KR101502806B1 - System and method for streaming based lod for navigation - Google Patents

Abstract

The present invention relates to a streaming system based on a stepwise detailed representation for navigation. When a user performs navigation while viewing a large-capacity three-dimensional urban information model using a mobile device or the like, a level-detail (LOD) It is possible to smoothly search for a destination while continuously displaying building information based on the location, time, and area of interest of the user. By highlighting and rendering a destination building, a landmark, and a main structure, The present invention provides a streaming system based on a stepwise detailed expression for navigation and a method thereof.
According to an aspect of the present invention, there is provided a system and method for selecting and compressing levels of a building model according to a stepwise detailed expression based on a current location and a time point of a user transmitted from a client terminal, To a streaming server; And a terminal for executing navigation according to a control signal of the user. The terminal transmits the current location and time of the user and the interest area information according to the current location to the streaming server, decompresses the building model information received from the streaming server A client terminal for performing rendering; .

Description

[0001] SYSTEM AND METHOD FOR STREAMING BASED LOD FOR NAVIGATION [0002]

The present invention relates to a streaming system based on a stepwise detailed representation for navigation, and more particularly, to a streaming system based on a step-by-step detailed representation, in which, when a user performs navigation while viewing a large- Detail: LOD), which continuously displays building information continuously, and smoothly searches for a destination.

3D city building information basically consists of large amount of building information, and consists of very complex polygons and textures.

Related to Korean Patent Laid-Open No. 10-2005-0103070 (hereinafter referred to as 'prior art document') regarding technologies for downloading route and map information through a mobile device and executing navigation, there have been many publications and applications.

The foregoing prior art document discloses a network system for performing navigation, comprising: a wired / wireless communication network; A mobile communication terminal for performing wireless Internet connection with the wired / wireless communication network and downloading geographical guidance information including route-specific coordinate information according to a user's request and geographic voice information corresponding to each route; A service server for providing route information to a destination, point-to-point coordinate information corresponding to the route, and geographical information for each route in response to geographical guidance request information provided from the mobile communication terminal; A database for storing geographical audio information corresponding to geographical information of each coordinate, an application for geographical guidance, and a geographical matching program for providing a geographical matching algorithm in cooperation with the service server, the geographical matching program being associated with map information having local coordinate information; (GPS), receives a geographical guidance application, a geographical matching program, and map information from the service server, receives map information corresponding to the route-specific coordinate information from the current location downloaded to the mobile communication terminal to the destination And a map display device for extracting the map information and displaying the extracted map information.

However, in the past including prior art documents, when navigation is performed by downloading such high-quality model information through a mobile device, a mobile device may experience a problem in a limited environment, that is, memory usage.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is an object of the present invention to provide a navigation system and a navigation system, By continuously rendering the building information continuously, it is possible to find the destination smoothly. By highlighting and rendering the destination building, the landmark, and the main structure based on the user's location, viewpoint and area of interest, The present invention provides a streaming system based on a stepwise detailed expression for navigation and a method thereof.

According to an aspect of the present invention, there is provided a streaming system based on a step-by-step detailed representation for navigation, the system comprising: a building model generating unit for generating, based on a current location and a time point of a user transmitted from a client terminal, A streaming server for selecting and compressing the level according to the stepwise detailed representation and transmitting the selected level to the client terminal; And a terminal for executing navigation according to a control signal of the user. The terminal transmits the current location and time of the user and the interest area information according to the current location to the streaming server, decompresses the building model information received from the streaming server A client terminal for performing rendering; .

The streaming server may include a building information database storing various geographical information including building information of a city; Determining a level of detail representation of the building models included in the ROI based on the current location and time of the user received from the client terminal and the ROI information, A level selecting unit for selecting models of the level having the level; And a compression unit for packing and compressing the building models of the selected level by level selected by the level selection unit and transmitting the packed building signals to the client terminal. And a control unit.

