image captured at the present time by the left side camera 33 or the right side camera 34. Thus, the historical image corresponds to an image captured in the past, i.e., before the present, by the front camera 31 or the rear camera 32, and the current image corresponds to an image captured at the present time by the left side camera 33 or the right side camera 34. The historical image includes a first area image corresponding to a first area ahead of the host vehicle C and a second area image corresponding to a second area outboard of the first area in the vehicle width direction. Specifically, the first area image includes an image of the road surface or ground ahead of the host vehicle C. The "road surface" refers to the surface facing the bottom of the host vehicle C when the host vehicle C is traveling on a paved road (i.e., during on-road driving). In contrast, "ground surface" refers to the surface opposite the bottom of the vehicle C when the vehicle C is traveling on a non-paved road (i.e., off-road driving). "Non-paved road" includes, for example, unpaved roads such as gravel roads, as well as grass, sand, wasteland, rivers, riverbeds, mountainous areas, etc. The second region image includes an image of the road surface or ground surface that is further outward in the vehicle width direction than the first region image. The configuration of the image processing unit 53 will be described in detail later.

The historical image storage unit 54 is configured to store captured images, including first area images and second area images, as historical images in chronological order. Specifically, the historical image storage unit 54 is configured to include a portion of the total storage capacity of the non-volatile rewritable memory and/or RAM, as well as the CPU functions for storing, erasing, and rewriting information therein. In this embodiment, the historical image storage unit 54 stores, in chronological order, historical images corresponding to images captured by at least the front camera 31 of the peripheral cameras 3 during forward driving, and stores, in chronological order, historical images corresponding to images captured by at least the rear camera 32 during reverse driving. The image signal output unit 55 is an output interface for display image signals for displaying images on the in-vehicle display device 2, and is connected to the in-vehicle display device 2 for signal communication.

(Image processing section)
The image processing unit 53 has a viewpoint conversion processing unit 531, a history image acquisition unit 532, an image matching processing unit 533, and a display processing unit 534 as functional components or units realized on a microcomputer.

The viewpoint conversion processing unit 531 converts the image captured by the peripheral camera 3 into a bird's-eye view image. Specifically, this conversion to a bird's-eye view image is the inverse of the conversion that projects the positional data of the ground image onto a screen plane T at a focal distance f from a camera position R at a height H above the ground. In other words, the conversion to a bird's-eye view image is a coordinate conversion of the image captured by the peripheral camera 3 into data in a ground plane coordinate system projected from the peripheral camera 3 as the viewpoint. Such viewpoint conversion technology is disclosed, for example, in Japanese Patent Application Laid-Open Nos. 14-087160 and 10-211849. The historical images are images after viewpoint conversion by the viewpoint conversion processing unit 531, and are stored in chronological order in the historical image storage unit 54 so that they can be read at any time.

The historical image acquisition unit 532 is configured to acquire historical images from the historical image storage unit 54. That is, the historical image acquisition unit 532 is configured to read historical images from the historical image storage unit 54 to be used as targets for matching by the image matching processing unit 533. In this embodiment, the historical image acquisition unit 532 is configured to read historical images from the historical image storage unit 54 that are within a predetermined driving time range or a predetermined driving distance range prior to the current time. Specifically, when traveling forward, if the driving distance or driving time from the front wheel position, i.e., the midpoint between the pair of wheels CT provided at the front of the vehicle C, to the first front region R1 and the second front region R2 is X, the historical image acquisition unit 532 extracts historical images in the range of X±X0 as targets for matching by the image matching processing unit 533, taking into account sensor error and the slip state between the wheels CT and the road surface or ground surface, etc.

The image matching processing unit 533 is configured to match a current image corresponding to a captured image of the surroundings of the vehicle C with the second area image in the historical image acquired by the historical image acquisition unit 532. Specifically, the image matching processing unit 533 is configured to match the current image with the second area image in the historical image using template matching.

The display processing unit 534 is configured to display, on the in-vehicle display device 2, a first area image included in the history image identified as matching the current image through matching by the image matching processing unit 533, as an underfloor image. The underfloor image is an image of the area directly below the bottom of the vehicle C, and in this embodiment, is an image that is estimated to represent the current state of the road surface or ground around the wheels CT of the vehicle C. Specifically, the display processing unit 534 generates a display image signal for displaying, on the in-vehicle display device 2, a composite image in which the underfloor image and the current image are arranged side by side, as shown in FIG. 3A. That is, the composite image shown in FIG. 3A includes an underfloor image displayed on the center screen V1 located in the widthwise center region of the in-vehicle display device 2, a left side image displayed on the left side screen V2 located to the left of the center screen V1, and a right side image displayed on the right side screen V3 located to the right of the center screen V1. In addition, a wheel image TG is composited and displayed on the underfloor image. The wheel image TG is a virtual image showing the wheels CT of the host vehicle C, and is formed by frame lines or semi-transparent patterns that show the outer shape of the wheels CT. The left side image is a display image corresponding to an image of the road surface or ground around the host vehicle C currently photographed by the left side camera 33. The right side image is a display image corresponding to an image of the road surface or ground around the host vehicle C currently photographed by the right side camera 34.

