Methods to support the creation of a digital street map

Abstract

The invention relates to a method for assisting in the creation of a digital road map, comprising: Capturing an image of the surroundings of a motor vehicle using a camera on the motor vehicle, Determining a skyline contour of the surroundings based on the captured image, Determining the current position of the motor vehicle, Determining a skyline contour descriptor based on the determined skyline contour and the current position, wherein the skyline contour descriptor describes the skyline contour of the vehicle's surroundings relative to the vehicle's current position. Sending the skyline contour descriptor to a remote map server to assist in creating the digital street map. The invention relates to a device for assisting in the creation of a digital road map, a motor vehicle, a method and a server for creating a digital road map, a computer program and a machine-readable storage medium.

Description

[0001] The invention relates to a method and a device for assisting in the creation of a digital road map, a motor vehicle, a method and a server for creating a digital road map, a computer program and a machine-readable storage medium. State of the art

[0002] The publication WO 2022 / 016044 A1 discloses a method for modeling a road geometry.

[0003] Publication DE 11 2020 002 764 T5 of the international application with publication number WO 2021 / 138618 discloses a method for vehicle navigation.

[0004] The patent application DE 10 2009 050 505 A1 discloses a method for detecting a free path for a vehicle.

[0005] Patent specification US 11,107,244 B1 discloses a method for determining a geographic location based on an image without GPS. Disclosure of the invention

[0006] The object underlying the invention is to provide a concept to support the creation of a digital road map and to create a digital road map.

[0007] This problem is solved by means of the corresponding subject matter of the independent claims. Advantageous embodiments of the invention are the subject matter of dependent claims.

[0008] Following an initial assessment, a comprehensive procedure is provided to support the creation of a digital street map: Capturing an image of the surroundings of a motor vehicle using a camera on the motor vehicle, Determining a skyline contour of the surroundings based on the captured image, Determining the current position of the motor vehicle, Determining a skyline contour descriptor based on the determined skyline contour and the current position, wherein the skyline contour descriptor describes the skyline contour of the vehicle's surroundings relative to the vehicle's current position. Sending the skyline contour descriptor to a remote map server to assist in creating the digital street map.

[0009] A second aspect involves providing a device to assist in the creation of a digital road map, including: a camera which is set up to take an image of the surroundings of a motor vehicle, a processor device which is set up to determine a skyline contour of the environment based on the captured image, a position determination device which is designed to determine the current position of the motor vehicle, wherein the processor setup is configured to determine a skyline contour descriptor based on the determined skyline contour and the instantaneous position, wherein the skyline contour descriptor describes the skyline contour of the motor vehicle's surroundings relative to the motor vehicle's instantaneous position, a communication device which is set up to send the skyline contour descriptor to a remote map server to assist it in creating the digital street map.

[0010] According to a third aspect, a motor vehicle is provided, comprising the device according to the second aspect.

[0011] Following a fourth aspect, a procedure for creating a digital road map is provided, comprising the following steps: Receiving a skyline contour descriptor, wherein the skyline contour descriptor describes a skyline contour of the motor vehicle's environment relative to a position of the motor vehicle, Creating the digital street map based on the skyline contour descriptor.

[0012] A fifth aspect involves providing a server for creating a digital street map, including: a communication device which is configured to receive a skyline contour descriptor, wherein the skyline contour descriptor describes a skyline contour of the environment of the motor vehicle relative to a position of the motor vehicle, a processor setup which is configured to create the digital street map based on the skyline contour descriptor.

[0013] According to a sixth aspect, a computer program is provided which includes instructions that, when executed by a computer, cause it to perform a procedure according to the first aspect and / or according to the fourth aspect.

[0014] According to a seventh aspect, a machine-readable storage medium is provided on which the computer program is stored according to the sixth aspect.

[0015] The invention is based on the understanding that the above problem is solved by using a camera mounted on the vehicle to capture an image of the vehicle's surroundings. The skyline contour of the surroundings is extracted from the captured image. Furthermore, the vehicle's instantaneous position is determined. Subsequently, a skyline contour descriptor is generated based on the extracted skyline contour and the vehicle's instantaneous position. This skyline contour descriptor describes the skyline contour of the vehicle's surroundings relative to the vehicle's instantaneous position. Thus, the skyline contour is a position-specific skyline contour. The skyline contour is therefore the skyline contour visible from the vehicle's instantaneous position.

