Graphing Device, Graphing Method, and Program

Abstract

To provide a charting device, a charting method and a program which can efficiently chart a compartment line.SOLUTION: A charting device comprises: storage means which stores charted data including data obtained by charting one or more compartment lines of a road by using measurement data obtained by measuring the road from a vehicle traveling on the road; image generation means which sets a center line of a region sectioned by one compartment line included in the charted data or the plurality of compartment lines included in the charted data as a reference line and generates a contraction image by converting the charted data such that the compartment line is contracted in an extension direction of the reference line; and display means which displays the contraction image.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present invention relates to a mapping device, a mapping method, and a program.

Background Art

[0002] For constructing a system for automatically driving a vehicle, construction of a high-precision road database including information on road lane lines is required. Conventionally, in order to construct such a database, an automobile equipped with an imaging device has been driven to acquire an image of a road, and an operator has grasped the position of the lane line from the image of the road and input it into the database.

[0003] Patent Document 1 describes a road surface marking map generation device that converts an image of a road into an orthoimage and displays it, and sets lane boundary line data by an operator making an instruction input with respect to the road surface markings included in the orthoimage.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, in a road database for automatic driving, the accuracy required for mapping data obtained by mapping road information such as lane lines is higher in the transverse direction than in the extending direction of the road. Therefore, when the user makes an instruction input, if the orthoimage is displayed with a 1:1 aspect ratio to ensure the resolution required in the transverse direction, it will be displayed with an unnecessarily high resolution in the extending direction. In this case, the user has to update the displayed road area in the extending direction many times, resulting in a problem of reduced work efficiency.

[0006] The present invention has been made to solve the above-described problems, and an object thereof is to provide a plotting device, a plotting method, and a program that enable efficient plotting of lane lines.

Means for Solving the Problems

[0007] The plotting device according to the present invention includes storage means for storing plotting data including data obtained by plotting one or more lane lines of a road using measurement data obtained by measuring the road from a vehicle traveling on the road, and one lane line included in the plotting data, or a center line of an area partitioned by a plurality of lane lines included in the plotting data is set as a reference line, and image generation means for generating a shortened image by converting the plotting data so that the lane line is reduced in the extending direction of the reference line, and display means for displaying the shortened image.

[0008] Further, in the plotting device according to the present invention, it is preferable that the storage means further stores a road image that is an orthographic projection of the measurement data, and the image generation means further generates a shortened image by reducing the road image in the extending direction of the reference line.

[0009] The plotting device according to the present invention includes storage means for storing a road image that is an orthographic projection of measurement data obtained by measuring a road from a vehicle traveling on the road, and a locus of the vehicle when the measurement data is measured, and image generation means for generating a shortened image by reducing the road image in the extending direction of the locus as a reference line, display means for displaying the shortened image, storage means for storing a plurality of points on a single lane line designated by a user based on the shortened image as designated points, and calculation means for calculating a lane line based on the plurality of designated points.

[0010] Further, in the plotting device according to the present invention, it is preferable that the image generation means sets a display target area, which is a rectangular geographical area displayed as a shortened image, so that the longitudinal direction of the display target area coincides with the extending direction of the reference line, and generates a shortened image for the display target area.

[0011] Further, in the mapping device according to the present invention, it is preferable that the image generation means generates a reduced image by applying a coordinate transformation that converts the reference line into a straight line and reduces the straight line in the extending direction to the mapping data.

[0012] Further, in the mapping device according to the present invention, it is preferable that the image generation means converts the mapping data so that the reduction is made at a ratio of the accuracy required in the extending direction of the road to the accuracy required in the transverse direction of the road in the mapping data.

[0013] The mapping method according to the present invention is a mapping method executed by a mapping device, including storing mapping data including data obtained by mapping one or more lane lines of a road using measurement data obtained by measuring the road from a vehicle traveling on the road, setting, as a reference line, a single lane line included in the mapping data or a center line of a region partitioned by a plurality of lane lines included in the mapping data, generating a reduced image by converting the mapping data so that the lane lines are reduced in the extending direction of the reference line, and displaying the reduced image.

[0014] The program according to the present invention is a program for a computer including a storage unit, and the storage unit stores mapping data including data obtained by mapping one or more lane lines of a road using measurement data obtained by measuring the road from a vehicle traveling on the road, sets, as a reference line, a single lane line included in the mapping data or a center line of a region partitioned by a plurality of lane lines included in the mapping data, generates a reduced image by converting the mapping data so that the lane lines are reduced in the extending direction of the reference line, and causes the computer to display the reduced image.

Advantages of the Invention

[0015] The mapping device, mapping method, and program according to the present invention enable efficient mapping of lane lines.

Brief Description of the Drawings

[0016]

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Modes for Carrying Out the Invention

[0017] Hereinafter, various embodiments of the present invention will be described with reference to the drawings. It should be noted that the technical scope of the present invention is not limited to those embodiments, but extends to the invention described in the claims and its equivalents.

[0018] FIG. 1 is a schematic diagram for explaining the outline of a mapping device according to the present invention. The mapping device acquires measurement data obtained by measuring a road using an MMS (Mobile Mapping System) mounted on a vehicle traveling on the road, and a trajectory T along which the vehicle has traveled on the road. Based on the measurement data, the mapping device generates and stores a road image R showing the road included in the measured geographical area. The mapping device generates a display image D including a portion included in a display target area A designated by a user in the road image R, and displays it to the user. The display target area A can be a rectangular area extending along the extending direction of the road, and the display image D can be an image obtained by reducing the portion included in the display target area A in the road image R in the extending direction.

[0019] The user operates the mapping device to specify a plurality of points on a demarcation line that demarcates one or more lanes on the road, such as a center line E1, a lane boundary line E2, and an outer lane line E3, in the display image D. The mapping device stores the specified plurality of points as specified points P. The user repeatedly specifies points on the demarcation line while moving the display target area A along the extending direction of the road. As a result, the specified points P are stored for the entire road included in the road image R.

[0020] The mapping device sets auxiliary points Q whose distances from the trajectory T are included in a distance range based on the distances from each specified point P to the trajectory T, and calculates a demarcation line candidate L based on the specified points P and the auxiliary points Q. The mapping device converts the demarcation line candidate L so as to be reduced in the extending direction of the road and draws it on the display image D. Further, the mapping device generates and outputs mapping data Z including the specified points P, the auxiliary points Q, and the demarcation line candidate L.

[0021] In this way, the mapping device sets the auxiliary point Q based on the specified point P and the trajectory T. Therefore, the user does not need to specify a point on the dividing line corresponding to the auxiliary point Q, and the workload of the user is reduced. Further, the auxiliary point Q is set to be included in a distance range based on the distance from the specified point P on the dividing line specified by the user to the trajectory T. Therefore, even when the vehicle travels outside the center of the lane or when the lane width is not constant, the possibility that the auxiliary point Q set by the mapping device is located on the dividing line becomes high, and the dividing line is mapped with high accuracy.

[0022] Further, as the display image D, the mapping device displays a reduced image obtained by reducing the road image R in the extending direction of the road and converting the dividing line candidate L so as to be reduced in the extending direction of the road. Thereby, since the display image D includes a wide range of roads, the number of times the user moves the display target area A along the extending direction of the road is reduced, and the work efficiency is improved. That is, the dividing line is efficiently mapped.

[0023] The above description of FIG. 1 is merely for deepening the understanding of the content of the present invention. The present invention is specifically implemented in various embodiments described below, and may be implemented by various modifications without substantially exceeding the principle of the present invention. All such modifications are included in the scope of the present invention and the disclosure of this specification.

[0024] FIG. 2 is a diagram showing a schematic configuration of the mapping system 1 according to the embodiment. The mapping system 1 includes a vehicle 2, a mapping device 3, and an external device 4.

[0025] The vehicle 2 is an automobile equipped with an MMS 21 and traveling on a road. The MMS 21 includes a GNSS (Global Navigation Satellite System) sensor, an inertial measurement device, a laser measuring device, a camera, and a control terminal for controlling each device. The MMS 21 is an example of road measurement means, and any road measurement means may be used as long as it includes a GNSS sensor and / or an inertial measurement device, a laser measuring device and / or a camera, and a control terminal for controlling each device.

