JP7452394B2 - Compression rate map generation device, compression rate information providing device, and compressed image transmission device - Google Patents

Description

The present invention relates to a device related to a map that records the compression rate of an image, and the present invention mainly relates to a compression rate map generation device and a compression rate information providing device realized in a center device, and an in-vehicle device installed mainly in a moving body. The present invention relates to a compressed image transmitting apparatus implemented by the apparatus, a method implemented by these apparatuses, and a program executed by these apparatuses.

In recent years, progress has been made in the development of self-driving vehicles that enable autonomous driving by controlling vehicle acceleration, deceleration, and steering using on-board systems. In such self-driving vehicles, the amount of processing required by the in-vehicle system is enormous, so one possible way to simplify the in-vehicle system and reduce the processing load is to control the running of the vehicle from a remote location. Even if an autonomous vehicle is not remotely controlled, it is desirable that the operation of the autonomous vehicle be monitored from a remote location to ensure vehicle safety. Images captured by onboard cameras can be used to remotely determine the condition of the vehicle. However, since the amount of information in the image is large, there is a risk that communication may be interrupted when transmitting the image to a remote location.

As a method of suppressing the amount of information in an image, for example, still image compression technology such as JPEG, MPEG, H. 264, H. Video compression techniques such as H.265 are known. As a video compression technology, a method that encodes the difference between images in the temporal direction is known. The amount of information will increase.

Patent Document 1 discloses a vehicle system that can suppress an increase in data transmitted from a remotely controllable vehicle. When a vehicle turns left or right, it is desirable to acquire image data that widens the angle of view to the right or left and sends it to a remote location. When an image is acquired using a conventional method, a problem arises in that the image data increases. Therefore, in the vehicle system described in Patent Document 1, when the vehicle makes a right or left turn, a lidar mounted on the vehicle detects an object that exists outside the field of view of the vehicle-mounted camera, and combines it with image data. Sends lidar detection results to a remote control device. As a result, the remote control device can grasp the direction in which the vehicle is turning from the pseudo image and image data generated based on the lidar detection results without significantly increasing the image data transmitted from the vehicle. becomes possible.

Japanese Patent Application Publication No. 2018-180585

Here, the present inventor discovered the following problem.
In Patent Document 1, the increase in the overall amount of information transmitted from the vehicle is suppressed by using the lidar detection results, but it is not possible to suppress the amount of information itself of the image data captured by the on-vehicle camera. Can not. In particular, when a vehicle makes a right or left turn, the image changes significantly, so when image data is compressed by time difference, the amount of information may suddenly increase. As a result, for example, there is a risk that the available bandwidth will be insufficient and video data will not be sent and received properly, resulting in a decrease in image quality. Further, a sudden increase in the amount of information may affect the transfer speed of image data, leading to a decrease in communication speed or interruption. Therefore, it is desirable to prevent the amount of image data from suddenly increasing by appropriately compressing the image data depending on the driving situation of the vehicle.

An object of the present invention is to generate and provide a compression rate map that includes image compression rate information that allows images to be transmitted at a desired transmission speed depending on the position of a vehicle.
Furthermore, it is an object of the present invention to compress and transmit images at a compression rate that can ensure a desired transmission speed depending on the position of the vehicle.

A compression rate map generation device according to one aspect of the present disclosure includes a compression rate map generation device (1200, 2200) that receives probe information from a probe information transmission device (1100, 2100) mounted on a mobile object and generates a compression rate map. ), the image is compressed using position information indicating the position of the moving body, compression rate information indicating a compression rate used for compressing the image by the probe information transmitting device, and the compression rate information. a receiving unit (201) that receives the probe information including actual transmission speed information indicating the transmission speed when the compressed image generated by the transmission is transmitted at the position; If the actual transmission rate information is equal to or higher than the target transmission rate information indicating the target value, corrective compression is performed such that the actual transmission rate information becomes equal to or less than the target transmission rate information using the actual transmission rate information, the target transmission rate information, and the compression rate information. a compression ratio calculation unit (205) that calculates ratio information; and a compression ratio map storage that stores the compression ratio map including the position information and reference compression ratio information that is the compression ratio information or the corrected compression ratio information. (202).

A compression rate information providing device according to another aspect of the present disclosure is a compression rate information providing device (1250) that receives a compression rate information request from a compressed image transmitting device (1150) mounted on a mobile object and transmits necessary information. A compression rate map storage unit (202) that stores a compression rate map including reference position information indicating a reference position and reference compression rate information indicating a compression rate used for compressing an image at the reference position. a receiving unit (201) that receives the compression rate information request including scheduled position information indicating the scheduled movement position of the moving body; A compression rate map extraction unit (207) that acquires the standard compression rate information, and a transmitting unit (204) that transmits a compression rate information reply including the standard compression rate information ,
The reference compression rate information includes transmission rate information indicating a transmission rate at which a compressed image generated by compressing an image using the reference compression rate information is transmitted at the reference position. This indicates a compression ratio that is less than or equal to target transmission rate information indicating a target value.

A compression rate information providing device according to another aspect of the present disclosure includes a compression rate information providing device (2250) that receives a compression rate information request from a compressed image transmitting device (2150) mounted on a mobile object and transmits necessary information. A compression rate map storage unit (202) that stores a compression rate map including reference position information indicating a reference position and reference compression rate information indicating a compression rate used for compressing an image at the reference position. a receiving unit (201) that receives the compression rate information request including scheduled position information indicating the scheduled movement position of the moving body; a compression rate map extraction unit (207) that acquires the reference compression rate information; and a control signal generation unit (208) that generates a control signal instructing to compress an image at the reference position using the reference compression rate information. and a transmitter (204) that transmits a compression rate information reply including the control signal.

A compressed image transmitting device according to another aspect of the present disclosure is a compressed image transmitting device (1150, 2150) mounted on a moving body, and includes scheduled position information for acquiring scheduled position information indicating a scheduled movement position of the moving body. an acquisition unit (106), a transmission unit (108) that transmits a compression ratio information request including the scheduled position information to the compression ratio information providing device (1250, 2250), and a receiving unit (109) that receives a compression rate information reply including reference compression rate information indicating a compression rate used for image compression from the compression rate information providing device; and an image acquisition unit that acquires an image of the surroundings of the moving body. (102), an image processing unit (111) that generates a compressed image by compressing the image using the reference compression rate information, and a wireless communication unit (103) that transmits the compressed image at the planned movement position. ) and ,
The reference compression rate information is a compression rate at which actual transmission rate information indicating a transmission rate when transmitting the compressed image at the planned movement position is equal to or less than a target transmission rate indicating a target value of the transmission rate at the reference position. It shows.

Note that the numbers in parentheses attached to the claims and the constituent features of the invention described in this section indicate the correspondence between the present invention and the embodiments described below, and are not intended to limit the present invention. .

With the above-described configuration, the compression rate map generation device and the compression rate information providing device of the present invention can generate a compression rate map including image compression rate information that allows images to be transmitted at a desired transmission speed for each vehicle position. It becomes possible to generate and provide rate maps.
The compressed image transmitting device of the present invention can use a compression rate map to compress and transmit an image at a compression rate that can ensure a desired transmission speed.

Diagram showing the overall configuration common to each embodiment of the present disclosure A block diagram showing a configuration example of a probe information transmitting device and a compressed image transmitting device that are in-vehicle devices of Embodiments 1 and 2. A block diagram showing a configuration example of a compression ratio map generation device and a compression ratio information providing device, which are the center devices of Embodiment 1. A diagram illustrating a compression ratio map generated and used in Embodiment 1. A diagram illustrating a compression ratio map generated and used in Embodiment 1. A diagram illustrating calculation of compression rate information by the compression rate map generation device that is the center device of Embodiment 1. A diagram illustrating calculation of compression rate information by the compression rate map generation device that is the center device of Embodiment 1. Flowchart showing operations of the probe information transmitting device and compression ratio map generating device of Embodiment 1 Flowchart showing operations of the compressed image transmitting device and compression rate information providing device of Embodiment 1 Flowchart showing the operation of the compressed image transmitting device of Embodiment 1 A block diagram showing a configuration example of a compression rate map generation device and a compression rate information providing device, which are the center devices of Embodiment 2. Flowchart showing the operation of the compressed image transmitting device and compression rate information providing device of Embodiment 2 A block diagram showing a configuration example of a probe information transmitting device and a compressed image transmitting device that are in-vehicle devices of Embodiment 3. A block diagram showing a configuration example of a compression rate map generation device and a compression rate information providing device, which are the center devices of Embodiment 3.