[0016] The skyline contour descriptor is sent to the remote map server to assist it in creating the digital street map, provided it can efficiently create a digital street map based on the skyline contour descriptor.

[0017] Typical digital road maps generally include information about traffic infrastructure elements, such as traffic lights or road signs, which enables a vehicle to drive, at least partially, autonomously. Such information from a digital road map is relevant, for example, when lane markings are obscured by dirt or snow, making them invisible to the vehicle's environmental sensors. In such cases, the vehicle can locate itself on the digital road map, provided that traffic infrastructure elements like traffic lights or road signs can still be detected by an environmental sensor even when the road surface is dirty or covered in snow.

[0018] However, if, for example, no such traffic infrastructure elements are present in the vicinity of the vehicle, localization based on a digital road map can be difficult. According to the concept described here, the skyline contour from a specific position of the vehicle is used to create a digital road map. Therefore, such a digital road map contains information about a skyline contour at a specific location within the map.

[0019] Thus, for example, a vehicle can efficiently locate itself during operation by comparing the skyline contour captured during operation with the skyline contour shown on the digital road map. Localization is therefore possible even when there are no prominent landmarks or traffic infrastructure elements in the vicinity of the vehicle.

[0020] The use of a camera within the framework of the concept described here offers the particular technical advantage that cameras are inexpensive and easy to implement. Modern vehicles are generally already equipped with a camera, for example, to capture the surroundings for driver assistance functions such as lane keeping assist. Therefore, a camera already installed in the vehicle can be used for the concept described here. Thus, a camera already installed in the vehicle can be used efficiently.

[0021] The concept described here can be scaled to a large number of motor vehicles, so that a large number of skyline contour descriptors can be sent to and received from the remote server, enabling it to efficiently create the digital road map based on this large amount of information.

[0022] This results in the particular technical advantage of providing a concept to support the creation of a digital road map and the creation of a digital road map.

[0023] Process characteristics arise analogously from corresponding device characteristics and server characteristics, and vice versa. This means, in particular, that characteristics of the process according to the first aspect arise from corresponding characteristics of the device according to the second aspect and / or of the motor vehicle according to the third aspect and / or of the process according to the fourth aspect and / or of the server according to the fifth aspect.

[0024] The device according to the second aspect is, for example, programmed to execute a computer program according to the sixth aspect, which includes instructions that, when the computer program is executed by a computer, cause it to execute a procedure according to the first aspect.

[0025] The server according to the fifth aspect is, for example, programmed to execute a computer program according to the sixth aspect, which includes commands that, when the computer program is executed by a computer, cause it to execute a procedure according to the fourth aspect.

[0026] A method in the sense of the description is, for example, a computer-implemented method.

[0027] The procedure according to the first aspect is carried out, for example, using the device according to the second aspect. The device according to the second aspect is, for example, configured to perform all the steps of the procedure according to the first aspect.

[0028] The procedure according to the fourth aspect is carried out, for example, using the server according to the fifth aspect. The server according to the fifth aspect is, for example, configured to execute all steps of the procedure according to the fourth aspect.

[0029] The terms “horizon” or “silhouette” can also be used instead of “skyline”.

[0030] The embodiments and examples described here can be combined in any way, even if this is not explicitly described.

[0031] In one embodiment of the method according to the first aspect, it is provided that the recorded image is segmented in order to define the sky of the surroundings as a segment of the image, whereby the skyline contour is determined based on the defined sky of the surroundings.

[0032] This results, for example, in the technical advantage that the skyline contour can be determined efficiently.

[0033] In one embodiment of the method according to the first aspect, it is provided that the segmentation of the recorded image includes semantic segmentation in order to assign a class to each pixel of the image, which is an element selected from a group of classes, wherein the group includes as elements the sky and at least one further class to define the sky as the segment of the image which is formed by the sky pixels.

[0034] This results, for example, in the technical advantage that segmentation can be carried out efficiently. According to this embodiment, a semantic meaning is assigned to each pixel of the image: a class from a group of classes.

[0035] Another class in the sense of the description is, for example, one of the following classes: road, pedestrian, motor vehicle, building, road user, road infrastructure element, cyclist, motorcycle, vegetation.