[0026] The GNSS sensor and the inertial measurement device generate the position information and the attitude information of the vehicle 2 at predetermined time intervals while the vehicle 2 is running. The control terminal generates time-series vehicle position data indicating the three-dimensional vehicle position of the vehicle 2 for each certain moving distance or each certain time interval based on the position information and the attitude information. Hereinafter, data indicating a line connecting adjacent vehicle positions in the generated vehicle position data may be referred to as a trajectory.

[0027] While the vehicle 2 is running, the laser measuring device sequentially irradiates the road with laser light while changing the irradiation direction, and detects the light reflected on the road. The laser measuring device generates data indicating the relative position of the reflection point based on the irradiation direction of the laser and the time from irradiating the laser light to detecting the reflected light. The control terminal converts the relative position into an absolute position based on the data indicating the relative position of the reflection point and the position information and the attitude information at the time when the data is generated, and generates data of a three-dimensional point cloud indicating the shape of the road.

[0028] Also, while the vehicle 2 is running, the camera sequentially images the road and generates an imaging image. The camera is fixed to the laser measuring device, and the correspondence between each irradiation direction and each pixel of the imaging image is determined. Thereby, the control terminal can generate measurement data in which the pixel value of the corresponding pixel is associated with each point constituting the three-dimensional point cloud. Hereinafter, the three-dimensional point cloud associated with the pixel value may be referred to as a colored point cloud.

[0029] The control terminal transmits the generated vehicle position data, the imaging image, and the measurement data which is the colored point cloud to the visualization device 3.

[0030] The visualization device 3 is a device that visualizes the lane lines that demarcate one or more lanes on the road, and is an information processing device such as a PC (Personal Computer) or a server. The visualization device 3 includes a storage unit 31, a communication unit 32, a display unit 33, an operation unit 34, and a processing unit 35.

[0031] The storage unit 31 is a configuration for storing data and programs, and includes, for example, a semiconductor memory. The storage unit 31 stores an operating system program, a driver program, an application program, data, etc. used in the processing by the processing unit 35. The program is installed by a setup program from a computer-readable and non-transitory portable storage medium such as a CD (Compact Disc)-ROM (Read Only Memory). Note that the storage unit 31 is an example of storage means.

[0032] The communication unit 32 is a configuration for enabling the visualization device 3 to communicate with other devices, and includes a communication interface circuit. The communication interface circuit included in the communication unit 32 is, for example, a communication interface circuit such as a wired LAN (Local Area Network), a wireless LAN, or an LTE (Long Term Evolution). The communication unit 32 supplies the data received from other devices to the processing unit 35, and transmits the data supplied from the processing unit 35 to other devices.

[0033] The display unit 33 is a configuration for displaying images, and includes, for example, a liquid crystal display or an organic EL (Electro-Luminescence) display. The display unit 33 displays an image based on the display data supplied from the processing unit 35.

[0034] The operation unit 34 is a configuration for receiving input operations on the visualization device 3, and includes, for example, a keyboard, a keypad, or a mouse. The operation unit 34 may include a touch panel integrated with the display unit 33. The operation unit 34 generates a signal corresponding to the input operation and supplies it to the processing unit 35.

[0035] The processing unit 35 is configured to comprehensively control the operation of the visualization device 3, and includes one or more processors (processing circuits) and their peripheral circuits. The processing unit 35 includes, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an LSI (Large Scale Integration), or an ASIC (Application Specific Integrated Circuit), etc. The processing unit 35 may include a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), etc. The processing unit 35 executes processing based on the program stored in the storage unit 31, and controls the operation of each component of the visualization device 3 so that the processing is executed appropriately.

[0036] The processing unit 35 includes an acquisition unit 351, a road image generation unit 352, a condition setting unit 353, a display image generation unit 354, a display processing unit 355, a candidate calculation unit 356, and an output unit 357. Each of these units is a functional module realized by a program executed by the processing unit 35. Each of these units may be implemented in the visualization device 3 as firmware. Note that the display image generation unit 354 functions as image generation means. The display processing unit 355 functions as display means. The candidate calculation unit 356 functions as calculation means.

[0037] The external device 4 is a device that is the output destination of the visualization data obtained by visualizing the partition lines, and is, for example, an information processing device such as a server. The external device 4 receives and stores at least the visualization data generated by the visualization device 3.

[0038] FIG. 3 is a diagram showing an example of the data structure of the point group table T1 stored in the storage unit 31. The point group table T1 shows colored point group data.

[0039] The point cloud table T1 stores by correlating with each other latitude, longitude, altitude, distance, pixel value, etc. Latitude, longitude, and altitude are information indicating the three-dimensional positions of the points constituting the three-dimensional point cloud generated by the laser measuring device of the MMS21. The distance is the distance from the laser measuring device to each point when each point is generated by the laser measuring device. The pixel value is the pixel value of the pixel corresponding to each point of the three-dimensional point cloud among the pixels constituting the captured image generated by the camera of the MMS21, and is, for example, an RGB value.

[0040] The data of the point cloud table T1 is acquired from the MMS21 by the plotting device 3 and stored in the storage unit 31.

[0041] FIG. 4 is a diagram showing an example of the data structure of the input point table T2 stored in the storage unit 31. The input point table T2 shows the point sequence data of a plurality of input points (referred to as designated points or auxiliary points) constituting the partition line candidate. The plotting device 3 calculates a line based on the plurality of input points stored in the input point table T2 as a partition line candidate.

[0042] The input point table T2 stores by correlating with each other point number, type, partition line number, latitude, longitude, altitude, etc. The point number is information for identifying each input point and defining the order of the input points. The type is information indicating whether the input point is of the type of designated point or auxiliary point. The partition line number is identification information for identifying the partition line corresponding to each input point. The same partition line number is assigned to the input points constituting the same partition line. Latitude, longitude, and altitude are information indicating the three-dimensional positions of the input points. By connecting the input points associated with the same partition line number in the order of the point numbers, a partition line candidate is calculated.

[0043] Among the data of the input point table T2, the data of the designated points is generated manually by the user or automatically by the plotting device 3. Among the data of the input point table T2, the data of the auxiliary points is generated automatically by the plotting device 3.

[0044] FIG. 5 is a diagram showing an example of the data structure of the diagram data T3 stored in the storage unit 31. The diagram data T3 is graphic data indicating a section line candidate calculated by the diagramming device 3. The diagram data T3 stores the section line number, coordinates, etc. in association with each other. The section line number is identification information for identifying the section line. The coordinates are information indicating the latitude, longitude, and altitude of each input point constituting the section line. Hereinafter, the section line candidate will be described as a polyline connecting each input point.

[0045] The diagram data T3 is generated by the diagramming device 3 based on the data in the input point table T2.

[0046] FIGS. 6 and 7 are flowcharts showing the flow of the diagramming process executed by the diagramming device 3. The diagramming process is realized by the processing unit 35 that executes the program stored in the storage unit 31 cooperating with each component of the diagramming device 3.

[0047] The diagramming process includes an initial setting process (steps S11 - S13), a display process (steps S14 - S15), a reception process (steps S21 - S27), and an output process (steps S28 - S29). In the initial setting process, acquisition of data necessary for displaying the road image on the display unit 33 and setting of display conditions are executed. In the display process, a process of displaying a display image including a part of the road image on the display unit 33 is executed. In the reception process, an instruction from the user for editing the section line candidate is received based on the displayed display image, and when an instruction is given, a process corresponding to the instruction is executed. When the reception process is executed, since the input points, section line candidates, or display conditions of the display image included in the display image are changed, the display process is executed again, and the display image with the changes reflected is displayed. When the calculation of the section line candidate is completed by repeating the reception process and the display process, the output process is executed according to the output instruction from the user. In the output process, a process of outputting the diagram data is executed.

[0048] Referring to FIG. 6, first, the acquisition unit 351 acquires measurement data including a trajectory, a colored point cloud, and a captured image from the MMS 21 via the communication unit 32 (step S11). The acquisition unit 351 stores the acquired measurement data in the storage unit 31.

[0049] Next, the road image generation unit 352 generates a road image for each of a plurality of preset scales (step S12). The road image is an image generated by projecting each point included in the colored point cloud onto an arbitrary plane. Hereinafter, the road image will be described as an orthographic projection image obtained by orthographically projecting the colored point cloud onto a horizontal plane.

