Method and device for generating topographic map

Abstract

The present application provides a method and device for generating a topographic map, wherein the method comprises: obtaining a group of topographic maps to be processed, the group of topographic maps to be processed comprising: a first orthophoto map corresponding to a first site, a first DEM map, a second orthophoto map corresponding to a second site, and a second DEM map; performing positioning auxiliary feature detection on the second orthophoto map to determine the auxiliary feature target area in the second orthophoto map; determining the relative position between the first site and the second site according to the auxiliary feature target area, the second DEM map, and the first DEM map; obtaining a global topographic map according to the relative position and the group of topographic maps to be processed. The present application can improve the automation and accuracy of generating a global topographic map, thereby improving the reliability of unmanned vehicle detection tasks.

Description

Technical Field

[0001] The present application relates to the field of aerospace measurement and control technology, and in particular to a method and device for generating a topographic map. Background Art

[0002] In the execution of unmanned vehicle detection tasks such as celestial body patrols and exploration of unknown areas, the process of "stop moving - fixed-point perception and imaging - stop imaging perception - terrain reconstruction and positioning mapping based on imaging - route planning based on mapping results - start moving" is repeated to implement mobile detection.

[0003] In the process of mobile detection by unmanned vehicles, the key processing link in the inspection is to use site imaging to reconstruct terrain and make topographic maps. Since there is no imaging during the mobile process, the usual method is to construct terrain based on the images of independent detection sites and locate the relative position of the unmanned vehicles between sites. The two processes are completed independently, and then the results of the two are combined to complete the global planning results and generate topographic maps.

[0004] In the existing methods, terrain reconstruction only reconstructs the image data of the detection site, while the position calculation between the sites is directly based on the registration of the images of the two sites. Due to the large difference in image resolution between the sites, the success rate of automatic matching is low, resulting in a low degree of automation in the relative position calculation, which makes the final global terrain map production slow. Summary of the invention

[0005] In response to the problems in the prior art, the present application proposes a method and device for generating a terrain map, which can improve the degree of automation and accuracy in generating a global terrain map, thereby improving the reliability of unmanned vehicle detection tasks.

[0006] In order to solve the above technical problems, this application provides the following technical solutions:

[0007] In a first aspect, the present application provides a method for generating a topographic map, comprising:

[0008] Obtaining a group of topographic maps to be processed, the group of topographic maps to be processed comprising: a first orthophoto map corresponding to a first site, a first DEM map, a second orthophoto map corresponding to a second site, and a second DEM map;

[0009] Performing positioning auxiliary feature detection on the second orthophoto image to determine an auxiliary feature target area in the second orthophoto image;

[0010] Determining a relative position between the first site and the second site according to the auxiliary feature target area, the second DEM map and the first DEM map;

[0011] A global topographic map is obtained according to the relative position and the group of topographic maps to be processed.

[0012] Furthermore, the performing positioning auxiliary feature detection on the second orthophoto image to determine the auxiliary feature target area in the second orthophoto image includes:

[0013] According to the second orthophoto map, determine the connection lines between the center point and each non-center pixel point; the center point is the pixel point corresponding to the shooting position of the stereo image sequence of the second station in the second orthophoto map; the non-center pixel point is the pixel point other than the center point in the second orthophoto map;

[0014] According to the connecting line corresponding to each non-central pixel point, determine the first pixel brightness standard deviation of a preset number of pixel points along the connecting line of the non-central pixel point with the non-central pixel point as the center, and the second pixel brightness standard deviation of a preset number of pixel points in a direction perpendicular to the connecting line of the non-central pixel point;

[0015] Determine whether there is a non-central pixel point in the second orthophoto image whose corresponding first pixel brightness standard deviation is less than the first standard deviation threshold and whose second pixel brightness standard deviation is greater than the second standard deviation threshold, and if so, determine that the non-central pixel point is a candidate auxiliary feature;

[0016] It is determined whether there are a plurality of adjacent candidate auxiliary features in the second orthophoto image. If so, the auxiliary feature target area is formed according to the adjacent candidate auxiliary features.

[0017] Further, determining the relative position between the first site and the second site according to the auxiliary feature target area, the second DEM map and the first DEM map includes:

[0018] Perform feature terrain matching positioning according to the auxiliary feature target area, the first DEM map and the second DEM map, determine the same-name registration points in the first DEM map and the second DEM map and the three-dimensional coordinate information of the same-name registration points in the first site coordinate system and the second site coordinate system respectively;

[0019] Determine the initial correspondence relationship of the same-name registration points according to the camera imaging projection relationship and the three-dimensional coordinate information;

[0020] According to the affine transformation least squares model and the initial correspondence relationship of the same-name registration points, an accurate correspondence relationship of the same-name registration points is obtained;

[0021] The relative position is obtained according to the three-dimensional coordinate information of the same-name registration points in the first site coordinate system and the second site coordinate system, a preset imaging relationship, a precise corresponding relationship of the same-name registration points and an optimization method.

[0022] Further, performing feature terrain matching positioning according to the auxiliary feature target area, the first DEM map and the second DEM map, determining the same-name registration points in the first DEM map and the second DEM map and the three-dimensional coordinate information of the same-name registration points in the first site coordinate system and the second site coordinate system respectively, includes:

[0023] If there are multiple auxiliary feature target areas, the maximum radius value among the radius values ​​of the auxiliary feature target areas and the first center position of each auxiliary feature target area are obtained, and all the first center positions form a circumscribed rectangle as an initial rectangle;

[0024] The coordinate value of the upper left point of the initial rectangle is reduced by the maximum radius value in both coordinate directions, and the coordinate value of the lower right point of the initial rectangle is increased by the maximum radius value in both coordinate directions to obtain a target rectangle, determine the area corresponding to the target rectangle in the second DEM map as the matching area, and determine the second center position of the matching area;

[0025] Determine, according to a terrain matching method, a matching area position corresponding to the second center position in the first DEM map;

[0026] According to the matching area position, determine the matching position corresponding to each first center position in the first DEM map, and the three-dimensional coordinate information of each first center position and its matching position; wherein the first center position and its corresponding position in the first DEM map are the same-name registration points, the three-dimensional coordinate information of the first center position is the three-dimensional coordinate information of the same-name registration point in the second site coordinate system, and the three-dimensional coordinate information of the matching position is the three-dimensional coordinate information of the same-name registration point in the first site coordinate system.

[0027] Further, the relative position is obtained according to the three-dimensional coordinate information of the same-name registration points in the first site coordinate system and the second site coordinate system, the preset imaging relationship, the precise correspondence relationship of the same-name registration points and the optimization method, including:

[0028] Constructing an objective function based on the three-dimensional coordinate information of the same-name registration points in the first site coordinate system and the second site coordinate system, the preset imaging relationship and the precise correspondence relationship of the same-name registration points;

[0029] The objective function is optimized to determine the relative position between the first site and the second site when the objective function value is minimum.

[0030] Further, obtaining a global topographic map according to the relative position and the topographic map group to be processed includes:

[0031] Determine corrected three-dimensional coordinate information corresponding to the pixel points in the second orthophoto image and the second DEM image according to the relative position, the three-dimensional coordinate information of the pixel points in the second orthophoto image and the second DEM image;

[0032] Determine the texture grayscale value and elevation value of the pixel point after correction according to the three-dimensional coordinate information before and after correction corresponding to the pixel point in the second orthophoto map and the second DEM map;

[0033] Obtaining a global DEM map according to the three-dimensional coordinate information and elevation values ​​of the pixel points in the first DEM map, and the corrected three-dimensional coordinate information and elevation values ​​corresponding to the pixel points in the second DEM map;

[0034] Obtaining a global orthophoto image according to the coordinate information and texture grayscale values ​​of the pixel points in the first orthophoto image, and the corrected coordinate information and texture grayscale values ​​corresponding to the pixel points in the second orthophoto image;

[0035] The global topographic map includes: a global DEM map and a global orthophoto map.

