CN114419136A - Method and device for evaluating relative accuracy of topographic map and storage medium - Google Patents

Abstract

The application discloses a method and a device for estimating relative accuracy of a topographic map, a storage medium and computer equipment, wherein the method comprises the following steps: acquiring preset point set data corresponding to a target element, and calculating a slope sequence and a curvature sequence corresponding to the preset point set, wherein the target element comprises an arc curve element and/or a curved river element, the preset point set comprises a plurality of break points, and the preset point set data comprises a plurality of break point data; determining a target arc point set corresponding to the target element based on the slope sequence and the curvature sequence; and determining the relative target precision corresponding to the target arc point set, and determining the relative precision of the topographic map based on the relative target precision. According to the method and the device, the relative accuracy of the topographic map can be automatically calculated according to the acquired preset point set data corresponding to the target elements, the cost of calculating the relative accuracy of the topographic map can be effectively reduced, and the evaluation efficiency of the relative accuracy of the topographic map is improved.

Description

Method and device for evaluating relative accuracy of topographic map, and storage medium

technical field

The present application relates to the technical field of surveying and mapping geographic information, and in particular, to a method and device for evaluating the relative accuracy of topographic maps, storage media, and computer equipment.

Background technique

The assessment of relative accuracy of topographic maps plays an important role in ensuring the quality of basic geographic information. The design accuracy of the topographic map is mainly determined by the scale of the map, and whether the actual accuracy of the topographic map is consistent with the design accuracy requires the calculation of the relative accuracy of the topographic map.

The relative accuracy of the existing topographic map needs to be calculated by the relative spatial position of the feature features. This calculation method is inefficient, and because it requires a lot of manpower and material resources, the cost is high. Therefore, how to reduce the cost of calculating the relative accuracy of the topographic map , improving the evaluation efficiency of the relative accuracy of topographic maps has become an urgent problem to be solved in this field.

SUMMARY OF THE INVENTION

In view of this, the present application provides a method and device, storage medium, and computer equipment for evaluating the relative accuracy of topographic maps, which can effectively reduce the cost of calculating relative accuracy of topographic maps and improve the efficiency of evaluating relative accuracy of topographic maps.

According to an aspect of the present application, a method for evaluating the relative accuracy of a topographic map is provided, including:

Acquire preset point set data corresponding to the target element, and calculate the slope sequence and curvature sequence corresponding to the preset point set, wherein the target element includes arc curve elements and/or curved river elements, and the preset point set includes a plurality of fold points, the preset point set data includes a plurality of fold point data;

determining a target arc point set corresponding to the target element based on the slope sequence and the curvature sequence;

The relative accuracy of the target corresponding to the target arc point set is determined, and based on the relative accuracy of the target, the relative accuracy of the topographic map is determined.

Optionally, the calculating the slope sequence and the curvature sequence corresponding to the preset point set specifically includes:

Determine the slope sequence corresponding to the preset point set based on the fold point data of every two adjacent fold points in the preset point set data corresponding to the target element;

Based on the vertex data of every three adjacent vertexes in the preset point set data corresponding to the target element, a target quadratic curve is fitted, and according to the target quadratic curve, it is determined that the preset point set corresponds to curvature sequence.

Optionally, the determining the target arc point set corresponding to the target element based on the slope sequence and the curvature sequence specifically includes:

Based on the empirical mode decomposition method, a curvature trend term is extracted from the curvature sequence, and the slope sequence is segmented based on the positive and negative values corresponding to the curvature trend term;

According to the segmented slope sequence, the preset point set is screened to obtain a target arc point set corresponding to the target element.

Optionally, according to the segmented slope sequence, the preset point set is screened to obtain the target arc point set corresponding to the target element, which specifically includes:

According to the segmented slope sequence, determine whether the segmented slope sequence is monotonic;

When it is monotonic, the preset point set data is fitted based on the preset exponential function to obtain a first fitting result, and the corresponding first coefficient of determination and the first fitting are calculated according to the first fitting result accuracy, and when the first determination coefficient is greater than the first preset coefficient threshold, and the first fitting accuracy is greater than the first preset accuracy threshold, the preset point set is retained, and the retained preset The point set is used as the target arc point set, otherwise, the preset point set is discarded;

When there is no monotonicity, the preset point set data is fitted based on a preset inverse proportional function to obtain a second fitting result, and a corresponding second coefficient of determination and a second fitting result are calculated according to the second fitting result. and when the second determination coefficient is greater than the second preset coefficient threshold and the second fitting accuracy is greater than the second preset accuracy threshold, the preset point set is retained, and the retained preset Set the point set as the target arc point set, otherwise, divide the preset point set into two sub-point sets according to monotonicity, and perform fitting respectively according to the preset exponential function to obtain a third fitting result, According to the third fitting result, the corresponding third determination coefficient and the third fitting accuracy are calculated respectively, and when the third determination coefficient is greater than the first preset coefficient threshold, and the third fitting accuracy is greater than When the first preset accuracy threshold is used, the corresponding sub-point set is reserved, and the reserved sub-point set is used as the target arc point set. When the third determination coefficient is smaller than the first preset When the coefficient threshold and/or the third fitting precision is smaller than the first preset precision threshold, the corresponding sub-point set is discarded.

Optionally, after determining the target arc point set corresponding to the target element, the method further includes:

Based on the least squares method, circle fitting is performed on the target circular arc point set to obtain a first circular curve corresponding to the target circular arc point set, and a first radius corresponding to the first circular curve and a target circle center are determined;

According to a preset culling condition, culling the vertices that satisfy the preset culling condition in the target arc point set to obtain a first arc point set;

Reusing the least squares method for circle fitting on the first arc point set to obtain a second circular curve, and determining a second radius corresponding to the second circular curve;

determining a radius change rate according to the first radius and the second radius;

When the radius change rate is less than or equal to the preset change rate threshold, the first circular arc point set is used as the specified circular arc point set, the second circular curve is used as the specified circular curve, and based on the specified circular arc Calculate the relative accuracy of the target with the point set and the specified circular curve;

When the radius change rate is greater than the preset change rate threshold, according to the preset culling condition again, culling the vertices that satisfy the preset culling condition from the set of first arc points, to obtain a second arc point set, and perform circle fitting again to obtain a third circular curve, determine the third radius corresponding to the third circular curve, and determine the radius change rate according to the second radius and the third radius, until The radius change rate is less than or equal to the preset change rate threshold.

Optionally, according to preset culling conditions, culling the vertices that satisfy the preset culling conditions in the target arc point set, specifically includes:

According to the preset culling conditions, respectively connect the three adjacent vertices of the head end and the three adjacent vertices of the end of the target arc point set, and obtain the connection angle of the head end and the connection angle of the end, when the connection angle is less than When the first preset angle threshold is greater than or equal to the flat angle, the end point corresponding to the connection angle is eliminated, wherein the connection angle is an angle on one side of the target circle center; and/or,

According to the preset culling conditions, respectively connect two adjacent vertices at the head end and two adjacent vertices at the end of the target arc point set to obtain a corresponding first line segment, and determine any one of the first line segments The first mid-perpendicular line of the For the second line segment corresponding to the line segment, determine the second mid-perpendicular line of the second line segment, and determine the included angle of the target vertical line based on the first mid-perpendicular line and the second mid-perpendicular line. When the target vertical line is When the included angle of the line is greater than the second preset angle threshold, remove the endpoints from the two vertices; and/or,

According to the preset culling conditions, respectively connect the three adjacent vertices at the head end and the three adjacent vertices at the end of the target arc point set to obtain the target connection line segment, when any of the three adjacent vertices corresponds to When the sum of the target connecting line segments is greater than or equal to the preset length threshold, the end points corresponding to the target arc point set in the adjacent three fold points are eliminated.