[0050] The road image generation unit 352 sets a two-dimensional geographical area divided by latitude and longitude so that each point of the colored point cloud is included. Subsequently, for each of the plurality of scales, the road image generation unit 352 determines the number of pixels in the width and height of the road image corresponding to the geographical area, and sets a projection function for orthographically projecting the latitude and longitude onto the coordinates (pixel positions) of the road image. Subsequently, the road image generation unit 352 calculates the pixel position that is the projection destination of each point in the point cloud table T1 by the set projection function, and generates a road image by setting the pixel value associated with each point as the pixel value of the projection destination pixel. When the projection destinations of multiple points are the same pixel, the point with the smallest distance from the laser range finder among the multiple points can be used as the projection source, or the representative value of the pixel values associated with the multiple points can be used as the pixel value of the projection destination pixel.

[0051] Next, the condition setting unit 353 receives the setting of the display conditions by the user (step S13). The display conditions include the scale of the display image, the center position of the display target area to be displayed as the display image, the width and height of the window in which the road image is displayed on the display unit 33, the display mode, and the reduction ratio in the case of the reduced display mode. The display mode is either a reduced display mode in which the road image is reduced and displayed, or a non-reduced display mode in which the road image is displayed without reduction. Note that the condition setting unit 353 may omit the setting of the display conditions by the user and set the display conditions to the initial values stored in advance. The scale E and the reduction ratio F are each set within the range of 0 < E < 1 and 0 < F < 1.

[0052] Next, the display image generation unit 354 determines whether it is in the non-reduced display mode or the reduced display mode (step S14).

[0053] When it is determined that it is in the non-reduced display mode (step S14-No), the display image generation unit 354 generates a display image that has not been reduced and rotated (step S14a). First, the display image generation unit 354 calculates a display target area that has not been enlarged and rotated.

[0054] FIG. 8(A) is a schematic diagram for explaining an example of the calculation of the display target area in the non-reduced display mode. The display image generation unit 354 sets a display target area A1 in the geographical area corresponding to the road image R based on the center position C, the width and height of the window W, and the scale E, which are the display conditions set in step S13. For example, the display image generation unit 354 sets, as the display target area A1, a rectangular area that has the center position C as the center, has a preset inclination, and has a width W1 and a height H1. The width W1 and the height H1 of the display target area A1 in the road image R with the scale E are equal to the width and height of the window W. The width and height of the window W are the number of pixels in the horizontal and vertical directions of the window W, respectively. Hereinafter, the window W will be described as a horizontally long rectangle whose width is greater than or equal to its height. Note that the actual width W1 and height H1 are values obtained by dividing the actual width and height of the window W by the scale E, respectively.

[0055] Subsequently, the display image generation unit 354 extracts the portion included in the display target area A1 from the road image R at scale E. Further, the display image generation unit 354 extracts the data of the input points included in the display target area A1 from the input point table T2. Further, the display image generation unit 354 extracts the data of the candidate division lines included in the display target area A1 from the graphic data T3. The display image generation unit 354 generates a display image by superimposing and drawing the extracted input points and the figures indicating the candidate division lines L1 and L2 on the extracted road image.

[0056] When it is determined in step S14 that the reduced display mode is selected (step S14 - Yes), the display image generation unit 354 generates a reduced and rotated display image (step S14b). Hereinafter, the display image generated in the reduced display mode may be referred to as a reduced image. First, the display image generation unit 354 calculates an enlarged and rotated display target area.

[0057] FIG. 8(B) is a schematic diagram for explaining an example of calculating the display target area in the reduced display mode. The display image generation unit 354 sets a display target area A2 in the geographical area corresponding to the road image R based on the center position C, the width and height of the window W, the scale E, and the reduction ratio F, which are the display conditions set in step S13. For example, the display image generation unit 354 sets a rectangular area having the center position C as the center and having a width W2 and a height H2 as the display target area A2. The width W2 of the display target area A2 in the road image R at scale E is a value obtained by dividing the width of the window W by the reduction ratio F. The height H2 of the display target area A2 in the road image R at scale E is equal to the height of the window W. That is, the display target area A2 in the reduced display mode has a shape obtained by enlarging the display target area A1 in the non-reduced display mode so that the width is the reciprocal multiple of the reduction ratio E. Note that the actual width W2 is a value obtained by dividing the actual width of the window W by the reduction ratio F and the scale E, and the actual height H2 is a value obtained by dividing the actual height of the window W by the scale E.

[0058] Subsequently, the display image generation unit 354 sets the section line candidate in the vicinity of the center position C as the reference line. For example, the display image generation unit 354 calculates the distance between each section line candidate included in a predetermined range from the center position C and the center position C, and sets the section line candidate with the smallest calculated distance as the reference line. In the example shown in FIG. 8(B), among the section line candidates L1 and L2, the section line candidate L1 is specified as the reference line. Subsequently, the display image generation unit 354 calculates the extension direction of the reference line in the vicinity of the center position C. For example, the display image generation unit 354 calculates the inclination Δ of the reference line based on the input point closest to the center position C among the input points constituting the reference line and the input point adjacent to the input point, and calculates the direction indicated by the inclination Δ as the extension direction of the reference line.

[0059] FIG. 9(A) is a schematic diagram for explaining an example of calculating the inclination of the reference line. The display image generation unit 354 specifies the input point B0 closest to the center position C among the input points constituting the section line candidate that is the reference line. The display image generation unit 354 -1 and B +1 adjacent to the front and back of the input point B0. The display image generation unit 354 calculates the inclination ΔA of the straight line passing through the input points B -1 and B +1 as the inclination Δ of the reference line.

[0060] FIG. 9(B) is a schematic diagram for explaining another example of calculating the inclination of the reference line. The display image generation unit 354 specifies the input point B0 closest to the center position C among the input points constituting the section line candidate that is the reference line. The display image generation unit 354 specifies two input points B -2 and B -1 adjacent to the front of the input point B0, and two input points B +1 and B +2 adjacent to the back of the input point B0. The display image generation unit 354 calculates the inclination ΔB1 of the straight line passing through the input points B -2 and B0, the inclination ΔB2 of the straight line passing through the input points B -1 and B +1 , and the inclination ΔB3 of the straight line passing through the input points B0 and B +2Calculate the slope ΔB3 of the straight line passing through and. The display image generation unit 354 calculates the average value of ΔB1, ΔB2, and ΔB3 as the slope Δ of the reference line.

[0061] FIG. 9(C) is a schematic diagram for explaining another example of the method for calculating the slope of the reference line. The display image generation unit 354 identifies the input point B0 closest to the center position C among the input points constituting the candidate section line that is the reference line. The display image generation unit 354 identifies two input points B -2 and B -1 adjacent to the front of the input point B0, and two input points B +1 and B +2 adjacent to the rear of the input point B0. The display image generation unit 354 linearly approximates the identified input points B -2 、B -1 、B0、B +1 and B +2 by the least squares method, and calculates the slope ΔC of the approximate straight line as the slope Δ of the reference line. Note that the display image generation unit 354 may identify one or three or more input points as the input points adjacent to the front and rear of the input point B0, respectively.

[0062] Returning to FIG. 8(B), the display image generation unit 354 rotates the display target area A2 so that the inclination in the width direction coincides with the stretching direction corresponding to the inclination Δ of the reference line.

[0063] Subsequently, in the same manner as in step S14a, the display image generation unit 354 extracts the portion included in the display target area A2 from the road image R at scale E, and reduces it in the extending direction of the reference line at reduction ratio F. Further, the display image generation unit 354 extracts the data of the input points included in the display target area A2 from the input point table T2, and converts the coordinate values (referring to latitude, longitude, and altitude) of each input point so as to be reduced and displayed in the extending direction of the reference line at reduction ratio F. Further, the display image generation unit 354 extracts the division line candidates L1 and L2 included in the display target area A2 from the visualization data T3, and converts the coordinate values of each input point so as to be reduced and displayed in the extending direction of the reference line at reduction ratio F. That is, the display image generation unit 354 performs, on each of these coordinate values, conversion by the projection function set in step 12, the same rotation as that applied to the display target area, and translation corresponding to the reduction in the width direction applied to the display target area, to convert these coordinate values. The display image generation unit 354 generates a reduced image for the display target area A2 by superimposing and drawing on the extracted road image the input points with their coordinate values converted and the figures indicating the division line candidates L1 and L2.