[0036] In one embodiment of the method according to the first aspect, it is provided that the determined skyline contour of the environment is projected onto a unit sphere to obtain a projected skyline contour, wherein the skyline contour descriptor is determined based on the projected skyline contour.

[0037] This results, for example, in the technical advantage that the projected skyline contour is rotationally invariant, camera-invariant, and easily indexable and searchable in the digital map.

[0038] In one embodiment of the method, it is provided that landmark data is determined on the vehicle side, which describes a landmark in the vicinity of the vehicle, and that the landmark data is sent to the remote server.

[0039] This results, for example, in the technical advantage that the remote server can be efficiently supported in creating the digital road map. The server uses, for example, the received landmark data to create the digital road map.

[0040] The determination of landmark data is carried out, for example, using the captured image of the surroundings. This means, for example, that one or more landmarks are extracted from the captured image and described by the landmark data.

[0041] For example, an additional environmental sensor can be provided to the vehicle to detect its surroundings and output environmental sensor data based on this detection. Based on this environmental sensor data, one or more landmarks can be identified.

[0042] Thus, the vehicle-side determination of landmark data includes, for example, capturing the vehicle's surroundings using one or more of the vehicle's environmental sensors in order to determine environmental sensor data based on the capture.

[0043] A landmark in the sense of the description is, for example, one of the following landmarks: infrastructure element, in particular traffic infrastructure element, for example traffic signal system or traffic sign, bridge, building, lamppost, pillar, fence.

[0044] In one embodiment of the method according to the fourth aspect, it is provided that the creation of the digital road map is an update of an already existing digital road map, so that an updated digital road map is created.

[0045] This results, for example, in the technical advantage that the existing digital road map can be updated efficiently.

[0046] In one embodiment of the method according to the fourth aspect, it is provided that a rotation alignment is carried out between the skyline contour and the existing digital road map in order to obtain a rotationally aligned skyline contour on the basis of which the existing digital road map is updated.

[0047] This results, for example, in the technical advantage that the street map can be updated efficiently. In particular, it results in the technical advantage that the rotationally aligned skyline contour fits correctly into the existing street map.

[0048] In one embodiment of the method according to the fourth aspect, it is provided that the update includes enriching the existing digital street map with the skyline contour descriptor and / or with the rotationally aligned skyline contour.

[0049] This results, for example, in the technical advantage that the existing digital road map can be enriched with particularly suitable information.

[0050] In one embodiment of the method according to the fourth aspect, it is provided that the updating includes updating an existing skyline contour descriptor of the existing digital street map based on the skyline contour descriptor and / or based on the rotationally aligned skyline contour.

[0051] This results, for example, in the technical advantage that an existing skyline contour descriptor can be efficiently updated.

[0052] In an embodiment of the method according to the fourth aspect, it is provided that a transition rule is determined which specifies how the skyline contour and / or the rotationally aligned skyline contour transitions into another (rotationally aligned) skyline contour of another skyline contour descriptor, whose described position is adjacent to the position described by the skyline contour descriptor, wherein the digital street map is created based on the determined transition rule.

[0053] This results, for example, in the technical advantage that a skyline contour can be efficiently determined based on the street map even for places for which no real measurement was available.

[0054] Furthermore, this allows for a particularly compact representation or description of the skyline contours at various locations on the digital street map.

[0055] A generated digital street map therefore includes, in particular, the skyline contour descriptor and / or the skyline contour and / or the determined transitional provision.

[0056] Sending and / or receiving, as described, includes, for example, sending and / or receiving via one or more communication networks, such as a wired communication network, such as an Ethernet communication network, or a wireless communication network, such as a WLAN communication network or a mobile network.

[0057] A processor system as described includes, for example, one or more processors.

[0058] A server as described is, for example, implemented in a cloud infrastructure.

[0059] The phrase “at least one” means “one or more”.

[0060] In addition to the position, it may be generally intended, for example, to determine the orientation of the vehicle, so that the skyline contour descriptor is determined based on the determined orientation. Thus, a correspondingly determined skyline contour descriptor describes the skyline contour of the vehicle's surroundings relative to its current position and orientation.

[0061] Therefore, for example, an orientation determination device is provided, which is designed to determine the current orientation of the motor vehicle.

[0062] The position determination device and the orientation determination device are, for example, implemented as a joint position-orientation determination device.

[0063] The combination of orientation and position can also be described as the location or pose of the motor vehicle.

