Technical Field

The present invention relates, in general, to a system and method for automatically producing a small-scale map and, more particularly, to a system and method for automatically producing a small-scale map using a large-scale map in a National Geographic Information Institute format.

Background Art

Generally, a small-scale map has a low ratio of actual distance on the earth's surface to a distance on the map when compared to a large-scale map, and indicates geographical features, such as buildings and roads, differently from the large-scale map. If the scale of the large-scale map is reduced by 1/5 or 1/10, geographic features indicated on a map cannot be identified by the naked eye, so that geographic features of relatively low importance are omitted and geographic features of relatively high importance are enlarged and, therefore, are more clearly indicated. As described above, a mapping method must vary with the scale. Korean mapping regulations, which are one of the Korean Construction and Transportation Ministry ordinances, prescribe mapping methods in detail. According to the mapping regulations, it is prescribed that the mapping regulations are applied to the cases where maps are produced based on basic and public measurements.

In the meantime, the National Geographic Information Institute (NGI) , which produces, manages and distributes a variety of Korean geographic information, including digital maps, produces digital maps in its own format and distributes them to the public for public purposes. In this case, the format of maps that is employed by the NGI is referred to as NGI format. Meanwhile, even when small-scale maps are produced using digital maps produced in the NGI format, the mapping regulations must be observed. In order to produce a small-scale map using a large- scale map as described above, it is necessary to convert a variety of geographic features indicated on the large-scale maps into indications that conform to the mapping regulations. In the past, the above-described work has been manually performed and takes a long time. Though part of the work is occasionally performed using a computer program, the work must be dependent on manual operations because interim amendment and inspection work must be performed. In brief, a technology for automatically producing a small-scale map from a large-scale map has not been developed yet, so that it takes a long time and incurs excessive personnel expenses to produce a small-scale map using a large-scale map.

Disclosure of the Invention

Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a system and method for automatically producing a small-scale map using a large-scale map in NGI format, which is capable

of automatically producing the small-scale map from the large-scale map using the attributes of NGI format.

In order to accomplish the above object, the present invention provides a system for automatically producing a small-scale map using large-scale map data in NGI format, including a mapping regulation database for storing information about indication regulations for the geographic features of the small-scale map; a geographic feature deletion module for deleting geographic features, which do not conform to mapping regulations for the small-scale map with reference to the mapping regulation database, and deleting all roads having width; a linestring joining module for deleting some contour lines to conform to the contour line regulations of mapping regulations for the small-scale map with reference to the mapping regulation database, and joining linestrings having an identical layer and/or a specific attribute; a road creation module for creating polygons in such a way as to join apexes that are acquired by offsetting the central lines of roads, and create new road having width by merging the polygons; and a control unit for loading the large-scale map data in NGI format, calling the modules and controlling the operations of the modules.

Preferably, the system may further include a building adjustment module for adjusting buildings to conform to the mapping regulations for the small-scale map with reference to the mapping regulation database in such a way as to merge adjacent buildings and to convert buildings smaller than a prescribed area into buildings of a prescribed size.

Preferably, the system may further include a polygon subtraction module for subtracting polygons that overlap with

the roads having width.

Preferably, the system may further include a polygon merging module for merging polygons, which have an identical layer and/or a specific attribute and are adjacent to each other within a tolerance range, into a single polygon.

Preferably, the system may further include a bridge adjustment module for adjusting existing bridges in such a way as to create new bridges from apexes that are acquired by offsetting central lines of roads existing inside bridges, and to cause the new bridges to reflect attributes of the existing bridges.

Preferably, the system may further include a partition merging module for merging a plurality of partitions into a single partition when large-scale map data corresponding to the plurality of partitions have been loaded.