[0064] In this way, in the reduced display mode, the display image generation unit 354 rotates the display target area so that the longitudinal direction of the display target area coincides with the extending direction of the reference line. Further, the display image generation unit 354 converts the visualization data included in the display target area so that the input points and the division line candidates are reduced and displayed in the extending direction of the reference line. Generally, when the user inputs a specified point for the division line of the display target area, the user moves the display target area in the extending direction of the road and inputs another specified point. Therefore, the user has to repeatedly perform an instruction to move the display target area in the extending direction of the road (for example, an operation of dragging the mouse). On the other hand, when the reduced image is displayed, since the user can input specified points for the division lines in a wide range with one setting of the display target area, the number of times of moving the display target area is reduced, and the working efficiency of the user is improved.

[0065] In the case of the reduced image, since reduction based on the reduction rate is not performed in the transverse direction of the road that is orthogonal to the extending direction of the reference line, even if the user inputs a specified point while viewing the reduced image, the accuracy of the division lines in the transverse direction will not be degraded by the reduction based on the reduction rate. Generally, in the drawing data of the division lines, higher accuracy is required in the transverse direction of the road than in the extending direction of the road. Therefore, by preventing the degradation of the accuracy in the transverse direction, it becomes easier to generate drawing data that meets the accuracy requirements.

[0066] Note that the display image generation unit 354 may reduce the road image and convert the drawing data using, as the reduction rate, the ratio of the accuracy required in the extending direction of the road to the accuracy required in the transverse direction of the road in the drawing data. Thereby, since the allowable error on the reduced image is the same in the transverse direction and the extending direction, it becomes easier for the operator to input a specified point while considering the accuracy requirements.

[0067] In step S14b, the display image generation unit 354 may set the center line of the area partitioned by a plurality of division line candidates as the reference line. In this case, the display image generation unit 354 identifies the two division line candidates that are closest to the center position C among the division line candidates. The display image generation unit 354 generates a center line, which is a set of points having equal distances from the two division line candidates, and sets it as the reference line. The display image generation unit 354 sets input points at predetermined intervals on the reference line, and calculates the inclination of the reference line by the method described with reference to FIGS. 9(A) - (C).

[0068] Also, in step S14b, the display image generation unit 354 may set the trajectory along which the vehicle 2 has traveled as the reference line. In this case, the display image generation unit 354 regards the vehicle positions constituting the trajectory as input points, and calculates the inclination of the reference line by the method described with reference to FIGS. 9(A) - (C).

[0069] Returning to FIG. 6, next, the display processing unit 355 displays the generated display image on the display unit 33 (step S15).

[0070] Referring to FIG. 7, next, the candidate calculation unit 356 receives an instruction from the user (step S21).

[0071] Next, the candidate calculation unit 356 determines whether the instruction from the user is a designated point addition instruction (step S22). The designated point addition instruction is an instruction that designates a section line number and a pixel in the display image and adds a corresponding designated point.

[0072] If it is determined that the instruction from the user is a designated point addition instruction (step S22 - Yes), the candidate calculation unit 356 adds a designated point (step S22a) and proceeds to step S14. In step S22a, the candidate calculation unit 356 sets the inverse function of the projection function set in step S12, calculates the latitude and longitude of the projection source of the pixel position of the designated pixel by the inverse function, refers to the point group table T1, obtains the altitude of the point having the calculated latitude and longitude, and adds the data of the designated point associated with the calculated latitude, longitude, the obtained altitude, and the designated section line number to the input point table T2 to store it in the storage unit 31. If there is no point having the latitude and longitude calculated by the inverse function, the candidate calculation unit 356 may obtain, as the altitude of the point corresponding to the designated pixel, a value interpolated by the altitudes of a plurality of points around the calculated latitude and longitude.

[0073] If it is determined that the instruction from the user is not a designated point addition instruction (step S22 - No), the candidate calculation unit 356 determines whether the instruction is an auxiliary point addition instruction (step S23). The auxiliary point addition instruction is an instruction that adds an auxiliary point based on a locus and a designated point.

[0074] If it is determined that the instruction from the user is an auxiliary point addition instruction (step S23 - Yes), the candidate calculation unit 356 adds an auxiliary point (step S23a) and proceeds to step S14.

[0075] FIG. 10(A) is a schematic diagram for explaining an example of calculating auxiliary points. In the example shown in FIG. 10(A), the candidate calculation unit 356 identifies an interval on the trajectory based on two adjacent designated points, and calculates auxiliary points corresponding to each of the vehicle positions included in the identified interval.

[0076] The candidate calculation unit 356 identifies two adjacent designated points P1 and P2 from among the designated points included in the input point table T2, and acquires from the storage unit 31 the trajectory including the vehicle positions C1, C2, C3, and C4 and the designated points P1 and P2. First, the candidate calculation unit 356 identifies the interval on the trajectory corresponding to the two designated points P1 and P2. The candidate calculation unit 356 identifies the line segment among the line segments constituting the trajectory that is closest to each designated point, and calculates the distance from each designated point to the identified line segment. In the example shown in FIG. 10(A), the candidate calculation unit 356 identifies the line segment M12 connecting the vehicle positions C1 and C2 as the line segment closest to the designated point P1, and calculates the distance J1 from the designated point P1 to the line segment M12. Similarly, the candidate calculation unit 356 identifies the line segment M34 connecting the vehicle positions C3 and C4 as the line segment closest to the designated point P2, and calculates the distance J2 from the designated point P2 to the line segment M34. The candidate calculation unit 356 divides the trajectory into a plurality of intervals with the intersections of the line segment closest to each designated point and the perpendicular line dropped from each designated point to the line segment closest to each designated point as endpoints. In the example shown in FIG. 10(A), the endpoint V1 is extracted as the corresponding point on the trajectory corresponding to the designated point P1, and the endpoint V2 is extracted as the corresponding point on the trajectory corresponding to the designated point P2. That is, the interval from the endpoint V1 to the endpoint V2 is identified as the interval on the trajectory corresponding to the designated points P1 and P2.

[0077] Subsequently, the candidate calculation unit 356 identifies the vehicle positions that connect the two line segments closest to both designated points and the line segment between the two line segments. The candidate calculation unit 356 calculates a straight line that passes through each identified vehicle position and is orthogonal to the straight line connecting the vehicle positions adjacent to the front and rear of each identified vehicle position. In the example shown in FIG. 10(A), the candidate calculation unit 356 identifies the vehicle positions C2 and C3 that connect the line segments M12 and M34 and the line segment M23 therebetween. The candidate calculation unit 356 calculates a straight line N2 that passes through the vehicle position C2 and is orthogonal to the straight line connecting the vehicle positions C1 and C3 adjacent to the front and rear of the vehicle position C2. Further, the candidate calculation unit 356 calculates a straight line N3 that passes through the vehicle position C3 and is orthogonal to the straight line connecting the vehicle positions C2 and C4 adjacent to the front and rear of the vehicle position C3. The calculated straight lines indicate the perpendiculars to the trajectory at the identified vehicle positions.

[0078] Subsequently, on the perpendicular to the trajectory passing through each vehicle position, the candidate calculation unit 356 sets an auxiliary point Q within a distance range based on the distances from each designated point to the trajectory from the trajectory. The distance range is the range between the distance from the trajectory to one designated point and the distance from the trajectory to the other designated point. The candidate calculation unit 356 sets the auxiliary point Q, for example, based on the distances from the trajectory to the two designated points and the distances from the endpoints corresponding to the two designated points on the trajectory to each vehicle position. Each vehicle position is an example of an arbitrary point located between the two endpoints on the trajectory. The candidate calculation unit 356 calculates, as a weighting coefficient, the ratio of the length of the trajectory from the endpoint corresponding to one designated point to each vehicle position to the length of the trajectory between the endpoints corresponding to the two designated points on the trajectory. The candidate calculation unit 356 calculates the distance from the trajectory to the auxiliary point corresponding to each vehicle position by adding the value obtained by multiplying the difference between the distances from the trajectory to the two designated points by the weighting coefficient, with the distance from the trajectory to one designated point as a reference. In the example shown in FIG. 10(A), the distances D2 and D3 from the trajectory to the auxiliary points corresponding to the vehicle positions C2 and C3 are respectively represented by the following equations.

