Abstract:
A method for displaying a photomap performed by a navigation system, the method comprising: loading a photomap and a numerical map from a map data storage; matching reference points between the photomap and the numerical map; matching a scale of the numerical map in line with a scale of the photomap; and extracting object information from the numerical map; and composing the object information and the photomap.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims the benefit of Korean Patent Application No. 10-2013-0038343, filed on Apr. 8, 2013, which is hereby incorporated by reference as if fully set forth herein. 
       FIELD OF THE INVENTION 
       [0002]    The present invention relates to a navigation system and a method for displaying a photomap on the navigation system. More specifically, the present invention relates to a navigation system and a method for displaying a photomap on the navigation system, adapted to compose object information of a numerical map and the photomap or remove vehicles from a road in the photomap when displaying the photomap on the navigation system. 
       BACKGROUND OF THE INVENTION 
       [0003]    Currently, as the number of moving bodies such as a vehicle continues to increase, the traffic congestion becomes worse and worse. Further, since the increasing speed of the number of the moving bodies is becoming faster than that of the infrastructure such as road, there occur severe problems such as traffic congestion. 
         [0004]    In such a situation, navigation systems are highlighted as one of the solutions to the traffic congestion. A navigation system receives a navigation message transmitted from satellites for GPS (Global Positioning System) to determine a current position of a moving body, matches the current position of the moving body to map data to display it on a screen of the navigation system, and searches for a driving route from the current position of the moving body to a destination. Further, the navigation system guides a user to drive a moving body along the searched driving route, whereby the user can make use of a road network given efficiently. 
         [0005]    Typically, the map displayed on a screen in a navigation system is a numerical map, which displays roads and geographic features using digitized map data on the basis of 2D images, or models the geographic features in 3D images to display them so that a user feels more real. 
         [0006]    Recently, images of driving route through the use of photomaps such as aerial photographs taken from aircrafts or satellite photographs taken from satellites are provided, so that it may be possible to precisely capture real road state and surrounding situation. 
         [0007]    Nonetheless, since a photomap displays a real space via the aerial photograph or satellite photographs, in the course of providing a guidance along a searched driving route, vehicles on a road or disordered structures on a rooftop of a building alongside of the route are also displayed on the photomap, which may hinder an identification of a shape of the road or the building. 
         [0008]    Related art of the disclosure of the present invention is disclosed in Korean Laid-Open Patent No. 10-2002-0047531, entitled “Method and apparatus for searching information of point of interest,” published on Sep. 5, 2002, which is incorporated by reference herein in its entirety. 
       SUMMARY OF THE INVENTION 
       [0009]    In view of the above, the present invention provides a navigation system and a method for displaying a photomap on the navigation system, adapted for extracting object information from a numerical map to compose the object information and the photomap or removing vehicles from a road in the photomap when displaying the photomap on the navigation system, thereby improving visibility of the photomap for the guidance of a route. 
         [0010]    In accordance with an embodiment of the present invention, there is provided a method for displaying a photomap performed by a navigation system, the method comprising: loading a photomap and a numerical map from a map data storage; matching reference points between the photomap and the numerical map; matching a scale of the numerical map in line with a scale of the photomap; and extracting object information from the numerical map; and composing the object information and the photomap. 
         [0011]    In the exemplary embodiment, wherein the object information comprises shape information and attribute information of roads and buildings. 
         [0012]    In the exemplary embodiment, wherein said composing the object information and the photomap comprises: displaying shapes of the roads and the buildings in accordance with the shape information. 
         [0013]    In the exemplary embodiment, wherein said composing the object information and the photomap comprises: processing the roads and the buildings in different colors in accordance with the attribute information. 
         [0014]    In accordance with another embodiment of the present invention, there is provided a method for displaying a photomap performed by a navigation system, which includes: loading a photomap and a numerical map from a map data storage; matching reference points between the photomap and the numerical map matching a scale of the numerical map in line with a scale of the photomap; extracting object information from the numerical map; and applying a road color to a road area in the photomap in accordance with the object information. 