[0036] In a second aspect, the present application provides a topographic map generating device, comprising:

[0037] An acquisition module is used to acquire a group of topographic maps to be processed, the group of topographic maps to be processed comprising: a first orthophoto map corresponding to a first site, a first DEM map, a second orthophoto map corresponding to a second site, and a second DEM map;

[0038] An area determination module is used to perform positioning auxiliary feature detection on the second orthophoto image to determine an auxiliary feature target area in the second orthophoto image;

[0039] A relative position determination module, used to determine the relative position between the first site and the second site according to the auxiliary feature target area, the second DEM map and the first DEM map;

[0040] The obtaining module is used to obtain a global topographic map according to the relative position and the topographic map group to be processed.

[0041] Furthermore, the region determination module includes:

[0042] A line determination unit is used to determine the lines between the center point and each non-center pixel point according to the second orthophoto image; the center point is the pixel point corresponding to the shooting position of the stereo image sequence of the second station in the second orthophoto image; the non-center pixel point is the pixel point other than the center point in the second orthophoto image;

[0043] A standard deviation determination unit, configured to determine, based on the connecting line corresponding to each non-central pixel point, a first pixel brightness standard deviation of a preset number of pixel points along the connecting line of the non-central pixel point with the non-central pixel point as the center, and a second pixel brightness standard deviation of a preset number of pixel points in a direction perpendicular to the connecting line of the non-central pixel point;

[0044] A first judging unit is used to judge whether there is a non-central pixel point in the second orthophoto image whose corresponding first pixel brightness standard deviation is less than a first standard deviation threshold and whose second pixel brightness standard deviation is greater than a second standard deviation threshold, and if so, determine that the non-central pixel point is a candidate auxiliary feature;

[0045] The second judgment unit is used to judge whether there are multiple adjacent candidate auxiliary features in the second orthophoto image, and if so, form the auxiliary feature target area according to the adjacent candidate auxiliary features.

[0046] In a third aspect, the present application provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method for generating a topographic map when executing the program.

[0047] In a fourth aspect, the present application provides a computer-readable storage medium having computer instructions stored thereon, which implement the topographic map generating method when the instructions are executed.

[0048] It can be seen from the above technical solutions that the present application provides a method and device for generating a topographic map. The method comprises: obtaining a group of topographic maps to be processed, the group of topographic maps to be processed comprising: a first orthophoto map corresponding to a first site, a first DEM map, a second orthophoto map corresponding to a second site, and a second DEM map; performing positioning auxiliary feature detection on the second orthophoto map to determine an auxiliary feature target area in the second orthophoto map; determining the relative position between the first site and the second site according to the auxiliary feature target area, the second DEM map, and the first DEM map; obtaining a global topographic map according to the relative position and the group of topographic maps to be processed, which can improve the automation and accuracy of generating a global topographic map, and thus improve the reliability of the unmanned vehicle detection task; specifically, the three-dimensional terrain data reconstructed between adjacent sites can be used to extract and match auxiliary positioning features and reversely project, which can provide accurate matching initial values ​​for image matching between adjacent sites, can significantly improve the reliability of automatic image matching, integrate the two processes of terrain construction and positioning calculation, can reduce manual intervention in the process of global topographic map construction, can improve the automation and accuracy of topographic map construction, and can improve the efficiency of global topographic map construction based on unmanned vehicles. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0050] Figure 1 is a schematic diagram of a flow chart of a method for generating a topographic map in an embodiment of the present application;

[0051] Figure 2 This is a schematic diagram of terrain reconstruction by imaging two stations of the probe vehicle in an embodiment of the present application;

[0052] Figure 3 is a flowchart of steps 210 to 240 of the method for generating a topographic map in an embodiment of the present application;

[0053] Figure 4 It is a logical schematic diagram of the second orthophoto map, imaging light, local area, and angles between connecting lines and image coordinate axes in the embodiment of the present application;

[0054] Figure 5 is a flowchart of steps 310 to 340 of the method for generating a topographic map in an embodiment of the present application;

[0055] Figure 6 is a schematic diagram of comparison between an initial rectangle and a target rectangle in an embodiment of the present application;

[0056] Figure 7 is a flowchart of steps 410 to 440 of the method for generating a topographic map in an embodiment of the present application;

[0057] Figure 8 It is a schematic diagram of the flow of the topographic map generation method in the application example of this application;

[0058] Fig. 9 is a schematic structural diagram of a topographic map generating device in an embodiment of the present application;

[0059] Fig.10 is a schematic structural diagram of a topographic map generating device in another embodiment of the present application;

[0060] Fig.11 A schematic block diagram of the system structure of an electronic device according to an embodiment of the present application. DETAILED DESCRIPTION

[0061] In order to enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0062] In the prior art, an independent link calculation method is usually used to independently implement terrain reconstruction and relative position positioning between sites. During the movement process, the terrain reconstruction process is carried out at each site, and the input is the environmental image collected by the site. The main steps of the processing process include stereo image matching, spatial point cloud computing, interpolation processing and other processes to obtain the three-dimensional terrain of the site. The purpose of relative position positioning between sites is to calculate the relative position between the detection sites during the movement. The relative position calculation method between sites is to use the imaging of the positions of two consecutive detection sites as input, and through the image registration results between the site imaging, the beam adjustment equation is constructed according to the principle of pinhole imaging of light linear propagation, and the relative position between two consecutive sites is obtained through optimization and solution. After the relative position positioning of the site is performed through the images between the consecutive sites, the three-dimensional terrain reconstruction results between the above-mentioned consecutive sites are converted into a unified coordinate system to produce a global terrain map as the input for the unmanned vehicle's mobile path planning.

[0063] In view of the low reliability of automatic direct two-dimensional image matching and positioning between consecutive sites in unmanned vehicle detection tasks, this application considers the orthophoto DOM positioning auxiliary feature detection method, the terrain matching positioning method of positioning auxiliary features, and the image same-name feature point registration method guided by reverse projection, etc., and proposes a topographic map generation method and device, which uses the orthophoto DOM in the initial topographic map to perform feature target detection and terrain matching positioning, and performs reverse projection based on terrain matching positioning to provide accurate and effective initial guidance values ​​for the matching of consecutive site images, thereby achieving reliable and automated image matching between sites, and then realizing position resolution between sites, and then introducing terrain reconstruction results to achieve fused rapid and automated topographic map construction; that is, calculations can be performed based on the data products of the two sites to be located, that is, based on the serial stereo images and terrain products of the first site S1 and the second site S2, the relative positions of the two sites are calculated, and a fused topographic map of the two sites is generated based on the calculation results.

[0064] Based on this, in order to improve the automation and accuracy of generating global terrain maps, and thus improve the reliability of unmanned vehicle detection tasks, the present application embodiment provides a terrain map generating device, which can be a server or client device, and the client device can include a smart phone, a tablet electronic device, a network set-top box, a portable computer, a desktop computer, a personal digital assistant (PDA), a vehicle-mounted device, and a smart wearable device, etc. Among them, the smart wearable device can include smart glasses, smart watches, and smart bracelets, etc.

[0065] In practical applications, the part of generating the topographic map can be executed on the server side as described above, or all operations can be completed in the client device. The selection can be made based on the processing capability of the client device and the limitations of the user's usage scenario. This application does not limit this. If all operations are completed in the client device, the client device can also include a processor.