[0079]

Equation

Equation

[0080] That is, in the example shown in FIG. 10(A), the distance from each auxiliary point to the locus is included in the distance range between the distance J1 from the designated point P1 to the locus and the distance J2 from the designated point P2 to the locus.

[0081] FIG. 10(B) is a schematic diagram for explaining another example of adding auxiliary points. In the example shown in FIG. 10(B), the candidate calculation unit 356 identifies an interval on the locus based on two adjacent designated points, and calculates auxiliary points corresponding to each line segment connecting to a vehicle position included in the identified interval.

[0082] The candidate calculation unit 356 acquires from the storage unit 31 a locus including vehicle positions C1, C2, C3, and C4 and designated points P1 and P2. The candidate calculation unit 356 identifies a line segment M12 connecting vehicle positions C1 and C2 as the line segment closest to the designated point P1, and calculates the distance J1 from the designated point P1 to the line segment M12. The candidate calculation unit 356 identifies a line segment M34 connecting vehicle positions C3 and C4 as the line segment closest to the designated point P2, and calculates the distance J2 from the designated point P2 to the line segment M34. The candidate calculation unit 356 divides the locus into a plurality of intervals with the intersection points of the line segment closest to each designated point and the perpendicular line dropped from each designated point to the line segment closest to each designated point as endpoints V1 and V2 (corresponding points on the locus corresponding to the designated points). The processing up to this point is the same as the example shown in FIG. 10(A).

[0083] Subsequently, for each line segment connecting adjacent vehicle positions, the candidate calculation unit 356 calculates a perpendicular line passing through the midpoint of the line segment. The candidate calculation unit 356 sets an auxiliary point Q on the perpendicular line of each line segment within a distance range based on the distance from the line segment to the trajectory from each specified point. For example, the candidate calculation unit 356 sets the auxiliary point Q based on the distances from the trajectory to the two specified points and the length of the trajectory from the endpoints corresponding to the two specified points on the trajectory to the midpoint of the line segment corresponding to each vehicle position. Each midpoint is an example of an arbitrary point located between the two endpoints on the trajectory. The candidate calculation unit 356 calculates, as a weighting coefficient, the ratio of the length of the trajectory from the endpoint corresponding to one specified point to each midpoint to the length of the trajectory between the endpoints corresponding to the two specified points on the trajectory. The candidate calculation unit 356 calculates the distance from the trajectory to the auxiliary point corresponding to each vehicle position by adding, to the difference between the distances from the trajectory to the two specified points, the value obtained by multiplying the difference by the weighting coefficient, with the distance from the trajectory to one specified point as a reference. In the example shown in FIG. 10(B), the distances D1, D2, and D3 from the line segments M12, M23, and M34 to the auxiliary point Q are respectively represented by the following equations.

[0084]

Equation

Equation

Equation

[0085] Also in the example shown in FIG. 10(B), the distance of each auxiliary point from the trajectory is included in the distance range between the distance J1 from the specified point P1 to the trajectory and the distance J2 from the specified point P2 to the trajectory.

[0086] As described with reference to FIGS. 10(A) and (B), the candidate calculation unit 356 calculates auxiliary points for each section of the trajectory divided by the perpendicular lines dropped from two adjacent designated points among the designated points included in the input point table T2, as described above. The candidate calculation unit 356 stores the calculated auxiliary points in the storage unit 31 by associating them with the same section line number as the latitude, longitude, altitude, and designated points and adding them to the input point table T2. Further, the candidate calculation unit 356 resets the point numbers in the input point table T2 so that the designated points and the added auxiliary points constitute a section line candidate. The candidate calculation unit 356 repeats the process of sequentially selecting two adjacent designated points for each candidate of the section line and setting auxiliary points, thereby setting auxiliary points for all sections where designated points are set.

[0087] Note that the candidate calculation unit 356 may execute step S23a for the added designated points to add auxiliary points without receiving an auxiliary point addition instruction from the user after the designated points are added in step S22a.

[0088] When it is determined that the instruction from the user is not an auxiliary point addition instruction (step S23 - No), the candidate calculation unit 356 determines whether the instruction is an input point deletion instruction (step S24). The input point deletion instruction is an instruction to specify and delete a designated point or an auxiliary point.

[0089] When it is determined that the instruction from the user is an input point deletion instruction (step S24 - Yes), the candidate calculation unit 356 deletes the designated point or the auxiliary point specified from the input point table T2 (step S24a), and proceeds to step S14.

[0090] When it is determined that the instruction from the user is not an input point deletion instruction (step S24 - No), the candidate calculation unit 356 determines whether the instruction is a candidate calculation instruction (step S25). The candidate calculation instruction is an instruction to calculate a section line candidate based on designated points and auxiliary points.

[0091] When it is determined that the instruction from the user is a candidate calculation instruction (step S25 - Yes), the candidate calculation unit 356 calculates a partition line candidate (step S25a) and proceeds to step S14. In this case, the display image to be displayed is an example of information regarding the partition line candidate.

[0092] In step S25a, the candidate calculation unit 356 extracts the designated points and auxiliary points associated with the same partition line number from the input point table T2. The candidate calculation unit 356 calculates a broken line obtained by connecting the extracted designated points and auxiliary points in the order of point numbers with line segments as the partition line candidate. The candidate calculation unit 356 generates graphic data indicating the calculated partition line candidate, associates the partition line number, and stores it in the storage unit 31 by adding it to the visualization data T3. The candidate calculation unit 356 calculates and stores the partition line candidate as described above for each of the partition line numbers included in the input point table T2.

[0093] When it is determined that the instruction from the user is not a candidate calculation instruction (step S25 - No), the candidate calculation unit 356 determines whether the instruction is an additional candidate calculation instruction (step S26). The additional candidate calculation instruction is an instruction to calculate a new partition line candidate by interpolation or extrapolation based on the calculated partition line candidate. The additional candidate calculation instruction specifies two partition line candidates for use in interpolation or extrapolation, the number of partition line candidates to be calculated, information indicating whether to calculate the partition line candidate by interpolation or extrapolation, and the internal division ratio in the case of interpolation or the external division ratio in the case of extrapolation.

[0094] When it is determined that the instruction from the user is an additional candidate calculation instruction (step S26 - Yes), the candidate calculation unit 356 calculates a partition line candidate by interpolation or extrapolation based on the two partition line candidates (step S26a) and proceeds to step S14.

[0095] In step S26a, the candidate calculation unit 356 extracts from the input point table T2 the designated points and auxiliary points associated with the section line numbers of two section line candidates (hereinafter referred to as the first section line candidate and the second section line candidate, respectively) to be used for interpolation or extrapolation. For each of the designated points and auxiliary points of the first section line candidate, the candidate calculation unit 356 specifies the designated point or auxiliary point of the second section line candidate closest to each designated point and each auxiliary point as the corresponding designated point and auxiliary point of the second section line candidate. According to the specification by the additional candidate calculation instruction, the candidate calculation unit 356 calculates one or more points obtained by internally dividing or externally dividing the designated points and auxiliary points of the first section line candidate and the designated points or auxiliary points of the corresponding second section line at the specified internal division ratio or external division ratio. The candidate calculation unit 356 calculates a polyline connecting the calculated points as a new section line candidate, and stores it by adding it to the visualization data T3.

[0096] On a road, there may be a case where three or more section lines such as the outside line of the lane, the center line, and the lane dividing line are marked in parallel. In such a case, the candidate calculation unit 356 automatically calculates a new section line candidate parallel to the two section line candidates, thereby reducing the workload of the user.

[0097] When it is determined that the instruction from the user is not an additional candidate calculation instruction (step S26 - No), the candidate calculation unit 356 determines whether the instruction is a display condition change instruction (step S27). The display condition change instruction is an instruction to change the display condition set in step S13. When it is determined that the instruction from the user is a display condition change instruction (step S27 - Yes), the condition setting unit 353 stores the changed display condition in the storage unit 31 (step S27a), and proceeds to step S14.

[0098] When it is determined that the instruction from the user is not a display condition change instruction (step S27 - No), the candidate calculation unit 356 determines whether the instruction is an output instruction (step S28). When it is determined that the instruction is not an output instruction (step S28 - No), the process proceeds to step S14.