Also, the level selection unit extracts, from the building information database, buildings corresponding to ROI (Region Of Interest) information located at the current position and time point of the user received from the client terminal, A level determination module for determining a level of detailed representation of a building model extracted from the building information database according to a destination building; And a level selection module for selecting building models having the highest complexity from the building level having the lowest complexity for the building, based on the detailed expression level determined through the level determination module; And a control unit.

The client terminal may further include: an information transmission unit for transmitting the current location and time of the user and the interest area information according to the current location to the streaming server; A decompression unit that receives the compressed building model information from the streaming server and decompresses the compressed building model information; A navigation execution unit for executing navigation based on decompressed building model information through the decompression unit; A rendering unit rendering at least one or more of a box model, a polygon model, and a texture model of a destination building and a neighboring building on the route in accordance with execution of navigation through the navigation execution unit; And a control unit.

The rendering unit is configured to receive the destination building, the landmark, and the main structure information on the navigation execution path from the navigation executing unit, and render the destination building, the landmark, and the main structure as a texture model with emphasis .

According to another aspect of the present invention, there is provided a streaming method based on a stepwise detailed representation for navigation, the method comprising: (a) transmitting, by a client terminal, a current location and a time point of a user and information on a region of interest corresponding to the current location to a streaming server; (b) extracting buildings corresponding to ROI (Region Of Interest) information located at a current location and a time point of the user received from the client terminal by the streaming server; (c) determining a level of detailed representation of the building model extracted through the step (b) according to the central area location and the destination building of the user at the streaming server; (d) selecting building models having the highest complexity from the building level having the lowest complexity for the building, based on the determined detailed expression level of the streaming server; (e) integrating, packing, compressing and transmitting the building models of the selected level of the building to the client terminal by the streaming server; (f) receiving the compressed building model information from the streaming server and decompressing the received building model information; (g) executing the navigation based on the decompressed building model information by the client terminal; And (h) rendering, by the client terminal, at least one of a box model, a polygon model, and a texture model of a neighboring building on a destination building and a route in accordance with execution of navigation; .

In step (h), the client terminal receives the destination building, the landmark, and the main structure information on the navigation execution path, and effects the destination building, the landmark, and the main structure with emphasis, .

According to the present invention, the problem of the memory usage of the mobile device can be solved by highlighting and rendering the destination building, the landmark, and the main structure based on the user's location, viewpoint, and ROI.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall schematic diagram conceptually showing a streaming system based on a stepwise detailed representation for navigation according to the present invention; FIG.
2 is a detailed configuration diagram of a level selector according to the present invention;
FIG. 3 illustrates an example of a user's viewpoint and a region of interest according to the present invention.
4 illustrates an example of a selected level model based on detailed presentation steps according to the present invention.
FIG. 5 is an exemplary view showing a stepwise detailed representation when executing navigation according to the present invention; FIG.
6 is a detailed flowchart of a streaming method based on a stepwise detailed representation for navigation according to the present invention;

Specific features and advantages of the present invention will become more apparent from the following detailed description based on the accompanying drawings. It is to be noted that the detailed description of known functions and constructions related to the present invention is omitted when it is determined that the gist of the present invention may be unnecessarily blurred.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the accompanying drawings.

A streaming system based on a stepwise detailed representation for navigation according to the present invention will be described with reference to FIGS. 1 to 5 as follows.

FIG. 1 is an overall configuration conceptually showing a streaming system S based on a stepwise detailed representation for navigation according to the present invention, and includes a streaming server 100 and a client terminal 200 as shown in FIG.

The streaming server 100 selects and compresses the building models according to the stepwise detailed representation based on the current location and time of the user transmitted from the client terminal 200 and the interest area information according to the current location, 200, as shown in FIG. 1, includes a building information database 110, a level selection unit 120, and a compression unit 130.

Specifically, the building information database 110 stores various types of geographical information including building information constituting a city.

At this time, the building information stored in the building information database 110 is composed of models having various levels of geometric complexity and texture complexity.