Optionally, the calculating the relative accuracy of the target based on the specified arc point set and the specified circular curve specifically includes:

Based on the specified arc point set, determine the length of the line segment corresponding to every two adjacent vertices in the specified arc point set, and obtain the total target length;

Based on the specified circular curve, determine the target arc length corresponding to the specified circular curve;

The relative accuracy of the target is determined according to the total length of the target and the length of the target arc.

According to another aspect of the present application, a device for evaluating the relative accuracy of topographic maps is provided, comprising:

A point set calculation module, configured to obtain preset point set data corresponding to target elements, and calculate slope sequences and curvature sequences corresponding to the preset point sets, wherein the target elements include arc curve elements and/or curved river channel elements, The preset point set includes a plurality of fold points, and the preset point set data includes a plurality of fold point data;

a point set determination module, configured to determine a target arc point set corresponding to the target element based on the slope sequence and the curvature sequence;

The accuracy determination module is configured to determine the relative accuracy of the target corresponding to the target arc point set, and determine the relative accuracy of the topographic map based on the relative accuracy of the target.

Optionally, the point set calculation module specifically includes:

a slope sequence determination unit, configured to determine a slope sequence corresponding to the preset point set based on the fold point data of every two adjacent fold points in the preset point set data corresponding to the target element;

A curvature sequence determination unit, configured to fit a target quadratic curve based on the vertex data of every three adjacent vertex points in the preset point set data corresponding to the target element, and determine the target quadratic curve according to the target quadratic curve The curvature sequence corresponding to the preset point set.

Optionally, the point set determination module specifically includes:

a segmentation unit, configured to extract a curvature trend item from the curvature sequence based on the empirical mode decomposition method, and segment the slope sequence based on the positive and negative values corresponding to the curvature trend item;

A screening unit, configured to screen the preset point set according to the segmented slope sequence to obtain a target arc point set corresponding to the target element.

Optionally, the screening unit is specifically used for:

According to the segmented slope sequence, determine whether the segmented slope sequence is monotonic; if it is monotonic, fit the preset point set data based on a preset exponential function to obtain the first the fitting result, according to the first fitting result to calculate the corresponding first determination coefficient and the first fitting accuracy, and when the first determination coefficient is greater than the first preset coefficient threshold, and the first fitting accuracy When it is greater than the first preset precision threshold, the preset point set is reserved, and the reserved preset point set is used as the target arc point set, otherwise, the preset point set is discarded; when it is not monotonic, Fit the preset point set data based on a preset inverse proportional function to obtain a second fitting result, calculate a corresponding second coefficient of determination and a second fitting accuracy according to the second fitting result, and calculate when the When the second determination coefficient is greater than the second preset coefficient threshold, and the second fitting accuracy is greater than the second preset accuracy threshold, the preset point set is reserved, and the reserved preset point set is used as the target Arc point set, otherwise, divide the preset point set into two sub-point sets according to monotonicity, and perform fitting respectively according to the preset exponential function to obtain a third fitting result, according to the third fitting As a result, the corresponding third determination coefficient and third fitting accuracy are calculated respectively, and when the third determination coefficient is greater than the first preset coefficient threshold, and the third fitting accuracy is greater than the first preset accuracy When the threshold is set, the corresponding sub-point set is reserved, and the reserved sub-point set is used as the target arc point set, and when the third determination coefficient is smaller than the first preset coefficient threshold and/or the When the third fitting accuracy is smaller than the first preset accuracy threshold, the corresponding sub-point set is discarded.

Optionally, the device further includes:

A circle fitting module is used to perform circle fitting on the target circular arc point set based on the least squares method after the target circular arc point set corresponding to the target element is determined to obtain the corresponding target circular arc point set the first circular curve, and determine the first radius corresponding to the first circular curve and the target center;

a culling module, used for culling the vertices that satisfy the preset culling conditions in the target arc point set according to the preset culling conditions, to obtain a first arc point set;

The circle fitting module is further configured to re-use the least squares method to perform circle fitting on the first circular arc point set to obtain a second circular curve, and determine a second radius corresponding to the second circular curve ;

a change rate determination module, configured to determine a radius change rate according to the first radius and the second radius;

The judgment module is configured to use the first circular arc point set as the designated circular arc point set and the second circular curve as the specified circular curve when the radius change rate is less than or equal to the preset change rate threshold value, based on The target relative accuracy is calculated from the specified arc point set and the specified circular curve; when the radius change rate is greater than the preset change rate threshold, the first The vertices that satisfy the preset elimination conditions are eliminated from the arc point set to obtain a second arc point set, and circle fitting is performed again to obtain a third circular curve, and the third radius corresponding to the third circular curve is determined, The radius change rate is determined according to the second radius and the third radius until the radius change rate is less than or equal to the preset change rate threshold.

Optionally, the culling module is specifically used for:

According to the preset culling conditions, respectively connect the three adjacent vertices of the head end and the three adjacent vertices of the end of the target arc point set, and obtain the connection angle of the head end and the connection angle of the end, when the connection angle is less than When the first preset angle threshold is greater than or equal to the flat angle, the end point corresponding to the connection angle is eliminated, wherein the connection angle is the angle on one side of the target circle center; and/or, according to the preset elimination condition, the connection angle is respectively Two adjacent vertices at the head end and two adjacent vertices at the end of the target arc point set, obtain the corresponding first line segment, determine the first mid-perpendicular line of any of the first line segments, and respectively Determine the two closest points of the two vertices corresponding to the first line segment on the first circular curve, connect the two closest points to obtain a second line segment corresponding to the first line segment, and determine The second vertical line of the second line segment, based on the first vertical line and the second vertical line, determine the target vertical line angle, when the target vertical line angle is greater than the second preset angle When the threshold value is reached, the endpoints in the consecutive vertices are removed; and/or, according to the preset culling conditions, respectively connect the three adjacent vertices at the head end and the three adjacent folds at the end of the target arc point set. point to obtain the target connecting line segment, and when the sum of the target connecting line segments corresponding to any of the three adjacent vertices is greater than or equal to the preset length threshold, compare the three adjacent vertices with the target arc The endpoints corresponding to the point set are culled.

Optionally, the judging module is also used for:

Based on the specified arc point set, determine the length of the line segment corresponding to every two adjacent vertices in the specified arc point set, and obtain the total length of the target; based on the specified circular curve, determine the target corresponding to the specified circular curve The arc length; the relative accuracy of the target is determined according to the total length of the target and the length of the target arc.

According to yet another aspect of the present application, a storage medium is provided on which a computer program is stored, and when the program is executed by a processor, the above-mentioned method for evaluating the relative accuracy of a topographic map is implemented.

According to another aspect of the present application, a computer device is provided, comprising a storage medium, a processor, and a computer program stored on the storage medium and executable on the processor, the processor implements the above-mentioned topographic map when executing the program. Relative Accuracy Assessment Methods.