(Operation overview)
Below, we will explain the operation of the in-vehicle system 1 and display control device 5 having the above configuration, as well as an overview of the display control method and display control program executed thereby, along with the effects achieved by such configuration. Note that the display control device 5 according to this embodiment and the display control method and display control program executed thereby will be collectively referred to simply as "this embodiment."

The peripheral cameras 3, i.e., the front camera 31, rear camera 32, left side camera 33, and right side camera 34, capture images of the surroundings of the vehicle C. Image signals generated as a result of images captured by the peripheral cameras 3 are input to the display control device 5 by the image signal input unit 51. In addition, information or signals corresponding to the driving state and driving environment of the vehicle C are input to the display control device 5 by the communication interface 52 via the in-vehicle communication bus 4. The display control device 5 controls the display of the in-vehicle display device 2 based on the acquired image signals, etc.

Specifically, for example, when a predetermined underfloor view start condition is met, the display control device 5 executes an underfloor view operation. The underfloor view operation is an operation that causes the in-vehicle display device 2 to display an underfloor image, which is an image of the area directly below the bottom of the current vehicle C, i.e., the area around the wheels CT, alongside a current image corresponding to the images currently captured by the left side camera 33 and right side camera 34. Such an underfloor view operation is effective, for example, when checking wheel chocks or rails in mechanical parking lots during parking maneuvers, or when checking the situation directly below the vehicle C or near the wheels CT while driving on narrow roads or off-road. Figure 3A shows, as an example, a screen display example when the vehicle C passes through a ditch ST partially blocked by a grating cover GC while driving forward.

In conventional technology, underfloor images are selected using odometry based on driving state information acquired from onboard sensors such as wheel speed sensors. However, with this method, estimation errors occur in odometry-based estimation of the vehicle C's position or movement amount due to sensor errors and the slippage between the wheels CT and the road or ground. These estimation errors accumulate over time, causing a discrepancy between the image displayed for the area directly below the current bottom of the vehicle C and the actual location. Figure 3B shows an example of a display in which such a discrepancy occurs. In the example display shown in Figure 3B, a discrepancy occurs in the direction of travel of the vehicle C between the underfloor image displayed on the center screen V1 and the images of the sides of the current vehicle C displayed on the left side screen V2 and the right side screen V3. Such a discrepancy in the screen display may cause discomfort to the user, i.e., the occupants, or may cause the user to misidentify the location of a target object such as a ditch ST. Furthermore, for example, if the front wheels of the vehicle C are actually in front of the ditch ST or grating cover GC as shown in Figure 3A, but the underfloor image shows the front wheels as being positioned above the ditch ST or grating cover GC, the impact and sound of the front wheels actually running over the ditch ST or grating cover GC will reach the occupants later than displayed on the screen, which may cause discomfort or discomfort to the occupants.

Therefore, this embodiment compares a current image corresponding to a captured image of the side of the current vehicle C with an area in a historical image captured in the past as an image of the vehicle C's future that overlaps with the current image. Specifically, this comparison can be performed using well-known template matching. When traveling forward, the template image can be an object that straddles both the first forward region R1 and the second forward region R2 shown in FIG. 2, such as the upper or lower end of the grating cover GC in the example shown in FIG. 3A. Alternatively, a white line WL, for example, can be used. This embodiment then displays an underfloor image corresponding to the historical image identified as matching the current image through comparison. This makes it possible to effectively reduce deviations from reality and the resulting discomfort felt by the user when displaying an image of the area directly below the bottom of the current vehicle C.

(Example of operation)
4 is a flowchart showing an example of a display control operation in this embodiment. In the figure, "S" is an abbreviation for "step." The processor and memory provided in the display control device 5 will be simply referred to as the "processor" and "memory" hereinafter.

In step 401, the processor inputs an image signal from the peripheral camera 3. In step 402, the processor performs image processing using the viewpoint conversion processing unit 531, i.e., viewpoint conversion processing. In step 403, the processor determines whether the current shift position is reverse shift. If the current shift position is reverse shift (i.e., step 403 = YES), the processor proceeds to step 404. In step 404, the processor extracts image areas behind and to the rear sides of the vehicle C from the image captured by the rear camera 32. In contrast, if the current shift position is not reverse shift (i.e., step 403 = NO), the processor proceeds to step 405. In step 405, the processor extracts image areas in front and to the front sides of the vehicle C from the image captured by the front camera 31. Then, in step 406, the processor stores the image extracted in step 404 or step 405 in memory as a history image.