[0099] When it is determined that the instruction from the user is an output instruction (step S28 - Yes), the output unit 357 outputs the diagram data (step S29) and ends the diagram generation process. The output unit 357 obtains the diagram data T3 from the storage unit 31 and outputs it by transmitting it to the external device 4 via the communication unit 32. The diagram data is an example of information regarding the candidates for the partition lines.

[0100] In step S29, the output unit 357 converts the partition line candidates included in the diagram data T3 into graphic data of a spline curve passing through the designated points and the auxiliary points and outputs them. Instead of the spline curve, a Bézier curve or a curve approximated by a polynomial using the least squares method or regression analysis may be used. Also, the output unit 357 may convert the partition line candidates into a curve passing through only a part of the designated points and the auxiliary points. For example, the output unit 357 may convert the partition line candidates into a B - spline curve that passes through the designated points and does not pass through the auxiliary points and output them. In this way, since the partition line candidates are converted from a polyline to a curve, the shape of the partition line candidates becomes closer to the shape of the actual partition lines, so that the partition lines can be diagrammed with high precision.

[0101] As described above, in the diagram generation device 3, the candidate calculation unit 365 sets auxiliary points in a distance range based on the distance from the designated points to the trajectory from the trajectory, and calculates partition line candidates based on the designated points and the auxiliary points. Thereby, the diagram generation device 3 can diagram the partition lines with high precision.

[0102] Also, the candidate calculation unit 365 displays a display image including a road image and stores the points designated by the user as designated points. Thereby, the diagram generation device 3 enables the user to efficiently designate the designated points while viewing the display image.

[0103] Also, the candidate calculation unit 365 calculates new partition line candidates by interpolation or extrapolation using two of the partition line candidates stored in the storage unit 31. Thereby, the diagram generation device 3 can reduce the workload of the user on roads with three or more partition lines.

[0104] Also, in the mapping device 3, the display image generation unit 354 sets a reference line based on the partition lines, and generates a shortened image by converting the mapping data so that the partition line candidates are reduced in the extending direction of the reference line. Thereby, the mapping device 3 enables the user to efficiently specify a designated point.

[0105] Also, the display image generation unit 354 generates a shortened image by reducing the coordinate system of the road image, which is the orthographic projection of the colored point cloud, in the extending direction of the reference line. Thereby, the mapping device 3 enables the user to efficiently specify a designated point while viewing the reduced road image.

[0106] Also, the display image generation unit 354 performs reduction of the coordinate system using, as the reduction rate, the ratio of the accuracy required in the longitudinal direction of the road to the accuracy required in the transverse direction of the road in the mapping data. Thereby, the mapping device 3 can map the partition lines based on the accuracy required for the mapping data.

[0107] The embodiment of the mapping device 3 is not limited to the above-described example. Various modifications as described below may be applied to the mapping device 3.

[0108] In the above-described example, it is assumed that pixel values such as RGB values are associated with each point included in the colored point cloud data, but the example is not limited to this. Luminance values of reflected light acquired by a laser measuring device may be associated with each point included in the colored point cloud data. In this case, in step S12 of the mapping process, the road image generation unit 352 generates a monochrome road image in which luminance values are associated with each pixel.

[0109] In the above example, it is assumed that the road image is an orthographic image, but it is not limited to such an example. A perspective projection image before orthographic projection can also be used as the road image. In this case, in step S12 of the diagram generation process, the road image generation unit 352 generates either one or both of the orthographic image and the perspective projection image as the road image. When both the orthographic image and the perspective projection image are generated, in step S15, the display processing unit 355 may display a display image including the orthographic image or the perspective projection image according to the selection of the user. Note that for the perspective projection image, it is not necessary to switch the road image according to the scale and the display mode.

[0110] In the above example, it is assumed that the lane line candidate is calculated as a broken line passing through the input point by the candidate calculation unit 356 and is converted into a curve by the output unit 357, but it is not limited to such an example. The lane line candidate may be calculated as a curve by the candidate calculation unit 356. As a result, since the lane line candidate is displayed in a shape close to the actual lane line in the display image, it becomes easy for the user to determine whether the designated point is designated with appropriate accuracy.

[0111] In this case, in the diagram data T3, curve parameters are further associated with each lane line candidate. Also, in this case, in step S14b of the diagram generation process, the display image generation unit 354 calculates the inclination of the reference line as follows. The display image generation unit 354 sets the lane line candidate, which is a curve, as the reference line. The display image generation unit 354 sets input points at a predetermined interval above the reference line. The display image generation unit 354 specifies the input point closest to the center point of the display target area among the set input points. The display image generation unit 354 calculates the inclination of the tangent line of the reference line at the specified input point as the inclination of the reference line. The inclination of the tangent line of the reference line at the specified input point may be calculated based on the curve parameters, or may be calculated by applying an image processing technique such as Hough transform to the image of the reference line.

[0112] In the above example, the locus is assumed to be a polyline connecting vehicle positions, but it is not limited to such an example. The locus may be a curve passing through the vehicle positions. In this case, in step S23a of the visualization process, the candidate calculation unit 356 calculates auxiliary points as follows.

[0113] FIG. 11 is a schematic diagram for explaining an example of calculating auxiliary points when the locus is a curve. In the example shown in FIG. 11, the candidate calculation unit 356 identifies a section on the locus based on two adjacent designated points, and calculates auxiliary points corresponding to each of the vehicle positions included in the identified section.

[0114] The candidate calculation unit 356 identifies two adjacent designated points P1 and P2 from among the designated points included in the input point table T2, and acquires the locus including vehicle positions C1, C2, C3, and C4 and the designated points P1 and P2. The candidate calculation unit 356 calculates a straight line that is orthogonal to the tangent of the locus and passes through the acquired designated points, and calculates the distance from the designated point to the tangent of the locus. In the example shown in FIG. 11, the candidate calculation unit 356 calculates a straight line that is orthogonal to the tangent of the locus and passes through the designated point P1, and calculates the distance J1 from the designated point P1 to the tangent of the locus. Similarly, the candidate calculation unit 356 calculates a straight line passing through the designated point P2 and calculates the distance J2 from the designated point P2 to the tangent of the locus.

[0115] Subsequently, the candidate calculation unit 356 calculates a straight line that is orthogonal to the tangent of the locus at each vehicle position, and sets an auxiliary point Q in a distance range based on the distance from each designated point to the locus on the calculated straight line from the locus. For example, the candidate calculation unit 356 calculates, as a weighting coefficient, the ratio of the length of the locus from the corresponding point V1 corresponding to one designated point to each vehicle position to the length of the locus between the corresponding points V1 and V2 corresponding to the two designated points on the locus. The candidate calculation unit 356 calculates the distance from the locus to the auxiliary point corresponding to each vehicle position by adding the value obtained by multiplying the difference between the distances from the locus to the two designated points by the weighting coefficient, with the distance from the locus to one designated point as a reference. In the example shown in FIG. 11, the distances D2 and D3 from the locus to the auxiliary points corresponding to the vehicle positions C2 and C3 are represented by the following equations, respectively.

[0116] [Number] [Number]

[0117] That is, in the example shown in FIG. 11, the distance from each auxiliary point to the locus is included in the distance range between the distance J1 from the specified point P1 to the locus and the distance J2 from the specified point P2 to the locus.

[0118] Note that, in the example shown in FIG. 11, the candidate calculation unit 356 calculates auxiliary points corresponding to each vehicle position in the same manner as in the example shown in FIG. 10(A), but it is not limited to such an example. The candidate calculation unit 356 may calculate auxiliary points corresponding to the midpoints of adjacent vehicle positions on the locus in the same manner as in the example shown in FIG. 10(B). Further, in the examples shown in FIGS. 10 and 11, the weight coefficient is calculated using the distance from the end point (corresponding point) V1 to an arbitrary point with the specified point P1 as a reference, but the candidate calculation unit 356 may calculate the weight coefficient using the distance from the end point (corresponding point) V2 to an arbitrary point with the specified point P2 as a reference.

[0119] In the above-described example, in step S14, it is assumed that the display image generation unit 354 can generate a display image in either the reduced display mode or the non-reduced display mode, but it is not limited to such an example. The display image generation unit 354 may further be capable of generating a display image in a straightened display mode in which a coordinate transformation that straightens the reference line and reduces the straight line in the extending direction is applied to the road image and the mapping data to generate the display image. Hereinafter, the display image generated in the straightened display mode may be referred to as a straightened image.