Embodiments of the present invention will be described below with reference to the drawings.

Note that the present invention refers to the invention described in the claims or the means for solving the problems, and is not limited to the following embodiments. Further, at least the words in angle brackets mean the words and phrases described in the claims or the means for solving the problem, and are not limited to the following embodiments.

The structures and methods described in the dependent claims are arbitrary structures and methods in the invention described in the independent claims. The configurations and methods of the embodiments corresponding to the configurations and methods described in the dependent claims, and the configurations and methods described only in the embodiments without being described in the claims are arbitrary configurations and methods in the present invention. In the case where the description of the claims is broader than the description of the embodiments, the configurations and methods described in the embodiments are also arbitrary configurations and methods in the present invention in the sense that they are examples of the configurations and methods of the present invention. . In either case, what is described in the independent claims of the claims constitutes an essential structure and method of the present invention.

The effects described in the embodiments are effects obtained when the present invention has the configuration of the exemplary embodiment, and are not necessarily effects that the present invention has.

When there are multiple embodiments, the configuration disclosed in each embodiment is not limited to each embodiment alone, but can be combined across the embodiments. For example, the configuration disclosed in one embodiment may be combined with other embodiments. Further, configurations disclosed in each of the plurality of embodiments may be collected and combined.

The problems described in "Problems to be Solved by the Invention" are not known problems, but were independently discovered by the present inventor, and are facts that affirm the inventive step of the invention together with the structure and method of the present invention.

1. Overall configuration common to each embodiment Using FIG. 1, the overall configuration showing equipment and mutual relationships common to each embodiment will be described first.

Vehicle-mounted device A and vehicle-mounted device C that are “mounted” on a vehicle that is a “mobile object” are connected to center device B via a communication network, and vehicle-mounted device C is connected to center device D.

Here, the term "moving object" refers to a movable object, and the moving speed is arbitrary. Naturally, this also includes cases where the moving object is stopped. Examples include, but are not limited to, automobiles, motorcycles, bicycles, pedestrians, ships, aircraft, and objects mounted on these.
Furthermore, "mounted" includes not only the case where the device is directly fixed to the moving object, but also the case where it is not fixed to the moving object but moves together with the moving object. For example, when the vehicle is carried by a person riding on a moving body, or when it is carried on cargo placed on the moving body.

The on-vehicle device A corresponds to a probe information transmitting device in each embodiment described below, and transmits probe information, which is information necessary for generating a compression ratio map, to the center device B via a communication network.

Center device B corresponds to the compression rate map generation device of each embodiment, receives probe information from vehicle-mounted device A via the communication network, and generates a "compression rate map" based on the probe information.

Here, the "compression rate map" refers to a value that indicates the degree of compression of a still image or video for each position, such as data rate (bps) and frame rate (fps) that indicate the image quality of the video. , or the image resolution (pixel) mapped to each grid point on the map. The value indicating the degree of compression may be a numerical value such as a data rate, a symbol to which a numerical value such as a data rate is assigned in advance (for example, high, medium, low), or a compression ratio (percentage). .

Further, the center device B corresponds to the compression ratio information providing device of each embodiment, and transmits the compression ratio map itself generated/updated by the compression ratio map generation device or the control signal generated based on the compression ratio map to the communication network. It is transmitted to the vehicle-mounted device C via.

The in-vehicle device C corresponds to the compressed image transmitting device of each embodiment. The compressed image transmitting device receives the compression rate map or control signal from the center device B, compresses the image based on this information, and transmits the generated compressed image.

The center device D corresponds to the remote control device of each embodiment. The remote control device acquires the compressed image transmitted from the in-vehicle device C and remotely controls the vehicle.

The in-vehicle device A and the in-vehicle device C receive positioning signals from a satellite positioning system such as GPS (Global Positioning System), and acquire their respective position information.

Communication networks include, for example, IEEE802.11 (WiFi (registered trademark)), IEEE802.16 (WiMAX (registered trademark)), W-CDMA (Wideband Code Division Multiple Access), HSPA (High Speed Packet Access), and LTE (Long Term Evolution), LTE-A (Long Term Evolution Advanced), 4G, 5G, and other wireless communication systems can be used. Alternatively, DSRC (Dedicated Short Range Communication) can be used.

The communication network can also use a wired communication method in addition to the above-mentioned wireless communication method. For example, a LAN (Local Area Network), the Internet, or a fixed telephone line can be used. When using a wired communication method, it is assumed that the vehicle is parked in a parking lot at home or other location, or is housed in a repair shop.

The communication network may combine a wireless communication method and a wired communication method. For example, in-vehicle device A and a base station (not shown) in a cellular system are connected by a wireless communication method, and from the base station are connected by a wired communication method such as a carrier's backbone line or the Internet. Good too.

Although an example has been described in which the on-vehicle device A and the on-vehicle device C are mounted on different vehicles, they may be mounted on one vehicle. Furthermore, in this case, in addition to implementing the in-vehicle device A and the in-vehicle device C as separate devices, the functions of the probe information transmitting device that is the in-vehicle device A and the functions of the compressed image transmitting device that is the in-vehicle device C can be integrated into one in-vehicle device. It may also be implemented as a device.

Although an example has been described in which the center device B and the center device D are separate devices, these center devices may be configured as one center device.

Further, although an example has been described in which the center device B has the functions of both the compression rate map generation device and the compression rate information providing device of this embodiment, it may be provided separately in separate center devices.

2. Embodiment 1
(1) Configuration of in-vehicle device (probe information transmitting device 1100, compressed image transmitting device 1150)

The configuration of the in-vehicle device of this embodiment will be explained using FIG. 2. In this embodiment, an example will be described in which an in-vehicle device is configured to implement the functions of both the probe information transmitting device 1100 and the compressed image transmitting device 1150.

The in-vehicle device includes a position information acquisition unit 101, an image acquisition unit 102, a wireless communication unit 103, a transmission speed information acquisition unit 104, a shooting environment information acquisition unit 105, a planned position information acquisition unit 106, a control unit 107, a transmission unit 108, and a reception unit. 109 and a storage section 110. Further, the control unit 107 implements an image processing unit 111 and a probe information generation unit 112.

The in-vehicle device can be configured with a general-purpose CPU (Central Processing Unit), volatile memory such as RAM, nonvolatile memory such as ROM, flash memory, or hard disk, various interfaces, and an internal bus that connects these. By executing software on these hardware, it is possible to configure the system so that the functions of each functional block shown in FIG. 2 are exhibited. The same applies to the center device shown in FIG. 3, which will be described later, and the devices described in Embodiment 2 and thereafter. Of course, the in-vehicle device may be realized using dedicated hardware such as an LSI.

In this embodiment, the in-vehicle device is assumed to be in the form of an electronic control unit (ECU, hereinafter abbreviated as ECU) as a semi-finished product, but is not limited to this. For example, the forms of parts include semiconductor circuits and semiconductor modules, and the forms of finished products include personal computers (PCs), smartphones, mobile phones, and navigation systems.
Note that the in-vehicle device may include a single ECU or a plurality of ECUs. For example, a communication ECU may be in charge of communication with the outside. Further, the probe information transmitting device 1100 and the compressed image transmitting device 1150 may be configured as separate ECUs.

Each block of the in-vehicle device in FIG. 2 includes a block used exclusively by the probe information transmitting device 1100, a block exclusively used by the compressed image transmitting device 1150, and a block used by both the probe information transmitting device 1100 and the compressed image transmitting device 1150. be. Hereinafter, blocks used in probe information transmitting device 1100 will be described first, and then blocks used in compressed image transmitting device 1150 will be described.

First, blocks used in probe information transmitting device 1100 will be explained.

The position information acquisition unit 101 acquires position information indicating the current position of the vehicle. The position information acquisition unit 101 is mainly composed of a positioning receiver of a satellite positioning device. The positioning receiver may be provided with a positioning receiver corresponding to the satellite system to be used. The position information acquisition unit 101 includes a positioning receiver as well as a device that supplies correction information used for correcting position information. For example, inertial sensors such as gyro sensors and acceleration sensors, laser sensors, and map information databases can also be grasped as the position information acquisition unit 101.

The image acquisition unit 102 acquires an image of the surroundings of the vehicle taken by an on-vehicle camera (corresponding to a "photographing device") mounted on the vehicle. The image acquired by the image acquisition unit 102 may be either a still image or a moving image.

The wireless communication unit 103 transmits a compressed image generated by an image processing unit 111 (described later) to a remote control device. Note that the wireless communication unit 103 transmits the compressed image to the remote control device via another communication device, for example, a base station such as an eNB of a cellular communication system, or via another vehicle, a roadside device, or an AP. Good too.