The level selection unit 120 determines the detail level of the building models included in the ROI based on the current location and the time of the user received from the client terminal 200 and the ROI information according to the current location, The level selection module 121 and the level selection module 122, as shown in FIG. 2, perform the function of selecting the models having the lowest complexity to the level having the highest complexity.

More specifically, the level determination module 121 determines the buildings corresponding to the ROI (Region Of Interest) information (see FIG. 3) located at the current position and time point of the user received from the client terminal 200, And determines the detail level of the extracted building model through the building information database 110 according to the center area location and the destination building of the user. At this time, if the user's viewpoint changes, the region of interest information may be changed.

On the other hand, the level determination module 121 calculates the level decision function D of the LOD to be transmitted and the center position of the point-of-view frustum based on G0, The level can be determined.

[Equation 1]

Here, G0 is the center position of the frustum, which is made based on the user point of view and the user point of view (G0), and D is the level determining function.

는 스트리밍의 LOD 모델의 가장 낮은 버전을 결정하기 위해 사용되는 에러 값이며,

는 영역의 중심 위치이며,

는 영역의 중심 위치에 있는 경우의 에러이며,

는 중심 영역의 반지름이다.

Is the error value used to determine the lowest version of the LOD model of streaming,

Is the center position of the region,

Is the error in the center position of the area,

Is the radius of the central region.

The level selection module 122 selects building models having the highest complexity from the building level having the lowest complexity for the building, based on the detailed expression levels determined through the level determination module 121. [

FIG. 4 shows an example of a selected level model based on the detailed representation step, wherein (a) is a building model of a level having the lowest complexity for the building, (b) Level building model, and (c) a building model with a high level of complexity for the building.

The compression unit 130 integrates and packs the building models of the selected level by the level selection unit 120, compresses the building models through the polygon compression model, and transmits the compressed building models to the client terminal 200.

Specifically, the method of compressing the position of a vertex is mainly a method of reducing the contents by expressing the coordinates in a different manner. The multi-resolution method is a method in which the size of a storage space is dynamically adjusted according to a resolution desired by a user to store coordinates. In this way, more detail is stored in a small data type, which is not important for large data types, and efficient storage space is used. The Progressive Geometry Compression method is a kind of multi-resolution method that transforms an object to have regular size and constant positional relationship through transformation of existing coordinate and position relation. The predication method calculates a virtual point by three points of a triangle using the property of a parallelogram, subtracts the value of the vertex actually connected to the triangle, displays the difference value, It is a way to reduce. Since normal vertices are close to the law of this parallelogram, they can be represented by a small range of values.

According to the present invention, a three-dimensional information data is grouped into various groups, and a prediction method is modified to change how the time when a time is changed based on the center point of the group, And the range of data representation is reduced, and the difference is again determined by setting an efficient storage space based on the concept of multi-resolution.

One way to check the error of three-dimensional data is to compare the original and decoded results to obtain a difference or measure how much it has changed. However, since it is not accurate as a simple frame comparison to apply to animation, the following method is used in the present invention. The KG error measurement method is as follows from Zacki Karni and Craig Gotsman.

[Equation 1]

는 A의 길이 norm 값을 나타내며, A는 기존의 벡터들이고 A'은 압축 후 다시 디코딩된 벡터들을 나타낸다. 그리고, E(A)는 시간에 따른 좌표들의 평균을 나타낸다. [수식 1] 을 본 발명에서는 [수식 2] 와 같이 적용하였다. here,

A denotes the length norm of A, A denotes the conventional vectors, and A 'denotes the decoded vectors after compression. And, E (A) represents the average of the coordinates with time. [Equation 1] is applied as Equation 2 in the present invention.

[Equation 2]

Here, At means vertex A of time t, and E (At) means an average of all times of one vertex. Then, to compare with the magnitude of the vector, we squared it, added and subtracted it, and put it on the route. Through such a method, it is possible to establish a criterion for comparing the original and decoded results with respect to each vertex for the entire time to determine how much difference there is.