[0120] FIG. 12(A) is a schematic diagram for explaining an example of setting a display target area in the straightened display mode based on the set display conditions, i.e., the center position C, the width and height of the window W, the scale E, and the reduction ratio F. Note that in FIG. 12(A), the section line candidate is illustrated as a curve, but even if it is a broken line, the display target area is set in the same manner.

[0121] The display image generation unit 354 sets the section line candidate L near the center position C as a reference line and calculates a perpendicular line dropped from the center position C to the reference line. The display image generation unit 354 identifies points that are separated by a length (W3÷2) from the intersection point of the calculated perpendicular line and the reference line, both in front of and behind the reference line. The length W3 in the road image with the scale E is a value obtained by dividing the width of the window W by the reduction ratio F. The display image generation unit 354 sets a strip-shaped area within a distance α or less from the reference line toward the center position C or within a distance β or less from the reference line in the opposite direction of the center position C in the section on the reference line with the identified points as endpoints as the display target area A3. The distance α is (H3÷2 + D), and the distance β is (H3÷2 - D). Here, the height H3 in the road image with the scale E is equal to the height of the window W, and the distance D is the distance from the center position C to the reference line.

[0122] The display image generation unit 354 extracts the portion included in the display target area A3 from the road image with the scale E, converts the reference line into a straight line, and applies a coordinate transformation (hereinafter referred to as straightening processing) that reduces the straight line in the stretching direction. Also, the display image generation unit 354 extracts the data of the input points included in the display target area A3 from the input point table T2 and applies the straightening processing. Further, the display image generation unit 354 extracts the section line candidates included in the display target area A3 from the plotting data T3 and applies the straightening processing.

[0123] FIG. 12(B) is a schematic diagram for explaining the straightening process. The display image generation unit 354 applies coordinate transformation to each transformation target S with each pixel of the extracted road image as the transformation target S as follows. The display image generation unit 354 calculates the intersection point between the reference line and the perpendicular line dropped from the transformation target S to the reference line, and calculates the length γ of the reference line from the start end of the section of the reference line to the intersection point and the distance δ from the transformation target S to the intersection point. The display image generation unit 354 sets, in a rectangle window having a width (W3×F) and a height H3, the point where the distance from the left end of the window is (γ×F) and the distance from the upper end of the window is (β + δ) as the coordinates after transformation of the transformation target S. Note that by this straightening process, the reference line is transformed into a straight line parallel to the upper side that is separated from the upper side of the rectangular window by a distance β.

[0124] The display image generation unit 354 calculates the coordinates after transformation for each pixel of the extracted road image, and sets the pixel value of each pixel before transformation to the pixel of the calculated coordinates. Note that when the coordinates after transformation of a plurality of pixels are the same coordinates, the display image generation unit 354 sets the average value of the pixel values of the plurality of pixels as the pixel value after transformation. Further, the display image generation unit 354 calculates the coordinates after transformation for each point constituting the extracted input point and the section line candidate, and draws a figure indicating the input point and the section line candidate at the calculated coordinates. In this way, the display image generation unit 354 generates a straightened image.

[0125] In this way, in the straightening display mode, the display image generation unit 354 applies coordinate transformation for straightening the reference line to generate a display image. Thereby, even when the curvature of the road is large, a wide range of the road can be displayed at once, so that the user can input a specified point for a wide range of section lines, and the working efficiency is improved.

[0126] Note that even in the straightening display mode, the display image generation unit 354 may set the center line of the area partitioned by a plurality of partition lines or the locus of the vehicle as the reference line in the same manner as in the shortening display mode. Further, when the partition line candidate or the locus is a broken line, the display image generation unit 354 may generate a curve connecting the points constituting the broken line and set the curve as the reference line.

[0127] Also, when the curvature of the reference line in the straightening display mode is equal to or greater than a predetermined value, the display image generation unit 354 may calculate a curve in which the curvature of the reference line is reduced to the predetermined value, and generate a straightened image using the calculated curve as the reference line. When the curvature of the reference line is large, the pixel value of a single pixel in the road image is associated with a plurality of pixels in the straightened image, which may make it difficult for the user to grasp the road conditions. By using a curve with a relaxed curvature as the reference line, it is possible to prevent the user from having difficulty in grasping the road conditions and to improve the user's work efficiency to some extent.

[0128] In the above-described example, in step S22a, the candidate calculation unit 356 adds the point on the partition line specified by the user as the specified point. However, the present invention is not limited to such an example. The candidate calculation unit 356 may add, as the specified point, a point on the partition line in the vicinity of the point on the road specified by the user based on the pixel value in the road image.

[0129] FIG. 13 is a schematic diagram for explaining an example of the calculation of the specified point. The candidate calculation unit 356 identifies the line segment M23 closest to the point U on the road specified by the user among the line segments constituting the locus, and calculates the perpendicular line NU dropped from the point U to the line segment M23. The candidate calculation unit 356 extracts, in the road image, pixels whose distance from the point U is within a predetermined distance and which are located on the calculated perpendicular line NU.

[0130] The candidate calculation unit 356 adds, as designated points, points among the extracted pixels that have the image features of the section line. For example, the candidate calculation unit 356 identifies pixels with a luminance equal to or higher than a predetermined value as the pixels of section I1 on the section line, identifies the point corresponding to the pixel located at the center of section I1 as the point P on the section line, and adds it as a designated point. Generally, since the section line is drawn with white paint, in the example shown in FIG. 13, among the pixels on the vertical line NU, the pixels of section I1 on the section line have a larger pixel value than the pixels of section I2 outside the section line. Therefore, the candidate calculation unit 356 can add, as designated points, points located near the center of the section line by identifying the point corresponding to the pixel located at the center of the section with a luminance equal to or higher than a predetermined value.

[0131] The candidate calculation unit 356 may identify edge pixels among the pixels on the vertical line N, for which the magnitude of the luminance difference from adjacent pixels is equal to or greater than a predetermined value, and identify the pixels between the identified edge pixels as the pixels of section I1. Generally, since the pixels of section I1 exhibit a color close to white, which is the color of the section line, and the pixels of section I2 exhibit a color close to black, which is the color of the road surface, the edge pixels indicate the boundary between section I1 and section I2. Therefore, the candidate calculation unit 356 can add, as designated points, points located near the center of the section line by identifying the point corresponding to the pixel located at the center of the edge pixel.

[0132] In addition, the candidate calculation unit 356 may identify, as points on the dividing line, points having image features similar to the designated points included in the input point table T2 from among the pixels on the perpendicular line NU. In the example shown in FIG. 13, the candidate calculation unit 356 extracts, from the input point table T2, the designated point P0 closest to the point U on the road designated by the user. The candidate calculation unit 356 extracts the feature amount of the pixel at the position of the extracted designated point P0. The feature amount is an arbitrary image feature amount calculated based on the pixel values of the pixels within a predetermined range centered on the pixel, and is, for example, the HOG (Histograms of Oriented Gradients) feature amount. The candidate calculation unit 356 identifies, as the point P on the dividing line, the point corresponding to the pixel among the pixels on the perpendicular line NU whose feature amount value is close to the feature amount of the designated point P0. By using the feature amounts of the pixels at the positions of the designated points near the point designated by the user among the stored designated points, the candidate calculation unit 356 can appropriately add the points on the dividing line as designated points even when the color of the dividing line or the road surface is locally different.

[0133] In this way, the candidate calculation unit 356 identifies the points on the dividing line on the perpendicular line dropped from the point on the road designated by the user to the trajectory. The candidate calculation unit 356 adds the identified points as designated points to the input point table T2. When the user designates a point on the road, the points on the dividing line whose positions in the extending direction of the road are substantially the same as the designated point are added as designated points, so that the user does not need to accurately designate the points on the dividing line, and the work efficiency is improved.

[0134] In the above-described example, in step S23a, the candidate calculation unit 356 is assumed to set the auxiliary points based only on the distance from the trajectory, but the present invention is not limited to such an example. The candidate calculation unit 356 may further set the auxiliary points based on the features of the pixels at the positions of the designated points. For example, the candidate calculation unit 356 sets, as the distance range, the range between each of the distances to the two designated points that define the end points of the section of the trajectory. The candidate calculation unit 356 sets, as the auxiliary points, the points that are located within the distance range from the trajectory and have image features similar to the designated points.