The transmission rate information acquisition unit 104 acquires actual transmission rate information indicating the transmission rate when the wireless communication unit 103 transmits the compressed image. For example, the transmission rate information acquisition unit 104 may use a device that measures the transmission rate, or may acquire actual transmission rate information from an external communication device or the like. The transmission speed information may be, for example, an instantaneous maximum transmission speed when transmitting a compressed image at the current position, or may be an average transmission speed. In the embodiments below, the transmission speed indicated by the transmission speed information will be explained using an average bit rate per unit time (bps) as an example, but the transmission speed is not limited to this. For example, the transmission rate may be a desired amount of communication data per unit of time.

The photographing environment information acquisition unit 105 acquires photographing environment information indicating the environment in which the image was photographed by the vehicle-mounted camera. The photographing environment information indicates, for example, the moving speed of the vehicle, the weather and time when the image was photographed, and the position of the vehicle-mounted camera that photographed the image. The position of the vehicle-mounted camera may be a general position such as the left and right or front and rear of the vehicle, or may be the height at which the vehicle-mounted camera is installed. The photographing environment information may indirectly indicate the left and right or front and rear positions of the vehicle by indicating the direction in which the in-vehicle camera photographs. Alternatively, in a case where the installation position of the vehicle-mounted camera is uniquely specified by the identification ID of the vehicle-mounted camera, the photographing environment information may indicate the identification ID of the vehicle-mounted camera.

The storage unit 110 stores the compression rate map. The compression rate map stored in the storage unit 110 is information included in the compression rate information reply received by the compressed image transmitting device 1150 (described later), and is the information contained in the compression rate map stored in the compression rate information providing device 1250 (described later). Part of it. By storing a part of the compression rate map stored in the compression rate information providing device 1250 in the on-vehicle device, it is possible to reduce the chances that the on-vehicle device accesses the compression rate information providing device 1250.

The control unit 107 controls the operations of the position information acquisition unit 101 , the image acquisition unit 102 , the wireless communication unit 103 , the transmission rate information acquisition unit 104 , the shooting environment information acquisition unit 105 , the transmission unit 108 , and the storage unit 110 . Further, the control unit 107 itself realizes an image processing unit 111 and a probe information generation unit 112.

The image processing unit 111 compresses the image acquired by the image acquisition unit 102 to generate a compressed image. The image processing unit 111 uses, for example, H. 264 and H. A compressed image is generated using an image compression technique such as H.265. The compression rate used by the image processing unit 111 to compress the image is compression rate information included in the compression rate map stored in the storage unit 110. The image processing unit 111 acquires compression rate information associated with the position information acquired by the position information acquisition unit 101 from the compression rate map stored in the storage unit 110, and uses the acquired compression rate information to process the image. Compress. Note that a high compression ratio means that the degree of compression is large and the amount of information after compression is small. Moreover, the term "compression rate is low" means that the degree of compression is small and the amount of information after compression is larger than when the compression rate is high. For example, when the compression rate is expressed as a data rate [Mbps], the smaller the numerical value of the data rate, the higher the compression rate. In this embodiment, when the compression rate is expressed as high, it indicates that the data rate value is low.

The probe information generation unit 112 includes the position information acquired by the position information acquisition unit 101, the actual transmission rate information acquired by the transmission rate information acquisition unit 104, and the compression rate information used for image compression by the image processing unit 111. generate probe information.

The transmitter 108 transmits the probe information generated by the probe information generator 112 to the compression ratio map generator 1200. For example, in the case of this embodiment, the following information is transmitted as probe information.

(probe information)
Timestamp: Time the image was taken (UTC)
Location information: latitude, longitude, altitude, or ID representing a grid point on the map
Actual transmission speed information: Transmission speed when transmitting compressed images [Mbps]
Compression rate information: Compressed image data rate [Mbps]
Shooting environment information: vehicle speed, weather, time, and/or location information of the in-vehicle camera

Note that other information may be sent as the probe information. Further, the information to be transmitted as probe information may be generated by a specific block other than the control unit 107.

As described above, according to the probe information transmitting device 1100 of this embodiment, the actual transmission rate information obtained when wirelessly communicating the compressed image is included in the probe information and transmitted along with the compression rate used when generating the compressed image. do. Thereby, the compression rate map generation device 1200 that has received the probe information can create a compression rate map that includes a compression rate such that the actual transmission rate information is equal to or less than the target transmission rate information.

Next, blocks used in compressed image transmitting device 1150 will be explained.

The planned position information acquisition unit 106 acquires "planned position information" indicating a planned movement position where the vehicle is scheduled to move in the future. For example, if the vehicle is a self-driving vehicle, the travel route of the vehicle to the destination is determined in advance by the self-driving system. Further, even when the vehicle is manually operated by the driver, the navigation system presents the driver with a recommended travel route to the destination. Therefore, the planned position information acquisition unit 106 acquires planned position information from a travel route determined in advance by an automatic driving system or a navigation system.

Here, "planned location information" is sufficient as long as it includes information on the location where the moving object is scheduled to move; for example, information indicating the destination of the moving object or information indicating the movement plan of the moving object. It may be information.

The transmitting unit 108 transmits a compression rate information request including the scheduled position information acquired by the scheduled position information acquiring unit 106 to the compression rate information providing device 1250. In addition to the planned position information, the compression rate information request may further include shooting environment information (corresponding to "estimated shooting environment information") that estimates the environment in which images will be shot by the vehicle-mounted camera at the planned movement position.

The compression rate information providing device 1250 that has received the compression rate information request selects the compression rate map corresponding to the scheduled position information included in the compression rate information request, and selects the compression rate map included in the compression rate information request from the selected compression rate map. "Reference position information and reference compression rate information corresponding to the planned position information are acquired." Details of the operation of the compression ratio information providing device 1250 will be described later.

Here, "corresponding to the planned position information" means that the position is the same as or near the position indicated by the planned position information.

The receiving unit 109 receives a compression rate information reply including reference position information and reference compression rate information from the compression rate information providing device 1250. Since the received reference position information and reference compression rate information are part of the compression rate map selected by the compression rate information providing device 1250, the received reference position information and reference compression rate information may also be referred to as a compression rate map. be. For example, in the case of this embodiment, the following information is received as the compression rate information reply.

(Compression rate information reply)
Reference location information: ID representing latitude, longitude, altitude or grid point on the map
Standard compression rate information: Standard compressed image data rate [Mbps]

The storage unit 110 stores the received compression rate information reply. Since the set of reference position information and reference compression ratio information stored in the storage unit 110 is part of the compression ratio map stored in the compression ratio information providing device 1250, a replica of the compression ratio map is stored in the storage unit. It can be said that this has been done.

The position information acquisition unit 101, the image acquisition unit 102, the image processing unit 111, and the wireless communication unit 103 of the compressed image transmission device 1150 function in the same manner as the functions described in the probe information transmission device 1100.
That is, the position information acquisition unit 101 acquires position information indicating the current position of the vehicle. The image acquisition unit 102 acquires an image taken by an on-vehicle camera mounted on a vehicle.
The image processing unit 111 generates a compressed image by compressing the image acquired by the image acquisition unit 102. Here, the compression rate used by the image processing unit 111 to compress the image is the reference compression rate information included in the compression rate information reply stored in the storage unit 110, and is the standard compression rate information acquired by the position information acquisition unit 101. This is the compression rate indicated by the standard compression rate information associated with the standard position information "corresponding to the position information."
The wireless communication unit 103 transmits a compressed image, which is an image compressed by the image processing unit 111, to the remote control device.

When the image processed by the image processing unit 111 is a moving image, the reference position information corresponding to the vehicle position information is set in accordance with the interval between the I frames among the frames (I frame, P frame, B frame) that make up the moving image. The reference compression rate information may be determined and associated with the determined reference position information. For example, when the interval between I frames constituting a video is 1 second, the image processing unit 111 selects a reference position information corresponding to the vehicle position information from among the reference position information stored in the storage unit 110 every 1 second. Position information is determined, and the image is compressed using reference compression rate information associated with the determined reference position information. The distance that a vehicle moves in one second, which corresponds to the interval between I frames, changes depending on the moving speed of the vehicle. Therefore, there are sections in which the image processing unit 111 of a vehicle traveling at 50 km/h compresses an image using specific standard compression rate information, and areas in which the image processing unit 111 of a vehicle traveling at 10 km/hour compresses images using specific standard compression rate information. The intervals used to compress the image will be at different distances.