[0066] The client device may have a communication module (i.e., a communication unit) that can communicate with a remote server to achieve data transmission with the server. The server may include a server on the task scheduling center side, and other implementation scenarios may also include a server on an intermediate platform, such as a server on a third-party server platform that has a communication link with the task scheduling center server. The server may include a single computer device, or a server cluster consisting of multiple servers, or a server structure of a distributed device.

[0067] The server and the client device may communicate using any suitable network protocol, including network protocols that have not yet been developed on the date of filing this application. The network protocol may include, for example, TCP / IP protocol, UDP / IP protocol, HTTP protocol, HTTPS protocol, etc. Of course, the network protocol may also include, for example, RPC protocol (Remote Procedure Call Protocol) and REST protocol (Representational State Transfer) used on top of the above protocols.

[0068] It should be noted that the topographic map generation method and device disclosed in the present application can be used in the fields of aerospace measurement and control technology, as well as in the fields of information technology and automatic control technology. The application field of the topographic map generation method and device disclosed in the present application is not limited.

[0069] The details are described through the following embodiments.

[0070] In order to improve the automation and accuracy of generating global terrain maps, and thus improve the reliability of unmanned vehicle detection tasks, this embodiment provides a terrain map generation method in which the execution subject is a terrain map generation device, and the terrain map generation device includes but is not limited to a server, such as Figure 1 As shown, the method specifically includes the following contents:

[0071] Step 100: Obtain a group of topographic maps to be processed, the group of topographic maps to be processed comprising: a first orthophoto map corresponding to a first site, a first DEM map, a second orthophoto map corresponding to a second site, and a second DEM map.

[0072] Specifically, the first orthophoto map and the first DEM map are the orthophoto map and the DEM map corresponding to the first site; the second orthophoto map and the second DEM map are the orthophoto map and the DEM map corresponding to the second site; Figure 2 As shown, a binocular camera 2 is installed on the exploration vehicle 1 at a single site. The terrain reconstruction process of a single site may include: imaging the field of view with the binocular camera 2 installed on the exploration vehicle 1 at the single site to obtain left and right eye images. The single site may be site S1 or site S2; imaging at the first site S1 to obtain a stereo image sequence I S1 1~I S1 n , generate DEM and DOM topographic maps based on stereo image sequences S1 After patrolling, the probe car arrives at site S2 and obtains a stereoscopic image sequence I at this site. S2 1~I S2 n , generate DEM, DOM topographic map M S2 That is, image matching can be performed based on the left and right stereo images, spatial front intersection, and then regular grid interpolation can be performed to obtain a topographic map (including: orthophoto map and DEM map) in the current site coordinate system.

[0073] Specifically, the topographic map M in the coordinate system of site S1 is obtained based on the stereoscopic image sequence at site S1. S1 , at the site S2 adjacent to the site S1, obtain the topographic map M in the coordinate system of the site S2 S2 (Including: orthophoto map and DEM map). The topographic data of a single site is obtained using the following method:

[0074] 1) Left and right image matching: Since it is a stereo pair, the classic least squares correlation method can be used to match and obtain the corresponding relationship between pl(x, y) and pr(x, y);

[0075] 2) According to the camera installation parameters R, T, the camera internal parameters such as f, x0 and y0, and the collinear equation, the left and right sides are intersected to obtain the spatial point cloud;

[0076] 3) Based on the spatial point cloud, the Kriging method is used for interpolation to obtain a topographic map in the S1 coordinate system; the method for obtaining the topographic map in the S2 coordinate system is similar; the first station may be station S1, and the second station may be station S2.

[0077] Step 200: Perform positioning auxiliary feature detection on the second orthophoto image to determine the auxiliary feature target area in the second orthophoto image.

[0078] Specifically, the DOM terrain product data of the two sites can be used. According to the positioning auxiliary feature detection method, the positioning auxiliary points can be detected on the DOM map of the second site through standard deviation discrimination in local areas in two directions, and then the auxiliary feature target area can be obtained by merging the coherent areas. It can be used as an auxiliary feature for image matching positioning between consecutive sites.

[0079] Step 300: Determine the relative position between the first site and the second site according to the auxiliary feature target area, the second DEM map and the first DEM map.

[0080] Step 400: Obtain a global topographic map according to the relative position and the group of topographic maps to be processed.

[0081] Specifically, the global topographic map may include: a global orthophoto map and / or a global DEM map.

[0082] To further improve the accuracy of determining the target area of ​​auxiliary features, see Figure 3 In one embodiment of the present application, step 200 includes:

[0083] Step 210: According to the second orthophoto image, determine the connecting lines between the center point and each non-center pixel point; the center point is the pixel point corresponding to the shooting position of the stereo image sequence of the second station in the second orthophoto image; the non-center pixel point is the pixel point other than the center point in the second orthophoto image.

[0084] Specifically, the pixel points of the second orthophoto image can be divided into: central points and non-central pixel points.

[0085] Step 220: Based on the lines corresponding to each non-center pixel point, determine the first pixel brightness standard deviation of a preset number of pixels along the line direction of the non-center pixel point with the non-center pixel point as the center, and determine the second pixel brightness standard deviation of a preset number of pixels in a direction perpendicular to the line direction of the non-center pixel point.

[0086] Specifically, the preset number can be set according to actual conditions, and the present application does not impose any restrictions on this; for example, the preset number is 5; the first pixel brightness standard deviation is the pixel brightness standard deviation of a preset number of pixel points in the direction of the line connecting the pixel points, and the second pixel brightness standard deviation is the pixel brightness standard deviation of a preset number of pixel points in the direction vertical to the line connecting the pixel points.

[0087] Step 230: Determine whether there is a corresponding non-central pixel point in the second orthophoto image whose first pixel brightness standard deviation is less than the first standard deviation threshold and whose second pixel brightness standard deviation is greater than the second standard deviation threshold. If so, determine that the non-central pixel point is a candidate auxiliary feature.

[0088] Specifically, the first standard deviation threshold and the second standard deviation threshold may be the same or different; the pixel points whose corresponding first pixel brightness standard deviation in the second orthophoto image is less than the first standard deviation threshold and whose second pixel brightness standard deviation is greater than the second standard deviation threshold may be determined as candidate auxiliary features.

[0089] Step 240: Determine whether there are multiple adjacent candidate auxiliary features in the second orthophoto image. If so, form the auxiliary feature target area based on the adjacent candidate auxiliary features.

[0090] Specifically, the DEM terrain product data of the two sites and the detection results of the DOM positioning auxiliary features can be used to form an external rectangle of the DOM positioning auxiliary features and expand it, and the expanded area can be mapped to the DEM map as a template for terrain matching between the two sites. The relative position calculation of the terrain of the two sites can be realized by using the terrain matching method.

[0091] Specifically, the input data is the orthophoto map DOM of the second site S2, and auxiliary positioning features that can be used for positioning are detected on the orthophoto map; the process of detecting the auxiliary positioning features for the second orthophoto map can be as follows:

[0092] According to the line connecting the center point and a non-center pixel point in the second orthophoto image, the imaging light of the non-center pixel point is formed, and the angle between the imaging light and the image coordinate axis v coordinate direction is θ. According to the consistency of the pixel brightness in the area in the ray θ direction, whether the non-center pixel point is a candidate auxiliary feature is determined. If the brightness in the local area in the imaging light direction of the non-center pixel point is consistent and the brightness in the local area in the vertical direction is inconsistent, then the non-center pixel point is determined to be a candidate auxiliary feature. Scan the entire second orthophoto image to determine whether each non-center pixel point is a candidate auxiliary feature, and merge multiple adjacent candidate auxiliary features in the second orthophoto image to obtain the final auxiliary feature target area.

