WO2001056009A1

WO2001056009A1 - Information presenting method and information storing method

Info

Publication number: WO2001056009A1
Application number: PCT/JP2001/000577
Authority: WO
Inventors: Hirohisa Mori
Original assignee: Center For Advanced Science And Technology Incubation, Ltd.
Priority date: 2000-01-27
Filing date: 2001-01-29
Publication date: 2001-08-02
Also published as: AU2001230524A1

Abstract

Items of space information with different accuracy are connected and displayed without imparting an unnatural feeling through a relatively light load of calculation. A plurality of items of information to be presented is prepared. A coordinate system unique to each item of information is given. The coordinate system is changed according to the description for changing the coordinate system. Information on the basis of the changed coordinate system is displayed.

Description

Description Information presentation method and information storage method

The present invention relates to an information presenting method and an information storing method, and more particularly to a method of presenting information represented by using a plurality of coordinate systems, and an information storing method suitable for the method. Background art

The need for applications that process large-scale two-dimensional and three-dimensional spatial information, such as GIS (Geographical Information Systems), has been recognized. The application range of these applications is increasing year by year, from those closely related to life to large applications such as research and development. For example, in the past car navigation, only road information was required, but in the current power navigation, landscape information is added, making it easier to understand. Furthermore, in recent years, attention has been paid to human navigation technology for navigating pedestrians who use public institutions instead of cars. In this case, it is necessary to connect not only road information but also all information on public places such as station premises and department stores.

The example of human navigation described above shows that accumulating map information is no longer possible only by government offices and cartographic companies that manage maps. For example, the layout of each floor of a department store should be a department store, and the structure of the station premises should be collected and entered into the database by the railway company that manages it. In addition, companies should also input information such as timetables and route maps for buses and railways. As described above, there is no human navigation system that accumulates the responsibilities of each person on its own server, automatically browses them, connects them seamlessly, and guides them from the starting point to the destination.

In addition, the layout of department stores and the placement of company reception desks, etc. can also be described, including the layout of reception desks inside the show windows and accompanying detailed explanations. For example, the user can obtain various information before visiting the destination. To be able to do this, it is necessary to provide not only a global map such as conventional GIS but also a detailed map such as a show window layout at the same level.

In addition to the large-scale, sophisticated, and fine-grained information, GIS is applied to other fields such as archeology and history, and it is used for purposes such as the restoration of historical cityscapes. I started to be told. In the future, such research will be connected to living information and used for tourism and regional development.

Many maps used in historical research are old pictorial maps, such as those made in the Middle Ages, which cannot be accommodated by the current GIS, which has produced survey maps. A pictorial map is a so-called last map, which is not drawn to a fixed scale, but is written in large size to show the desire to cooperate, and small in others. Therefore, in order to view this and the modern map in an overlapping manner, it is necessary to perform an operation to distort one of them. Looking back at modern times, there are few places where accurate survey maps are meaningful even on modern maps, such as department store in-store layouts or JR route maps, and people are familiar with illustration maps. I have. It must be able to handle such maps without scale.

It is expected that information will be freely stored by multiple institutions in accordance with the spread of such GIS to new applications. However, GIS has not yet been developed that can browse these seamlessly without being aware of joints and that can display maps that do not have a reduced scale such as illustration maps and pictorial maps. Disclosure of the invention

According to the information presentation method of the present invention, a coordinate system (that is, a unique) corresponding to each of a plurality of pieces of information accumulated to be presented is provided, and the coordinate system is used to convert the coordinate system. It is configured to switch based on the description and present information based on the switched coordinate system. The description for transforming the coordinate system is provided as information so that the system can be used, and may be located inside or outside the system. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is an explanatory diagram for explaining the concept of mapping. FIG. 2 is an explanatory diagram showing an example of mapping. FIG. 3 and FIG. 4 are explanatory diagrams for explaining the size of the mapping. FIG. 5 is an explanatory diagram showing a configuration example of a client terminal. BEST MODE FOR CARRYING OUT THE INVENTION

A first embodiment of the present invention will be described below. Although this example deals with a map displayed in two-dimensional or three-dimensional coordinates as information, the present invention is not limited to this, and the present invention can be applied to information displayed in a coordinate system. is there.