[0064] Thus, it may be intended, for example, to determine not only the position, but also the general location or pose of the motor vehicle. The term "position" can therefore be expanded or replaced, in particular, by "pose" or "location".

[0065] One example of a camera is a front camera.

[0066] The invention is explained in more detail below using preferred embodiments. These show: Fig. 1 a flowchart of a method according to the first aspect, Fig. 2 a device according to the second aspect, Fig. 3 a motor vehicle according to the third aspect, Fig. 4. A flowchart of a procedure according to the fourth aspect. Fig. 5 a server according to the fifth aspect, Fig. 6 a machine-readable storage medium according to the seventh aspect, Fig. 7. A picture of the surroundings of a motor vehicle. Fig. 8 the image of the Fig. 7 with the skyline outline drawn in, Fig. 9 a projection of a skyline contour onto a unit sphere, Fig. 10 a digital street map and Fig. 11 a block diagram.

[0067] Fig. Figure 1 shows a flowchart of a procedure to support the creation of a digital road map, comprising: Taking 101 a picture of the surroundings of a motor vehicle by a camera of the motor vehicle, Determine 103 a skyline contour of the surroundings based on the captured image, Determine 105 a current position of the motor vehicle, Determine 107 a skyline contour descriptor based on the determined skyline contour and the instantaneous position, wherein the skyline contour descriptor describes the skyline contour of the environment of the motor vehicle relative to the instantaneous position of the motor vehicle, Send 109 of the skyline contour descriptor to a remote map server to assist in creating the digital street map.

[0068] Fig. Figure 2 shows a device 201 for assisting in the creation of a digital road map, comprising: a camera 203, which is set up to take an image of the surroundings of a motor vehicle, a processor unit 205, which is configured to determine a skyline contour of the surroundings based on the captured image, a position determination device 207, which is designed to determine a current position of the motor vehicle, wherein the processor device 205 is configured to determine a skyline contour descriptor based on the determined skyline contour and the instantaneous position, wherein the skyline contour descriptor describes the skyline contour of the environment of the motor vehicle relative to the instantaneous position of the motor vehicle, a communication device 209, which is set up to send the skyline contour descriptor to a remote map server to assist it in creating the digital street map.

[0069] Fig. Figure 3 shows a motor vehicle 301 comprising the device 201 of the Fig. 2.

[0070] Fig. Figure 4 shows a flowchart of a procedure for creating a digital street map, comprising the following steps: Receiving 401 of a skyline contour descriptor, where the skyline contour descriptor describes a skyline contour of the motor vehicle's surroundings relative to a position of a motor vehicle, Create 403 of the digital street map based on the skyline contour descriptor.

[0071] Fig. Figure 5 shows a 501 server for creating a digital street map, including: a communication device 503 which is configured to receive a skyline contour descriptor, wherein the skyline contour descriptor describes a skyline contour of the environment of the motor vehicle relative to a position of the motor vehicle, a processor unit 505, which is configured to create the digital street map based on the skyline contour descriptor.

[0072] Fig. Figure 6 shows a machine-readable storage medium 601 on which a computer program 603 is stored. The computer program 603 comprises instructions which, when the computer program 603 is executed by a computer, for example by the device 201 and / or by the server 501, cause it to execute a procedure according to the first aspect and / or according to the second aspect.

[0073] Fig. Figure 7 shows image 701 of the surroundings of a motor vehicle from the perspective of the motor vehicle, so that the vehicle itself is not visible in the captured image. Image 701 was captured by a camera on the motor vehicle. This camera is, for example, a front camera.

[0074] Several road users are in the vicinity of the motor vehicle, one of which is exemplified by reference sign 703: another motor vehicle. The motor vehicle is traveling on road 705.

[0075] According to the concept described here, for example, image 701 is semantically segmented to determine the sky pixels. The sky is labeled with the reference symbol 707.

[0076] Fig. Figure 8 shows the result after semantic segmentation. The skyline contour 801, which was determined based on the semantic segmentation, is shown.

[0077] The skyline contour 801, for example, can be sent to the remote server along with the current position of the vehicle. The determined skyline contour can then be projected onto a unit sphere to obtain a projected skyline contour, which is subsequently sent to the remote server.