As described above, according to the compressed image transmitting device 1150 of the present embodiment, the compression rate information request includes the scheduled position information and is transmitted, so it is possible to obtain the compression rate map corresponding to the scheduled position information from the compression rate information providing device 1250. can. In addition, by compressing an image using the reference compression rate information included in the compression rate map and sending the compressed image to a remote control device, it is possible to send the compressed image at a transmission rate that is lower than the target transmission rate. can.

(2) Configuration of center device (compression rate map generation device 1200, compression rate information providing device 1250) The configuration of the center device of this embodiment will be described using FIG. 3. In this embodiment, an example will be described in which the center device is configured to realize the functions of both the compression rate map generation device 1200 and the compression rate information providing device 1250.

The center device includes a receiving section 201, a compression rate map storage section 202, a control section 203, and a transmitting section 204. Further, the control unit 203 implements a compression rate calculation unit 205, a compression rate map update unit 206, and a compression rate map extraction unit 207.

Although the center device is assumed to be in the form of a finished product in this embodiment, it is not limited to this. For example, the form of parts includes semiconductor circuits and semiconductor modules, the form of semi-finished products includes ECUs, and the form of finished products include personal computers (PCs), workstations, smartphones, and mobile phones.

Each block of the center device in FIG. 3 includes a block used exclusively by the compression rate map generation device 1200, a block used exclusively by the compression rate information providing device 1250, and a block used exclusively by the compression rate map generation device 1200 and the compression rate information providing device 1250. There are blocks used. Hereinafter, the blocks used in the compression rate map generation device 1200 will be described first, and then the blocks used in the compression rate information providing device 1250 will be explained.

First, blocks used in the compression ratio map generation device 1200 will be explained. In the embodiment below, the compression rate map generation device 1200 is described as generating a compression rate map, but generation of a compression rate map means updating the values included in an already existing compression rate map. This can also be understood as generating a new compression ratio map. That is, the compression rate map generation device means a device that generates or updates a compression rate map.

Receiving section 201 receives probe information from probe information transmitting device 1100. The probe information is generated by compressing an image using position information indicating the current position of the vehicle, compression rate information indicating the compression rate used to compress the image by the probe information transmitting device 1100, and the compression rate information. actual transmission speed information indicating the transmission speed when the compressed image is transmitted at the position indicated by the position information. The probe information may further include imaging environment information indicating the environment in which the image was taken. The probe information used in this embodiment is the same as the example described in (1).

The compression rate map storage unit 202 is a memory that stores a compression rate map, and is configured with a nonvolatile device such as an HDD or a flash memory. The compression rate map stored in the compression rate map storage unit 202 includes reference position information, reference compression rate information, and target transmission rate information.

FIG. 4 is a diagram showing an example of a compression rate map stored in the compression rate map storage unit 202 in this embodiment. The reference position information is, for example, latitude and longitude information. The reference compression rate information indicates a reference compression rate used for image compression in the compressed image transmitting device 1150 at the reference position indicated by the reference position information. The target transmission speed information indicates a target value of the transmission speed when transmitting a compressed image at the reference position indicated by the reference position information. In this embodiment, since it is assumed that the target transmission rate information differs depending on the reference position, the compression ratio map has target transmission rate information at each reference position. However, the target transmission rate information may always be constant regardless of the position. In this case, since it is not necessary to store target transmission speed information for each reference position, the compression ratio map may not include target transmission speed information, and target transmission speed information indicating a constant transmission speed may be stored separately.

FIG. 5 is a diagram illustrating reference position information and reference compression rate information included in the compression rate map. FIG. 5A is a diagram showing the compression ratio indicated by the reference compression ratio information divided into three stages on a map. The stages of compression ratio are indicated by different types of arrows. In the example of FIG. 5(a), a low compression rate (>0.7 Mbps) is shown in a straight section of the road, and a medium compression rate (0.5 to 0.7 Mbps) is shown near an intersection. Furthermore, the compression rate is high (<0.5 Mbps) at positions where the vehicle turns right or left. FIG. 5(b) further shows an enlarged view of the intersection in FIG. 5(a). Figure 5(b) shows that before the intersection, the compression rate indicated by the standard compression rate information is 1.0 Mbps, and as it approaches the intersection, the compression rate increases to 0.7 Mbps and 0.6 Mbps. There is.

The example in FIG. 5 shows that the standard compression ratio is high at positions near intersections. Near intersections, especially at locations where left or right turns are to be made, the subject of images taken by in-vehicle cameras is expected to change significantly. Therefore, when using image compression technology that encodes the difference between images, The amount of information can be large. Therefore, by setting the reference compression rate information at a reference position near an intersection to a high compression rate, it is possible to prevent the amount of information of a compressed image from suddenly increasing when a vehicle moves near an intersection. Note that the position associated with high reference compression rate information is not limited to the vicinity of an intersection.

Note that the reference position information may further include information indicating the effective range of the reference position in addition to information indicating a specific point such as latitude and longitude information. The effective range of the reference position is specified by, for example, the distance from the reference position, the lane width of the road, and the like.

The compression rate calculation unit 205 calculates corrected compression rate information using the actual transmission rate information and compression rate information included in the probe information and the target transmission rate information stored in the compression rate map storage unit 202. The corrected compression rate information is stored in the compression rate map instead of the standard compression rate information, and can be said to be an updated value of the standard compression rate information.

In this embodiment, since the target transmission rate information is included in the compression rate map, the compression rate calculation unit 205 calculates the position information included in the probe information from the compression rate map stored in the compression rate map storage unit 202. The target transmission speed information associated with the reference position corresponding to is acquired.

For example, when the actual transmission rate information included in the probe information is "more than" the target transmission rate information, the compression rate calculation unit 205 calculates the actual transmission rate information and compression rate information included in the probe information, as well as the target transmission rate information. Then, corrected compression ratio information is calculated so that the actual transmission rate information is equal to or less than the target transmission rate information.

Here, "more than" and "less than" include both cases where the same value as the comparison target is included and cases where it is not included.

An example of a formula used by the compression ratio calculation unit 205 to calculate the corrected compression ratio information is shown below. The compression ratio calculation unit 205 calculates the corrected compression ratio information using Equation 1, for example. Here, in the formula below, Dr represents actual transmission rate information [Mbps], Du represents compression rate information [Mbps], Dt represents target transmission rate information [Mbps], and Dc represents corrected compression rate information [Mbps]. are shown respectively.

Calculating the corrected compression rate information using Formula 1 can be applied when the compression rate indicated by the compression rate information is expressed in the amount of data per unit time like the target transmission rate information and the actual transmission rate information. can. Calculation of corrected compression ratio information using Equation 1 will be explained using FIG. 6. In Equation 1, the value obtained by subtracting the difference (Dr - Dt) between the actual transmission rate information (Dr) and the target transmission rate information (Dt) from the compression rate information (Du) used to generate the compressed image is Set in the corrected compression ratio information (Dc). The actual transmission rate information (Dr_a shown in FIG. 6(b)) obtained when transmitting an image compressed using the compression rate indicated by the corrected compression rate information (Dc) has a value that does not exceed the target transmission rate information. Probability is high.

As another method of calculating the corrected compression ratio information, Equation 2 may be used.

Equation 2, like Equation 1, can be applied when the compression rate indicated by the compression rate information is expressed in the amount of data per unit time like the target transmission rate information and the actual transmission rate information. Calculation of the corrected compression ratio information using Equation 2 will be explained using FIG. 7. In Equation 2, α is the ratio of the compression rate information (Du) used to generate the compressed image and the actual transmission rate information (Dr). Then, the ratio (Dc) of the corrected compression rate information (Dc) and the actual transmission rate information (Dr_a shown in FIG. 7(b)) obtained when an image compressed using the compression rate indicated by the corrected compression rate information is transmitted. /Dr_a) is estimated to be equal to α. If the value of the actual transmission rate information (Dr_a) obtained using the corrected compression rate information (Dc) is the value of the target transmission rate information (Dt), the corrected compression rate information can be calculated using Equation 2.