[0135] FIG. 14 is a schematic diagram for explaining another example of the calculation of the auxiliary point.

[0136] The candidate calculation unit 356 identifies the designated points P1 and P2 adjacent to each other, and acquires a locus including the vehicle positions C1, C2, C3, and C4 and the designated points P1 and P2. The candidate calculation unit 356 identifies, among the line segments constituting the locus, the line segment closest to each designated point, and calculates the distance from each designated point to the identified line segment. In the example shown in FIG. 14, the candidate calculation unit 356 identifies the line segment M12 connecting the vehicle positions C1 and C2 as the line segment closest to the designated point P1, and calculates the distance J1 from the designated point P1 to the identified line segment. Similarly, the candidate calculation unit 356 identifies the line segment M34 connecting the vehicle positions C3 and C4 as the line segment closest to the designated point P2, and calculates the distance J2 from the designated point P2 to the identified line segment.

[0137] The candidate calculation unit 356 sets a distance range I in which the larger of the calculated distances J1 and J2 is the maximum value and the smaller is the minimum value. In the example shown in FIG. 14, the distance range I is a range with the minimum value being the distance J1 and the maximum value being the distance J2. The candidate calculation unit 356 calculates, in the same manner as the example shown in FIG. 9(A), straight lines N2 and N3 orthogonal to the straight lines connecting the vehicle positions adjacent to each of the vehicle positions C2 and C3 before and after each vehicle position. The candidate calculation unit 356 extracts pixels that are located on the calculated straight lines N2 and N3 and are located within the distance range I from the locus.

[0138] The candidate calculation unit 356 calculates feature amounts for each of the pixels at the positions of the specified points P1 and P2 and the extracted pixels. The candidate calculation unit 356 calculates the similarity between the feature amount of the extracted pixel and the feature amount of the pixel at the position of each specified point. The similarity is calculated based on, for example, the distance between the feature vectors indicating the feature amounts. For each of the straight lines N2 and N3, the candidate calculation unit 356 identifies a point having image features similar to the specified point and sets the identified point as an auxiliary point. For example, the candidate calculation unit 356 identifies, among the pixels located on the straight line N2 and included in the distance range I from the trajectory, the pixel with the largest total value of the similarity between the specified point P1 and the similarity between the specified point P2. The candidate calculation unit 356 identifies the point at the position of the identified pixel as a point having image features similar to the specified point and sets it as an auxiliary point.

[0139] In this way, the candidate calculation unit 356 sets a point having image features similar to the specified point as an auxiliary point. Thereby, even when the distance between the trajectory and the dividing line changes locally, the auxiliary point can be set with high accuracy based on the road image, and the dividing line can be visualized.

[0140] Also, although the dividing line is exemplified as the visualization data, the visualization data may further include data representing the coordinate values and shapes of other road surface markings such as speed markings, and attribute information (numerical values, characters, etc.) associated with the data of the dividing line and / or road surface markings. By storing the data of the road surface markings and the attribute information input by the user via the operation unit 34 in the storage unit 31, and further drawing the graphics and texturized attribute information based on the data of the road surface markings in the reduced image by the display image generation unit 354, these input operations and inspection operations can be performed efficiently.

[0141] In the above example, the designated point and the auxiliary point were assumed to be three-dimensional data having latitude, longitude, and altitude, but the example is not limited to this. The designated point and the auxiliary point may be two-dimensional data having latitude and longitude but not having altitude. In this case, in step S22a, the candidate calculation unit 356 does not acquire the altitude of the designated point from the point group table T1. Further, in step S23a, the candidate calculation unit 356 sets an auxiliary point, which is two-dimensional data, based on the latitude and longitude of the vehicle position constituting the trajectory and the designated point, which is two-dimensional data. Then, in steps S25a and S26a, the candidate calculation unit 356 acquires the altitudes of the designated point and the auxiliary point from the point group table T1 and calculates a section line candidate, which is three-dimensional data. As a result, the calculation load in calculating the designated point and the auxiliary point is reduced.

[0142] It should be understood by those skilled in the art that various changes, substitutions, and modifications can be added to this without departing from the spirit and scope of the present invention. For example, the above-described embodiments and modifications may be implemented in appropriate combination within the scope of the present invention.

Explanation of Signs

[0143] 3 Mapping device 31 Storage unit 32 Communication unit 33 Display unit 34 Operation unit 351 Acquisition unit 352 Road image generation unit 353 Condition setting unit 354 Display image generation unit 355 Display processing unit 356 Candidate calculation unit 357 Output unit

Claims

1. Storage means for storing visualization data including data obtained by visualizing one or more lane lines of the road using measurement data obtained by measuring the road from a vehicle traveling on the road, and a road image that is an orthographic projection of the measurement data; Image generation means for setting, as a reference line, a center line of a region partitioned by one lane line included in the visualization data or a plurality of lane lines included in the visualization data, and generating a shortened image by converting the visualization data so that the lane line is reduced in the extending direction of the reference line and reducing the road image in the extending direction of the reference line; Display means for displaying the shortened image; A visualization device characterized by comprising the above.

2. Storage means for storing visualization data including data obtained by visualizing one or more lane lines of the road using measurement data obtained by measuring the road from a vehicle traveling on the road; Image generation means for setting, as a reference line, a center line of a region partitioned by one lane line included in the visualization data or a plurality of lane lines included in the visualization data, generating a shortened image by converting the visualization data so that the lane line is reduced in the extending direction of the reference line, setting a display target area, which is a rectangular geographical area displayed as the shortened image, so that the longitudinal direction of the display target area coincides with the extending direction of the reference line, and generating the shortened image for the display target area; Display means for displaying the shortened image; A visualization device characterized by comprising the above.

3. Storage means for storing visualization data including data obtained by visualizing one or more lane lines of the road using measurement data obtained by measuring the road from a vehicle traveling on the road; Image generation means for setting, as a reference line, a center line of a region partitioned by one lane line included in the visualization data or a plurality of lane lines included in the visualization data, and generating a shortened image by converting the visualization data so that the lane line is reduced in the extending direction of the reference line at a ratio of the accuracy required in the extending direction of the road to the accuracy required in the lateral direction of the road in the visualization data; Display means for displaying the shortened image; A visualization device characterized by comprising the above.

4. Storage means for storing a road image that is an orthographic projection of measurement data obtained by measuring the road from a vehicle traveling on the road, and the trajectory of the vehicle when the measurement data was measured; Image generation means for generating a shortened image by using the trajectory as a reference line and reducing the road image in the extending direction of the reference line; Display means for displaying the shortened image; Calculation means for storing a plurality of points on a single dividing line designated by a user based on the shortened image as designated points, and calculating the dividing line based on the plurality of designated points; A mapping device characterized by comprising the above.

5. The image generation means generates the shortened image by applying a coordinate transformation that converts the reference line into a straight line and reduces the straight line in the extending direction to the mapping data. The mapping device according to claim 1 or 2.

6. A mapping method executed by a mapping device, Storing mapping data including data mapping one or more dividing lines of a road using measurement data obtained by measuring the road from a vehicle traveling on the road, and a road image that is an orthographic projection of the measurement data; Setting, as a reference line, a center line of a region partitioned by one dividing line included in the mapping data or a plurality of dividing lines included in the mapping data, converting the mapping data so that the dividing line is reduced in the extending direction of the reference line, and reducing the road image in the extending direction of the reference line to generate a shortened image; Displaying the shortened image; A mapping method characterized by including the above.

7. A program for a computer provided with a storage unit, The storage unit stores mapping data including data mapping one or more dividing lines of a road using measurement data obtained by measuring the road from a vehicle traveling on the road, and a road image that is an orthographic projection of the measurement data; Setting, as a reference line, a center line of a region partitioned by one dividing line included in the mapping data or a plurality of dividing lines included in the mapping data, converting the mapping data so that the dividing line is reduced in the extending direction of the reference line, and reducing the road image in the extending direction of the reference line to generate a shortened image; Displaying the shortened image; A program characterized by causing the computer to execute the above.

Images