(Definition of coordinate system and matting)

First, a coordinate system that does not consider the accuracy of expressing coordinates and matting are defined. Next, define the events related to the accuracy of the coordinate representation.

Definition of coordinate system and mapping: A coordinate system is defined as a set of real powers (ie, real vectors) and a distance d.

(C zR ⁿ , d)

Is defined. Also, the mapping between the coordinate system c ,, c ₂ are subsets

Continuous bijective mapping between ½ cC ₂ m'.H-- refers to a flying _2.

Between the coordinate system c ,, c _2, c _3,

cC, m ₂ U; cC ₂ ~> ¾cQ, / « ₃ : hi ~> (/ ₃ cC ₃ Three Matsubingu must be defined in, shed ₂ n monument ₂ 'when, m ~ ^l (U ₂ n Monument _2'). H Within a predetermined error range,

Must be satisfied.

When 1 ^ = t or U ₂ = C ₂ , m is called an include 'mapping. When U, ≠ C i and U ₂ ≠ C ₂ , it is called cross mapping. Scripts and definition files that describe these mappings are called mapping descriptions or mappings.

Definition of display coordinate system and visualization: Display is one of the two-dimensional coordinate systems. When placing this is D, and d, C ₂ is currently being _{_{displayed, p 1: D 1 → D}} (D {z Q), p 2: Include that _{_{D 2 → D (D 2 c}} C 2) · Says that Matsubing is defined. The definition depends on the visualization conditions.

And a range of predetermined error is set, the mapping between c ₂ m: upsilon U _2, when c correct shed ₂匚and ₂ is defined,

Above, within the range of the error ₂ ° w ⁵⁵ A must hold.

Coordinate system of the display accuracy:. When the coordinate system c _t is Matsubingu p 'D ^ Q-- displayed in the bitmap display D by D, C with the 1-bit display, the length s of the above It can be used as an indicator of the display accuracy of the coordinate system. S is used as a numerical value with units and dimensions that represent precision. This r is a function of the mapping m, the coordinates on the display, and the direction to take one bit.

The above r can be used as L0D when selecting the accuracy of the image data arranged in C, and the accuracy of the shape data.

L0D of coordinate system: In order to select the target coordinate system for display, it is necessary to provide L0D in the coordinate system. L0D is a value unique to a coordinate system having the same dimensional unit as the display accuracy. This coordinate system is defined as R, and whether or not this coordinate system is to be displayed is determined based on the relationship with the display accuracy r determined by the visualization conditions. The relationship with r can be defined in any way, but here we show two methods. The first method is to determine a constant a> 1 for the whole system and display it when aR>r> R. The second method is to determine a constant a <1 in the entire system, and to display c coordinates in order from the one with the smallest R in the coordinate system that satisfies r / R> a. In either method, a coordinate system with a smaller R is displayed when a wider range is displayed on the display, and a smaller R is displayed as the display zooms. r is a value corresponding to the enlargement ratio in the two-dimensional coordinate system, and the distance from the viewpoint to the coordinate position in the three-dimensional coordinate system. First, we decide the distribution of r above, and select the coordinate system and p according to this distribution.

Direction of Matsubingu: different coordinate systems C have C ₂ respectively L0D of L0D, and R ,, R _2. Also, when a mapping m between the two coordinate systems, m: hi i ~~ U ₂ (hi hi hi ₂ c C ₂ ) is defined and R!> R ₂ ,

m: U _y > U ₂

Is the forward direction.

(Coordinate system search method)

Once the distribution of r is determined, the next step is to determine the coordinate system to use. The following definition is newly defined because it is necessary to efficiently switch the coordinate system to be used depending on the change in the distribution of r.

Explicit mapping and implicit mapping (corresponding to search information): When configuring spatial information, the mapping explicitly defined by the constructor is called explicit mapping. On the other hand, the matching that is automatically defined by the system from the explicit matching for the search of the coordinate system is called implicit mapping. When an explicit mapping is deleted, any associated implicit matching is removed by the system. This is because explicit mappings are not visible to the constituents of the information, and adding or removing explicit mappings can be confusing unless the behavior is the same as without explicit mappings. is there.