         [0015]    In the exemplary embodiment, wherein the object information comprises shape information and attribute information of roads and buildings. 
         [0016]    In the exemplary embodiment, wherein said applying a road color to a road area in the photomap in accordance with the object information comprises: extracting the road area form the photomap in accordance with the shape information; extracting lane components from the road area; and applying the road color to the road area except the lane components. 
         [0017]    In the exemplary embodiment, wherein said applying a road color to a road area in the photomap in accordance with the object information comprises: applying the road color in a different color in accordance with the attribute information. 
         [0018]    In accordance with another embodiment of the present invention, there is provided a navigation system comprising: a display unit; a map data storage configured to store a numerical map and a photomap; and a control unit configured to load the numerical map and the photomap from the map data storage, to match reference points and scales between the numerical map and the photomap, to extract object information from the numerical map, and to compose the extracted object information and the photomap or to apply a road color to a road area in the photomap based on the object information in order to display the resultant photomap through the display unit. 
         [0019]    In the exemplary embodiment, wherein the object information comprises shape information and attribute information of roads and buildings. 
         [0020]    In the exemplary embodiment, wherein the control unit is configured to display shapes of the roads and the buildings in accordance with the shape information the roads and the buildings. 
         [0021]    In the exemplary embodiment, wherein the control unit is configured to process the roads and the buildings in different colors in accordance with the attribute information. 
         [0022]    In the exemplary embodiment, wherein the control is configured to apply the road color in a different color in accordance with the attribute information. 
         [0023]    In the exemplary embodiment, wherein the control is configured to extract the road area from the photomap in accordance with the object information and to extract lane components from the road area and apply the road color to the road area except the lane components. 
         [0024]    In the exemplary embodiment, wherein the photomap includes an aerial photomap or a satellite photomap. 
         [0025]    As described above, in the embodiment of the navigation system and the method for displaying a photomap on the navigation system in accordance with the present invention, the object information is extracted from the numerical map to compose the object information and the photomap or the vehicles are removed from the road in the photomap when displaying the resultant photomap on the navigation system. As a result, it is possible to improve visibility of the photomap for the guidance of a route. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]    The above and other objects and features of the present invention will become apparent from the following description of the embodiments given in conjunction with the accompanying drawings, in which: 
           [0027]      FIG. 1  is a block diagram of a navigation system in accordance with an embodiment of the present invention; 
           [0028]      FIG. 2  illustrates an exemplary numerical map displayed on a navigation system in accordance with an embodiment of the present invention; 
           [0029]      FIG. 3  illustrates an exemplary photomap displayed on a navigation system in accordance with an embodiment of the present invention; 
           [0030]      FIG. 4  is a flowchart illustrating a method for displaying a photomap on a navigation system in accordance with an embodiment of the present invention; 
           [0031]      FIG. 5  illustrates an exemplary photomap in which object information is composed on a basis of a method for displaying a photomap on a navigation system in accordance with an embodiment of the present invention; 
           [0032]      FIG. 6  is a flowchart illustrating a method for displaying a photomap on a navigation system in accordance with another embodiment of the present invention; and 
           [0033]      FIG. 7  illustrates an exemplary photomap from which a vehicle on a road is removed through the use of a method for displaying a photomap on a navigation system in accordance with another embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0034]    Hereinafter, an embodiment of a method for displaying a photomap on a navigation system in accordance with the present invention will be described with reference to the accompanying drawings. In referring to the drawings, thickness of lines and size of components shown in the drawings may be exaggerated for the purpose of descriptive clarity and for the sake of convenience. Further, the following terms are defined in consideration of the functions of the present invention, which may vary depending on the intentions of a user or an operator or practices. Therefore, the definition of such terms should be made on the basis of the disclosure throughout the present specification. 