Preferably, the system may further include a symbol insertion module for creating symbols, which are compatible with attributes of the geographic features, from the mapping regulation database to be matched to the geographic features. In accordance with another aspect of the present invention, there is provided a method for automatically producing a small-scale map using large-scale map data in NGI format with reference to a mapping regulation database, including the data loading step of loading the large-scale map data in NGI format; the geographic feature deletion step of deleting geographic features, which do not conform to mapping regulations for the small-scale map with reference to the mapping regulation database, and deleting all roads having width; the linestring joining step of deleting some contour lines to conform to contour line regulations of

mapping regulations for the small-scale map with reference to the mapping regulation database, and joining linestrings having an identical layer and/or a specific attribute; and road having width creation step of creating polygons in such a way as to join apexes that are acquired by offsetting central lines of roads, and creating new roads having width by merging the polygons.

Preferably, the method may further include, after the road having width creation step, the building adjustment step of adjusting buildings to conform to the mapping regulations for the small-scale map with reference to the mapping regulation database in such a way as to merge adjacent buildings and to convert buildings smaller than a prescribed area into buildings of a prescribed size; the polygon subtraction step of subtracting polygons that overlap with the roads having width; the polygon merging step of merging polygons, which have an identical layer and/or a specific attribute and are adjacent to each other within a tolerance range, into a single polygon; the bridge adjustment step of adjusting existing bridges in such a way as to create new bridges from apexes that are acquired by offsetting central lines of roads existing inside bridges, and to cause the new bridges to reflect attributes of the existing bridges; the partition merging step of merging a plurality of partitions into a single partition when large-scale map data corresponding to the plurality of partitions have been loaded; and the symbol insertion step of creating symbols, which are compatible with attributes of the geographic features, from the mapping regulation database to be matched to the geographic features.

Brief Description of the Drawings

The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a diagram showing the construction of a system for automatically producing a small-scale map according to an embodiment of the present invention;

FIG. 2 is a flowchart showing a method of automatically producing small-scale map according to an embodiment of the present invention;

FIG. 3a is a flowchart showing the geographic feature deletion step of the automatic small-scale map production method according to the embodiment of the present invention; FIG. 3b is a view showing an example of a map before the geographic feature deletion step of the automatic small- scale map production method according to the embodiment of the present invention;

FIG. 3c is a view showing an example of a map after the geographic feature deletion step of the automatic small-scale map production method according to the embodiment of the present invention;

FIG. 4a is a flowchart showing the linestring joining step of the automatic small-scale map production method according to the embodiment of the present invention;

FIG. 4b is a view showing an example of a map before the linestring joining step of the automatic small-scale map production method according to the embodiment of the present

invention;

FIG. 4c is a view showing an example of a map after the linestring joining step of the automatic small-scale map production method according to the embodiment of the present invention;

FIG. 5a is a flowchart showing the road having width creation step of the automatic small-scale map production method;

FIG. 5b is a view showing an example of a map before the road having width creation step of the automatic small- scale map production method according to the embodiment of the present invention;

FIG. 5c is a view showing an example of a map after the road having width creation step of the automatic small-scale map production method according to the embodiment of the present invention;

FIG. 6a is a flowchart showing the building adjustment step of the automatic small-scale map production method;

FIG. 6b is a view showing an example of a map before the building adjustment step of the automatic small-scale map production method according to the embodiment of the present invention;

FIG. 6c is a view showing an example of a map after the building adjustment step of the automatic small-scale map production method according to the embodiment of the present invention;

FIG. 7a is a flowchart showing the polygon subtraction step of the automatic small-scale map production method;

FIG. 7b is a view showing an example of a map before the polygon subtraction step of the automatic small-scale map

production method according to the embodiment of the present invention;

FIG. 7c is a view showing an example of a map after the polygon subtraction step of the automatic small-scale map production method according to the embodiment of the present invention;

FIG. 8a is a flowchart showing the polygon merging step of the automatic small-scale map production method;

FIG. 8b is a view showing an example of a map before the polygon merging step of the automatic small-scale map production method according to the embodiment of the present invention;

FIG. 8c is a view showing an example of a map after the polygon merging step of the automatic small-scale map production method according to the embodiment of the present invention;

FIG. 9a is a flowchart showing the bridge adjustment step of the automatic small-scale map production method;

FIG. 9b is a view showing an example of a map before the bridge adjustment step of the automatic small-scale map production method according to the embodiment of the present invention;