With the above technical solutions, the present application provides a method and device for evaluating the relative accuracy of topographic maps, a storage medium, and a computer device. First, the preset point set data corresponding to the target element is obtained, and the obtained preset point set data is Basically, calculate the slope sequence and curvature sequence corresponding to each preset point set. Next, the target arc point set corresponding to the target element may be determined based on the slope sequence and the curvature sequence. Specifically, a part of the preset point set may be removed from the acquired preset point set according to the slope sequence and the curvature sequence, and the last remaining preset point set is the target arc point set. After the target arc point set is determined, the relative accuracy of the target corresponding to the target arc point set can be further determined according to the target arc point set, and then the relative accuracy of the topographic map can be determined according to the relative accuracy of the target. The present application can automatically calculate the relative accuracy of the topographic map according to the acquired preset point set data corresponding to the target element, which can effectively reduce the cost of calculating the relative accuracy of the topographic map and improve the evaluation efficiency of the relative accuracy of the topographic map.

The above description is only an overview of the technical solution of the present application. In order to be able to understand the technical means of the present application more clearly, it can be implemented according to the content of the description, and in order to make the above-mentioned and other purposes, features and advantages of the present application more obvious and easy to understand , and the specific embodiments of the present application are listed below.

Description of drawings

The drawings described herein are used to provide further understanding of the present application and constitute a part of the present application. The schematic embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation of the present application. In the attached image:

1 shows a schematic flowchart of a method for evaluating the relative accuracy of a topographic map provided by an embodiment of the present application;

2 shows a schematic diagram of discrete points at both ends of a refined target arc point set provided by an embodiment of the present application;

3 shows a schematic diagram of the discrete points at both ends of another refinement target arc point set provided by an embodiment of the present application;

FIG. 4 shows another schematic diagram of the discrete points at both ends of the refined target arc point set provided by an embodiment of the present application;

FIG. 5 shows a schematic structural diagram of an apparatus for evaluating relative accuracy of a topographic map provided by an embodiment of the present application.

Detailed ways

Hereinafter, the present application will be described in detail with reference to the accompanying drawings and in conjunction with the embodiments. It should be noted that the embodiments in the present application and the features of the embodiments may be combined with each other in the case of no conflict.

In this embodiment, a method for evaluating the relative accuracy of topographic maps is provided, as shown in FIG. 1 , the method includes:

Step 101: Acquire preset point set data corresponding to target elements, and calculate slope sequences and curvature sequences corresponding to the preset point sets, wherein the target elements include arc curve elements and/or curved river elements, and the preset The point set includes a plurality of fold points, and the preset point set data includes a plurality of fold point data;

The method for evaluating the relative accuracy of a topographic map provided in this application can be specifically applied to the client side or the server side. For topographic maps, relative accuracy assessment is very important to ensure the quality of the underlying geographic information on topographic maps. The road elements in the topographic map are basically composed of straight lines and curves. Among them, the curves are mainly composed of circular curves. It can be considered that there must be circular arc features in the road elements. The road elements corresponding to the circular arc features include circular arc curve elements, curved river elements, etc. This application mainly calculates the relative accuracy of road elements with arc features in topographic maps. In this application, arc curve elements and curved river elements can be used as target elements. First, you can call the preset topographic map toolbox to convert the preset topographic map data into the preset point set data corresponding to the target feature. Here, the preset topographic map data can be data in shp format, and the preset topographic map toolbox can be the Python geopandas library. Calling the Python geopandas library can convert the data in shp format into preset point set data, in which the preset point set It may include multiple vertices, the preset point set data includes multiple vertices, and the vertices may be data with coordinates. Next, based on the acquired preset point set data, a slope sequence and a curvature sequence corresponding to each preset point set are calculated. The topographic map can include multiple preset point sets, each preset point set corresponds to a set of preset point set data, so multiple preset point set data can be obtained, and then multiple slope sequences and curvature sequences can be calculated. The slope sequences and curvature sequences correspond to a preset point set.

Step 102, based on the slope sequence and the curvature sequence, determine the target arc point set corresponding to the target element;

In this embodiment, after calculating the slope sequence and curvature sequence corresponding to each preset point set, the target arc point set corresponding to the target element may be further determined based on the slope sequence and the curvature sequence. Specifically, a part of the preset point set may be removed from the acquired preset point set according to the slope sequence and the curvature sequence, and the last remaining preset point set is the target arc point set.

Step 103: Determine the relative accuracy of the target corresponding to the target arc point set, and determine the relative accuracy of the topographic map based on the relative accuracy of the target.

In this embodiment, after the target arc point set is determined, the relative accuracy of the target corresponding to the target arc point set can be further determined according to the target arc point set, and then the relative accuracy of the topographic map can be determined according to the relative accuracy of the target. For example, a topographic map with a scale of 1:1 million and a design accuracy of 10m can determine which target arc point sets meet the design accuracy of 10m according to the relative accuracy of the target, and further calculate the target arc point sets that meet the design accuracy of 10m The proportion in the set of all the obtained arc points, and then the relative accuracy corresponding to the target element in the topographic map is obtained.

By applying the technical solution of this embodiment, first, the preset point set data corresponding to the target element is acquired, and based on the acquired preset point set data, the slope sequence and the curvature sequence corresponding to each preset point set are calculated. Next, the target arc point set corresponding to the target element may be determined based on the slope sequence and the curvature sequence. Specifically, a part of the preset point set may be removed from the acquired preset point set according to the slope sequence and the curvature sequence, and the last remaining preset point set is the target arc point set. After the target arc point set is determined, the relative accuracy of the target corresponding to the target arc point set can be further determined according to the target arc point set, and then the relative accuracy of the topographic map can be determined according to the relative accuracy of the target. The present application can automatically calculate the relative accuracy of the topographic map according to the acquired preset point set data corresponding to the target element, which can effectively reduce the cost of calculating the relative accuracy of the topographic map and improve the evaluation efficiency of the relative accuracy of the topographic map.

Further, as a refinement and extension of the specific implementation manner of the above-mentioned embodiment, in order to fully describe the specific implementation process of this embodiment, another method for evaluating the relative accuracy of topographic maps is provided, and the method includes:

Step 201: Acquire preset point set data corresponding to a target element, and determine a slope corresponding to the preset point set based on the fold point data of every two adjacent fold points in the preset point set data corresponding to the target element sequence; based on the vertex data of every three adjacent vertexes in the preset point set data corresponding to the target element, fit a target quadratic curve, and determine the preset point according to the target quadratic curve Set the corresponding curvature sequence;

In this embodiment, one or more sets of preset point set data corresponding to the target element are acquired, and the slope sequence and curvature sequence corresponding to each set of preset point set data are calculated respectively. Wherein, the calculation method of the slope is to calculate a slope according to the data of each two adjacent inflection points in the preset point set data, and finally put these slopes together to obtain a slope sequence. For example, the preset point set data includes 5 vertex data, which are a ₁ (x ₁ , y ₁ ), a ₂ (x ₂ , y ₂ ), a ₃ (x ₃ , y ₃ ), a ₄ ( x ₄ , y ₄ ), a ₅ (x ₅ , y ₅ ), for the inflection point a ₁ and the inflection point a ₂ , the corresponding slope can be h ₁ =(y ₂ -y ₁ )/(x ₂ -x ₁ ), h ₂ =(y ₃ -y ₂ )/(x ₃ -x ₂ ), h ₃ =(y ₄ -y ₃ )/(x ₄ -x ₃ ), and h ₄ =(y ₅ -y ₄ ) /(x ₅ -x ₄ ), the final slope sequence can be [h ₁ , h ₂ , h ₃ , h ₄ ]. The calculation method of the curvature is to fit a target quadratic curve according to the data of every three adjacent inflection points in the preset point set data, and then calculate a corresponding curvature according to the target quadratic curve, and finally These curvatures are put together to get a sequence of curvatures. For example, for the adjacent three vertices in the preset point set, if the parameter t satisfies the quadratic curve, the parameter equation is:

In the above formula (1), there are 6 unknown quantities (α ₁ , α ₂ , α ₃ ) and (β ₁ , β ₂ , β ₃ ), among which, there are a total of 6 breakpoint coordinates for the three adjacent breakpoints The known quantities are (x ₁ , x ₂ , x ₃ ) and (y ₁ , y ₂ , y ₃ ), respectively, so three sets of equations can be listed according to the known coordinates of these six breakpoints, and then solved ( α ₁ , α ₂ , α ₃ ) and (β ₁ , β ₂ , β ₃ ) are six unknowns. First, the range of values obtained by two straight lines formed by three points is as follows:

The conditions that t in the parametric equation should satisfy are:

Then there are:

The solution then has the curvature k as:

According to formula (6) and (α ₁ , α ₂ , α ₃ ) and (β ₁ , β ₂ , β ₃ ) obtained by solving the data of every three adjacent inflection points, the corresponding curvature k can be obtained. Finally put the curvature k together to get the curvature sequence.

Step 202, extracting a curvature trend item from the curvature sequence based on the empirical mode decomposition method, and segmenting the slope sequence based on the positive and negative values corresponding to the curvature trend item; according to the segmented slope sequence, screening the preset point set to obtain the target arc point set corresponding to the target element;

In this embodiment, after the slope sequence and curvature sequence corresponding to each preset point set are calculated and obtained, since the curvature of the present application is calculated through a series of discrete inflection points, abnormal curvature values may occur, resulting in curvature The trend term for is "overwhelmed" by outliers. In order to obtain the curvature trend term and determine the basic features (arcs) formed by the fold points, the present application uses empirical mode decomposition (EMD) to decompose the nonlinear curvature sequence from high frequency to low frequency and convert it into multiple Different, non-sinusoidal multi-scale signal components, namely intrinsic mode function (intrinsic mode function, IMF). The algorithm is able to retain more available trend information. The core of EMD is to obtain the upper and lower envelopes based on cubic spline interpolation, and finally constitute the IMF process. Given the signal χ(t), represented by the multiscale components as:

Among them, r _n (t) is represented as the nth component, that is, the residual component. And the first step for decomposition is to calculate the mean of the envelope:

In the formula, χ _a (t) is the mean value of the envelope; χ _u (t) and χ _d (t) are the upper and lower envelopes, respectively.

IMF(t)=χ(t)-χ _a (t) (9)

IMF(t) needs to satisfy the condition that the mean value is 0, if it is satisfied, it is the IMF component, otherwise the envelope is recalculated until the condition is satisfied. When there are only monotonic components, the signal is considered to be decomposed. At this time, there are:

r _n (t)=χ(t)-IMF _i (t) (10)

At this point, the extracted curvature trend item can be obtained. After the curvature trend item is obtained, the curvature trend item can have a positive value or a negative value. For a whole segment of positive values, the corresponding slope sequence can be divided into one segment. For For a whole segment of negative values, the corresponding slope sequence can also be divided into one segment. After segmenting the slope sequence according to the positive and negative values of the curvature trend item, multiple corresponding segments of the slope sequence can be obtained. After the segmented slope sequence is obtained, it can be determined whether the preset point set needs to be discarded according to each segment of the slope sequence, that is, the preset point set is screened, and the preset point set that does not meet the requirements is discarded from the preset point set, thereby Get the target arc point set.

Step 203, based on the least squares method, perform circular fitting on the target arc point set, obtain a first circular curve corresponding to the target circular arc point set, and determine the first radius corresponding to the first circular curve and target center;

In this embodiment, after the target arc point set is obtained, the least squares method can be used to perform circle fitting on each group of target arc point sets, and after fitting, the first arc point set corresponding to the target arc point set can be obtained. circular curve, and then calculate the corresponding first radius according to the first circular curve, and determine the target circle center corresponding to the first circular curve.

Step 204, according to the preset culling conditions, culling the vertices that satisfy the preset culling conditions in the target arc point set, to obtain a first arc point set;

In this embodiment, after the first circular curve is obtained, according to the preset culling conditions, the vertices that satisfy the preset culling conditions can be further culled from the target arc point set, and the first arc point set can be obtained after culling.

Step 205, reusing the least squares method to perform circle fitting on the first circular arc point set to obtain a second circular curve, and determining a second radius corresponding to the second circular curve;

In this embodiment, since the vertices contained in the first arc point set and the target arc point set are different, after the first arc point set is obtained, the first arc point set can be rounded by using the least squares method again. After fitting, a second circular curve corresponding to the first circular arc point set is obtained, and a second radius corresponding to the second circular curve is calculated at the same time.

Step 206, determining a radius change rate according to the first radius and the second radius;

In this embodiment, after determining the first radius corresponding to the first circular curve and the second radius corresponding to the second circular curve, the corresponding radius change rate may be determined based on the first radius and the second radius.

Step 207, when the radius change rate is less than or equal to a preset change rate threshold, use the first arc point set as a specified arc point set, and use the second circular curve as a specified circular curve, based on the Calculate the relative accuracy of the target by specifying the arc point set and the specified circular curve;

In this embodiment, if the rate of change of the radius corresponding to the first radius and the second radius is less than or equal to the preset rate of change threshold, it means that the fitting degree of the circular curve is already good, and it is not necessary to continue fitting. The first arc point set is directly used as the specified arc point set, and the second circular curve can be directly used as the specified circular curve, and then the corresponding target relative accuracy is calculated based on the pointing arc point set and the specified circular curve .

Here, the degree of circle fitting can also be judged by other conditions. For example, the number of iterations is preset, and when the circle fitting operation is repeated to reach the preset number of times threshold, the circle fitting is stopped, and the circle curve obtained by the last fitting is used as the specified circle curve. In addition, it is also possible to determine whether to stop the circle fitting operation by judging the change of the circle center corresponding to the circle curve of each circle fitting. The circular curve obtained by the last fitting is used as the specified circular curve.

Optionally, the "calculating the relative accuracy of the target based on the specified arc point set and the specified circular curve" specifically includes: based on the specified arc point set, determining each The lengths of the line segments corresponding to the adjacent two vertices are obtained to obtain the total target length; based on the specified circular curve, the target arc length corresponding to the specified circular curve is determined; according to the total target length and the target arc length, The target relative accuracy is determined.

In this embodiment, after the designated arc point set is determined, the length of the line segment corresponding to every two adjacent vertices in the designated arc point set may be determined based on the designated arc point set, for example, the designated arc point The set can include 5 vertices, namely vertices 1 to 5, which connect vertices 1 and 2, 2 and 3, 3 and 4, and 4 and 4 respectively. 5. The line segments corresponding to 4 segments can be obtained, and then the lengths of these 4 segments can be added to obtain the total length of the target. In addition, the target arc length corresponding to the specified circular curve can also be calculated, and finally the relative accuracy of the target can be determined according to the calculated total target length and target arc length. Specifically, assuming that the total length of the target is L _total and the length of the target arc is L _arc , then the relative accuracy of the target may be (L _arc - L _total )/L _total .