In step 407, the processor reads from memory a historical image covering a specified driving time range or a specified driving distance range prior to the current time, and compares it with the current image using template matching. In step 408, the processor extracts an underfloor image from the matched historical image based on the comparison result from template matching. In step 409, the processor generates a display image signal for displaying a composite image of the underfloor image and the current image side by side on the in-vehicle display device 2. In step 410, the processor outputs the display image signal generated in step 409 to the in-vehicle display device 2.

(Modification)
The present invention is not limited to the above-described embodiment. Therefore, the above-described embodiment can be modified as appropriate. Representative modifications will be described below. In the following description of the modifications, differences from the above-described embodiment will be mainly described. Furthermore, identical or equivalent parts between the above-described embodiment and the modifications are given the same reference numerals. Therefore, in the following description of the modifications, the description of the above-described embodiment can be used as appropriate for components having the same reference numerals as those in the above-described embodiment, unless there is a technical contradiction or special additional explanation.

The present invention is not limited to the specific device configurations shown in the above embodiments. For example, the host vehicle C is not limited to a standard automobile, but may be a large vehicle such as a bus or cargo truck. There is no particular limitation on the number of wheels, and the host vehicle C may be a three-wheeled vehicle, or a six- or eight-wheeled vehicle such as a cargo truck. The type of host vehicle C may be a conventional vehicle equipped with only an internal combustion engine, an electric vehicle or fuel cell vehicle without an internal combustion engine, or a so-called hybrid vehicle. There are also no particular limitations on the use of the host vehicle C, the number of occupants, etc.

The in-vehicle display device 2 may be dedicated to displaying images corresponding to images of the surroundings of the vehicle C captured by the surrounding camera 3. Furthermore, the in-vehicle display device 2 is not limited to a CID device, and may be, for example, part of a meter panel, or all or part of the display screen of an in-vehicle navigation device provided separately from the CID device. Furthermore, one or both of the left side screen V2 and right side screen V3 on the in-vehicle display device 2 may be omitted. In other words, the present invention is not limited to displaying an underfloor image and a current image side by side.

The in-vehicle display device 2 is not limited to a flat display device or a curved display device provided on the dashboard of the host vehicle C. That is, for example, the in-vehicle display device 2 may be a so-called head-up display. Alternatively, the in-vehicle display device 2 may be a portable terminal such as a smartphone or tablet terminal brought by an occupant of the host vehicle C. In this case, when the in-vehicle display device 2, which is a portable terminal, is brought into the host vehicle C, it is connected to the display control device 5 via short-range wireless communication such as Bluetooth (registered trademark) or TransferJet (registered trademark) so as to be able to communicate information.

The display control device 5 may be connected to an ECU in a driving assistance system or an autonomous driving system via the in-vehicle communication bus 4, and receive information or signals corresponding to the driving state and driving environment of the vehicle C from the ECU. ECU stands for Electronic Control Unit.

The program of the present invention, which enables the various operations, procedures, or processes described in the above embodiments to be executed, can be downloaded or upgraded via V2X communication. V2X stands for Vehicle to X. Alternatively, such a program can be downloaded or upgraded via a terminal device installed at a vehicle manufacturing plant, repair shop, dealership, etc. Such a program can be stored on a memory card, optical disk, magnetic disk, etc.

In the above embodiment, the display control device 5 was configured as a so-called in-vehicle microcomputer equipped with a CPU and other components. However, the present invention is not limited to such a configuration. For example, all or part of the display control device 5 may be configured with a digital circuit, such as an ASIC or FPGA, configured to enable the above-described operations. ASIC stands for Application Specific Integrated Circuit. FPGA stands for Field Programmable Gate Array. In other words, the display control device 5 may have both an in-vehicle microcomputer portion and a digital circuit portion.

In this way, each of the above functional configurations and methods may be implemented by a special-purpose computer provided by configuring a processor and memory programmed to execute one or more functions embodied in a computer program. Alternatively, each of the above functional configurations and methods may be implemented by a special-purpose computer provided by configuring a processor with one or more dedicated hardware logic circuits.

The present invention is not limited in any way to the specific functional configurations and operational examples shown in the above embodiment. For example, while the operation in the above embodiment was described for forward driving, the present invention can also be effectively applied to reverse driving. In other words, the image capture area corresponding to the first forward area R1 and second forward area R2 shown in Figure 2 can be defined behind the host vehicle C when reversing.

The viewpoint conversion processing unit 531 may convert the images captured by the peripheral camera 3 into an around-view image looking down vertically, rather than a bird's-eye view image looking down diagonally.

Similar expressions such as "acquire," "calculate," "estimate," "detect," "sensing," and "determine" may be substituted for each other as appropriate, to the extent that no technical contradiction exists. "Detection" or "sensing" and "extraction" may also be substituted for each other as appropriate, to the extent that no technical contradiction exists.