Implementation constraints: Spatial information constructor defines forward coordinates from any coordinate system, forces that have at least one mapping, and mappings starting from the coordinate system. You must define the entire coordinate system when you combine the regions. In the case where there is an include masking, for example, an inclusive / reverse Include masking to the coordinate systems C and C is performed.

m: U ^ Q C

The moment the is defined, the system searches for a forward mapping where U i and the domain intersect. Forward mating from all found C, m _f : V, —— C ₂ (C ₂ is a coordinate system)

about,

m _f ° m ~ ^l : mi V n U ^ → ₂

Make an implicit mapping. The same applies when reverse mapping is found. Forward and reverse of the final specific Matsubingu is adjusted C, the LOD difference in C _2.

If explicit and implicit mappings are defined as above, the coordinate system search required for visualization is as follows.

When the distribution of the display accuracy of each point on the current display changes and becomes large, the mapping can be traced in the forward direction from the currently displayed coordinate system to find the L0D coordinate system that has the new display accuracy. . Follow the forward direction, and stop searching when the lower limit of L0D exceeds the display system. If the distribution of display accuracy changes and becomes smaller, follow the mapping in the opposite direction, and stop searching when the upper limit falls below the display accuracy. The current coordinate system is converted to the coordinate system searched in this way, and a new display is performed.

The operation of implicit mapping is as follows. When a person composes a mapping, it is not always the case that the mapping is performed in the order of the labeling system. It is possible to return to the opposite direction and move forward by explicit mapping. However, especially when information is distributed and arranged, such processing may cause movement between networks, and thus causes problems such as processing delay and increase in communication volume. On the other hand, the use of implicit mubbing, which is automatically created by the system, has the advantage of being able to move across the ri-ri structure.

As information, information based on a plurality of coordinate systems may be simultaneously (adjacently) displayed on one display (display device). For example, when a map is displayed so as to give a three-dimensional bird's-eye view of the earth's surface, it may be desirable to display the near side in detail and the far away in a rough view. In this case, a coordinate system suitable for detailed information can be used for an image indicating the near side, and a coordinate system suitable for information in a wide area can be used for an image indicating a distant place. In this case, for example, it is possible to use the Euclidean coordinate system on the near side and the spherical coordinate system on the distant side. Next, the present invention will be described in further detail using a second embodiment of the present invention. "How to store information"

For the purpose of this example, some words will be redefined. The individual information stored is called a resource. The types of resources can be broadly classified into three types: “object”, “coordinate system”, and “mapping”. An object is a description of various types of information such as scanned pixel data and shape data (vector data). The coordinate system is information about the dimensions, range, and topological structure of the coordinate system where the object is placed. In particular, the range must be a finite range. A mapping defines a coordinate transformation function between two coordinate systems. Since objects themselves may have simple coordinates, mappings may be set up between the object and the coordinate system. The coordinate system that is the end point or start point of the function is called the start point and end point of the mapping, respectively. The direction from the start point to the end point of the mapping is called the forward direction, and the opposite direction is called the reverse direction.

A server is a collection of databases that manage resources. Resources are named and stored in the database. Each and every database has a name, which distinguishes it from the others. One database consists of "a resource 'database that can extract information such as its type and data format from the resource's name," and "a resource belonging to the database and a mapping whose end point or start point is the resource. And a mapping 'database' that allows the mapping to be searched for from the resource. Assuming that a resource can be referred to by a certain protocol with a URL of the form gbp: \ [server name] / [database name] / [resource name], as shown in Fig. 1 You can make a base. Each of the servers A to C in FIG. 1 has a mapping DB. As shown in the figure, each mapping DB records a URL for a mapping start point, a mapping end point, a location of a mapping body, and the like. Here, Map-c in the figure is the file that records the information of the mating body.