Step 208, when the radius change rate is greater than the preset change rate threshold, according to the preset rejection condition again, remove the vertices that satisfy the preset rejection condition from the set of first arc points, Obtain a second arc point set, and perform circle fitting again to obtain a third circular curve, determine the third radius corresponding to the third circular curve, and determine the radius change according to the second radius and the third radius rate until the radius change rate is less than or equal to the preset change rate threshold;

In this embodiment, if the rate of change of the radius corresponding to the first radius and the second radius is greater than the preset rate of change threshold, it indicates that the fitting degree of the circular curve is not ideal, and the fitting needs to be continued. Preset culling conditions, culling the vertices that satisfy the preset culling conditions in the first arc point set, and then obtain the second arc point set. Next, based on the second arc point set, circle fitting is also performed by using the least square method to obtain a third circular curve, and a third radius corresponding to the third circular curve is calculated. After the third radius is obtained, the change rate of the radius of this fitting can be calculated according to the third radius and the second radius, and the change size of the third radius can be determined. If the current radius change rate is less than or equal to the preset change rate threshold, the second arc point set can be used as the specified arc point set, and the third circular curve can be used as the specified circular curve, and then the target relative accuracy can be calculated; When the secondary radius change rate is greater than the preset change rate threshold, continue the above operations until the radius change rate is less than or equal to the preset change rate.

Step 209, based on the relative accuracy of the target, determine the relative accuracy of the topographic map.

In this embodiment, after the relative accuracy of the target is obtained, the relative accuracy of the topographic map can be further determined according to the relative accuracy of the target. In addition, the relative accuracy of the topographic map can be determined based on the feature distribution state and node density. Among them, for the feature distribution state, by remapping the elements that meet the design accuracy of the topographic map to the topographic map, observe the distribution state, establish the spatial mapping relationship between the distribution of the elements and the basic geographic information map, and analyze the local characteristics of the distribution of the elements; node density, Calculate the ratio of the number of vertices of each feature and the sum of the distance between two adjacent points, that is, the number of vertices within the unit distance of each feature, where the number of vertices refers to the number of vertices in the preset point set.

In the embodiment of the present application, optionally, in step 202, "screen the preset point set according to the segmented slope sequence to obtain the target arc point set corresponding to the target element", Specifically, it includes: according to the segmented slope sequence, judging whether the segmented slope sequence is monotonic; if it is monotonic, fitting the preset point set data based on a preset exponential function, Obtain a first fitting result, calculate a corresponding first coefficient of determination and a first fitting accuracy according to the first fitting result, and when the first coefficient of determination is greater than a first preset coefficient threshold, and the first When the fitting accuracy is greater than the first preset accuracy threshold, the preset point set is retained, and the retained preset point set is used as the target arc point set, otherwise, the preset point set is discarded; when there is no monotonicity When the performance is correct, fit the preset point set data based on the preset inverse proportional function to obtain a second fitting result, calculate the corresponding second coefficient of determination and the second fitting accuracy according to the second fitting result, and When the second determination coefficient is greater than a second preset coefficient threshold, and the second fitting accuracy is greater than a second preset accuracy threshold, the preset point set is reserved, and the reserved preset point set is used as The target arc point set, otherwise, divide the preset point set into two sub-point sets according to monotonicity, and perform fitting according to the preset exponential function respectively to obtain a third fitting result, which is based on the third fitting result. The corresponding third determination coefficient and third fitting accuracy are calculated respectively for the three fitting results, and when the third determination coefficient is greater than the first preset coefficient threshold, and the third fitting accuracy is greater than the first When the accuracy threshold is preset, the corresponding sub-point set is reserved, and the reserved sub-point set is used as the target arc point set, when the third determination coefficient is smaller than the first preset coefficient threshold and/ Or when the third fitting accuracy is smaller than the first preset accuracy threshold, the corresponding sub-point set is discarded.

In this embodiment, after the slope sequence is segmented by the curvature trend item, it can be further determined whether each segment of the slope sequence is monotonic according to the segmented slope sequence. For example, if the curvature trend term divides the slope sequence corresponding to the curvature sequence into four segments, it can be determined whether the four segments of the slope sequence are monotonic. When there is monotonicity, a preset exponential function can be used to fit the acquired preset point set, and a first fitting result corresponding to the preset point set can be obtained. Further, according to the first fitting result and the preset The point set calculates the corresponding first coefficient of determination and the first fitting accuracy. The preset exponential function may be y _fit =a*exp(b*x)+c, the first coefficient of determination may be expressed as R ² , the first fitting accuracy may be expressed as RMSE, and the first coefficient of determination may be expressed by the following Formula to calculate:

Among them, SS _res and SS _tot are respectively expressed as residual sum of squares and total sum of squares, which are expressed as follows:

Among them, n is the number of vertices in the preset point set, y is the y coordinate value corresponding to the vertices in the preset point set, and y _fit is the y coordinate value obtained after fitting. Obviously, the smaller the residual sum of squares is, the better the fitting degree is, that is, the closer the first coefficient of determination R ² is to 1, the better the fitting degree is. Again, the formula for the first fit accuracy is as follows:

After calculating the first determination coefficient and the first fitting accuracy, further determine the relationship between the first determination coefficient and the first preset coefficient threshold, and the relationship between the first fitting accuracy and the first preset accuracy threshold. When the first determination coefficient is greater than the first preset coefficient threshold, and at the same time the first fitting accuracy is greater than the first preset accuracy threshold, it means that the preset point set is an arc point set, and the preset point set can be retained, And use the preset point set as the target arc point set. On the contrary, it means that the preset point set is not an arc point set and can be discarded.

When there is no monotonicity, it can be verified whether the preset point set belongs to a hyperbola, so the preset inverse proportional function can be used to fit the preset point set, and a second fitting result can be obtained after fitting. Further, the second coefficient of determination and the second fitting precision may be calculated by formula (11) and formula (13) according to the second fitting result and the preset point set. The preset inverse proportional function may be y _fit =1/(a*x+b). After the second determination coefficient and the second fitting accuracy are calculated, the relationship between the second determination coefficient and the second preset coefficient threshold, and the relationship between the second fitting accuracy and the second preset accuracy threshold can be determined. If the second determination coefficient is greater than the second preset coefficient threshold, and at the same time the second fitting accuracy is greater than the second preset accuracy threshold, then the preset point set is an arc point set, and the preset point set can be retained, And use the preset point set as the target arc point set. Conversely, the preset point set can be further divided into two sub-point sets with monotonicity, so that each sub-point set is monotonic, and then each sub-point set is fitted according to the preset exponential function, and the fitting Afterwards, the corresponding third fitting result can be obtained, and the third determination coefficient and the third fitting accuracy can be calculated according to the third fitting result, wherein each sub-point set can correspond to a third fitting coefficient and a third fitting accuracy. combined accuracy. Next, the third fitting coefficient is compared with the first preset coefficient threshold, and the third fitting accuracy is compared with the first preset accuracy threshold. When the third determination coefficient is greater than the first preset coefficient threshold, and the third When the fitting accuracy is greater than the first preset accuracy threshold, it means that the corresponding sub-point set is a circular arc point set, the sub-point set can be retained, and the sub-point set can be used as the target circular arc point set. On the contrary, it means that the corresponding sub-point set is not an arc point set and can be discarded.