FIG. 9c is a view showing an example of a map after the bridge adjustment step of the automatic small-scale map production method according to the embodiment of the present invention;

FIG. 10a is a flowchart showing the partition merging step of the automatic small-scale map production method;

FIG. 10b is a view showing an example of a map before the partition merging step of the automatic small-scale map

production method according to the embodiment of the present invention;

FIG. 10c is a view showing an example of a map after the partition merging step of the automatic small-scale map production method according to the embodiment of the present invention;

FIG. 11a is a flowchart showing the symbol insertion step of the automatic small-scale map production method;

FIG. lib shows an example of a map before the symbol insertion step of the automatic small-scale map production method according to the embodiment of the present invention,-

FIG. lie shows an example of a map after the symbol insertion step of the automatic small-scale map production method according to the embodiment of the present invention; and

FIG. 12 is a view showing an example of a small-scale map that is produced by the automatic small-scale map production method according to the embodiment of the present invention.

Best Mode for Carrying Out the Invention

Reference should now be made to the drawings, in which the same reference numerals are used throughout the different drawings to designate the same or similar components.

A preferred embodiment of the present invention is described in detail with reference to the accompanying drawings.

Prior to the description of the preferred embodiment, an overview of NGI format is described first.

As described above, NGI format is a digital map format that was made by the NGI. In the NGI format, geographic objects are classified into a point object, a line object and a polygon object. The point object represents a point that has a meaning by itself. The line object is composed of a plurality of points. The polygon object is a spatial object that represents a closed region. The spatial objects of the NGI format are defined as in the following Table 1.

Table 1 Definitions of spatial objects of NGI format

All the geographical features of the NGI format are represented by spatial objects that are defined as described above.

The layers and attributes, with which individual geographic features are represented in NGI format, are described below. The following table 2 is an example of representing the names and attributes of geographic features.

Table 2 Names and attributes of geographic features for layers

The geographic features include 100 features, such as a building, the central line of a road and a bridge, which are

represented in the form of a point, line or surface. Furthermore, each of the geographic features is assigned a layer and a variety of attributes. In the automatic small- scale map production method of the present invention, operations of joining and merging objects are performed many times. In this case, the joining or merging operation is performed on sets of objects having the same layers or specific attributes.

FIG. 1 is a diagram showing the construction of a system for automatically producing a small-scale map according to an embodiment of the present invention. Referring to FIG. 1, the system 100 includes a control unit 101, a geographic feature deletion module 111, a linestring joining module 112, a road generation module 113, a building adjustment module 114, a polygon subtraction module 115, a polygon merging module 116, a bridge adjustment module 117, a partition merging module 118, a symbol insertion module 119, a mapping regulation database 131, and a small-scale map database 132. The control unit 101 handles processes required for the call of the modules and the production of a small-scale map after large-scale map data in NGI format has been loaded.

The geographic feature deletion module 111, the linestring joining module 112, the road generation module 113, the building adjustment module 114, the polygon subtraction module 115, the polygon merging module 116, the bridge adjustment module 117, the partition merging module 118, and the symbol insertion module 119 are modules for performing a geographic feature deletion step S200, a linestring joining step S300, a road generation step S400, a

building adjustment step S500, a polygon subtraction step S700, a polygon merging step S700, a bridge adjustment step S800, a partition merging step S900 and a symbol insertion step SlOOO, respectively, so that descriptions thereof are replaced with descriptions of steps S200 to SlOOO.

The mapping regulation database 131 is a database in which the contents of the mapping regulations, which are one of the Korean Construction and Transportation Ministry ordinances, are stored. The mapping regulation database 131 stores information about methods for indicating geographic features for various scales. In detail, the information includes geographic features for various scales, a guide principle for the intervals between contour lines for various scales, the minimum regulation areas of a building for various scales and the symbols (marks) of geographic features for various scales.

The small-scale map database 132 is a database in which small-scale map data produced through a series of processes by the modules are stored to be mapped to information about a small-scale map.