Note that in this embodiment, a configuration has been described in which when the actual transmission rate information is equal to or higher than the target transmission rate information, corrected compression ratio information is calculated such that the actual transmission rate information is equal to or less than the target transmission rate information. Even when the information is less than or equal to the target transmission rate information, the compression ratio calculation unit 205 may be configured to calculate the corrected compression ratio information.
A remote control device, which will be described later, decodes the compressed image transmitted from the compressed image transmitting device 1150 and uses it for remote control. However, most image compression techniques involve irreversible compression, and it is difficult to completely decode an image before compression. The higher the compression rate, the worse the quality of the image obtained by decoding, so it is desirable to keep the image compression rate as low as possible. Therefore, if the actual transmission rate information is less than or equal to the target transmission rate information, for example, corrected compression rate information that indicates the minimum compression rate among the compression rates at which the actual transmission rate information is less than or equal to the target transmission rate information is calculated. Good too. This corrected compression ratio information can be calculated using Equation 2 described above, for example.

The compression rate map updating unit 206 converts the standard compression rate information stored in the compression rate map storage unit 202 in association with the standard position information corresponding to the position information into the corrected compression rate information calculated by the compression rate calculation unit 205. Update to.

Note that although FIG. 4 illustrates a compression rate map including reference position information, reference compression rate information, and target transmission rate information, the compression rate map may further include other information. For example, the compression rate map storage unit 202 may further store a compression rate map that includes imaging environment information included in the probe information in addition to each piece of information shown in FIG. 4 . The photographing environment information includes, for example, the moving speed of the vehicle, the weather at which the image was taken by the on-vehicle camera, the time, and the position of the on-vehicle camera. In this case, the compression ratio map updating unit 206 updates the reference compression ratio information stored in association with the reference position information and imaging environment information included in the probe information.

When the moving speed of the vehicle is fast, the changes in the subject included in the images taken by the on-vehicle camera become large, and therefore the differences that occur between the images in the time direction also become large. As a result, when using an image compression technique that encodes the difference between images in the time direction, the faster the moving speed of the vehicle, the greater the possibility that the amount of information after compression will become larger. Therefore, the compression ratio map further includes photographing environment information (corresponding to "standard photographing environment information") indicating vehicle speed information and reference compression ratio information corresponding to the vehicle speed information. The moving speed of the vehicle indicated by the photographing environment information may be classified into a plurality of stages (50 km/h or more, less than 50 km/h, etc.), and reference compression ratio information corresponding to each stage may be included.

The weather and time at which the images were taken can also affect the differences that occur between images in the temporal direction. For example, it is conceivable that an image taken when the weather is cloudy has less color change than an image taken when the weather is sunny, and the difference that occurs between images in the time direction becomes smaller. Images taken in the evening or night also have less color change than images taken in the morning or during the day, and it is thought that the differences between images in the time direction are smaller. . Therefore, the compression rate map further includes shooting environment information indicating the weather and/or time at which the image was taken (corresponding to "standard shooting environment information"), and standard compression rate information corresponding to the weather and time at which the image was taken. shall be included respectively.

The location of the in-vehicle camera that captured the images can also affect the differences that occur between images in the temporal direction. For example, if a similar scenery continues on the right side of the vehicle, but the scenery changes on the left side, the differences that occur in the images in the time direction taken by the in-vehicle cameras installed on the left and right sides of the vehicle will be different. Therefore, if the same compression rate is used to compress images taken by the left and right on-vehicle cameras of a vehicle, the amount of information after compression may differ for each on-vehicle camera. Therefore, the compression rate map further includes shooting environment information (corresponding to "standard shooting environment information") indicating the position of the on-board camera that took the image, and standard compression rate information corresponding to the position of the on-board camera. .

In the above example, the compression rate map included only one target transmission rate information for one reference position, but the compression rate map includes two or more target transmission speed information for one reference position. It may also include speed information. For example, the compression rate map storage unit 202 associates and stores reference position A (X1, Y1), reference compression rate information a, and target transmission rate information a (corresponding to "first target transmission rate information"). At the same time, the reference position A (X1, Y1), reference compression ratio information b, and target transmission rate information b (corresponding to "second target transmission rate information") are stored in association with each other. In this case, the standard compression rate information a is the compression rate at which the actual transmission rate information is less than or equal to the target transmission rate information a, and the standard compression rate information b is the compression rate at which the actual transmission rate information is less than or equal to the target transmission rate information b. ing.

As described above, according to the compression rate map generation device 1200 of this embodiment, it is possible to generate a compression rate map that includes reference compression rate information such that the actual transmission rate information is equal to or less than the target transmission rate information. Thereby, the transmission rate obtained when transmitting an image using the compression rate map generated or updated by the compression rate map generation device 1200 of this embodiment can be made equal to or lower than the target transmission rate.

Next, blocks used in the compression rate information providing device 1250 will be explained.

As explained in the compression rate map generation device 1200, the compression rate map storage unit 202 stores a compression rate map including reference position information, reference compression rate information, and target transmission rate information.

Receiving unit 201 receives a compression rate information request including scheduled position information indicating the scheduled moving position of the vehicle from compressed image transmitting device 1150.

The compression ratio map extraction unit 207 acquires from the compression ratio map storage unit 202 the reference position information indicating the reference position “corresponding to the planned position information” included in the compression ratio information request, and the reference compression ratio information at the reference position. .

The transmitter 204 transmits a compression rate information reply that includes the reference position information and reference compression rate information acquired by the compression rate map extractor 207. The compression rate information reply in this embodiment is the same as the example described in (1).

Note that when the compression rate map storage unit 202 includes a plurality of pieces of target transmission rate information (corresponding to "first target transmission rate information" and "second target transmission rate information") for one reference position, compression The rate map extraction unit 207 selects appropriate target transmission rate information and acquires reference compression rate information associated with the selected target transmission rate information.

For example, the compression rate map extraction unit 207 estimates the available bandwidth of the compressed image transmitting device 1150 at the planned movement position, and selects a target transmission rate that does not exceed the estimated available bandwidth from among a plurality of pieces of target transmission rate information included in the compression rate map. Select speed information (corresponding to "first target transmission speed information"). Then, reference compression rate information associated with the selected target transmission rate information is acquired.

Alternatively, the compression rate map extraction unit 207 determines the priority of the image acquired by the compressed image transmitting device 1150 at the planned movement position, and selects a plurality of pieces of target transmission speed information included in the compression rate map according to the determined priority. One of the target transmission rate information may be selected. For example, consider a case where a plurality of vehicles (for example, vehicles A and B) exist, and vehicle A plans to turn left or right at an intersection, and vehicle B plans to go straight. In such a case, there is a higher possibility that vehicle A requires driving support by a remote control device than vehicle B, and it can be said that the priority of the image acquired by vehicle A is higher. Therefore, the compression ratio map extraction unit 207 determines that the priority of the image acquired by vehicle A is higher than the priority of the image acquired by vehicle B (corresponding to the "predetermined priority"), and Select the target transmission speed information that shows the highest value among the target transmission speed information, and obtain the standard compression ratio information associated with the selected target transmission speed information (corresponding to "first target transmission speed information") do. The priority is determined not only by the vehicle's planned movement position, but also by comprehensively considering, for example, the type of vehicle, the attributes of the occupants of the vehicle, the speed of movement of the vehicle, and information sent from the vehicle to the remote control device. The priority may be determined by making a judgment. For example, even if both vehicle A and vehicle B are traveling straight ahead, vehicle A requests driving assistance from the operator and vehicle B is able to drive autonomously without requesting driving assistance. In this case, it may be determined that the priority of the image acquired by vehicle A is higher than the priority of the image acquired by vehicle B. Furthermore, when determining the priority of images acquired by vehicle A described above, the "predetermined" priority to be compared is limited to the priority of images acquired by other vehicles (for example, vehicle B). The priority may be a specific value set in advance.

Here, "predetermined" includes not only the case where it is always constant but also the case where it is uniquely determined according to conditions.

As described above, according to the compression rate information providing device 1250 of this embodiment, the standard compression used for compressing images at the scheduled movement position of the vehicle indicated by the scheduled position information is determined according to the scheduled position information included in the compression rate information request. A compression ratio map including ratio information can be provided.

(3) Operations of the probe information transmitting device 1100 and the compression rate map generating device 1200 in the compression rate map generation process The probe information transmitting device 1100 and the compression rate map generating device 1200 are both involved in generating the compression rate map. The operations of the probe information transmitting device 1100 and the compression rate map generation device 1200 in the compression rate map generation process of this embodiment will be described below using the flowchart of FIG. 8.

Note that the following operations not only indicate the probe information transmitting method executed by the probe information transmitting device 1100, but also indicate the processing procedure of the probe information transmitting program that can be executed by the probe information transmitting device 1100. Furthermore, the following operations not only show the compression ratio map generation/update method executed by the compression ratio map generation device 1200, but also show the processing procedure of the compression ratio map generation/update program that can be executed by the compression ratio map generation device 1200. It is something. These processes are not limited to the order shown in the figure. That is, the order may be changed unless there is a restriction such that a certain step uses the result of the previous step.