[0093] like Figure 4As shown, the specific method is as follows: for the non-central pixel point p on the second orthophoto image, i (u, v), a line is drawn from the center point c0 to the non-center pixel, and the angle between the line and the image coordinate axis v is θ. In the vicinity of the non-center pixel, the length d in the θ direction is counted. θ The standard deviation of the pixel brightness of the local area A1 (value 5 pixels) and the length d in the vertical θ direction θ The standard deviation of the pixel brightness of the local area A2 (value 5 pixels), where the length in the θ direction is d θ The local area A1 (value 5 pixels) can be equivalent to the non-central pixel point p i (u,v) is the center, 5 pixels in the θ direction; the length in the vertical θ direction is d θ The local area A2 (value 5 pixels) can be equivalent to the non-central pixel point p i (u, v) is the center, and there are 5 pixels in the vertical θ direction; if the standard deviation of the pixel brightness in the local area in the θ direction is D p1 Less than the threshold D H (take 25), and the standard deviation D of the area in the vertical θ direction p2 Greater than the threshold D V (Take 25), then determine the pixel point p i (u,v) is the auxiliary feature C i ′, all points with point p i The pixels that are connected (u, v) and meet the above conditions are merged into an auxiliary feature target area, denoted by C i After the entire image is processed, the set of all auxiliary feature target areas on the second orthophoto is recorded as

[0094] In order to further improve the accuracy of obtaining the exact correspondence between the same-name registration points and thus improve the reliability of obtaining the relative position, see Figure 5 In one embodiment of the present application, step 300 includes:

[0095] Step 310: Perform feature terrain matching positioning according to the auxiliary feature target area, the first DEM map and the second DEM map to determine the same-name registration points and the three-dimensional coordinate information of the same-name registration points in the first site coordinate system and the second site coordinate system respectively.

[0096] Step 320: Determine the initial correspondence relationship of the registration points with the same name according to the camera imaging projection relationship and the three-dimensional coordinate information.

[0097] Specifically, the three-dimensional coordinate information and the imaging projection matrix of the left-eye camera of the first station can be substituted into the camera imaging projection relationship to obtain the initial registration point of the same-name registration point on the stereo image of the first station (the image in the stereo image sequence); the three-dimensional coordinate information and the imaging projection matrix of the left-eye camera of the second station can be substituted into the camera imaging projection relationship to obtain the initial registration point of the same-name registration point on the stereo image of the second station; according to the initial registration points corresponding to the first station and the second station respectively, the initial corresponding relationship of the same-name registration points is determined.

[0098] Step 330: Obtaining precise correspondence between registration points of the same name based on the affine transformation least squares model and the initial correspondence between registration points of the same name.

[0099] Specifically, according to the initial correspondence relationship between the registration points with the same name, an affine transformation least squares model is applied to perform an iterative solution to determine the precise correspondence relationship between the registration points with the same name corresponding to the stereo images at the first station and the second station.

[0100] Among them, according to the relative position between the two stations given by the DEM terrain matching results, the image points of the same spatial point on the three-dimensional images of the two stations can be calculated by using the spatial point projection imaging relationship. In this way, the image points of the same spatial point imaged by the cameras of the two stations are used as the initial registration points for image registration. With this initial registration point as the initial value, the least squares matching method based on the affine change model is used on the three-dimensional images of the two stations to calculate the precise same-name registration points of the two station images.

[0101] Step 340: Obtain the relative position according to the three-dimensional coordinate information of the same-name registration points in the first site coordinate system and the second site coordinate system, the preset imaging relationship, the precise correspondence relationship of the same-name registration points and the optimization method.

[0102] Specifically, the process of performing feature terrain matching and positioning in step 310 may include:

[0103] 1) Matching area determination: The set of all auxiliary feature target areas on the second orthophoto map is: The superscript indicates the site number, which is 2 here, and the subscript indicates the number of the auxiliary feature target area. The center position of each auxiliary feature target area is represented by Indicates that the radius of the region is calculated based on the area of ​​the region by the formula Get, where S n is the area of ​​the region. The maximum radius is R Max ,by The bounding rectangle of all center positions is the initial rectangle, and the maximum values ​​of the u and v coordinate directions of the bounding rectangle are The minimum values ​​are like Figure 6 As shown, the upper left point of the rectangle (u min ,v min ) Reduce R along the u and v coordinate directions Max , we get (u minnew ,v minnew ); lower right point (u max ,v max ) Increase R along the u and v coordinate directions Max , we get (u maxnew ,v maxnew ), determine the new rectangle as the target rectangle, the maximum values ​​of the new rectangle in the coordinate u and v directions are u maxnew =u max +R max , v maxnew =v max +R max , and their minimum values ​​are u minnew =u min -R max , v minnew =v min -R max , the area corresponding to the target rectangle on the second DEM map is determined as the matching area T2, and the center position of the matching area T2 is P T2 , whose coordinates are P T2 (u T2 ,v T2 ),

[0104] 2) Regional matching positioning calculation: Taking T2 as the template and the DEM topographic map reconstructed at the first station (i.e., the first DEM map mentioned above) M0 as the reference map, the center position P of T2 is obtained through terrain matching. T2 The matching area position P on the first station topographic map M0 T1 The terrain matching method is the classic normalized cross-correlation (COR) method. The correlation coefficient between the real-time map and each point near the initial position of the reference map is calculated, and the correlation coefficient is fitted quadratically to take the extreme point position as the positioning result. Relative to point P on T2 template T2 The positional relationship and the matching point P on M0 T1 (u T1 ,v T1 ), calculate the position point on M0 That is, on the topographic map M0, point The coordinates are Among them, point and The same-name registration points are constructed. According to the DEM terrain data of the first and second stations, by accessing the standard grid DEM map, the X, Y, and Z physical values ​​corresponding to the matching point positions can be read to obtain the three-dimensional coordinate information of the same-name registration points in the first and second station coordinate systems, which are recorded as and

[0105] The process of determining the initial correspondence relationship of the registration points with the same name in step 320 may specifically include:

[0106] Combined DEM, DOM local site reverse projection: according to the corresponding registration point and Using the same-name registration points and The three-dimensional coordinate information in the coordinate system of the first site and the second site is projected by the camera imaging Get the image I of the stereo image sequence of the same-name registration point at the first station S1 i and image I in the stereo image sequence of the second site S2 i Initial correspondence of the same-name registration points on Specifically, the calculation method is in The imaging projection matrices of the left eye cameras at the first and second stations, respectively, can be obtained according to the internal and external parameters of the cameras at the corresponding stations.

[0107] The process of obtaining the precise correspondence between the registration points with the same name in step 330 may specifically include:

[0108] According to I S1 i and I S2 i Initial correspondence of the same-name registration points on Using the affine transformation least squares model, iterative solution is performed to determine I S1 i and I S2 i The exact correspondence between the same-name registration points on

[0109] In order to further improve the automation and accuracy of determining the same-name registration points and the three-dimensional coordinate information of the same-name registration points in the first site coordinate system, in one embodiment of the present application, step 310 includes:

[0110] Step 311: If there are multiple auxiliary feature target areas, obtain the maximum radius value among the radius values ​​of each auxiliary feature target area and the first center position of each auxiliary feature target area, and use all the first center positions to form a circumscribed rectangle as the initial rectangle.

[0111] Specifically, the center position of each auxiliary feature target area is used as the first center position of the auxiliary feature target area.