FIG. 2 is a flowchart showing a method of automatically producing small-scale map according to an embodiment of the present invention. The automatic small-scale map production method according to the embodiment of the present invention includes an initial file loading step SlOO, a geographic feature deletion step S200, a linestring joining step S300, a road creation step S400, a building adjustment step S500, a polygon subtraction step S600, a polygon merging step S700, a bridge adjustment step S800, a partition merging step S900, and a symbol insertion step SlOOO.

First, in order to produce a small-scale map from a large-scale map file, the large-scale map file in NGI format is loaded at step SlOO. Tlie large-scale map file may be stored in a database located in the system 100, or in an external storage medium.

In that case, the large-scale map file is a file that is a material to be used to produce a small-scale map, and a file that has a scale larger than that of a target small- scale map. According to mapping regulations, scales are classified into 1:5000, 1:10000, 1:25000 and 1:50000. When the large- scale map has a scale of 1:5000, the small-scale map automatically produced can have scales of 1:10000, 1:25000 and 1:50000. When the large-scale map has a scale of 1:10000, the small-scale map automatically produced can have scales of 1:50000. When the large-scale map has a scale of 1:25000, the small-scale map automatically produced can have a scale of 1:50000.

Although a corresponding small-scale map may be produced after a large-scale map file corresponding to a single partition has been loaded at step SlOO, it is preferred to perform step S200 and its following steps after loading large-scale files corresponding to a plurality of partitions. For example, when a 1:25000 scale map is produced using a 1:5000 scale map, large-scale map files corresponding to 25 partitions are loaded and step S200 and its following steps are performed on the large-scale map files at the same time.

After a large-scale map file in NGI format has been loaded at step SlOO, operations of producing a small-scale

file using the attributes of the NGI format are performed at steps S200 to SlOOO.

The geographic feature deletion step S200 is the step of deleting geographic features that do not conform to mapping regulations for the small-scale map, and all roads that are wider than a prescribed width with reference to the mapping regulation database.

The linestring joining step S300 is the step of deleting some of the contour lines to allow the resulting contour lines to conform to the contour interval regulations of the mapping regulations for the small-scale map with reference to the mapping regulation database, and joining linestrings having the same layer/specific attribute.

The road creation step S400 is the step of creating new roads having width in such a way as to create polygons by joining apexes, which are obtained by offsetting the central lines of roads, and to merge the created polygons.

The building adjustment step S500 is the step of adjusting building to allow resulting buildings to conform to the mapping regulations for the small-scale map in such a way as to merge adjacent buildings and convert buildings smaller than a prescribed area into buildings of the prescribed area.

The polygon subtraction step S600 is the step of subtracting polygons that overlap with the roads having width.

The polygon merging step S700 is the step of merging some of the polygons, which have the same layer and/or specific attribute and are adjacent to each other within a tolerance range, into a single one. The bridge adjustment step S800 is the step of

adjusting bridges in such a way as to create new bridges from apexes, which are obtained by offsetting the central lines of the roads, and to cause the new bridges to reflect the existing bridges. The partition merging step S900 is the step of merging a plurality of partitions into a single one when large-scale map data corresponding to the plurality of partitions has been loaded at step SlOO.

The symbol insertion step SlOOO is the step of creating symbols in such a way as to match the symbols, which conform to the attributes of geographic features, to the geographic features based on the mapping regulation database.

As described above, the large-scale map in NGI format is loaded at step SlOO and steps S200 and its following steps are performed, so that a small-scale map file, which conforms to the mapping regulations for the small-scale map, is automatically produced. Detailed descriptions of steps S200 to SlOOO will be made later in conjunction with FIGS. 3 to 11. FIG. 3a is a flowchart showing the geographic feature deletion step S200 of the automatic small-scale map production method according to the embodiment of the present invention. Referring to FIG. 3a, all the geographic features are extracted from the large-scale map at step S210. Thereafter, geographic features, which are not suitable for being indicated on the small-scale map based on the mapping regulation database, are all searched for at step S220. For example, since a half-interval contour line can be indicated only on 1:1000 and 1:5000 scale maps, the half-interval contour line is one of the geographic features that is not

suitable for being indicated on a corresponding small-scale map (for example, a 1:25000 scale map) when the 1:25000 scale map is produced using a 1:5000 scale map. The geographic features found at step S210 are all deleted at step S230. The roads having width of the large-scale map are all deleted at step S240. The roads having width are all deleted to create new roads having width suitable for the small-scale map because the roads having width are differently indicated according to the scale. The creation of the roads having width is performed at step S400.