[0078] In general, based on the skyline contour 801 and the current position of the motor vehicle, a skyline contour descriptor is determined that describes the skyline contour of the motor vehicle's surroundings relative to the current position of the motor vehicle.

[0079] In addition to the position, it may be generally intended, for example, to determine the orientation of the vehicle, so that the skyline contour descriptor is determined based on the determined orientation. Thus, a correspondingly determined skyline contour descriptor describes the skyline contour of the vehicle's surroundings relative to its current position and orientation.

[0080] Therefore, for example, an orientation determination device is provided, which is designed to determine the current orientation of the motor vehicle.

[0081] The position determination device and the orientation determination device are, for example, implemented as a joint position-orientation determination device.

[0082] The combination of orientation and position can also be described as the location or pose of the motor vehicle.

[0083] Thus, it may be intended, for example, to determine not only the position, but also the general location or pose of the motor vehicle. The term "position" can therefore be expanded or replaced, in particular, by "pose" or "location".

[0084] The step of determining the current position of the motor vehicle can be carried out simultaneously with the step of taking the picture of the motor vehicle's surroundings, or before or after it.

[0085] Fig. Figure 9 shows a projection of a skyline contour onto a unit sphere.

[0086] In detail, Fig. 9 an image 901 of a mountain 903. The skyline contour is marked with the reference symbol 905.

[0087] This is projected onto the unit sphere 907. The projected skyline contour is marked with the reference symbol 909.

[0088] Fig. Figure 10 shows a digital road map 1001. For example, a first location 1003 and a second location 1005 are marked on the digital road map 1001.

[0089] The reference symbol 1007 designates the unit sphere.

[0090] A projected skyline outline is shown for each of these two locations, 1003 and 1005. Thus, the first projected skyline outline, 1009, is assigned to the first location, 1003. Similarly, the second projected skyline outline, 1011, is assigned to the second location, 1005.

[0091] Furthermore, the digital road map 1001 includes a transitional provision 1013, which specifies how the first skyline contour 1009 transitions into the second skyline contour 1005 when moving directly from the first location 1003 to the second location 1005.

[0092] Skyline contours 1009 and 1011, for example, may be rotationally aligned skyline contours.

[0093] Fig. Figure 11 shows a block diagram 1101, which illustrates the concept described here by way of example.

[0094] According to function block 1103, a skyline contour is determined according to the concept described here. Function block 1105 stipulates that a skyline contour descriptor is determined based on the calculated skyline contour, also according to the concept described here. Both function blocks 1103 and 1105 are executed on the vehicle side, i.e., within the vehicle. To symbolically indicate this, a symbol with the reference numeral 1107 is used, which encompasses both function blocks 1103 and 1105. On the vehicle side, the calculated skyline contour descriptor is sent to a remote server 1109. All subsequent function blocks described, which are located within server 1109, are therefore executed server-side.

[0095] According to a function block 1111, a rotation alignment is performed between the skyline contour and an existing digital street map to obtain a rotationally aligned skyline contour.

[0096] According to function block 1113, it is determined whether the position described by the skyline contour descriptor is a new position for which no skyline contour descriptor has yet been received, i.e., for which there is no skyline contour in the digital street map.

[0097] If, according to function block 1113, it has been determined that there is no skyline contour for this location or position in the digital street map, the rotationally aligned skyline contour is stored or assigned to this location.

[0098] If no, i.e., if a skyline contour already exists for this location, the existing skyline contour or the existing rotationally aligned skyline contour will be updated based on the rotationally aligned skyline contour according to function block 1111.

[0099] After assigning the rotationally aligned skyline contour to the new location according to function block 1115, function block 1119 provides that a transition rule is determined from this new location to neighboring locations for which there are rotationally aligned skyline contours, which specifies how the rotationally aligned skyline contour of the new location can be transformed or transitioned into the corresponding further rotationally aligned skyline contours of the neighboring locations or positions.