In the embodiment of the present application, optionally, in step 204, "according to the preset culling conditions, culling the vertices that satisfy the preset culling conditions in the set of target arc points" specifically includes: according to preset culling conditions Eliminate the condition, respectively connect the three adjacent vertices at the head end and the three adjacent vertices at the end in the target arc point set, and obtain the connection angle of the head end and the connection angle of the end, when the connection angle is smaller than the first predetermined angle. When the angle threshold is set to be larger than the flat angle, the end point corresponding to the connection angle is eliminated, wherein the connection angle is the angle on one side of the center of the target circle; and/or, according to the preset elimination condition, the target circle is respectively connected Two adjacent vertices at the head end and two adjacent vertices at the end of the arc point set, obtain the corresponding first line segment, determine the first mid-perpendicular line of any of the first line segments, and determine the The two vertices corresponding to the first line segment are the two closest points on the first circular curve, connect the two closest points to obtain the second line segment corresponding to the first line segment, and determine the first line segment. The second vertical line of the two line segments, based on the first vertical line and the second vertical line, determine the target vertical line angle, when the target vertical line angle is greater than the second preset angle threshold, Eliminate the endpoints in the consecutive vertices; and/or, according to preset culling conditions, respectively connect the three adjacent vertices at the head end and the three adjacent vertices at the end in the target arc point set, to obtain The target connecting line segment, when the sum of the target connecting line segments corresponding to any of the three adjacent vertices is greater than or equal to the preset length threshold, the three adjacent vertices are corresponding to the target arc point set endpoint culling.

In this embodiment, after the target arc point set is determined, the vertices in the target arc point set may be further eliminated according to preset elimination conditions. For example, three adjacent vertices at the head end of the target arc point set can be connected together, and three adjacent vertices at the end can be connected together, and the connected three vertices can form a connecting angle, where three The middle point of the vertices is the vertex corresponding to the connecting angle, which refers to the corner whose opening faces the target center of the fitting circle. Specifically, the three adjacent fold points of the head end correspond to the connection angle of the head end, and the three adjacent fold points of the end correspond to the connection angle of the end. When the angle of any connecting angle is less than the first preset angle threshold, or the angle is greater than the flat angle, it means that the three adjacent vertices at the head end or the end points of the three adjacent vertices at the end have a relatively large influence on the circle fitting result. big, can be discarded. As shown in Figure 3, assuming that vertex A, vertex B and vertex C are three vertexes adjacent to the head end of the target arc point set, then the angle ABC can be the connection angle of the head end, and the angle corresponding to the connection angle is equal to α ₁ +α ₂ , since the connecting angle is larger than the straight angle, the vertex A can be discarded.

In addition, two adjacent vertices at the head end and two adjacent vertices at the end of the target arc point set can be connected together, respectively, to obtain corresponding first line segments, and then each first line segment can be determined. The first mid-perpendicular line corresponding to the line segment. Next, the second line segment corresponding to each first line segment can be further determined. Taking the first line segment corresponding to the two adjacent vertices at the head end as an example, find the first line segment corresponding to the first line segment on the first circular curve respectively. The closest point of the two vertices, and further connect the two closest points, the second line segment corresponding to the two closest points can be obtained, and the second mid-perpendicular line corresponding to the second line segment can be determined, wherein, the second mid-perpendicular line is a straight line through the center of the circle. Since the first mid-perpendicular line and the second mid-perpendicular line intersect, the target vertical line angle can be obtained. Determine the relationship between the angle between the target vertical line and the second preset angle threshold. If the angle between the target vertical line is greater than the second preset angle threshold, it means that the endpoints in the two adjacent fold points have an effect on the circle fitting result. The impact is large and can be discarded. Here, the endpoint is the first or last point in the target arc point set. As shown in Figure 4, the vertex X and the vertex Y can be two adjacent vertexes at the head end, connecting these two nodes, the corresponding line segment XY is the first line segment, and the straight line L1 is the corresponding line segment of the first line segment. The first vertical line, the straight line L2 is the second vertical line, and the included angle β is the included angle of the target vertical line.

In addition, it is also possible to connect the three adjacent vertices at the head end in the target arc point set, and similarly, connect the three adjacent vertices at the end, so that four target connection line segments can be obtained correspondingly. The three adjacent vertices correspond to two target connecting line segments, and the three adjacent vertices at the end correspond to two target connecting line segments. When the sum of the lengths of the two target connecting line segments corresponding to the three adjacent vertices at the head end is greater than or equal to the preset length threshold, the head end vertices in the target arc point set can be eliminated. When the sum of the lengths of the two target connecting line segments corresponding to the vertexes is greater than or equal to the preset length threshold, the end vertexes in the target arc point set can also be eliminated. As shown in Figure 5, the vertex M, the vertex N, and the vertex P can be three vertexes connected at the head end, and the corresponding target connection line segments are the line segment MN and the line segment NP, respectively. When the sum of the lengths of the line segment MN and the line segment NP is greater than When the length threshold is preset, if the vertex M is the first vertex in the target arc point set, then the vertex M can be eliminated from the target arc point set.

In the real world, it is very likely that there are long-distance roads or extremely short tortuous roads, and the circular curve fitting may be successful. At this time, it is necessary to eliminate the overfitting point set. When the distance between any two adjacent vertices in the target arc point set is greater than the preset distance threshold, the target arc point set is directly eliminated; when the radius of the circle after fitting is smaller than the preset radius threshold and a circular curve is fitted When the fitting accuracy is greater than the preset accuracy threshold, the target arc point set is directly deleted; when the determination coefficient obtained from the fitted circular curve and the target arc point set is less than the preset coefficient threshold, the target arc point set is deleted. Sets are deleted directly.

Further, as a specific implementation of the method in FIG. 1 , an embodiment of the present application provides a device for evaluating the relative accuracy of topographic maps. As shown in FIG. 5 , the device includes:

A point set calculation module, configured to obtain preset point set data corresponding to target elements, and calculate slope sequences and curvature sequences corresponding to the preset point sets, wherein the target elements include arc curve elements and/or curved river channel elements, The preset point set includes a plurality of fold points, and the preset point set data includes a plurality of fold point data;

a point set determination module, configured to determine a target arc point set corresponding to the target element based on the slope sequence and the curvature sequence;

The accuracy determination module is configured to determine the relative accuracy of the target corresponding to the target arc point set, and determine the relative accuracy of the topographic map based on the relative accuracy of the target.

Optionally, the point set calculation module specifically includes:

a slope sequence determination unit, configured to determine a slope sequence corresponding to the preset point set based on the fold point data of every two adjacent fold points in the preset point set data corresponding to the target element;

A curvature sequence determination unit, configured to fit a target quadratic curve based on the vertex data of every three adjacent vertex points in the preset point set data corresponding to the target element, and determine the target quadratic curve according to the target quadratic curve The curvature sequence corresponding to the preset point set.

Optionally, the point set determination module specifically includes:

a segmentation unit, configured to extract a curvature trend item from the curvature sequence based on the empirical mode decomposition method, and segment the slope sequence based on the positive and negative values corresponding to the curvature trend item;

A screening unit, configured to screen the preset point set according to the segmented slope sequence to obtain a target arc point set corresponding to the target element.