The client terminal 200 is a mobile terminal that carries out navigation according to a control signal of a user. The client terminal 200 transmits the current location and time of the user and the interested area information according to the current location to the streaming server 100, The decompression unit 220, the navigation execution unit 230, and the navigation unit 230, as shown in FIG. 1, And a rendering unit 240.

Specifically, the information transmission unit 210 transmits the current location and time of the user and the interest area information according to the current location to the streaming server 100.

The decompression unit 220 receives the compressed building model information from the streaming server 100 and decompresses it. At this time, even if the building information is disconnected due to a network transmission problem, the minimum polygon information can be preserved.

The navigation execution unit 230 executes navigation based on the decompressed building model information through the decompression unit 220.

The rendering unit 240 renders the surrounding building on the destination building and the route as a box model, a polygon model, and a texture model according to the navigation through the navigation execution unit 230.

At this time, the rendering unit 240 can render a landmark, a main structure, and the like, which are helpful on the destination building and the navigation execution path of the user, as a texture model with emphasis effect. The information may be input from the navigation executing unit 220 according to the internal setting of the navigation executing unit 230. [

That is, the rendering unit 240 renders only the box model as the first stage, the polygon model as the second stage, the polygon as the third stage, and renders the textures (since the level is not important yet, Level polygon rendering, texture model rendering, 5th level original polygon rendering, and rendering with texture model with emphasis effect.

FIG. 5 is a diagram illustrating an example of a stepwise detailed representation when performing navigation according to the present invention. FIG. 5 (a) is a view showing an initial navigation function being performed in a city area, FIG. (c) is a semi-transparent representation of models that are not important to the destination, (d) is the rendering of landmarks that are important to the destination in a texture close to the original, ) Is a highlighted effect of the destination building.

Hereinafter, a streaming method based on the stepwise detailed expression for navigation using the above-described system will be described with reference to FIG.

FIG. 6 is an overall flowchart of a step-by-step detailed representation-based streaming method for navigation according to the present invention. As shown in FIG. 6, the information transmitting unit 210 of the client terminal 200 transmits a current position and a current position of a user, To the streaming server 100 (S10).

The level determination module 121 of the level selection unit 120 of the streaming server 100 determines whether or not the current position of the user received from the client terminal 200 and the region of interest information The corresponding buildings are extracted from the building information database 110 (S20), and the level of detailed representation of the building model extracted through the building information database 110 is determined according to the center area location and the destination building at the user's point of view S30).

The level selection module 122 of the level selection unit 120 selects a level having the highest complexity from the building level having the lowest complexity for the building based on the detailed expression level determined through the level determination module 121 (S40). The compression unit 130 integrates and packs the building models of the selected level by the level selection unit 120, compresses the building models through the polygon compression model, and outputs the compressed building models to the client terminal 200 (S50).

The decompression unit 220 of the client terminal 200 receives the compressed building model information from the streaming server 100 and decompresses the decompressed building model information in operation S60. The navigation execution unit 230 decompresses the compressed model information, The navigation unit 230 executes navigation based on the decompressed building model information in step S70. The rendering unit 240 performs a navigation operation on the destination building and surrounding buildings on the route, Polygon model, and texture model (S80).

At this time, the rendering unit 240 can render a landmark, a main structure, and the like that are helpful on the destination building and the navigation execution path of the user as a texture model with emphasis effect. The landmark on the navigation execution path, Can be input from the navigation execution unit 220 according to the internal setting of the navigation execution unit 230. [

While the present invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. It will be appreciated by those skilled in the art that numerous changes and modifications may be made without departing from the invention. Accordingly, all such appropriate modifications and changes, and equivalents thereof, should be regarded as within the scope of the present invention.