         [0035]      FIG. 1  is a block diagram of a navigation system in accordance with an embodiment of the present invention;  FIG. 2  illustrates an exemplary numerical map displayed on a navigation system in accordance with an embodiment of the present invention; and  FIG. 3  illustrates an exemplary photomap displayed in a navigation system in accordance with an embodiment of the present invention. 
         [0036]    As illustrated in  FIG. 1 , the navigation system includes a GPS module  10 , a map data storage  20 , a memory unit  60 , a key input unit  40 , a control unit  30 , and a display unit  50 . 
         [0037]    The GPS module  10  receives navigation messages from a plurality of GPS satellites (not shown) positioned over the earth and provides them to the control unit  30  so that its current position can be acquired. 
         [0038]    The map data storage  20  stores map data of both a numerical map and a photomap used to guide a driving route of a moving body such as a vehicle (not shown) obtained after searching for the driving route. 
         [0039]    As illustrated in  FIG. 2 , the numerical map refers to a map that displays roads and geographic features based on a 2D image through digitized map data or that realistically displays geographic features by modeling roads and geographic features in a 3D image. 
         [0040]    The digitized map data contains shape information and attribute information of roads and geographic features, wherein the roads and geographic features are represented with different colors in accordance with the attributes thereof so that they can be easily distinguished for the identification. 
         [0041]    Meanwhile, as illustrated in  FIG. 3 , the photomap refers to a map that provides an image of a driving route along a coordinate through an aerial photograph really taken from an aircraft to easily recognize real road states and surrounding situations. The photomap may include a satellite photomap displayed on the basis of satellite photographs taken from satellites. 
         [0042]    The memory unit  60  stores various kinds of data including setting values to operate the navigation system and searched driving routes. 
         [0043]    The key input unit  40  includes a plurality of function keys or buttons to receive from a user each setting value to operate the navigation system and a destination chosen to set a driving route. 
         [0044]    The control unit  30  detects a current position of the moving body using the navigation messages received through the GPS module  10 , and reads out map data stored in the map data storage  20  to display the current position of the moving body on the map. 
         [0045]    When displaying the photomap, the control unit  30  also reads out the numerical map along with the photomap from the map data storage  20 , matches a reference point and scale between the photomap and the numerical map, extracts the object information from the numerical map, and then composes the extracted object information and the photomap to display the resultant photomap. 
         [0046]    In other words, the control unit  30  extracts shape and attribute information of roads and buildings, represents shapes of the roads and buildings on the photomap in accordance with the extracted shape information of the roads and buildings, and processes the roads and buildings in different colors in accordance with the extracted attribute information, thereby improving visibility of the roads and buildings displayed on the photomap when providing a guidance of a route. 
         [0047]    Further, where the object information extracted from the numerical map is a road, the control unit  30  extracts lane components in a road area from the photomap and removes unwanted vehicles on the road by applying a road color to the road area except the lane components or by painting over the road area except the lane components with the road color. Consequently, it is possible to improve visibility of the road that is displayed on the photomap when providing a guidance of a route. 
         [0048]    The term used herein “a road color” refers to a color of the road, which may be commonly a dark grey. However, the color of the road may vary depending on the type of the road. Accordingly, the road color disclosed in the embodiment may be defined by a color taking up most of the region extracted from the photomap or a color that is determined in advance on the basis of attribute of the road. 
         [0049]    Also, the control unit  30  may apply the road color in a different color, based on the attribute information, i.e., depending on the type of roads such as national roads and highways. 
         [0050]    For example, the road color may be differently represented as a variety of colors such as blue, green, yellow, orange, and red, depending on the speed limit of the roads. By way of example, the blue may be applied to highways, and the reddish color may be applied as the speed limit is slower. 
         [0051]    In addition, it may be possible to treat the buildings with colors as defined in advance depending on the attributes of the buildings, for example, public offices with light blue, hospitals with white, kindergartens with yellow, schools with green and the like. 