Optionally, the screening unit is specifically used for:

According to the segmented slope sequence, determine whether the segmented slope sequence is monotonic; if it is monotonic, fit the preset point set data based on a preset exponential function to obtain the first the fitting result, according to the first fitting result to calculate the corresponding first determination coefficient and the first fitting accuracy, and when the first determination coefficient is greater than the first preset coefficient threshold, and the first fitting accuracy When it is greater than the first preset precision threshold, the preset point set is reserved, and the reserved preset point set is used as the target arc point set, otherwise, the preset point set is discarded; when it is not monotonic, Fit the preset point set data based on a preset inverse proportional function to obtain a second fitting result, calculate a corresponding second coefficient of determination and a second fitting accuracy according to the second fitting result, and calculate when the When the second determination coefficient is greater than the second preset coefficient threshold, and the second fitting accuracy is greater than the second preset accuracy threshold, the preset point set is reserved, and the reserved preset point set is used as the target Arc point set, otherwise, divide the preset point set into two sub-point sets according to monotonicity, and perform fitting respectively according to the preset exponential function to obtain a third fitting result, according to the third fitting As a result, the corresponding third determination coefficient and third fitting accuracy are calculated respectively, and when the third determination coefficient is greater than the first preset coefficient threshold, and the third fitting accuracy is greater than the first preset accuracy When the threshold is set, the corresponding sub-point set is reserved, and the reserved sub-point set is used as the target arc point set, and when the third determination coefficient is smaller than the first preset coefficient threshold and/or the When the third fitting accuracy is smaller than the first preset accuracy threshold, the corresponding sub-point set is discarded.

Optionally, the device further includes:

A circle fitting module is used to perform circle fitting on the target circular arc point set based on the least squares method after the target circular arc point set corresponding to the target element is determined to obtain the corresponding target circular arc point set the first circular curve, and determine the first radius corresponding to the first circular curve and the target center;

a culling module, used for culling the vertices that satisfy the preset culling conditions in the target arc point set according to the preset culling conditions, to obtain a first arc point set;

The circle fitting module is further configured to re-use the least squares method to perform circle fitting on the first circular arc point set to obtain a second circular curve, and determine a second radius corresponding to the second circular curve ;

a change rate determination module, configured to determine a radius change rate according to the first radius and the second radius;

The judgment module is configured to use the first circular arc point set as the designated circular arc point set and the second circular curve as the specified circular curve when the radius change rate is less than or equal to the preset change rate threshold value, based on The target relative accuracy is calculated from the specified arc point set and the specified circular curve; when the radius change rate is greater than the preset change rate threshold, the first The vertices that satisfy the preset elimination conditions are eliminated from the arc point set to obtain a second arc point set, and circle fitting is performed again to obtain a third circular curve, and the third radius corresponding to the third circular curve is determined, The radius change rate is determined according to the second radius and the third radius until the radius change rate is less than or equal to the preset change rate threshold.

Optionally, the culling module is specifically used for:

According to the preset culling conditions, respectively connect the three adjacent vertices of the head end and the three adjacent vertices of the end of the target arc point set, and obtain the connection angle of the head end and the connection angle of the end, when the connection angle is less than When the first preset angle threshold is greater than or equal to the flat angle, the end point corresponding to the connection angle is eliminated, wherein the connection angle is the angle on one side of the target circle center; and/or, according to the preset elimination condition, the connection angle is respectively Two adjacent vertices at the head end and two adjacent vertices at the end of the target arc point set, obtain the corresponding first line segment, determine the first mid-perpendicular line of any of the first line segments, and respectively Determine the two closest points of the two vertices corresponding to the first line segment on the first circular curve, connect the two closest points to obtain a second line segment corresponding to the first line segment, and determine The second vertical line of the second line segment, based on the first vertical line and the second vertical line, determine the target vertical line angle, when the target vertical line angle is greater than the second preset angle When the threshold value is reached, the endpoints in the consecutive vertices are removed; and/or, according to the preset culling conditions, respectively connect the three adjacent vertices at the head end and the three adjacent folds at the end of the target arc point set. point to obtain the target connecting line segment, and when the sum of the target connecting line segments corresponding to any of the three adjacent vertices is greater than or equal to the preset length threshold, compare the three adjacent vertices with the target arc The endpoints corresponding to the point set are culled.

Optionally, the judging module is also used for:

Based on the specified arc point set, determine the length of the line segment corresponding to every two adjacent vertices in the specified arc point set, and obtain the total length of the target; based on the specified circular curve, determine the target corresponding to the specified circular curve The arc length; the relative accuracy of the target is determined according to the total length of the target and the length of the target arc.

It should be noted that, for other corresponding descriptions of the functional units involved in the apparatus for evaluating the relative accuracy of topographic maps provided in the embodiments of the present application, reference may be made to the corresponding descriptions in the method in FIG. 1 , which will not be repeated here.

Based on the above method shown in FIG. 1 , correspondingly, an embodiment of the present application further provides a storage medium on which a computer program is stored, and when the computer program is executed by a processor, the above-mentioned topographic map shown in FIG. Accuracy assessment method.

Based on this understanding, the technical solution of the present application can be embodied in the form of a software product, and the software product can be stored in a non-volatile storage medium (which may be CD-ROM, U disk, mobile hard disk, etc.), including several The instructions are used to cause a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the methods described in various implementation scenarios of this application.

Based on the above method shown in FIG. 1 and the virtual device embodiment shown in FIG. 5 , in order to achieve the above purpose, an embodiment of the present application further provides a computer device, which may specifically be a personal computer, a server, a network device, etc., The computer device includes a storage medium and a processor; the storage medium is used to store a computer program; and the processor is used to execute the computer program to implement the above-mentioned method for evaluating the relative accuracy of a topographic map as shown in FIG. 1 .

Optionally, the computer device may further include a user interface, a network interface, a camera, a radio frequency (Radio Frequency, RF) circuit, a sensor, an audio circuit, a WI-FI module, and the like. The user interface may include a display screen (Display), an input unit such as a keyboard (Keyboard), etc., and the optional user interface may also include a USB interface, a card reader interface, and the like. Optional network interfaces may include standard wired interfaces, wireless interfaces (such as Bluetooth interfaces, WI-FI interfaces), and the like.

Those skilled in the art can understand that the structure of a computer device provided in this embodiment does not constitute a limitation on the computer device, and may include more or less components, or combine some components, or arrange different components.

The storage medium may also include an operating system and a network communication module. An operating system is a program that manages and saves the hardware and software resources of computer equipment, supports the operation of information processing programs and other software and/or programs. The network communication module is used to realize the communication between various components inside the storage medium, as well as the communication with other hardware and software in the physical device.

From the description of the above embodiments, those skilled in the art can clearly understand that the present application can be implemented by means of software plus a necessary general hardware platform, and can also be implemented by hardware. First, the preset point set data corresponding to the target element is acquired, and based on the acquired preset point set data, the slope sequence and the curvature sequence corresponding to each preset point set are calculated. Next, the target arc point set corresponding to the target element may be determined based on the slope sequence and the curvature sequence. Specifically, a part of the preset point set may be removed from the acquired preset point set according to the slope sequence and the curvature sequence, and the last remaining preset point set is the target arc point set. After the target arc point set is determined, the relative accuracy of the target corresponding to the target arc point set can be further determined according to the target arc point set, and then the relative accuracy of the topographic map can be determined according to the relative accuracy of the target. The present application can automatically calculate the relative accuracy of the topographic map according to the acquired preset point set data corresponding to the target element, which can effectively reduce the cost of calculating the relative accuracy of the topographic map and improve the evaluation efficiency of the relative accuracy of the topographic map.

Those skilled in the art can understand that the accompanying drawing is only a schematic diagram of a preferred implementation scenario, and the modules or processes in the accompanying drawing are not necessarily necessary to implement the present application. Those skilled in the art can understand that the modules in the device in the implementation scenario may be distributed in the device in the implementation scenario according to the description of the implementation scenario, or may be located in one or more devices different from the implementation scenario with corresponding changes. The modules of the above implementation scenarios may be combined into one module, or may be further split into multiple sub-modules.