[0112] Step 312: Reduce the coordinate value of the upper left point of the initial rectangle by the maximum radius value in both coordinate directions, and increase the coordinate value of the lower right point of the initial rectangle by the maximum radius value in both coordinate directions, to obtain the target rectangle and determine the matching area corresponding to the target rectangle in the second DEM map and the second center position of the matching area.

[0113] Specifically, the second center position is the center position P of the matching area T2. T2 .

[0114] Step 313: Determine the matching area position corresponding to the second center position in the first DEM map according to a terrain matching method;

[0115] Specifically, the terrain matching method may be a classical normalized cross correlation (COR) method; the matching area position P T1 is the position corresponding to the second center position in the first DEM map.

[0116] Step 314: According to the matching area position, determine the matching position corresponding to each first center position in the first DEM map, and the three-dimensional coordinate information of each first center position and its matching position; wherein, the first center position and its corresponding position in the first DEM map are the same-name registration points, the three-dimensional coordinate information of the first center position is the three-dimensional coordinate information of the same-name registration point in the second site coordinate system, and the three-dimensional coordinate information of the matching position is the three-dimensional coordinate information of the same-name registration point in the first site coordinate system.

[0117] Specifically, the matching position is the position corresponding to the first center position in the first DEM map.

[0118] In order to obtain a reliable relative position and then use the reliable relative position to improve the accuracy of generating a global terrain map, in one embodiment of the present application, step 340 includes:

[0119] Step 341: construct an objective function based on the three-dimensional coordinate information of the same-name registration points in the first site coordinate system and the second site coordinate system, the preset imaging relationship and the precise correspondence relationship of the same-name registration points.

[0120] Step 342: Optimize the objective function to determine the relative position between the first site and the second site when the objective function value is minimum.

[0121] Specifically, the relative position between the first site and the second site may be the position T of the origin of the second site coordinate system in the first site coordinate system.

[0122] Among them, the reprojection can be optimized to accurately locate the two stations: let the coordinate origin of the second station in the coordinate system of the first station be T, and the image points with the same name accurately matched at the two stations be and In the optimization iterative solution process, the first station image and the second station image (the image in the stereo image sequence of the first station and the second station) are respectively directed to the above-mentioned exact matching image points with the same name and The point that the iteration approaches is p″ i 1 (u″ i 1 ,v″ i 1 ) and p″ i 2 (u″ i 2 ,v″ i 2 ), like point p″ i 1 (u″ i 1 ,v″ i 1 ) and p″ i 2 (u″ i 2 ,v″ i 2 ) corresponds to the spatial point in the first station coordinate system: In the second site coordinate system, The two satisfy the relationship described by the following formula (1), where R is a known quantity, which can be calculated based on the attitude measurement equipment of the camera between the two stations. The precise positioning process between the two stations is the process of solving the T value.

[0123]

[0124] According to the pinhole imaging principle, the corresponding imaging relationship between the spatial object point and the image point is: M P is the imaging projection matrix, which can be obtained according to the internal and external parameters of the camera. The imaging projection matrices of the left camera at the first and second stations are Therefore, for the first site, according to formula (2), the spatial point Calculate the image point p″ i 1 (u″ i 1 ,v″ i 1 ):

[0125]

[0126] The error between the calculated image point and the actual image point is as follows:

[0127]

[0128] Similarly, for the point p″ on the second station image (the image in the stereoscopic image sequence of the second station) i 2 (u″ i 2 ,v″ i 2 ) and the spatial point Through equations (1) and (4), we can get equation (5):

[0129]

[0130]

[0131] The error between the calculated image point and the actual image point is as follows:

[0132]

[0133] The reprojection error minimization point of P1 and P2 on the two-station images, that is, the above objective function is as follows:

[0134]

[0135] Take the N registration points of the same name at the two sites as input, and use the spatial coordinates (x i ,y i ,z i ) and the relative position T between the two stations are taken as independent variables, δ is taken as the optimization target, and the relative position T between the two stations is solved by the optimization method.

[0136] In order to further improve the accuracy and efficiency of obtaining global topographic maps, such as Figure 7 As shown, in one embodiment of the present application, step 400 includes:

[0137] Step 410: Determine corrected three-dimensional coordinate information corresponding to the pixel points in the second orthophoto image and the second DEM image according to the relative position, the three-dimensional coordinate information of the pixel points in the second orthophoto image and the second DEM image;

[0138] Step 420: Determine the texture grayscale value and elevation value of the pixel point after correction according to the three-dimensional coordinate information before and after correction corresponding to the pixel point in the second orthophoto image and the second DEM image;

[0139] Specifically, the texture grayscale value of the pixel point after correction is determined according to the three-dimensional coordinate information before and after correction corresponding to the pixel point in the second orthophoto map; the elevation value of the pixel point after correction is determined according to the three-dimensional coordinate information before and after correction corresponding to the pixel point in the second DEM map.

[0140] Step 430: obtaining a global DEM map according to the three-dimensional coordinate information and elevation values ​​of the pixel points in the first DEM map and the corrected three-dimensional coordinate information and elevation values ​​corresponding to the pixel points in the second DEM map;

[0141] Step 440: Obtain a global orthophoto map based on the coordinate information and texture grayscale values ​​of the pixel points in the first orthophoto map, and the corrected coordinate information and texture grayscale values ​​corresponding to the pixel points in the second orthophoto map; the global topographic map includes: the global DEM map and the global orthophoto map.

[0142] Specifically, the second DEM map and the DOM map are adjusted according to the relative position T, and the correction map can be the adjusted DEM map or DOM map. The original three-dimensional coordinate information corresponding to the pixel point in the second DEM map is: (x2, y2, z2), and the three-dimensional coordinate information corresponding to the pixel point after correction is: (x1, y1, z1); the relationship between (x2, y2, z2) and (x1, y1, z1) is shown in the following formula (8).

[0143]

[0144] (x2, y2, z2) can be determined based on (x1, y1, z1) and T; for the DEM map, the elevation value of the correction map position (x1, y1) is obtained by v′2(x1, y1) = v2(x2, y2) + z T , where v′2(x1,y1) and v2(x2,y2) represent the elevation values ​​of the corresponding positions respectively; for the DOM map, the grayscale value acquisition relationship of the correction map position (x1,y1) is v′2(x1,y1)=v2(x2,y2), where v′2(x1,y1) and v2(x2,y2) represent the grayscale values ​​of the corresponding positions respectively.

[0145] The range of the fused topographic map, i.e., the global topographic map mentioned above, is the union of the topographic map M1 of the first station and the corrected topographic map M′2 of the second station. The two station data corresponding to the adjusted image are fused, and the fusion method is the following formula (9), where v(x, y) is the DEM elevation value or the texture grayscale value of DOM at the point P(x, y) of the fused topographic map, v1(x, y) is the DEM elevation value or the texture grayscale value of DOM at the point P(x, y) of the first station, v2(x, y) is the DEM elevation value or the texture grayscale value of DOM at the point P(x, y) of the second station, and M′2 represents the corrected DEM or DOM map of the second station. The fused topographic map is determined according to the DEM elevation value or the texture grayscale value of DOM at the point P(x, y) of the fused topographic map.

[0146]

[0147] To further illustrate the present invention, the present application provides an application example of a method for generating a topographic map. Figure 8 The specific description is as follows:

[0148] Obtain the terrain DEM / DOM map in the coordinate system of the two stations; determine whether there are auxiliary features in the DOM map of the second station, that is, the orthophoto map positioning auxiliary feature detection; if so, perform DEM feature matching and positioning, which includes: matching area determination and area matching positioning calculation; if not, perform DOM least squares matching; reverse projection to obtain the initial correspondence of the same-name registration points, that is, reverse projection of the joint DEM and DOM local stations; least squares precise registration; calculate the relative position of the two stations based on reprojection; and generate a global terrain map.