Through the above-described process, the performance of the geographic feature deletion step is completed.

FIG. 3b shows an example of a map before the geographic feature deletion step S200 of the automatic small-scale map production method according to the embodiment of the present invention, and FIG. 3c shows an example of a map after the geographic feature deletion step S200 of the automatic small- scale map production method according to the embodiment of the present invention. FIG. 4a is a flowchart showing the linestring joining step S300 of the automatic small-scale map production method according to the embodiment of the present invention. Referring to FIG. 4a, all the linestrings are extracted from the large-scale map at step S310. Since mapping regulations for a contour line interval vary with the scale, information about a contour line interval compatible with the small-scale map is retrieved from the mapping regulation database 131, and contour lines that are not suitable for the small-scale map are deleted at step S320. The adjustment of contour lines may be performed using a method of deleting objects that do

not have a remainder of zero when the contour values of the objects are divided by two, but the present invention is not limited to this method.

Thereafter, some of the contour lines and linestrings, which have the same layer and specific attribute and are adjacent to each other, are joined together at step S330. In this case, contour values, that is, attribute values, are caused to be reflected by contour lines.

After step S320, information about the length of linestrings of the small-scale map is retrieved from the mapping regulation database 131, whether the lines of linestrings of the large-scale map are shorter than the length prescribed by the mapping regulations is determined, and linestrings that are shorter than the prescribed length are deleted at step S340. However, the linestrings that are shorter than the prescribed length and adjacent to an outer partition are not deleted. In this case, the outer partition refers to the outermost partition when large-scale map files corresponding to a plurality of partitions have been downloaded at step SlOO.

Through the above-described process, the performance of the linestring joining step is completed.

FIG. 4b shows an example of a map before the linestring joining step S300 of the automatic small-scale map production method according to the embodiment of the present invention, and FIG. 4c shows an example of a map after the linestring joining step S300 of the automatic small-scale map production method according to the embodiment of the present invention.

FIG. 5a is a flowchart showing the road having width creation step S400 of the automatic small-scale map

production method. The road having width creation step S200 is the step of newly creating the roads having width, which have all been deleted at step S200, to conform to the mapping regulations for the small-scale map using the attribute of the central line of the road. First, all the central lines of the roads are extracted from the large-scale map at step S410. Thereafter, apexes are acquired by offsetting the road width attribute values of the central lines of the roads at step S410. For example, offsetting is performed on offset interval variables, with offset interval variables 7.5, 10 and 11 being assigned to the central lines of the roads having a road width range of 3 m to 5.5 m, a road width range of 5.5 m to 11 m and a road width range wider than 11 m, respectively. Offset apexes can be acquired in such a way that an offset module acquires an offset apex using first and second apexes in a vector direction, an offset apex using second and third apexes, an offset apex using third and fourth apexes and so forth.

Thereafter, polygons are created by joining the apexes acquired at step S410, at step S430. Thereafter, roads having width are represented by merging the polygons at step S440. If a road having width is a paved road, the paved road is represented by assigning a weight to the central line of the road having width at step S450. Through the above-described process, the performance of the road having width creation step is completed.

FIG. 5b shows an example of a map before the road having width creation step S400 of the automatic small-scale map production method according to the embodiment of the present invention, and FIG. 5c shows an example of a map

after the road having width creation step S400 of the automatic small-scale map production method according to the embodiment of the present invention.

FIG. 6a is a flowchart showing the building adjustment step S500 of the automatic small-scale map production method. Referring to FIG. 6a, all the buildings are extracted from the objects of the large-scale map at step S510. Thereafter, adjacent buildings are merged together at step S520. Some of the buildings smaller than a prescribed area are converted to buildings having the prescribed area at step S530. For example, buildings smaller than 156.25 m ² are converted into buildings having a size of 156.25 m ² . Since there are buildings that become enlarged at step S530, the enlarged buildings may overlap with other geographic features (for example, roads, branch streams and prescribed waterways) , which are adjusted at steps S540 to S590.