         [0052]    Furthermore, the control unit  30  searches a driving route from a current position to a destination on the basis of map data, which is stored in the map data storage  20 , in response to the commands inputted through the key input unit  40 , and guides a user along the searched driving route. 
         [0053]    The display unit  50  displays various operation states of the components under the control of the control unit  30  and the driving route searched by the control unit  30 , and the numerical map and photomap matched by the control unit  30 . 
         [0054]      FIG. 4  is a flowchart illustrating a method for displaying a photomap on a navigation system in accordance with an embodiment of the present invention; and  FIG. 5  is an exemplary photomap in which object information is composed on a basis of a method for displaying a photomap on a navigation system in accordance with an embodiment of the present invention. 
         [0055]    As illustrated in  FIG. 4 , in a method for displaying a photomap on a navigation system in accordance with an embodiment of the present invention, the control unit  30  loads from the map data storage  20  a photomap and a numerical map of a current position detected through the GPS module  10  or position selected through the key input unit  40  in block S 10 . 
         [0056]    In this case, the photomap may include an aerial photomap or a satellite photomap of which coordinates are established based on aerial photographs taken from an aircraft, or satellite photographs taken from satellites. 
         [0057]    Subsequently, in block S 20 , the control unit  30  matches reference points between the photomap and the numerical map using the longitudinal and latitudinal coordinates of both maps. Here, the term “reference points” means base points used to match corresponding points of the photomap and the numerical map, which may be set in various positions and schemes depending on each system specification. 
         [0058]    After matching the reference points of the numerical map and the photomap each other as described above, the control unit  30  adjusts a scale of the numerical map in line with a scale of the photomap to match both the maps in block S 30 . 
         [0059]    That is, when the photomap is displayed in a large scale in the navigation system, the numerical map is also controlled in a large scale correspondingly to that of the photomap. In contrast, when the photomap is displayed in a small scale in the navigation system, the numerical map is also controlled in a small scale correspondingly to that of the photomap. Therefore, both maps can be matched to be displayed at the same size. 
         [0060]    After matching the reference points and scales between the photomap and the numerical map, the control unit  30  extracts the object information of the roads and buildings from the numerical map in block S 40 . 
         [0061]    In other words, the control unit  30  extracts shape information used for representing shapes of the roads and buildings and attribute information used for representing the type of the roads or attribute of the buildings from the numerical map when displaying the roads and buildings on the numerical map. 
         [0062]    Next, in block S 50 , the control unit  30  shows the shapes of the roads and buildings on the photomap in accordance with the extracted shape information and then processes the roads and buildings in different colors in accordance with the attribute information in order for the composition of the shape information. 
         [0063]    For example, it may be possible to display the respective roads in blue, green, yellow, orange, red, and the like depending on the speed limit of the roads. By way of example, the blue may be applied to highways, and the reddish color may be applied as the speed limit is slower. 
         [0064]    In addition, it may be possible to treat the buildings with colors as defined in advance depending on the attributes of the buildings, for example, public offices with light blue, hospitals with white, kindergartens with yellow, schools with green and the like. 
         [0065]    That is, as illustrated in  FIG. 5 , the control unit  30  extracts the object information of the roads and buildings and then composes the extracted object information and the photomap to display the resultant photomap as the moving body is moving in block S 60 . 
         [0066]    As a result, when a moving body is moving, the shape of the roads and buildings may be viewed in relatively simple and may be easily distinguishable. Therefore, unlike an original disordered aerial photograph or satellite photograph, a user relatively easily identifies the roads and buildings in the photomap. In addition, the roads and buildings are processed in different colors in accordance with attribute information and thus, the user clearly recognizes what a building is and where a road is from the photomap. 