The position information acquisition unit 101 of the probe information transmitting device 1100 acquires position information indicating the current position of the vehicle (S101).
The image acquisition unit 102 acquires an image captured by the vehicle-mounted camera (S102).
The image processing unit 111 acquires standard compression rate information associated with the standard position information corresponding to the position information acquired in S101 from the compression rate map stored in the storage unit 110, and uses the standard compression rate information. A compressed image is generated by compressing the image acquired in S102 (S103).
The wireless communication unit 103 transmits the compressed image generated in S103 to the remote control device (S104).
The transmission rate acquisition unit 104 acquires actual transmission rate information indicating the transmission rate when the compressed image was transmitted in S104 (S105).
The transmitting unit 108 transmits probe information including the position information acquired in S101, the compression rate information used to compress the image in S103, and the actual transmission rate information acquired in S105 to the compression rate map generation device (S106 ).

The receiving unit 201 of the compression rate map generation device 1200 compresses the image using position information indicating the position of the vehicle, compression rate information indicating the compression rate used to compress the image, and the compression rate indicated by the compression rate information. Probe information including actual transmission speed information indicating the transmission speed obtained when the compressed image generated in is transmitted at the position indicated by the position information is received (S201).
Target transmission speed information indicating the target value of the transmission speed in the position information included in the probe information is acquired (S202).
Here, it is determined whether the actual transmission rate information received in S201 is greater than or equal to the target transmission rate information acquired in S202 (S203).
If the actual transmission speed information is equal to or higher than the target transmission speed information (S203: Yes), the compression ratio calculation unit 205 uses the actual transmission speed information, the target transmission speed information, and the compression ratio information so that the actual transmission speed information is equal to or higher than the target transmission speed information. Corrected compression ratio information that is equal to or lower than the transmission rate information is calculated (S204).
Among the reference compression ratio information included in the compression ratio map stored in the compression ratio map storage unit 202, the reference compression ratio information associated with the reference position information corresponding to the position information included in the probe information is calculated in S204. By updating the corrected compression ratio information, the compression ratio map is updated and saved (S205).

In this way, by updating the compression ratio map using actual transmission speed information and target transmission speed information, a compression ratio map is generated and updated that shows the compression ratio at which the desired transmission speed can be obtained for each vehicle position. can do.

(4) Operations of the compression rate information providing device 1250 and the compressed image transmitting device 1150 in the compression rate map utilization process The compressed image transmitting device 1150 and the compression rate information providing device 1250 are both involved in the use of the compression rate map. The operations of the compressed image transmitting device 1150 and the compression rate information providing device 1250 in the compression rate map usage process of this embodiment will be described below using the flowchart of FIG.

Note that the following operations not only indicate the compression rate information providing method executed by the compression rate information providing device 1250, but also show the processing procedure of the compression rate information providing program that can be executed by the compression rate information providing device 1250. be. Furthermore, the following operations not only show a compressed image sending method executed by the compressed image sending device 1150, but also show the processing procedure of a compressed image sending program that can be executed by the compressed image sending device 1150. These processes are not limited to the order shown in FIG. 9. That is, the order may be changed unless there is a restriction such that a certain step uses the result of the previous step.

The planned position information acquisition unit 106 of the compressed image transmitting device 1150 acquires planned position information indicating the planned movement position of the vehicle (S151).
The transmitting unit 108 transmits a compression rate information request including the scheduled position information acquired in S151 to the compression rate information providing device 1250 (S152).

The receiving unit 201 of the compression rate information providing device 1250 receives a compression rate information request including scheduled position information (S251).
The compression rate map extraction unit 207 acquires reference position information and reference compression rate information corresponding to the scheduled position information included in the compression rate information request received in S251 (S252).
The transmitter 204 transmits a compression rate information reply including the reference position information and reference compression rate information acquired in S252 (S253).

The receiving unit 109 of the compressed image transmitting device 1150 receives the compression rate information reply transmitted from the compression rate information providing device 1250 (S153).
The storage unit 110 stores the reference position information and reference compression ratio information included in the compression ratio information reply received in S153 (S154).

FIG. 10 describes an operation in which the compressed image transmitting device 1150 compresses and transmits an image using the compression rate map obtained through the series of processes shown in FIG.

The position information acquisition unit 101 acquires position information indicating the current position of the vehicle (S155).
The image acquisition unit 102 acquires an image captured by the vehicle-mounted camera (S156).
The image processing unit 111 acquires standard compression rate information associated with the standard position information corresponding to the position information acquired in S155 from the compression rate map stored in the storage unit 110, and also uses the acquired standard compression rate. A compressed image is generated by compressing the image acquired in S156 using the information (S157).
The wireless communication unit 103 transmits the compressed image generated in S157 to the remote control device (S158).

In this embodiment, by compressing and transmitting an image using the reference compression rate information included in the compression rate map, it is possible to transmit the compressed image to the remote control device at a transmission rate lower than the desired transmission rate. As a result, for example, even when the vehicle is driving in a place where the amount of image information increases, it is possible to suppress sudden increases in transmission speed, resulting in delays in transmitting compressed images. This makes it possible to prevent this from happening. As a result, the reliability of remote control of the vehicle by the remote control device can be improved.

3. Embodiment 2
In the first embodiment, a compression rate information providing device, which is a center device, provides a compression rate map, and a compressed image transmitting device, which is an in-vehicle device, uses the received compression rate map to compress an image at an appropriate compression rate. Explained the configuration for sending. In this embodiment, a compression rate information providing device, which is a center device, generates a control signal based on a compression rate map and provides it to a compressed image transmitting device, and the compressed image transmitting device transmits an image based on the control signal. The configuration for compressing and transmitting will be explained.

Note that the configuration and operation of the probe information transmitting device and the compression rate map generating device in this embodiment are the same as in Embodiment 1, and therefore description thereof will be omitted. The compression rate information providing device and the compressed image transmitting device will be described below, focusing on the differences from the first embodiment.

(1) Configuration of vehicle-mounted devices (probe information transmitter 2100, compressed image transmitter 2150) The configurations of the probe information transmitter 2100 and compressed image transmitter 2150, which are the vehicle-mounted devices of this embodiment, are the same as in the first embodiment. , will be explained with reference to FIG.

The compression rate information reply that the receiving unit 109 of the compressed image transmitting device 2150 of this embodiment receives from the compression rate information providing device 2250 includes a control signal instead of the compression rate map. The control signal is a signal that instructs to compress an image using a specific compression ratio at a planned movement position where the vehicle is scheduled to move.

In this embodiment, the receiving unit 109 is assumed to have a configuration in which it receives in advance a plurality of control signals at a plurality of planned movement positions of the vehicle. However, the receiving unit 109 may sequentially receive the control signal from the compression ratio information providing device 2250 at the planned movement position of the vehicle.

The image processing unit 111 generates a compressed image by compressing the image acquired by the image acquisition unit 102 using compression rate information specified by the control signal. Then, the wireless communication unit 103 transmits the compressed image to the remote control device.

(2) Configuration of center device (compression rate map generation device 2200, compression rate information providing device 2250) The configuration of the center device of this embodiment will be described using FIG. 11. As shown in FIG. 11, the center device of this embodiment includes a control signal generation section 208 in addition to the components of the center device shown in FIG.

The control signal generation unit 208 generates a control signal instructing to compress the image using the standard compression rate indicated by the standard compression rate information acquired by the compression rate map extraction unit 207 at the standard position.

The transmitter 204 of this embodiment transmits the compression rate information reply including the control signal generated by the control signal generator 208 to the compressed image transmitter 2150.

(3) Operations of the compression rate information providing device 2250 and the compressed image transmitting device 2150 in the compression rate map usage process The following describes the compression rate information providing device 2250 and the compressed image transmitting device 2150 of this embodiment using the flowchart of FIG. Explain the operation. Note that the compression rate map generation process of this embodiment is the same as the compression rate map generation process of Embodiment 1, and the description thereof will be omitted.

The control signal generation unit 208 of the compression rate information providing device 2250 generates a control signal instructing to compress the image using the reference compression rate information acquired by the compression rate map extraction unit 207 in S252 at the reference position ( S261).
The transmitter 204 transmits the compression rate information reply including the control signal generated in S261 to the compressed image transmitter 2150 (S253).