The above serial numbers in the present application are only for description, and do not represent the pros and cons of the implementation scenarios. The above disclosures are only a few specific implementation scenarios of the present application, however, the present application is not limited thereto, and any changes that can be conceived by those skilled in the art should fall within the protection scope of the present application.

Claims (10)

1. A method for evaluating the relative accuracy of topographic maps, comprising: Acquire preset point set data corresponding to the target element, and calculate the slope sequence and curvature sequence corresponding to the preset point set, wherein the target element includes arc curve elements and/or curved river elements, and the preset point set includes a plurality of fold points, the preset point set data includes a plurality of fold point data; determining a target arc point set corresponding to the target element based on the slope sequence and the curvature sequence; The relative accuracy of the target corresponding to the target arc point set is determined, and based on the relative accuracy of the target, the relative accuracy of the topographic map is determined. 2. The method according to claim 1, wherein the calculating the slope sequence and the curvature sequence corresponding to the preset point set specifically comprises: Determine the slope sequence corresponding to the preset point set based on the fold point data of every two adjacent fold points in the preset point set data corresponding to the target element; Based on the vertex data of every three adjacent vertexes in the preset point set data corresponding to the target element, a target quadratic curve is fitted, and according to the target quadratic curve, it is determined that the preset point set corresponds to curvature sequence. 3 . The method according to claim 1 , wherein determining the target arc point set corresponding to the target element based on the slope sequence and the curvature sequence, specifically comprising: 3 . Based on the empirical mode decomposition method, a curvature trend term is extracted from the curvature sequence, and the slope sequence is segmented based on the positive and negative values corresponding to the curvature trend term; According to the segmented slope sequence, the preset point set is screened to obtain a target arc point set corresponding to the target element. 4. The method according to claim 3, wherein the preset point set is screened according to the segmented slope sequence to obtain a target arc point set corresponding to the target element, Specifically include: According to the segmented slope sequence, determine whether the segmented slope sequence is monotonic; When it is monotonic, the preset point set data is fitted based on the preset exponential function to obtain a first fitting result, and the corresponding first coefficient of determination and the first fitting are calculated according to the first fitting result accuracy, and when the first determination coefficient is greater than the first preset coefficient threshold, and the first fitting accuracy is greater than the first preset accuracy threshold, the preset point set is retained, and the retained preset The point set is used as the target arc point set, otherwise, the preset point set is discarded; When there is no monotonicity, the preset point set data is fitted based on a preset inverse proportional function to obtain a second fitting result, and a corresponding second coefficient of determination and a second fitting result are calculated according to the second fitting result. and when the second determination coefficient is greater than the second preset coefficient threshold and the second fitting accuracy is greater than the second preset accuracy threshold, the preset point set is retained, and the retained preset Set the point set as the target arc point set, otherwise, divide the preset point set into two sub-point sets according to monotonicity, and perform fitting respectively according to the preset exponential function to obtain a third fitting result, According to the third fitting result, the corresponding third determination coefficient and the third fitting accuracy are calculated respectively, and when the third determination coefficient is greater than the first preset coefficient threshold, and the third fitting accuracy is greater than When the first preset accuracy threshold is used, the corresponding sub-point set is reserved, and the reserved sub-point set is used as the target arc point set. When the third determination coefficient is smaller than the first preset When the coefficient threshold and/or the third fitting precision is smaller than the first preset precision threshold, the corresponding sub-point set is discarded. 5. The method according to claim 1, wherein after determining the target arc point set corresponding to the target element, the method further comprises: Based on the least squares method, circle fitting is performed on the target circular arc point set to obtain a first circular curve corresponding to the target circular arc point set, and a first radius corresponding to the first circular curve and a target circle center are determined; According to a preset culling condition, culling the vertices that satisfy the preset culling condition in the target arc point set to obtain a first arc point set; Reusing the least squares method for circle fitting on the first arc point set to obtain a second circular curve, and determining a second radius corresponding to the second circular curve; determining a radius change rate according to the first radius and the second radius; When the radius change rate is less than or equal to the preset change rate threshold, the first circular arc point set is used as the specified circular arc point set, the second circular curve is used as the specified circular curve, and based on the specified circular arc Calculate the relative accuracy of the target with the point set and the specified circular curve; When the radius change rate is greater than the preset change rate threshold, according to the preset culling condition again, culling the vertices that satisfy the preset culling condition from the set of first arc points, to obtain a second arc point set, and perform circle fitting again to obtain a third circular curve, determine the third radius corresponding to the third circular curve, and determine the radius change rate according to the second radius and the third radius, until The radius change rate is less than or equal to the preset change rate threshold. 6 . The method according to claim 5 , wherein, according to a preset culling condition, culling the vertices that satisfy the preset culling condition in the target arc point set, specifically comprising: 6 . According to the preset culling conditions, respectively connect the three adjacent vertices of the head end and the three adjacent vertices of the end of the target arc point set, and obtain the connection angle of the head end and the connection angle of the end, when the connection angle is less than When the first preset angle threshold is greater than or equal to the flat angle, the end point corresponding to the connection angle is eliminated, wherein the connection angle is an angle on one side of the target circle center; and/or, According to the preset culling conditions, respectively connect two adjacent vertices at the head end and two adjacent vertices at the end of the target arc point set to obtain a corresponding first line segment, and determine any one of the first line segments The first mid-perpendicular line of the For the second line segment corresponding to the line segment, determine the second mid-perpendicular line of the second line segment, and determine the included angle of the target vertical line based on the first mid-perpendicular line and the second mid-perpendicular line. When the target vertical line is When the included angle of the line is greater than the second preset angle threshold, remove the endpoints from the two vertices; and/or, According to the preset culling conditions, respectively connect the three adjacent vertices at the head end and the three adjacent vertices at the end of the target arc point set to obtain the target connection line segment, when any of the three adjacent vertices corresponds to When the sum of the target connecting line segments is greater than or equal to the preset length threshold, the end points corresponding to the target arc point set in the adjacent three fold points are eliminated. 7. The method according to claim 5, wherein the calculating the relative accuracy of the target based on the specified arc point set and the specified circular curve specifically comprises: Based on the specified arc point set, determine the length of the line segment corresponding to every two adjacent vertices in the specified arc point set, and obtain the total target length; Based on the specified circular curve, determine the target arc length corresponding to the specified circular curve; The relative accuracy of the target is determined according to the total length of the target and the length of the target arc. 8. A device for evaluating the relative accuracy of topographic maps, comprising: A point set calculation module, configured to obtain preset point set data corresponding to target elements, and calculate slope sequences and curvature sequences corresponding to the preset point sets, wherein the target elements include arc curve elements and/or curved river channel elements, The preset point set includes a plurality of fold points, and the preset point set data includes a plurality of fold point data; a point set determination module, configured to determine a target arc point set corresponding to the target element based on the slope sequence and the curvature sequence; The accuracy determination module is configured to determine the relative accuracy of the target corresponding to the target arc point set, and determine the relative accuracy of the topographic map based on the relative accuracy of the target. 9 . A storage medium on which a computer program is stored, characterized in that, when the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented. 10 . 10. A computer device comprising a storage medium, a processor and a computer program stored on the storage medium and running on the processor, wherein the processor implements claims 1 to 7 when executing the computer program The method of any of the above.

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