[0149] From the software level, in order to improve the automation and accuracy of generating global terrain maps, and thus improve the reliability of unmanned vehicle detection tasks, the present application provides an embodiment of a terrain map generating device for implementing all or part of the contents of the terrain map generating method, see Fig. 9 , the topographic map generating device specifically includes the following contents:

[0150] An acquisition module 10 is used to acquire a group of topographic maps to be processed, the group of topographic maps to be processed comprising: a first orthophoto map and a first DEM map corresponding to a first site, a second orthophoto map and a second DEM map corresponding to a second site;

[0151] The region determination module 20 is used to perform positioning auxiliary feature detection on the second orthophoto image to determine the auxiliary feature target region in the second orthophoto image;

[0152] A relative position determination module 30, configured to determine the relative position between the first station and the second station according to the auxiliary feature target area, the second DEM map and the first DEM map;

[0153] The obtaining module 40 is used to obtain a global topographic map according to the relative position and the group of topographic maps to be processed.

[0154] In one embodiment of the present application, see Fig.10 , the area determination module 20 comprises:

[0155] A connection line determination unit 21 is used to determine the center point of the second site and the connection lines between the center point and each pixel point in the second orthophoto map according to the second orthophoto map;

[0156] A standard deviation determining unit 22 is used to determine, based on the connecting line corresponding to each non-central pixel point, a first pixel brightness standard deviation of a preset number of pixel points along the connecting line of the non-central pixel point with the non-central pixel point as the center, and a second pixel brightness standard deviation of a preset number of pixel points in a direction perpendicular to the connecting line of the non-central pixel point;

[0157] The first judging unit 23 is used to judge whether there is a non-central pixel point in the second orthophoto image whose corresponding first pixel brightness standard deviation is less than the first standard deviation threshold and whose second pixel brightness standard deviation is greater than the second standard deviation threshold, and if so, determine that the non-central pixel point is a candidate auxiliary feature;

[0158] The second judging unit 24 is configured to judge whether there are a plurality of adjacent candidate auxiliary features in the second orthophoto image, and if so, to form the auxiliary feature target area according to the adjacent candidate auxiliary features.

[0159] In one embodiment of the present application, the relative position determination module includes:

[0160] A same-name registration point determination unit is used to perform feature terrain matching positioning according to the auxiliary feature target area, the first DEM map and the second DEM map, and determine the same-name registration points in the first DEM map and the second DEM map and the three-dimensional coordinate information of the same-name registration points in the first site coordinate system and the second site coordinate system respectively;

[0161] An initial relationship determination unit, used to determine the initial corresponding relationship of the same-name registration points according to the camera imaging projection relationship and the three-dimensional coordinate information;

[0162] An accurate relationship determination unit, used for obtaining an accurate correspondence relationship between registration points of the same name according to an affine transformation least squares model and the initial correspondence relationship between registration points of the same name;

[0163] The relative position determination unit is used to obtain the relative position according to the three-dimensional coordinate information of the same-name registration points in the first site coordinate system and the second site coordinate system, the preset imaging relationship, the precise correspondence relationship of the same-name registration points and the optimization method.

[0164] In one embodiment of the present application, the same-name registration point determination unit includes:

[0165] an initial rectangle determination subunit, for obtaining, if there are multiple auxiliary feature target areas, a maximum radius value among the radius values ​​of the auxiliary feature target areas and a first center position of each auxiliary feature target area, and forming a circumscribed rectangle with all the first center positions as an initial rectangle;

[0166] a target rectangle determination subunit, configured to reduce the coordinate value of the upper left point of the initial rectangle by a maximum radius value in both coordinate directions, and increase the coordinate value of the lower right point of the initial rectangle by a maximum radius value in both coordinate directions, to obtain a target rectangle, determine an area corresponding to the target rectangle in the second DEM map as a matching area, and determine a center of the matching area as a second center position;

[0167] A terrain matching subunit, used for determining a matching area position corresponding to the second center position in the first DEM map according to a terrain matching method;

[0168] The same-name registration point determination subunit is used to determine the matching position corresponding to each first center position in the first DEM map, and the three-dimensional coordinate information of each first center position and its matching position according to the matching area position; wherein the first center position and its corresponding position in the first DEM map are the same-name registration points, the three-dimensional coordinate information of the first center position is the three-dimensional coordinate information of the same-name registration point in the second site coordinate system, and the three-dimensional coordinate information of the matching position is the three-dimensional coordinate information of the same-name registration point in the first site coordinate system.

[0169] In one embodiment of the present application, the relative position determination unit includes:

[0170] A construction subunit is used to construct an objective function based on the three-dimensional coordinate information of the same-name registration points in the first site coordinate system and the second site coordinate system, the preset imaging relationship and the precise correspondence relationship of the same-name registration points;

[0171] The relative position determination subunit is used to optimize the objective function and determine the relative position between the first site and the second site when the objective function value is minimum.

[0172] In one embodiment of the present application, the obtaining module includes:

[0173] A correction unit, used to determine corrected three-dimensional coordinate information corresponding to the pixel points in the second orthophoto image and the second DEM image according to the relative position, the three-dimensional coordinate information of the pixel points in the second orthophoto image and the second DEM image;

[0174] The elevation value determination unit is used to determine the texture grayscale value and elevation value of the pixel point after correction according to the three-dimensional coordinate information before and after correction corresponding to the pixel point in the second orthophoto map and the second DEM map;

[0175] A global DEM map obtaining unit is used to obtain a global DEM map according to the three-dimensional coordinate information and elevation values ​​of the pixel points in the first DEM map and the corrected three-dimensional coordinate information and elevation values ​​corresponding to the pixel points in the second DEM map;

[0176] A global orthophoto map obtaining unit is used to obtain a global orthophoto map according to the coordinate information and texture grayscale values ​​of the pixel points in the first orthophoto map, and the corrected coordinate information and texture grayscale values ​​corresponding to the pixel points in the second orthophoto map; wherein the global topographic map includes: a global DEM map and a global orthophoto map.

[0177] The embodiment of the topographic map generating device provided in this specification can be specifically used to execute the processing flow of the embodiment of the topographic map generating method described above, and its functions will not be described in detail here, and reference can be made to the detailed description of the embodiment of the topographic map generating method described above.

[0178] From the above description, it can be seen that the terrain map generation method and device provided by the present application can improve the degree of automation and accuracy in generating global terrain maps, thereby improving the reliability of unmanned vehicle detection tasks; specifically, the three-dimensional terrain data reconstructed between adjacent sites can be used to perform auxiliary positioning feature extraction and matching as well as reverse projection, which can provide accurate matching initial values ​​for image matching between adjacent sites, can significantly improve the reliability of automatic image matching, integrate the two processes of terrain construction and positioning calculation, can reduce manual intervention in the process of global terrain map construction, can improve the degree of automation and accuracy of terrain map construction, and can improve the efficiency of global terrain map construction based on unmanned vehicles.

[0179] From the hardware level, in order to improve the automation and accuracy of generating a global terrain map, and thus improve the reliability of the unmanned vehicle detection task, the present application provides an embodiment of an electronic device for implementing all or part of the contents of the terrain map generation method. The electronic device specifically includes the following contents:

[0180] A processor, a memory, a communications interface and a bus; wherein the processor, the memory and the communications interface communicate with each other through the bus; the communications interface is used to realize information transmission between the topographic map generating device and related devices such as user terminals; the electronic device can be a desktop computer, a tablet computer and a mobile terminal, etc., but the present embodiment is not limited thereto. In the present embodiment, the electronic device can be implemented with reference to the embodiments for realizing the topographic map generating method and the embodiments for realizing the topographic map generating device, and the contents thereof are incorporated herein, and the repeated parts are not repeated.