The receiving unit 109 of the compressed image transmitting device 2150 receives the compression rate information reply including the control signal transmitted from the compression rate information providing device 1250 (S153).
The image acquisition unit 102 acquires an image taken by the vehicle-mounted camera (S161).
The image processing unit 111 compresses the image acquired in S161 based on the control signal included in the compression rate information reply (S163).
The wireless communication unit 103 transmits the compressed image generated in S163 to the remote control device (S164).

In this embodiment, the compressed image transmitting device 2150 receives a control signal from the compression rate information providing device 2250 instead of the compression rate map, and compresses the image based on the instruction of the control signal. As a result, the compressed image transmitting device 2150 does not need to save the compression rate map or extract and obtain the reference compression rate information of the compression rate map every time the vehicle moves, thereby suppressing the processing load on the in-vehicle device. It becomes possible to do so.

4. Embodiment 3
In the first and second embodiments, the compression rate map generation device generates and updates the compression rate map using probe information including the compression rate used for image compression in the probe information transmitting device and actual transmission speed information. It was the composition. In the present invention, a configuration will be described in which a compression ratio map is generated using probe information that includes information different from that in the first and second embodiments.

(1) Configuration of in-vehicle devices (probe information transmitting device 3100, compressed image transmitting device 3150) The configurations of the probe information transmitting device 3100 and compressed image transmitting device 3150, which are in-vehicle devices of this embodiment, will be explained using FIG. . As shown in FIG. 13, the in-vehicle device of this embodiment does not include the transmission speed information acquisition unit 104. Further, the probe information transmitting device 3100 does not require the functions of the wireless communication section 103 and the image processing section 111. Since the compressed image transmitting device 3150 of this embodiment has the same configuration as the first and second embodiments, the configuration of the probe information transmitting device 3100 will be described below.

The image acquisition unit 102 of the probe information transmitting device 3100 acquires an image captured by an on-vehicle camera, as in the first and second embodiments. However, unlike the first and second embodiments, the image acquired by the image acquisition unit 102 of this embodiment is not compressed by the image processing unit 111, but is stored in the storage unit 110 as an uncompressed image.

The probe information generation unit 112 generates probe information including the position information acquired by the position information acquisition unit 101 and the uncompressed image stored in the storage unit 110.

The transmitter 108 transmits the probe information generated by the probe information generator 112 to the compression ratio map generator 3200. However, since an uncompressed image has a larger amount of data than a compressed image, the transmitting unit 108 transmits the uncompressed image using a communication method that allows large-capacity data communication, such as a wired communication method or WiFi. do.

(2) Configuration of the center device (compression rate map generation device 3200, compression rate information providing device 3250) Using FIG. Explain the configuration. As shown in FIG. 14, the control unit 203 of the center device of this embodiment realizes an image processing unit 209.

Receiving section 201 receives probe information transmitted from probe information transmitting device 3100. This probe information includes position information and uncompressed images.

The image processing unit 209 generates a compressed image by compressing the uncompressed image included in the probe information received by the receiving unit 201 using a plurality of preset compression ratios. A plurality of compression ratios used for compressing an uncompressed image in the image processing unit 209 are taken as compression ratio candidates.

The compression ratio calculation unit 205 estimates and calculates the transmission speed when each compressed image generated using a plurality of compression ratio candidates is transmitted at the position indicated by the position information. Information indicating the estimated transmission speed is assumed to be estimated transmission speed information. The compression ratio calculation unit 205 further performs corrective compression on the estimated transmission speed information that is equal to or lower than the target transmission speed information and that is the maximum estimated transmission speed information among the calculated estimated transmission speed information and regards it as the actual transmission speed information. Calculate rate information.

The storage unit 202 stores the corrected compression ratio information calculated by the compression ratio calculation unit 205 in a compression ratio map as a reference compression ratio.

According to this embodiment, the probe information transmitting device of the vehicle-mounted device does not need to acquire actual transmission speed information, so that the processing load of the vehicle-mounted device can be reduced. In addition, in this embodiment, by transmitting probe information including uncompressed images all at once in an environment where wired communication or WiFi can be used, there is no need to constantly transmit probe information using wireless communication. It becomes possible to reduce the load on the communication network.

Further, according to the present embodiment, by compressing an uncompressed image using a plurality of compression ratios, it is possible to estimate the actual transmission speed corresponding to various compression ratios. As a result, when creating multiple pieces of corrected compression ratio information that are each linked to multiple pieces of target transmission speed information under the same environmental conditions, it is possible to drive the vehicle multiple times under the same environmental conditions to obtain different target transmission speeds. It becomes possible to estimate the plurality of pieces of corrected compression ratio information from blow part information and uncompressed images collected in one run without collecting probe information having speed information.

5. Other Inventions In the embodiments described above, the compression ratio map generation device generated the compression ratio map using probe information provided from the probe information transmission device. However, the compression rate map may be generated without using the probe information transmitted from the probe information transmitting device.

For example, a compression rate map generation device uses a three-dimensionally visualized simulation space to generate a simulated image in place of the image captured by the on-vehicle camera, and uses the simulated image to determine the compression rate of the image. You may. In this method, a simulated image is compressed using various compression rate candidates, and the transmission speed when the image compressed using a plurality of compression rate candidates is transmitted is simulated. Then, the compression rate candidate whose transmission rate information obtained through the simulation is equal to or less than the target transmission rate information, and which is the smallest, is set as reference compression rate information and stored as being included in the compression rate map.

7. Summary The characteristics of the compression ratio map generation device, compression ratio information providing device, and compressed image transmission device in each embodiment of the present invention have been described above.

Since the terms used in each embodiment are merely examples, they may be replaced with synonymous terms or terms that include synonymous functions.

The block diagram used to explain the embodiment is a diagram in which the configuration of the device is classified and organized by function. Blocks representing respective functions are realized by any combination of hardware or software. Further, since the block diagram shows the functions, it can be understood as a disclosure of the invention of the method and the invention of the program that implements the method.

Regarding the functional blocks that can be understood as processes, flows, and methods described in each embodiment, the order may be changed unless there is a restriction such that one step uses the result of another step before it. Good too.

The terms first, second, to Nth (N is an integer) used in each embodiment and the claims are used to distinguish two or more configurations or methods of the same type. , it does not limit the order or superiority.

Each embodiment is based on a probe information transmitting device and a compressed image transmitting device mounted on a vehicle, but the present invention does not apply to a dedicated or general-purpose device other than a vehicle, unless otherwise specified in the claims. It also includes.

Each embodiment has been described on the premise that the probe information transmitting device and the compressed image transmitting device disclosed in each embodiment are mounted on a vehicle, but it may also be assumed that the device is carried by a pedestrian.

Further, examples of the configuration of the device of the present invention include the following.
Examples of the form of parts include semiconductor elements, electronic circuits, modules, and microcomputers.
Examples of semi-finished products include electronic control units (ECUs) and system boards.
Examples of finished products include mobile phones, smartphones, tablets, personal computers (PCs), workstations, and servers.
Other devices include devices with communication functions, such as video cameras, still cameras, and car navigation systems.

Further, necessary functions such as an antenna and a communication interface may be added to each device.

It is assumed that the compression rate map generation device and the compression rate information providing device of the present invention are used for the purpose of providing various services. In providing such services, the apparatus of the present invention is used, the method of the present invention is used, and/or the program of the present invention is executed.

In addition, the present invention can be realized not only by dedicated hardware having the configuration and functions described in each embodiment, but also by a program for realizing the present invention recorded on a recording medium such as a memory or a hard disk, and a program for realizing the present invention recorded on a recording medium such as a memory or a hard disk. It can also be realized in combination with general-purpose hardware having an executable dedicated or general-purpose CPU, memory, and the like.

A program stored in a non-transitional physical recording medium of dedicated or general-purpose hardware (for example, an external storage device (hard disk, USB memory, CD/BD, etc.) or an internal storage device (RAM, ROM, etc.)) is It can also be provided to dedicated or general-purpose hardware via a recording medium or from a server via a communication line without using a recording medium. This allows us to always provide the latest functionality through program upgrades.

The probe information transmitting device and compressed image transmitting device of the present invention have been described as electronic control devices mainly installed in automobiles. It is possible to apply to all moving bodies.
Furthermore, it is applicable to devices used for various purposes, such as mobile phones, tablets, and game consoles.