It goes without saying that the elements constituting the above embodiments are not necessarily essential, except when expressly stated as essential or when they are clearly considered essential in principle. Furthermore, when numerical values such as the number, amount, range, etc. of components are mentioned, the present invention is not limited to those specific numerical values, except when expressly stated as essential or when they are clearly limited to specific numerical values in principle. Similarly, when the shape, direction, positional relationship, etc. of components are mentioned, the present invention is not limited to those shapes, directions, positional relationships, etc., except when expressly stated as essential or when they are clearly limited to specific shapes, directions, positional relationships, etc., in principle.

The variations are not limited to the examples above. For example, all or part of one of the variations may be combined with all or part of another variation, provided that no technical inconsistency exists. Furthermore, all or part of the above-described embodiments may be combined with all or part of the above-described variations, provided that no technical inconsistency exists. In other words, the disclosure of this specification is not limited to the illustrated embodiments. The disclosure encompasses the illustrated embodiments and modifications made by those skilled in the art based on them. For example, the disclosure is not limited to the combinations of parts and elements shown in the embodiments, but can be implemented in various modifications. The disclosure can be implemented in various combinations. The disclosure can have additional parts that can be added to the embodiments. The disclosure encompasses embodiments in which parts and elements are omitted. The disclosure encompasses the substitution or combination of parts and elements between one embodiment and another embodiment. The disclosed technical scope is not limited to the description of the embodiments. The disclosed technical scope is defined by the claims, and should be interpreted as including all modifications within the meaning and scope of the claims.

2 In-vehicle display device 31 Front camera 32 Rear camera 33 Left side camera 34 Right side camera 5 Display control device 532 Historical image acquisition unit 533 Image matching processing unit 534 Display processing unit 54 Historical image storage unit

Claims (8)

A display control device (5) that controls the display of an in-vehicle display device (2),
a historical image acquisition unit (532) that acquires the historical images from a historical image storage unit (54) that stores, in chronological order, photographed images including a first area image corresponding to a first area (R1) around the host vehicle equipped with the on-vehicle display device and a second area image corresponding to a second area (R2) outside the first area in the vehicle width direction as historical images;
an image matching processing unit (533) that matches a current image corresponding to a currently captured image of the surroundings of the vehicle with the second area image in the history image acquired by the history image acquisition unit;
a display processing unit (534) that displays, on the in-vehicle display device, the first area image included in the history image that has been identified as matching the current image through matching in the image matching processing unit, as an underfloor image that is an image of a portion directly below the bottom of the vehicle;
Equipped with
the image matching processing unit matches the current image with the second region image in the history image using template matching;
Display control device. the first area image and the second area image include an image of a road surface or a ground surface;
The display control device according to claim 1 . The history image corresponds to an image captured by a front camera (31) that captures images in front of and on the front sides of the vehicle or a rear camera (32) that captures images in the rear of and on the rear sides of the vehicle,
The current image corresponds to an image captured by a left side camera (33) capturing an image on the left side of the vehicle or a right side camera (34) capturing an image on the right side of the vehicle.
The display control device according to claim 1 or 2 . the display processing unit causes the in-vehicle display device to display the under-floor image and the current image side by side.
The display control device according to any one of claims 1 to 3 . A display control program executed by a display control device (5) that controls the display of an in-vehicle display device (2),
The process executed by the display control device is
a historical image acquisition process for acquiring the historical images from a historical image storage unit (54) that stores, in chronological order, photographed images including a first area image corresponding to a first area (R1) around the host vehicle equipped with the on-vehicle display device and a second area image corresponding to a second area (R2) outside the first area in the vehicle width direction as historical images;
an image matching process for matching a current image corresponding to a currently captured image of the surroundings of the host vehicle with the second area image in the history image acquired by the history image acquisition process;
a display process for displaying, on the in-vehicle display device, the first area image included in the history image identified as matching the current image through the comparison in the image comparison process, as an underfloor image that is an image of a portion directly below the bottom of the vehicle;
Including,
the image matching process is a process of matching the current image with the second region image in the history image using template matching;
Display control program. the first area image and the second area image include an image of a road surface or a ground surface;
The display control program according to claim 5 . The history image corresponds to an image captured by a front camera (31) that captures images in front of and on the front sides of the vehicle or a rear camera (32) that captures images in the rear of and on the rear sides of the vehicle,
The current image corresponds to an image captured by a left side camera (33) capturing an image on the left side of the vehicle or a right side camera (34) capturing an image on the right side of the vehicle.
7. The display control program according to claim 5 . the display process displays the underfloor image and the current image side by side on the in-vehicle display device.
The display control program according to any one of claims 5 to 7 .