[0181] Fig.11 FIG. 9 is a schematic block diagram of the system structure of the electronic device 9600 according to an embodiment of the present application. Fig.11 As shown, the electronic device 9600 may include a central processor 9100 and a memory 9140; the memory 9140 is coupled to the central processor 9100. It is worth noting that Fig.11 is exemplary; other types of structures may also be used to supplement or replace this structure to implement telecommunication functions or other functions.

[0182] In one or more embodiments of the present application, the topographic map generation function may be integrated into the central processor 9100. The central processor 9100 may be configured to perform the following control:

[0183] Step 100: Obtain a group of topographic maps to be processed, the group of topographic maps to be processed comprising: a first orthophoto map corresponding to a first site, a first DEM map, a second orthophoto map corresponding to a second site, and a second DEM map.

[0184] Step 200: Perform positioning auxiliary feature detection on the second orthophoto image to determine the auxiliary feature target area in the second orthophoto image.

[0185] Step 300: Determine the relative position between the first site and the second site according to the auxiliary feature target area, the second DEM map and the first DEM map.

[0186] Step 400: Obtain a global topographic map according to the relative position and the group of topographic maps to be processed.

[0187] From the above description, it can be seen that the electronic device provided by the embodiment of the present application can improve the degree of automation and accuracy in generating global terrain maps, thereby improving the reliability of unmanned vehicle detection tasks.

[0188] In another embodiment, the topographic map generating device may be configured separately from the central processing unit 9100. For example, the topographic map generating device may be configured as a chip connected to the central processing unit 9100, and the topographic map generating function is realized under the control of the central processing unit.

[0189] like Fig.11 As shown, the electronic device 9600 may also include: a communication module 9110, an input unit 9120, an audio processor 9130, a display 9160, and a power supply 9170. It is worth noting that the electronic device 9600 does not necessarily have to include Fig.11 In addition, the electronic device 9600 may also include Fig.11 For components not shown, reference may be made to the prior art.

[0190] like Fig.11 As shown, the central processing unit 9100 is sometimes also referred to as a controller or an operation control, and may include a microprocessor or other processor device and / or logic device. The central processing unit 9100 receives input and controls the operation of various components of the electronic device 9600.

[0191] The memory 9140 may be, for example, one or more of a cache, a flash memory, a hard drive, a removable medium, a volatile memory, a non-volatile memory or other suitable devices. The above-mentioned information related to the failure may be stored, and a program for executing the relevant information may also be stored. The CPU 9100 may execute the program stored in the memory 9140 to implement information storage or processing, etc.

[0192] The input unit 9120 provides input to the central processing unit 9100. The input unit 9120 is, for example, a key or a touch input device. The power supply 9170 is used to provide power to the electronic device 9600. The display 9160 is used to display display objects such as images and texts. The display may be, for example, an LCD display, but is not limited thereto.

[0193] The memory 9140 may be a solid-state memory, such as a read-only memory (ROM), a random access memory (RAM), a SIM card, etc. It may also be a memory that saves information even when the power is off, can be selectively erased, and is provided with more data, examples of which are sometimes referred to as EPROMs, etc. The memory 9140 may also be some other type of device. The memory 9140 includes a buffer memory 9141 (sometimes referred to as a buffer). The memory 9140 may include an application / function storage unit 9142, which is used to store application programs and function programs or processes for executing the operation of the electronic device 9600 through the central processor 9100.

[0194] The memory 9140 may also include a data storage unit 9143 for storing data, such as contacts, digital data, pictures, sounds, and / or any other data used by the electronic device. The driver storage unit 9144 of the memory 9140 may include various drivers for communication functions of the electronic device and / or for executing other functions of the electronic device (such as messaging applications, address book applications, etc.).

[0195] The communication module 9110 is a transmitter / receiver 9110 that sends and receives signals via an antenna 9111. The communication module (transmitter / receiver) 9110 is coupled to the central processor 9100 to provide input signals and receive output signals, which may be the same as the case of a conventional mobile communication terminal.

[0196] Based on different communication technologies, multiple communication modules 9110 may be provided in the same electronic device, such as a cellular network module, a Bluetooth module and / or a wireless LAN module, etc. The communication module (transmitter / receiver) 9110 is also coupled to a speaker 9131 and a microphone 9132 via an audio processor 9130 to provide an audio output via the speaker 9131 and receive an audio input from the microphone 9132, thereby realizing a common telecommunication function. The audio processor 9130 may include any suitable buffer, decoder, amplifier, etc. In addition, the audio processor 9130 is also coupled to the central processor 9100, so that recording can be performed on the local machine through the microphone 9132, and the sound stored on the local machine can be played through the speaker 9131.

[0197] It can be seen from the above description that the electronic device provided by the embodiments of the present application can improve the degree of automation and accuracy in generating global terrain maps, thereby improving the reliability of unmanned vehicle detection tasks.

[0198] The embodiment of the present application also provides a computer-readable storage medium capable of implementing all the steps in the method for generating a topographic map in the above embodiment. The computer-readable storage medium stores a computer program. When the computer program is executed by a processor, all the steps in the method for generating a topographic map in the above embodiment are implemented. For example, when the processor executes the computer program, the following steps are implemented:

[0199] Step 100: Obtain a group of topographic maps to be processed, the group of topographic maps to be processed comprising: a first orthophoto map corresponding to a first site, a first DEM map, a second orthophoto map corresponding to a second site, and a second DEM map.

[0200] Step 200: Perform positioning auxiliary feature detection on the second orthophoto image to determine the auxiliary feature target area in the second orthophoto image.

[0201] Step 300: Determine the relative position between the first site and the second site according to the auxiliary feature target area, the second DEM map and the first DEM map.

[0202] Step 400: Obtain a global topographic map according to the relative position and the group of topographic maps to be processed.

[0203] From the above description, it can be seen that the computer-readable storage medium provided in the embodiment of the present application can improve the degree of automation and accuracy in generating global terrain maps, thereby improving the reliability of unmanned vehicle detection tasks.

[0204] In this application, each embodiment of the above method is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. For relevant parts, refer to the partial description of the method embodiment.

[0205] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0206] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0207] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0208] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0209] Specific embodiments are used in this application to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core idea of ​​this application. At the same time, for those skilled in the art, according to the idea of ​​this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on this application.

Claims

1. A method for generating a topographic map, characterized in that: include: Obtaining a group of topographic maps to be processed, the group of topographic maps to be processed comprising: a first orthophoto map corresponding to a first site, a first DEM map, a second orthophoto map corresponding to a second site, and a second DEM map; Performing positioning auxiliary feature detection on the second orthophoto image to determine an auxiliary feature target area in the second orthophoto image; Determining a relative position between the first site and the second site according to the auxiliary feature target area, the second DEM map and the first DEM map; Obtaining a global topographic map according to the relative position and the topographic map group to be processed; The determining the relative position between the first site and the second site according to the auxiliary feature target area, the second DEM map and the first DEM map includes: Perform feature terrain matching positioning according to the auxiliary feature target area, the first DEM map and the second DEM map, determine the same-name registration points in the first DEM map and the second DEM map and the three-dimensional coordinate information of the same-name registration points in the first site coordinate system and the second site coordinate system respectively; Determine the initial correspondence relationship of the same-name registration points according to the camera imaging projection relationship and the three-dimensional coordinate information; According to the affine transformation least squares model and the initial correspondence relationship of the same-name registration points, an accurate correspondence relationship of the same-name registration points is obtained; The relative position is obtained according to the three-dimensional coordinate information of the same-name registration points in the first site coordinate system and the second site coordinate system, a preset imaging relationship, a precise corresponding relationship of the same-name registration points and an optimization method.

