A POI thinning method based on buffer and priority

Abstract

The present invention provides a method for thinning POIs based on a buffer and priority, which includes the following steps: grid the electronic map into a plurality of grids; determine the priority of each POI (Point of Interest) in the electronic map; extract one POI in each grid; generate a buffer for the POI according to a set distance and perform intersection fusion processing, and fuse the buffers of the POIs with intersections into an aggregation block; extract one POI for each aggregation block. By combining the importance, type and distance information of the POIs, the present invention establishes corresponding thinning rules, efficiently and reasonably thins the POIs, ensures the mapping effect of the POIs, reduces the amount of POI data, and improves the subsequent mapping efficiency of the electronic map.

Description

Technical Field

[0001] The present invention belongs to the technical field of electronic maps, and particularly relates to a method for thinning POIs based on buffer zones and priorities. Background Art

[0002] With the rapid update and development of the information-based world, the application of maps has become increasingly widespread. It can be said that maps have penetrated into all aspects of people's lives, bringing great convenience to people's lives. In this era of increasingly developed intelligence, the application of electronic maps is even more extensive. And an important element in electronic maps is the annotation of electronic maps. The richer and more reasonable the electronic map annotation is, the more it can meet people's application needs.

[0003] However, in the case of limited electronic screens and map capacities, tens of millions of POI (Point of Interest) interest points cannot be fully displayed as annotations on the map. Therefore, how to select and display POI interest points is a difficult problem and a problem that must be solved for many map providers. How to balance the aesthetic appearance of the map surface and meet people's usage needs is a research topic worthy of study.

[0004] POI interest points are an important part of electronic maps. When displaying a large number of dense POI interest points, thinning processing is often required first. How to make the distributed POI interest points after thinning be uniform and reasonable and take into account elements such as their priorities is something that needs to be solved key. When existing electronic maps process the display of POI interest points, they basically thin and display POI interest points with reference to distance. The results after thinning often have important or concerned interest points blocked and unimportant interest points displayed, which cannot meet people's usage needs and have problems of unreasonable thinning and display effects of POI interest points and poor practicability. Summary of the Invention

[0005] Aiming at the defects existing in the prior art, the present invention provides a method for thinning POIs based on buffer zones and priorities, which can effectively solve the above problems.

[0006] The technical solution adopted by the present invention is as follows:

[0007] The present invention provides a method for thinning POIs based on buffer zones and priorities, including the following steps:

[0008] Step S1, according to the screen resolution and the spatial distribution of POI interest points, set the grid size at the corresponding scale as n*n, so as to grid the electronic map into multiple grids; where, the meaning of n*n is: each grid includes n rows and n columns of pixels;

[0009] Step S2, determine the priority of each POI interest point in the electronic map;

[0010] Step S3, in each grid, extract a POI (Point of Interest) using the following rules;

[0011] First, extract the POI with the highest priority; if there are two or more POIs with the highest priority, then among the POIs with the highest priority, extract the POI closest to the center of the grid.

[0012] Step S4, for each extracted POI, generate a buffer zone of the POI at a set distance;

[0013] For the buffer zones of each generated POI, perform an intersection and fusion process, that is: fuse the buffer zones of the POIs with intersections into one aggregation block, thereby obtaining multiple aggregation blocks after the intersection and fusion process;

[0014] Step S5, for each aggregation block, extract a POI using the following rules:

[0015] First, extract the POI with the highest priority within the aggregation block; if there are two or more POIs with the highest priority within the aggregation block, then among the POIs with the highest priority, extract the POI closest to the aggregation center of the aggregation block as the finally required POI to be displayed.

[0016] Preferably, in step S2, determine the priority of each POI in the electronic map according to the id number, type value, and importance degree of the POI.

[0017] Preferably, step S2 is specifically as follows:

[0018] Step S21, each POI has a unique id number, store the id numbers of the POIs that must be extracted according to requirements into the id number configuration table;

[0019] Step S22, for each POI, assign an importance degree score F1 according to its importance degree; assign a type score F2 according to its type;

[0020] Step S23, use the following formula to obtain the total priority score F0:

[0021] F0 = α * id number + β * F1 + γ * F2

[0022] Where: α, β, and γ are the id number weight, importance degree weight, and type weight respectively;

[0023] For the weight of the ID number, if the ID number is in the ID number configuration table, the weight α of the ID number is assigned positive infinity; if the ID number is not in the ID number configuration table, the weight α of the ID number is assigned 0.

[0024] Preferably, the types of POI points of interest include major categories, medium categories, and minor categories.

[0025] Preferably, in step S4, a buffer area of the POI point of interest is generated with a radius of n / 2 distance.