1100, 2100 probe information transmitting device, 1150, 2150 compressed image transmitting device, 1200, 2200 compression rate map generation device, 1250, 2250 compression rate information providing device, 102 image acquisition unit, 103 wireless communication unit, 108 transmitting unit, 109 reception unit, 111 image processing unit, 201 reception unit, 202 compression rate map storage unit, 204 transmission unit, 205 compression rate calculation unit, 207 compression rate map extraction unit, 208 control signal generation unit

Claims (17)

A compression rate map generation device (1200, 2200) that receives probe information from a probe information transmission device (1100, 2100) mounted on a mobile body and generates a compression rate map,
The image is generated by compressing the image using position information indicating the position of the moving object, compression rate information indicating the compression rate used for compressing the image by the probe information transmitting device, and the compression rate information. a receiving unit (201) that receives the probe information including actual transmission speed information indicating the transmission speed when the compressed image is transmitted at the position;
If the actual transmission rate information is greater than or equal to the target transmission rate information indicating the target value of the transmission rate at the position, the actual transmission rate is determined using the actual transmission rate information, the target transmission rate information, and the compression rate information. a compression rate calculation unit (205) that calculates corrected compression rate information such that the information is equal to or less than the target transmission rate information;
a compression rate map storage unit (202) that stores the compression rate map including the position information and reference compression rate information that is the compression rate information or the corrected compression rate information;
A compression ratio map generation device comprising: When the actual transmission rate information is less than or equal to the target transmission rate information, the compression rate calculation unit calculates the corrected compression that indicates a minimum compression rate among the compression rates at which the actual transmission rate information is less than or equal to the target transmission rate information. calculate rate information,
The compression ratio map generation device according to claim 1. The probe information further includes photographing environment information indicating an environment in which the image was photographed,
The compression rate map further includes the shooting environment information.
The compression ratio map generation device according to claim 1. The photographing environment information indicates a moving speed of the moving body.
The compression ratio map generation device according to claim 3. The shooting environment information indicates weather and/or time;
The compression ratio map generation device according to claim 3. The photographing environment information indicates the position of the photographing device that photographed the image.
The compression ratio map generation device according to claim 3. The target transmission rate information includes first target transmission rate information and second target transmission rate information,
The compression rate map is
the position information, the first target transmission rate information , first reference compression rate information such that the actual transmission rate information is less than or equal to the first target transmission rate information , the second target transmission rate information, and the actual transmission rate information; second reference compression rate information in which the transmission rate information is equal to or less than the second target transmission rate information;
The compression ratio map generation device according to claim 1. A compression rate map generation method executed by a compression rate map generation device (1200, 2200) that receives probe information from a probe information transmission device (1100, 2100) mounted on a mobile object and generates a compression rate map, ,
The image is generated by compressing the image using position information indicating the position of the moving object, compression rate information indicating the compression rate used for compressing the image by the probe information transmitting device, and the compression rate information. receiving the probe information including actual transmission speed information indicating the transmission speed when the compressed image is transmitted at the position;
If the actual transmission rate information is greater than or equal to the target transmission rate information indicating the target value of the transmission rate at the position, the actual transmission rate is determined using the actual transmission rate information, the target transmission rate information, and the compression rate information. Calculate corrected compression rate information such that the information is less than or equal to the target transmission rate information,
storing the compression rate map including the position information and reference compression rate information that is the compression rate information or the corrected compression rate information;
Compression ratio map generation method. A compression rate map generation program that can be executed by a compression rate map generation device (1200, 2200) that receives probe information from a probe information transmission device (1100, 2100) mounted on a mobile object and generates a compression rate map. ,
The image is generated by compressing the image using position information indicating the position of the moving object, compression rate information indicating the compression rate used for compressing the image by the probe information transmitting device, and the compression rate information. receiving the probe information including actual transmission speed information indicating the transmission speed when the compressed image is transmitted at the position;
If the actual transmission rate information is greater than or equal to the target transmission rate information indicating the target value of the transmission rate at the position, the actual transmission rate is determined using the actual transmission rate information, the target transmission rate information, and the compression ratio information. Calculate corrected compression rate information such that the information is less than or equal to the target transmission rate information,
storing the compression rate map including the position information and reference compression rate information that is the compression rate information or the corrected compression rate information;
Compression ratio map generator. A compression rate information providing device (1250) that receives a compression rate information request from a compressed image transmitting device (1150) mounted on a mobile object and transmits necessary information,
a compression rate map storage unit (202) that stores a compression rate map including reference position information indicating a reference position and reference compression rate information indicating a compression rate used for compressing an image at the reference position;
a receiving unit (201) that receives the compression rate information request including scheduled position information indicating a scheduled movement position of the mobile body;
a compression rate map extraction unit (207) that acquires the reference compression rate information at the reference position corresponding to the planned position information from the compression rate map storage unit;
a transmitter (204) that transmits a compression rate information reply including the reference compression rate information;
Equipped with
The reference compression rate information includes transmission rate information indicating a transmission rate at which a compressed image generated by compressing an image using the reference compression rate information is transmitted at the reference position. Indicates the compression rate that is less than the target transmission rate information indicating the target value,
Compression ratio information providing device. A compression rate information providing device (2250) that receives a compression rate information request from a compressed image transmitting device (2150) mounted on a mobile object and transmits necessary information,
a compression rate map storage unit (202) that stores a compression rate map including reference position information indicating a reference position and reference compression rate information indicating a compression rate used for compressing an image at the reference position;
a receiving unit (201) that receives the compression rate information request including scheduled position information indicating a scheduled movement position of the mobile body;
a compression rate map extraction unit (207) that acquires the reference compression rate information at the reference position corresponding to the planned position information from the compression rate map storage unit;
a control signal generation unit (208) that generates a control signal instructing to compress an image at the reference position using the reference compression rate information;
a transmitter (204) that transmits a compression rate information reply including the control signal;
A compression ratio information providing device comprising: The reference compression rate information includes transmission rate information indicating a transmission rate at which a compressed image generated by compressing an image using the reference compression rate information is transmitted at the reference position. Indicates the compression rate that is less than the target transmission speed information indicating the target value,
The compression ratio information providing device according to claim 11 . The compression rate map further includes first target transmission rate information and second target transmission rate information indicating the target value of the transmission rate at the reference position, and the first target transmission rate information and the second target transmission rate information. and the reference compression ratio information associated with each piece of speed information,
The compression rate map extracting unit estimates the available bandwidth of the compressed image transmitting device at the planned movement position, and the first target transmission rate information is configured such that the first target transmission rate information does not exceed the estimated available bandwidth and the second target transmission rate If the information exceeds the available bandwidth, acquiring the reference compression rate information associated with the first target transmission rate information;
The compression ratio information providing device according to claim 10 or 11. The compression rate map further includes first target transmission rate information and second target transmission rate information indicating the target value of the transmission rate at the reference position, and the first target transmission rate information and the second target transmission rate information. and the reference compression ratio information associated with each piece of speed information,
The compression rate map extraction unit determines the priority of the image acquired at the planned movement position, and if the priority is higher than a predetermined priority, the compression rate map extraction unit determines the priority of the image acquired at the planned movement position, and if the priority is higher than a predetermined priority, the compression rate map is higher than the second target transmission speed information. obtaining the reference compression rate information associated with the first target transmission rate information;
The compression ratio information providing device according to claim 10 or 11. The compression rate information request further includes estimated photographing environment information estimating the environment in which the image is photographed at the planned movement position,
The compression rate map further includes reference photographing environment information indicating a photographing environment of an image photographed at the reference position,
The compression rate map extraction unit acquires the reference compression rate information in the shooting environment corresponding to the estimated shooting environment information.
The compression ratio information providing device according to claim 10 or 11. A compressed image transmitting device (1150) mounted on a mobile object,
a scheduled position information acquisition unit (106) that acquires scheduled position information indicating a scheduled movement position of the mobile body;
a transmitting unit (108) that transmits a compression rate information request including the scheduled position information to a compression rate information providing device (1250);
a receiving unit (109) that receives from the compression rate information providing device a compression rate information reply including standard compression rate information indicating a compression rate to be used for compressing an image at a standard position corresponding to the scheduled position information;
an image acquisition unit (102) that acquires an image around the moving object;
an image processing unit (111) that generates a compressed image by compressing the image using the reference compression rate information;
a wireless communication unit (103) that transmits the compressed image at the planned movement position;
Equipped with
The reference compression rate information is a compression rate at which actual transmission rate information indicating a transmission rate when transmitting the compressed image at the planned movement position is equal to or less than a target transmission rate indicating a target value of the transmission rate at the reference position. shows,
Compressed image transmitter. The compression rate information request further includes estimated photographing environment information estimating the environment in which the image is photographed at the planned movement position,
The compression rate information reply includes the reference compression rate information according to the estimated shooting environment information.
The compressed image transmitting device according to claim 16.