2. The method for generating a topographic map according to claim 1, characterized in that: The performing positioning auxiliary feature detection on the second orthophoto image to determine the auxiliary feature target area in the second orthophoto image includes: According to the second orthophoto map, determine the connection lines between the center point and each non-center pixel point; the center point is the pixel point corresponding to the shooting position of the stereo image sequence of the second station in the second orthophoto map; the non-center pixel point is the pixel point other than the center point in the second orthophoto map; According to the connecting line corresponding to each non-central pixel point, determine the first pixel brightness standard deviation of a preset number of pixel points along the connecting line of the non-central pixel point with the non-central pixel point as the center, and the second pixel brightness standard deviation of a preset number of pixel points in a direction perpendicular to the connecting line of the non-central pixel point; Determine whether there is a non-central pixel point in the second orthophoto image whose corresponding first pixel brightness standard deviation is less than the first standard deviation threshold and whose second pixel brightness standard deviation is greater than the second standard deviation threshold, and if so, determine that the non-central pixel point is a candidate auxiliary feature; It is determined whether there are a plurality of adjacent candidate auxiliary features in the second orthophoto image. If so, the auxiliary feature target area is formed according to the adjacent candidate auxiliary features.

3. The method for generating a topographic map according to claim 1, characterized in that: The method of performing feature terrain matching positioning according to the auxiliary feature target area, the first DEM map and the second DEM map, and determining the same-name registration points in the first DEM map and the second DEM map and the three-dimensional coordinate information of the same-name registration points in the first site coordinate system and the second site coordinate system respectively, includes: If there are multiple auxiliary feature target areas, the maximum radius value among the radius values ​​of the auxiliary feature target areas and the first center position of each auxiliary feature target area are obtained, and all the first center positions form a circumscribed rectangle as an initial rectangle; The coordinate value of the upper left point of the initial rectangle is reduced by the maximum radius value in both coordinate directions, and the coordinate value of the lower right point of the initial rectangle is increased by the maximum radius value in both coordinate directions to obtain a target rectangle, and the area corresponding to the target rectangle in the second DEM map is determined as the matching area, and the center of the matching area is determined as the second center position; Determine, according to a terrain matching method, a matching area position corresponding to the second center position in the first DEM map; Determine, according to the matching area position, the matching position corresponding to each first center position in the first DEM map, and the three-dimensional coordinate information of each first center position and its matching position; Among them, the first center position and its corresponding position in the first DEM map are the same-name registration points, the three-dimensional coordinate information of the first center position is the three-dimensional coordinate information of the same-name registration point in the second site coordinate system, and the three-dimensional coordinate information of the matching position is the three-dimensional coordinate information of the same-name registration point in the first site coordinate system.

4. The method for generating a topographic map according to claim 1, characterized in that: The relative position is obtained according to the three-dimensional coordinate information of the same-name registration points in the first site coordinate system and the second site coordinate system, the preset imaging relationship, the precise correspondence relationship of the same-name registration points and the optimization method, including: Constructing an objective function based on the three-dimensional coordinate information of the same-name registration points in the first site coordinate system and the second site coordinate system, the preset imaging relationship and the precise correspondence relationship of the same-name registration points; The objective function is optimized to determine the relative position between the first site and the second site when the objective function value is minimum.

5. The method for generating a topographic map according to claim 1, characterized in that: The step of obtaining a global topographic map according to the relative position and the topographic map group to be processed comprises: Determine corrected three-dimensional coordinate information corresponding to the pixel points in the second orthophoto image and the second DEM image according to the relative position, the three-dimensional coordinate information of the pixel points in the second orthophoto image and the second DEM image; Determine the texture grayscale value and elevation value of the pixel point after correction according to the three-dimensional coordinate information before and after correction corresponding to the pixel point in the second orthophoto map and the second DEM map; Obtaining a global DEM map according to the three-dimensional coordinate information and elevation values ​​of the pixel points in the first DEM map, and the corrected three-dimensional coordinate information and elevation values ​​corresponding to the pixel points in the second DEM map; Obtaining a global orthophoto image according to the coordinate information and texture grayscale values ​​of the pixel points in the first orthophoto image, and the corrected coordinate information and texture grayscale values ​​corresponding to the pixel points in the second orthophoto image; The global topographic map includes: a global DEM map and a global orthophoto map.

6. A topographic map generating device, characterized in that: include: An acquisition module is used to acquire a group of topographic maps to be processed, the group of topographic maps to be processed comprising: a first orthophoto map corresponding to a first site, a first DEM map, a second orthophoto map corresponding to a second site, and a second DEM map; An area determination module is used to perform positioning auxiliary feature detection on the second orthophoto image to determine an auxiliary feature target area in the second orthophoto image; A relative position determination module, used to determine the relative position between the first site and the second site according to the auxiliary feature target area, the second DEM map and the first DEM map; An obtaining module, used for obtaining a global topographic map according to the relative position and the topographic map group to be processed; The relative position determination module includes: A same-name registration point determination unit is used to perform feature terrain matching positioning according to the auxiliary feature target area, the first DEM map and the second DEM map, and determine the same-name registration points in the first DEM map and the second DEM map and the three-dimensional coordinate information of the same-name registration points in the first site coordinate system and the second site coordinate system respectively; An initial relationship determination unit, used to determine the initial corresponding relationship of the same-name registration points according to the camera imaging projection relationship and the three-dimensional coordinate information; An accurate relationship determination unit, used for obtaining an accurate correspondence relationship between registration points of the same name according to an affine transformation least squares model and the initial correspondence relationship between registration points of the same name; The relative position determination unit is used to obtain the relative position according to the three-dimensional coordinate information of the same-name registration points in the first site coordinate system and the second site coordinate system, the preset imaging relationship, the precise correspondence relationship of the same-name registration points and the optimization method.

7. The topographic map generating device according to claim 6, characterized in that: The area determination module comprises: A line determination unit is used to determine the lines between the center point and each non-center pixel point according to the second orthophoto image; the center point is the pixel point corresponding to the shooting position of the stereo image sequence of the second station in the second orthophoto image; the non-center pixel point is the pixel point other than the center point in the second orthophoto image; A standard deviation determination unit, configured to determine, based on the connecting line corresponding to each non-central pixel point, a first pixel brightness standard deviation of a preset number of pixel points along the connecting line of the non-central pixel point with the non-central pixel point as the center, and a second pixel brightness standard deviation of a preset number of pixel points in a direction perpendicular to the connecting line of the non-central pixel point; A first judging unit is used to judge whether there is a non-central pixel point in the second orthophoto image whose corresponding first pixel brightness standard deviation is less than a first standard deviation threshold and whose second pixel brightness standard deviation is greater than a second standard deviation threshold, and if so, determine that the non-central pixel point is a candidate auxiliary feature; The second judgment unit is used to judge whether there are multiple adjacent candidate auxiliary features in the second orthophoto image, and if so, form the auxiliary feature target area according to the adjacent candidate auxiliary features.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the topographic map generating method according to any one of claims 1 to 5 is implemented.

9. A computer-readable storage medium having computer instructions stored thereon, characterized in that: When the instructions are executed, the method for generating a topographic map according to any one of claims 1 to 5 is implemented.

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