[0026] A method for thinning POIs based on buffer and priority provided by the present invention has the following advantages:

[0027] By combining the importance, type, and distance information of POI points of interest, the present invention establishes corresponding thinning rules, efficiently and reasonably thins the POI points of interest, ensures the display effect of POI points of interest on the map, reduces the amount of POI point data, and improves the efficiency of subsequent electronic map mapping. Description of the Drawings

[0028] Figure 1 is a schematic flow chart of a method for thinning POIs based on buffer and priority provided by the present invention;

[0029] Figure 2 is a schematic diagram of the gridification principle of the electronic map provided by the present invention. Detailed Embodiments

[0030] In order to make the technical problems, technical solutions, and beneficial effects solved by the present invention clearer, the present invention will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0031] Due to the limitations of the range and resolution of the electronic map display device, combined with the real-time and dynamic nature of the electronic map display, during the browsing and querying of the electronic map, it is often necessary to use the window zoom-in and zoom-out display of the map. Therefore, in order to display important POI points of interest when the window is reduced and avoid phenomena such as the overlapping and covering of annotations, and to see more details and more reasonable content when the window is enlarged, the present invention is proposed.

[0032] The present invention provides a method for thinning POIs based on buffer and priority. The advantages of the present invention lie in fully considering the priority and mandatory display points of POI points of interest, reasonably thinning the POI points of interest according to requirements, and the thinning effect takes into account aspects such as importance, type, distance, and project requirements, improving the aesthetics and practicality of displaying POI points of interest in the electronic map.

[0033] The main idea of the present invention is as follows: First, a grid of n by n pixels is set according to the screen resolution, and it is required to extract a POI (Point of Interest) from within n by n pixels; secondly, priorities are assigned to the POI, and the priorities are divided according to the ID number and the type importance value; furthermore, one POI is extracted from each grid according to the priority; finally, a buffer zone is established for each POI based on the extraction points, and then buffer zone intersection fusion is performed, and the POIs with low priority and close distance are deleted, so as to ensure that the points with high priority are extracted and the problem of map annotation covering is avoided to the greatest extent, improving the aesthetics and practicality of the map.

[0034] Reference Figure 1 , the present invention provides a method for thinning POIs based on buffer zones and priorities, including the following steps:

[0035] Step S1, according to the screen resolution and the spatial distribution of POI, set the grid size at the corresponding scale as n*n, so as to grid the electronic map into multiple grids; wherein, the meaning of n*n is: each grid includes n rows and n columns of pixels;

[0036] Specifically, during the process of zooming in and out of the map window, the corresponding grid size is dynamically set according to the screen resolution to meet the display requirements.

[0037] Specifically, according to the screen resolution and the spatial distribution of POI, set the grid size at the corresponding scale. For example, when the scale is 1:288895, a grid is generated by setting 80 by 80 pixels, as Figure 2 shown.

[0038] Step S2, determine the priority of each POI in the electronic map;

[0039] Specifically, according to the id number, type value and importance of the POI, determine the priority of each POI in the electronic map.

[0040] This step specifically includes:

[0041] Step S21, each POI has a unique id number, and store the id numbers of the POIs that must be extracted according to requirements into the id number configuration table;

[0042] Step S22, for each POI, assign an importance score F1 according to its importance; assign a type score F2 according to its type;

[0043] The types of POIs include major categories, medium categories and minor categories.

[0044] Step S23, use the following formula to obtain the total priority score F0:

[0045] F0=α*id+β*F1+γ*F2

[0046] Among them: α, β and γ are id number weight, importance weight and type weight respectively;

[0047] For the id number weight, if the id number is an id number in the id number configuration table, its id number weight α is assigned a value of positive infinity; if the id number is not an id number in the id number configuration table, its id number weight α is assigned a value of 0.

[0048] The principle of calculating the total priority score using the above method is:

[0049] 1) For POI points of interest that must be extracted according to the requirements, since they must be extracted, their weight is positive infinity, which means that for such POI points of interest, their total priority score F0 is infinite, ensuring that they can be extracted.

[0050] For example, for the POI point of interest Shanghai Binhai Forest Park, configure its id number to 1013044284. For the POI point of interest Shanghai Auto Expo Park, configure its id number to 1013108459. For the POI point of interest Binjiang Forest Park, configure its id number to 1013172024. Then, store the id numbers 1013044284, 1013108459, and 1013172024 in the id number configuration table, indicating that the POI points of interest corresponding to these id numbers must be extracted. Thus, the id number weights of these POI points of interest are configured to be positive infinity.

[0051] 2) The importance score F1 of each POI is configured as follows:

[0052] Assign importance values of 0-9 to specific POI points of interest. The higher the importance, the higher the importance score. The example of assignment rules is as follows:

[0053] Importance 9, the corresponding importance score is 90 points.

[0054] Importance 8, the corresponding importance score is 80 points.

[0055] Importance 7, the corresponding importance score is 70 points.

[0056] Importance 6, the corresponding importance score is 60 points.

[0057] Importance 5, the corresponding importance score is 50 points.

[0058] Importance 4, the corresponding importance score is 40 points.

[0059] Importance level 3, corresponding importance score is 30 points.

[0060] Importance level 2, corresponding importance score is 20 points.

[0061] Importance level 1, corresponding importance score is 10 points.

[0062] Importance level 0, corresponding importance score is 0 points.