"How to present information (browsing mechanism)"

First, give one coordinate system to be displayed on the client display. Disp The center position of the ray is indicated by coordinates in the coordinate system. The coordinate system given first to specify the display position is called the current coordinate system. When the coordinate system is two-dimensional, the display range can be specified by the magnification. Magnification is defined as the number of dots on the display of the unit length of the coordinate system shown on the display. The following description assumes two dimensions, but it is easy to extend this to three dimensions. In that case, the display range is indicated by the viewpoint position, viewing direction, and viewing angle. The magnification is a parameter determined by the relationship between the display visualization conditions and the coordinate system. In the case of two dimensions, there is one enlargement factor per display, but in the case of three dimensions, since the distance from the viewpoint to the coordinate system is determined, different enlargement factors will be distributed on the display. For this reason, the calculation becomes complicated, but the basic idea remains the same.

Fig. 2 shows that in the two-dimensional information, the user instructed the client terminal to "set the coordinate system D as the current coordinate system" and "display the coordinate indicated by X at the center of the display". This is for explaining the case. As a premise, the display can also be considered as a two-dimensional coordinate system. Therefore, the state in which the halftone dot area of the coordinate system D is displayed on the display can be considered as a state in which mapping is temporarily defined between the halftone dot area of the coordinate system D and the display. This temporarily defined mapping is called a temporary mapping. This temporary mapping is indicated by the symbol Ml in FIG. The temporary mapping Ml is defined by the client terminal so as to satisfy the requirements of "the display position of X should be exactly at the center of the display" and "the enlargement ratio given by the user". . If the coordinate system D is not a Euclidean coordinate system, Ml is constructed using an appropriate coordinate transformation (projection method).

Next, a search is made for a coordinate system that is mapped to D (or from) in “within the visible range” of coordinate system D. Here, “visualized” means that it can be displayed on the display. In the example of FIG. 2, the dot area in the coordinate system B is targeted by the mapping ml. At this time, within the range where the mapping ml between the halftone dot regions of the coordinate systems B and D is already defined, the composite transformation of the mapping Ml and ml (Ml 〇 ml " ¹ ) Is a temporary mapping from the coordinate system B. The temporary mapping M2 can be obtained by expanding the mapping to the whole coordinate system B, and its significance and method will be described later. When the visualization of B is completed, the mappings in the visualized range related to the coordinate systems B and D (that is, these are set as the mapping start points or the mapping end points) are searched again, and a new mapping is similarly performed. Define and show on the display. For example, in the example of FIG. 2, the coordinate system A is the target as the next coordinate system, as in the example of the coordinate system B, and this is converted by the mapping and displayed on the display.

At the client terminal, the display position is moved and scaled. Then, a coordinate system out of the display range on the display is generated. In this case, the temporary mapping defined between the coordinate system and the display is released to exclude the coordinate system from the display target. If the position of the center of the display is out of the range of the current coordinate system due to movement or enlargement, one of the coordinate systems displayed at the center of the display at that time is replaced with the new current coordinate system. And In this way, the client terminal can browse the combined coordinate system.

"How to extend the range of the coordinate system"

In the foregoing, there has been a process of extending the temporary mapping to its entire coordinate system. The significance of the expansion is as follows. That is, the user may move the display area within the coordinate system. At that time, it is necessary to determine the mapping from the entire coordinate system to the display. This enlargement corresponds to “conversion description for enabling information on the entire coordinate system to be displayed on the display” in the present invention.

Here is an example of a two-dimensional example of how this is done. First, a common implementation of mapping is to create a list of coordinate value pairs for corresponding points between two coordinate systems.

If the point representing this correspondence is one point, the two coordinate systems are considered to be in a parallel movement relationship, and their coordinates are (u, v) (X, y).

u = X + a, v = y + b Can be represented by For two points, a combination of translation, rotation and scaling, u = ax-by + cv = bx + ay + d

It can be expressed as In the case of three points, it is general linear transformation,

u = ax + by + c v = dx + ey + r

Becomes The mapping that can be expressed by the linear transformation can be extended to the point at infinity in both the coordinate system and the mapping, as this equation shows. If more than four points are given, they cannot be represented by linear transformation. Although it is possible to represent the mapping with a quadratic or higher expression, it is common to use multiple primary transformations to make the calculation easier. When the coordinate system is decomposed into multiple triangles with three of the four points as vertices (hereinafter referred to as “TIN”), a linear transformation can be defined inside each triangle. In this way, coordinates can be matched within the minimum rectangle or triangle including four points, but not outside (see Fig. 3).