[0100] Server 1109 updates an existing digital road map. The updated digital road map is symbolically marked by a block with the reference symbol 1121. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] WO 2022 / 016044 A1

[0002] DE 11 2020 002 764 T5

[0003] WO 2021 / 138618

[0003] DE 10 2009 050 505 A1

[0004] US 11,107,244 B1

[0005]

Claims

[1] A method for assisting in the creation of a digital road map (1001), comprising: Recording (101) an image of an environment of a motor vehicle (301) by a camera of the motor vehicle (301), Determining (103) a skyline contour of the surroundings based on the recorded image (701), Determining (105) a current position of the motor vehicle (301), Determining (107) a skyline contour descriptor based on the determined skyline contour and the current position, wherein the skyline contour descriptor describes the skyline contour of the surroundings of the motor vehicle (301) related to the current position of the motor vehicle (301), Sending (109) the skyline contour descriptor to a remote map server to assist it in creating the digital road map (1001). [2] The method of claim 1, wherein the captured image (701) is segmented to define the surrounding sky as a segment of the image, wherein the skyline contour is determined based on the defined surrounding sky. [3] The method of claim 2, wherein segmenting the captured image (701) comprises semantic segmentation to assign to each pixel of the image a class which is an element selected from a group of classes, the group comprising as elements the sky and at least one further class to define the sky as the segment of the image formed by the sky pixels. [4] Method according to one of the preceding claims, wherein the determined skyline contour of the environment is projected onto a unit sphere (907, 1007) to obtain a projected skyline contour (909, 1009, 1011), wherein the skyline contour descriptor is determined based on the projected skyline contour (909, 1009, 1011). [5] Method according to one of the preceding claims, wherein landmark data describing a landmark in the surroundings of the motor vehicle (301) are determined on the motor vehicle side, wherein the landmark data are sent to the remote server. [6] Device (201) for assisting in the creation of a digital road map (1001), comprising: a camera (203) which is arranged to take an image of the surroundings of a motor vehicle (301), a processor device (205) which is configured to determine a skyline contour of the surroundings based on the recorded image (701), a position determination device (207) which is arranged to determine a current position of the motor vehicle (301), wherein the processor device (205) is configured to determine a skyline contour descriptor based on the determined skyline contour and the current position, wherein the skyline contour descriptor describes the skyline contour of the surroundings of the motor vehicle (301) related to the current position of the motor vehicle (301), a communication device (209) which is arranged to send the skyline contour descriptor to a remote map server in order to assist it in creating the digital road map (1001). [7] Motor vehicle (301) comprising the device (201) according to claim 6. [8] Method for creating a digital road map (1001), comprising the following steps: Receiving (401) a skyline contour descriptor, wherein the skyline contour descriptor describes a skyline contour of the surroundings of the motor vehicle (301) related to a position of a motor vehicle (301), Creating (403) the digital road map (1001) based on the skyline contour descriptor. [9] The method of claim 8, wherein creating the digital road map (1001) is updating an already existing digital road map (1001) so that an updated digital road map (1001) is created. [10] The method according to claim 9, wherein a rotational alignment between the skyline contour and the pre-existing digital road map (1001) is performed to obtain a rotationally aligned skyline contour, based on which the pre-existing digital road map (1001) is updated. [11] Method according to claim 9 or 10 with regard to the rotationally aligned skyline contour as far as dependent on claim 10, wherein the updating comprises enriching the already existing digital road map (1001) with the skyline contour descriptor and / or with the rotationally aligned skyline contour. [12] Method according to one of claims 9 to 11 with regard to the rotationally aligned skyline contour as far as dependent on claim 10, wherein the updating comprises updating an already existing skyline contour descriptor of the already existing digital road map (1001) based on the skyline contour descriptor and / or based on the rotationally aligned skyline contour. [13] Method according to one of claims 8 to 12 with regard to the rotationally aligned skyline contour as far as dependent on claim 10, wherein a transition rule is determined which indicates how the skyline contour and / or the rotationally aligned skyline contour transitions into a further (rotationally aligned) skyline contour of a further skyline contour descriptor whose described position is adjacent to the position described by the skyline contour descriptor, wherein the digital road map (1001) is created based on the determined transition rule. [14] Server (501) for creating a digital road map (1001), comprising: a communication device which is configured to receive a skyline contour descriptor, wherein the skyline contour descriptor describes a skyline contour of the surroundings of the motor vehicle (301) related to a position of a motor vehicle (301), a processor device which is arranged to create the digital road map (1001) based on the skyline contour descriptor. [15] Computer program (601) comprising instructions which, when the computer program (601) is executed by a computer, cause the computer to carry out a method according to one of claims 1 to 5 and / or 8 to 13. [16] Machine-readable storage medium (603) on which the computer program (601) according to claim 15 is stored.

Images