         [0067]      FIG. 6  is a flowchart illustrating a method for displaying a photomap on a navigation system in accordance with another embodiment of the present invention; and  FIG. 7  illustrates an exemplary photomap from which a vehicle on a road is removed through the use of a method for displaying a photomap on a navigation system in accordance with another embodiment of the present invention. 
         [0068]    As illustrated in  FIG. 6 , in a method for displaying a photomap on a navigation system in accordance with another embodiment of the present invention, the control unit  30  loads from the map data storage  20  a photomap and a numerical map at a current position detected through the GPS module  10  or at a position selected through the key input unit  40  in block S 100 . 
         [0069]    In this case, the photomap may include an aerial photomap or a satellite photomap of which coordinates are established based on aerial photographs taken from an aircraft, or satellite photographs taken from satellites. 
         [0070]    Subsequently, in block S 110 , the control unit  30  matches reference points between the photomap and the numerical map using the longitudinal and latitudinal coordinates of both maps. Here, the reference points mean base points used to match corresponding points of the photomap and the numerical map and display them, which may be set in various positions and schemes depending on each system specification. 
         [0071]    After matching the reference points of the numerical map and the photomap each other, the control unit  30  adjusts a scale of the numerical map in line with a scale of the photomap to match both the maps in block S 120 . 
         [0072]    That is, when the photomap is displayed in a large scale in the navigation system, the numerical map is also controlled in a large scale correspondingly to that of the photomap. In contrast, when the photomap is displayed in a small scale, the numerical map is also controlled in a small scale correspondingly to that of the photomap. Therefore, both maps can be matched to be displayed at the same size. 
         [0073]    After the completion of the matching of the reference points and scales between the photomap and the numerical map, the control unit  30  extracts object information of the roads from the numerical map in block S 130 . 
         [0074]    In other words, the control unit  30  extracts shape information used for representing the shapes of the roads and attribute information used for representing the type of the roads from the numerical map when displaying the roads on the numerical map. 
         [0075]    Next, in block S 140 , the control unit  30  extracts a road area from the photomap based on the extracted object information. 
         [0076]    In block S 150 , the control unit  30  performs an image processing on the extracted road area to extract lane components from the road area. 
         [0077]    Thereafter, in block S 160 , the control unit  30  applies road color to the road area except the lane components to remove unwanted vehicles from the road displayed in the photomap. 
         [0078]    The road color may be different depending on the type of the roads such as a national road, highway, etc. 
         [0079]    For example, the road color may include such colors as blue, green, yellow, orange, and red, depending on the speed limit of the roads. By way of example, the blue may be applied to highways, and the reddish color may be applied as the speed limit is slower. 
         [0080]    That is, as illustrated in  FIG. 7 , when the object information extracted from the numerical map is a road, the control unit  30  extracts the lane components from the road area in the photomap and removes unwanted vehicles from the road by applying the road color to the road area except the lane components, so that the resultant photomap from which the vehicles are removed is displayed as the moving body is moving in block S 170 . 
         [0081]    As a result, when a moving body is moving, the photomap is displayed without the image of vehicles on a road therein. Therefore, unlike an original disordered aerial photograph or satellite photograph, a user relatively easily identifies the roads in the photomap. Further, the roads are processed in different colors for the display thereof in accordance with the attribute information of the roads, whereby the user clearly recognizes where a road is from the photomap. 
         [0082]    As described above, in accordance with the method for displaying a photomap on the navigation system in accordance with the present invention, when the photomap is displayed in the navigation system, the object information is extracted from the numerical map to compose the object information and the photomap or the vehicles are removed from the road in the photomap. As a result, it is possible to improve visibility of the photomap for the guidance of a route. 
         [0083]    While the present invention has been shown and described with respect to the embodiments illustrated with drawings, the embodiments are exemplary only and not limited thereto. It will be understood by those skilled in the art that it is possible to make various changes and equivalent another embodiment based on the disclosure. Therefore, the scope of the present invention should be defined by the appended claims rather than by the foregoing embodiments.