Therefore, there is a need for a method to expand this TIN area around. This can be said to be the same as long as the number of points is 4 or more. We propose one of these enlargement methods. Expansion method ₃ for the method is preferable to be able to expand while maintaining vector comprising the properties of the distribution of the corresponding points already given, were averaged coefficients of the linear transformation relating the conversion of TIN, prepared a new linear transformation A I do. This first-order transformation is considered to represent the global property of the transformation in the TIN, and this is the transformation at the point at infinity. Next, we consider a method of continuously complementing between the point at infinity and the part where the corresponding point exists. In a coordinate system (for example, coordinate system D), four points are prepared at a position sufficiently far from the position of the existing TIN or point so as to form a rectangle that largely surrounds the points that make up this TIN. The points in another coordinate system (for example, coordinate system B) corresponding to these four points are transformed by the primary transformation A described above. The outside of these four corresponding points is transformed by transformation A.

A place inside this rectangle that does not belong to an already existing TIN creates a new TIN between the four points of this rectangle and the first given vertex, and realizes point correspondence by a linear transformation on that TIN. I do. In this way, coordinate system D and coordinate system B reach the point at infinity. Points can be handled (see Fig. 4).

If such a coordinate system and mapping are extended at the time of registering the coordinate system and the mapping in the server, it is efficient without any new calculation when presenting information.

"A method of saving the coordinate system search by setting the magnification at the time of information presentation to L0D"

When the coordinate system to be displayed is searched by the method described above, the amount of the target coordinate system becomes enormous depending on the method of matching. One way to prevent this is to introduce LOD (Level Of Detail) into the coordinate system.

First, define the resource resolution. Many object resolutions are already defined. Based on this, the resolution for the coordinate system is defined from the ratio of the length when mapped to the coordinate system. For example, when one image data as an object is mapped to a certain coordinate system, “the number of dots of the image data per unit length in the coordinate system” is defined as the resolution of this image data. Even if the object is vector data, a method such as using the distance between the vertices of the polygon as the resolution can be adopted.

The resolution of the coordinate system is defined as the resolution of each object distributed in the coordinate system. Therefore, the resolution of the coordinate system is not uniform, and at the location of an object, the resolution of the object is the resolution of the coordinate system. If multiple objects overlap at the same position, the one with the highest resolution among them is the resolution at that position. By definition, the resolution of a resource is a function of location. L0D of the coordinate system is the average value of the resolution of the coordinate system (which is not uniform within the coordinate system as described above). In other words, L0D of the coordinate system can be said to be the average value of the resolution of the object existing in the coordinate system.

Next, a constant a <1 is determined in advance, and the maximum number C of coordinate systems to be displayed is determined. The client determines that the ratio of the L0D of the coordinate system to the display magnification is the magnification ratio / L0D. > Among the coordinate systems that satisfy a, C objects are displayed in ascending order of L0D. Then, due to this inequality, those with an excessively small magnification are excluded from the display. Magnification An excessively small coordinate system means, for example, the coordinate system of the map of the entire earth when trying to view a map of Japan. Such a coordinate system can be excluded from the target. Furthermore, since the display is performed in ascending order of L0D, the display can be advanced from a large portion to a small portion. Furthermore, under this condition, a coordinate system to be displayed can usually exist, and a situation where there is no display target can be prevented.

As described above, by introducing L0D, the number of coordinate systems to be displayed can be reduced, and at the same time, a display with an appropriate display accuracy for the magnification can be selected. Therefore, the efficiency of the display algorithm is expected to improve.

In the following description, we make the promise that "all mappings have a direction, and the direction is from the L0D high-resolution coordinate system to the low-resolution coordinate system."

FIG. 5 shows an example of the structure of a client that performs the information presentation method described above. In Fig. 5, resources related to the currently displayed area are fetched from the server (not shown in Fig. 5) through the loader and the network by the user interface processing part. With this information, the mapping information connecting the coordinate systems is imported into the cache in the client. From this cache, the C coordinate systems selected by the L0D function are drawn on the display memory for visualization. Overlay the drawings and display them on the display.