[0063] 3) The type score F2 of each POI is configured as follows:

[0064] The types include major categories, medium categories, and minor categories, and certain score values are given respectively. An example of the type score rule is as follows:

[0065] For a railway station, the type score is assigned 150 points according to the major category;

[0066] For a passenger railway station, the type score is assigned 70 points according to the minor category.

[0067] 4) The importance weight β can be set to 40%, and the type weight γ to 60%.

[0068] For a POI not in the ID number configuration table, if its type score is 100 points and its importance score is 60, then its total priority score F0 is: 100 * 60% + 60 * 40% = 84 points. The higher the score of a POI, the more preferentially it is extracted during the extraction process. However, if there is a POI corresponding to a configured ID within the extraction range, then the POI corresponding to the ID is extracted.

[0069] Step S3, in each grid, one POI is extracted using the following rules;

[0070] First, extract the POI with the highest priority; if there are two or more POIs with the highest priority, then among the POIs with the highest priority, extract the POI closest to the center of the grid.

[0071] Step S4, for each extracted POI, generate a buffer zone for the POI according to the set distance;

[0072] For example, a buffer zone for the POI can be generated with a radius of n / 2 distance. The number of buffer zones is equal to the number of extracted POIs.

[0073] For the generated buffer zones of each POI, perform an intersection and fusion process, that is: fuse the buffer zones of the POIs with intersections into one aggregation block, and thus obtain multiple aggregation blocks after the intersection and fusion process;

[0074] Step S5. For each aggregation block, extract a POI (Point of Interest) using the following rules:

[0075] First, extract the POI with the highest priority within the aggregation block. If there are two or more POIs with the highest priority within the aggregation block, then among the POIs with the highest priority, extract the POI closest to the aggregation center of the aggregation block as the POI to be finally displayed.

[0076] The purpose of buffer intersection fusion and extracting one POI for each aggregation block is to ensure that the distance between the extracted POIs in adjacent grids is not less than n pixel distances, thereby ensuring that the annotations do not overlap each other.

[0077] The core idea of the embodiment of the present invention is: assign priorities to POIs, then generate grids according to the spatial distribution of POIs, split and group POIs according to grids, extract the POI with the highest priority within each grid. To avoid the POIs extracted in adjacent grids being too close, establish buffers for the extracted POIs, and then perform buffer intersection fusion, and eliminate the POIs with two or more points in each face after fusion, ensuring that each face retains one POI with the highest priority according to the priority, so as to achieve a POI thinning method that takes into account both priority and distance.

[0078] By adopting the above-mentioned disclosed technical solution, the following beneficial effects are obtained: The present invention combines the importance, type, and distance information of POIs, establishes corresponding thinning rules, efficiently and reasonably thins the POIs, ensures the mapping effect of POIs, reduces the amount of POI data, and improves the subsequent electronic map mapping efficiency.

[0079] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A POI thinning method based on buffer and priority, characterized in that, It includes the following steps: Step S1: According to the screen resolution and the spatial distribution of POI (Point of Interest), set the grid size at the corresponding scale to n*n, thereby gridifying the electronic map into multiple grids; where the meaning of n*n is that each grid includes n rows and n columns of pixels; Step S2: Determine the priority of each POI in the electronic map; Step S3: In each grid, extract one POI using the following rules; First, extract the POI with the highest priority; if there are more than two POIs with the highest priority, then among the POIs with the highest priority, extract the POI closest to the center of the grid; Step S4: For each extracted POI, generate a buffer zone for the POI at a set distance; For the buffer zones of each generated POI, perform an intersection and fusion process, that is: fuse the buffer zones of the POIs with intersections into one aggregation block, thereby obtaining multiple aggregation blocks after the intersection and fusion process; Step S5: For each aggregation block, extract one POI using the following rules: First, extract the POI with the highest priority within the aggregation block; if there are more than two POIs with the highest priority within the aggregation block, then among the POIs with the highest priority, extract the POI closest to the aggregation center of the aggregation block as the POI to be finally displayed; 2. The POI thinning method based on buffer and priority according to claim 1, wherein In Step S2, determine the priority of each POI in the electronic map according to the id number, type value, and importance degree of the POI; 3. The POI thinning method based on buffer and priority according to claim 2, characterized in that Step S2 is specifically as follows: Step S21: Each POI has a unique id number, and store the id numbers of the POIs that must be extracted according to requirements into the id number configuration table; Step S22: For each POI, assign an importance score F1 according to its importance degree; assign a type score F2 according to its type; Step S23: Use the following formula to obtain the total priority score F0: F0 = α * id number + β * F1 + γ * F2 Where: α, β, and γ are the id number weight, importance degree weight, and type weight respectively; For the id number weight, if the id number is the id number in the id number configuration table, then its id number weight α is assigned positive infinity; if the id number is not the id number in the id number configuration table, then its id number weight α is assigned 0; 4. A method for thinning POI based on buffer and priority according to claim 3, characterized in that, The type of POI includes major categories, medium categories, and minor categories; 5. A method for thinning POI based on buffer and priority according to claim 1, characterized in that In Step S4, generate a buffer zone for the POI with a radius of n / 2 distance.

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