S: Streaming system based on stepwise detail for navigation
100: streaming server 200: client terminal
110: building information database 120: level selection unit
130 compression unit 121 level determination module
122: level selection module 210: information transmission unit
220: decompression unit 230: navigation execution unit
240:

Claims (7)

A streaming system based on a stepwise detailed representation for navigation,
Based on the current location and time of the user transmitted from the client terminal and the interest region information according to the current location, the detailed representations of the specific regions are expressed in at least two stages with respect to the building models included in the ROI information And selects the building models from the expression stage having the lowest complexity to the expression stage having the highest complexity among the two or more stages included in the determined level, compressing the selected building models A streaming server for transmitting to a client terminal; And
A mobile terminal that carries out navigation according to a user's control signal, transmits the current location and time of the user and the interest area information according to the current location to the streaming server, decompresses the building model information received from the streaming server And a client terminal performing rendering, wherein the streaming system is based on a stepwise detailed representation for navigation.
The method according to claim 1,
The streaming server includes:
A building information database storing various geographical information including building information of the city;
The detailed description of the specific region may be different for the building models included in the ROI based on the current location and time of the user received from the client terminal and the ROI information, A level selection unit which determines a geometric complexity and a texture complexity level to be expressed and selects building models from a presentation stage having the lowest complexity to a presentation stage having the lowest complexity among two or more stages included in the determined level; And
A compression unit for integrating and packing the selected building models through the level selection unit, compressing the building models, and transmitting the packed building models to the client terminal; Wherein the streaming system is based on a step-by-step detailed representation for navigation.
3. The method of claim 2,
Wherein the level selecting unit comprises:
Extracting, from the building information database, building models corresponding to ROI (Region Of Interest) information located at a current location and a time point of the user received from the client terminal, A level determination module for determining a geometric complexity and a texture complexity level expressed in at least two stages by varying a detailed representation of a specific area of the building model extracted through the building information database; And
A level selection module for selecting building models from the expression level having the lowest complexity to the expression level having the highest complexity among the two or more levels included in the level determined through the level determination module; Wherein the streaming system is based on a step-by-step detailed representation for navigation.
The method according to claim 1,
The client terminal,
An information transmission unit for transmitting the current location and time of the user and the interest area information according to the current location to the streaming server;
A decompression unit that receives the compressed building model information from the streaming server and decompresses the compressed building model information;
A navigation execution unit for executing navigation based on decompressed building model information through the decompression unit; And
A rendering unit rendering at least one or more of a box model, a polygon model, and a texture model of a destination building and a neighboring building on the route in accordance with execution of navigation through the navigation execution unit; Wherein the streaming system is based on a step-by-step detailed representation for navigation.
5. The method of claim 4,
The rendering unit may include:
A landmark, and main structure information on a navigation execution path from the navigation execution unit, and the corresponding destination building, landmark, and main structure are highlighted and rendered as a texture model. Expression - based streaming system.
A streaming method based on a stepwise detailed representation for navigation,
(a) transmitting, by the client terminal, the current location and time of the user and the interest area information according to the current location to the streaming server;
(b) extracting building models corresponding to ROI (Region Of Interest) information located at a current location and a time point of the user received from the client terminal by the streaming server;
(c) a streaming server configured to generate a geometric representation of the building model extracted through the step (b) according to the central area location and the destination building of the user, Determining complexity and texture complexity levels;
(d) selecting building models from a presentation stage having the lowest complexity to a presentation stage having the highest complexity among the two or more stages included in the determined level of the streaming server;
(e) the streaming server integrates and packs selected building models, compresses the building models, and transmits the packed building models to the client terminal;
(f) receiving the compressed building model information from the streaming server and decompressing the received building model information;
(g) executing the navigation based on the decompressed building model information by the client terminal; And
(h) rendering the destination building and surrounding buildings on the route as one or more of a box model, a polygon model, and a texture model according to the execution of navigation by the client terminal; Based streaming method for navigation comprising a step-by-step detailed representation for navigation.
The method according to claim 6,
In the step (h)
Wherein the client terminal receives the destination building, the landmark, and the main structure information on the navigation execution path, and renders the destination building, the landmark, and the main structure as a texture model and renders it as a texture model. Based streaming method.

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