"Introduction of explicit mapping"

If the above information presentation method is performed using only the coordinate system and mapping that are freely defined by the information sender, the client checks all coordinate systems that can be traced from the currently displayed coordinate system and displays the range Will be selected. Even if the coordinate system that could be traced by mapping is out of the display range, the coordinate system that has been further traced from that coordinate system may be within the display range, which is a very inefficient coordinate system search. Becomes In the worst case, you have to find all the servers connected to the network.

If you follow only the coordinate system that spans the display range and find a coordinate system that protrudes from it Then, ignoring all the coordinate systems that can be traced from it will solve the problem if all coordinate systems covering the display range can be searched. This state will be referred to as a normal state of matbing. This state is an efficient state, but it is a burden on the sender to encourage the information sender to set the mapping to satisfy this normal state.

For this reason, we propose a function that automatically generates matching that satisfies the above conditions from the mapping explicitly prepared by the information sender using the function provided in the server. The former is called implicit mapping, and the latter is called implicit mapping. The process of the function is as follows.

First, consider the situation where a new coordinate system is about to be added by the publisher. It is assumed that the normal state is satisfied on the server when no new coordinate system has been added. The information sender will map a new coordinate system to one of the coordinate systems C where this normal condition is satisfied. At this point, the normal state breaks down.

Let's say that C is the current coordinate system, and that the whole new coordinate system is displayed on the display as it is. Everything except the new coordinate system is in normal state, so the display should show all the coordinate systems to be displayed in that range. If the temporary mapping at this time is a new mapping and an implicit mapping from the coordinate system, a normal state with the new mapping and the coordinate system can be created.

Because implicit mappings are created automatically by the server's capabilities, they may not always be satisfactory to the publisher. In this case, a new explicit mapping may be prepared to satisfy the information publisher.

If there is implicit mapping and explicit mapping between the same two coordinate systems, then no implicit mapping is needed. The ability to remove these unnecessary implicit mappings, and also the associated implicit mapping when the explicit mapping that caused the implicit mapping was deleted by the publisher. It is preferable that the server be provided with a function to perform this.

The description of the present embodiment is merely an example of the embodiment, and does not show a configuration essential to the present invention. Absent. The practice of the present invention can be performed in any manner that achieves the spirit of the present invention. Industrial applicability

Advantageous Effects of Invention According to the present invention, it is possible to provide a plurality of pieces of information having different accuracies without any discomfort, and to provide an information presenting method with a relatively small load on computation.

Claims

The scope of the claims

1. A unique coordinate system is assigned to each of a plurality of pieces of information accumulated to be presented, and the coordinate system is switched based on the description for converting the coordinate system, and the switched coordinates are used. An information presentation method characterized by presenting information based on a system.

2. The coordinate system is switched based on the “description for converting the coordinate system” and “display accuracy on a display device on which the plurality of pieces of information are presented”. Information presentation method.

3. The “description for converting a coordinate system” includes “search information for searching for an appropriate coordinate system based on display accuracy on the display device”. Information presentation method.

4. The search information comprises an explicit mapping explicitly defined by the information originator and an implicit matching which is automatically added by the system, wherein the explicit mapping is provided by the information constructor. The information presentation method according to claim 3, wherein the implicit mapping is automatically generated based on the explicit mapping.

5. An information storage method, wherein a plurality of pieces of information to be presented are stored in a state where a unique coordinate system is assigned to each of the plurality of pieces of information.

6. The information storage method according to claim 5, further comprising storing the plurality of pieces of information together with a description for converting the coordinate system.

7. Make it possible to present information in the first coordinate system on the display of the client terminal, and further search for a second coordinate system having coordinates that can be displayed on the display;

2. A method for presenting information, characterized by generating a conversion description for enabling information on the entire coordinate system to be displayed on the display.

8. When presenting information in a plurality of coordinate systems on the display of the client terminal, the information in the plurality of coordinate systems is converted into c pieces of coordinate systems satisfying the magnification ZLOD a in descending order of LOD. An information presentation method characterized by indicating the following. here,

Magnification: The number of dots on the display of the unit length of the coordinate system shown on the display,

L O D: Average value of the resolution of the object existing in the coordinate system,

a: constant less than 1,

It is.