Whether the enlarged buildings overlap with other geographic features is determined at step S540.

If none of the enlarged buildings overlap with other geographic features at step S540, the building adjustment step S500 ends. In contrast, if one of the enlarged buildings overlaps with one of the other geographic features at step S540 ("YES" at step S540) , whether the building is a principal building is determined at step S550. In this case, whether the building is a principal building is determined with reference to the attribute of the building.

If the enlarged building is not a principal building at step S530 ("YES" at step S530) , the enlarged building is deleted at step S560. In contrast, if the enlarged building is a principal building ("YES" at step S530) , whether a moved

enlarged building overlaps with other geographic features when the enlarged building is moved to another location is determined at step S570.

If the moved building does not overlap with any of other geographic features ("YES" at step S570) , the enlarged building is conclusively moved to the location at step S580.

In contrast, if the moved building overlaps with one of other geographic features when the enlarged building is moved

("YES" at step S570) , the enlarged building is deleted, or a circle mark is left at an original location to allow the enlarged building to be utilized during manual work at step

S590.

Through the above-described process, the performance of the building adjustment step is completed. FIG. 6b shows an example of a map before the building adjustment step S500 of the automatic small-scale map production method according to the embodiment of the present invention, and FIG. 6c shows an example of a map after the building adjustment step S500 of the automatic small-scale map production method according to the embodiment of the present invention.

FIG. 7a is a flowchart showing the polygon subtraction step S600 of the automatic small-scale map production method.

Referring to FIG. 7a, all the roads having width and polygons are subtracted from the objects of the large-scale map at step S610.

Thereafter, it is examined whether the polygons overlap with the roads having width at step S620.

If none of the polygons overlap with the roads having width ("NO" at step S620) , the polygon subtraction step S600

ends. In contrast, if one of the polygons overlaps with one of the roads having width ("YES" at step S620) , it is examined whether the polygon exists inside a road having width (that is, the polygon is completely included in the road having width) at step S630.

If the polygon does not completely exist inside the road having width (that is, a part of the polygon overlaps with the road having width) ("NO" at step S630) , the overlapped part of the road having width is cut out and deleted at step S640.

In contrast, if the polygon exists inside the road having width ("YES" at step S630) , the polygon is deleted at step S650.

Through the above-described process, the polygon subtraction step S600 ends at step S650.

FIG. 7b shows an example of a map before the polygon subtraction step S600 of the automatic small-scale map production method according to the embodiment of the present invention, and FIG. 7c shows an example of a map after the polygon subtraction step S600 of the automatic small-scale map production method according to the embodiment of the present invention.

FIG. 8a is a flowchart showing the polygon merging step S700 of the automatic small-scale map production method. While the small-scale map is created from the large-scale map, the large-scale map is entirely reduced. Accordingly, the sizes of objects and the distances between the objects are also reduced and, therefore, objects, which are adjacent to each other within a tolerance range, are generated, so that an operation of merging the polygons that are adjacent

to each other within the tolerance range must be performed.

First, all of the polygons are extracted from the objects of the large-scale map at step S710.

Thereafter, polygons that are adjacent to each other within the tolerance range are searched for at step S720.

If the polygons that are adjacent to each other within the tolerance range have the same layer and specific attribute, the polygons are trimmed using crossing points and then merged at step S730. If the area of a polygon obtained by the merging at step S730 is smaller than a prescribed area, the polygon is deleted at step S740. However, polygons adjacent to the outer partition are not deleted.

Through the above-described process, the performance of the polygon merging step S700 is completed. FIG. 8b shows an example of a map before the polygon merging step S700 of the automatic small-scale map production method according to the embodiment of the present invention, and FIG. 8c shows an example of a map after the polygon merging step S700 of the automatic small-scale map production method according to the embodiment of the present invention.

FIG. 9a is a flowchart showing the bridge adjustment step S800 of the automatic small-scale map production method. At the bridge adjustment step S800, bridges are newly created to be compatible with the small-scale map. First, all the bridges are extracted from the objects of the large-scale map at step S810. Thereafter, the central lines of roads that exist inside the bridges are searched for at step S820. Road width values are extracted from the attributes of the central lines of roads, and new bridges are created from apexes obtained by offsetting the central lines

of the roads by numerical values based on the road width values at step S830. In this case, if any bridge has a length shorter than a prescribed length, the bridge is deleted. However, if bridges having lengths shorter than the prescribed length are adjacent to the outer partition, the bridges are not deleted.

Thereafter, the attributes of the existing bridges are caused to be reflected by the new bridges, and the existing bridges are then deleted at step S840. Through the above-described process, the performance of the bridge adjustment step S800 is completed.

FIG. 9b shows an example of a map before the bridge adjustment step S800 of the automatic small-scale map production method according to the embodiment of the present invention, and FIG. 9c shows an example of a map after the bridge adjustment step S800 of the automatic small-scale map production method according to the embodiment of the present invention.

FIG. 10a is a flowchart showing the partition merging step S900 of the automatic small-scale map production method. At step SlOO, a plurality of partitions is merged into a single partition when large-scale files corresponding to the plurality of partitions have been loaded and processed. For example, when a 1:5000 scale map composed of 25 partitions has been loaded, the map is converted into a map composed of a single partition at the present step.

In order to merge partitions, information about a partition is extracted at step S910. Thereafter, partitions each having two or more crossing points are searched for at step S920. Thereafter, partitions found at step S920 are

merged together at step S930.

Through the above-described process, the performance of the partition merging step is completed.

FIG. 10b shows an example of a map before the partition merging step S900 of the automatic small-scale map production method according to the embodiment of the present invention, and FIG. 10c shows an example of a map after the partition merging step S900 of the automatic small-scale map production method according to the embodiment of the present invention. FIG. 11a is a flowchart showing the symbol insertion step SlOOO of the automatic small-scale map production method. The symbol insertion step SlOOO is the step of inserting symbols, which are compatible with the small-scale map, into the small-scale map that has passed through steps S200 to SlOOO.

First, all the polygons are extracted at step S910. Thereafter, the centers of gravity of the polygons are calculated at step S920. The symbols compatible with the attributes of geographic features existing in the form of polygons are inserted into the centers of gravity of the geographic features at step S930.

Through the above-described process, the performance of the symbol insertion step SlOOO is completed.

FIG. lib shows an example of a map before the symbol insertion step SlOOO of the automatic small-scale map production method according to the embodiment of the present invention, and FIG. lie shows an example of a map after the symbol insertion step SlOOO of the automatic small-scale map production method according to the embodiment of the present invention.

FIG. 12 shows an example of a small-scale map that is produced by the automatic small-scale map production method according to the embodiment of the present invention. FIGS. 3a and 3b, 4a and 4b, 5a and 5b, 6a. and 6b, 7a and 7b, 8a and 8b, 9a and 9b, 10a and 10b, and 11a and lib show a portion of the small-scale map of FIG. 12 to illustrate the small-scale map in detail. Through steps S200 to SlOOO, the small-scale map is finished, as illustrated in FIG. 12.

The present invention can automatically produce a small-scale map using the attributes of a large-scale map through the above-described processes.

Industrial Applicability

As described above, in accordance with an aspect of the present invention, the entire process of producing a small- scale map from a large-scale map is automated, so that personnel expenses for producing a small-scale map can be considerably reduced.

In accordance with another aspect of the present invention, while a small-scale map is produced from a large- scale map, the NGI attributes can be maximally maintained, so that the change in the NGI attributes can be minimized.

In accordance with another aspect of the present invention, the process of converting a large-scale map into a small-scale map takes a few minutes to a few hours, so that the time required for the conversion of a map is considerably reduced.

In accordance with another aspect of the present invention, a small-scale map can be automatically produced at

low cost in a short time, which contributes to the development of the Geographic Information System (GIS) industry related with a digital map.

Although the preferred embodiment of the present invention has been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.