JP2006048070A - Three-dimensional map generation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To automatically generate three-dimensional map data by generating three-dimensional information of facilities in a map by using an existent two-dimensional map. <P>SOLUTION: The height, color, etc., of facilities in the map are determined based upon either one of or a combination of a plurality of (a) to (c). Here, (a) is the size or area of an outline in the two-dimensional map, (b) is properties of the facilities corresponding to the outline, and (c) is the color of an aerial photograph of the part corresponding to the outline in an aerial photomap. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for creating a three-dimensional map that automatically creates a wide range of data of a three-dimensional facility that actually exists based on a map database alone or a map database and an aerial photograph.

A map information system that records topographic graphics data and data such as altitude and land use form in a database is used for collecting and analyzing regional information.
For example, such a map information system is commercially available as an electronic map or used as a road map database for an in-vehicle navigation device.

  However, the map information in the above system is usually two-dimensional plane data represented by latitude and longitude, or only three-dimensional data with elevation data added to it, such as individual buildings, parks, roads, etc. The data of the height (hereinafter collectively referred to as “facility”) (hereinafter simply “height” means the ground height) is not included in the map information. The reason is that when such data is included, the amount of stored data becomes enormous.

However, from the viewpoint of the user, in order to view a map image having a depth that has been subjected to 3D CG (computer graphics) processing, the actual three-dimensional shape or height data of the facility is required.
In addition, if the color or pattern data of the facility is included, the image becomes more realistic when displayed on the screen.

Therefore, an object of the present invention is to realize a three-dimensional map creation method capable of automatically creating three-dimensional information of facilities included in a two-dimensional map with a minimum amount of stored data.
In addition, the present invention realizes a three-dimensional map creation method capable of automatically creating map data including color information and pattern information of individual facilities included in a two-dimensional map with a minimum storage data amount. For the purpose.

In this specification, (a) to (f) are defined as follows.
(a) the size or area of the contour in the map,
(b) Facility attributes in the map,
(c) the color of the aerial photo of the part corresponding to the contour in the map,
(c1) Aerial color of the side of the part corresponding to the contour in the map,
(d) the height of the stereo aerial photograph of the part corresponding to the contour in the map,
(e) the color of the top surface of the determined facility,
(f) The determined facility side color.

  FIG. 1 is a diagram showing a part of a map copied from a map database. There are many closed curves in the map (each one of these closed curves is called "contour"), and the contour may be a square or a rectangle close to a square as shown in Fig. A. If there is, there is a rectangular shape as shown in FIG. B, and there is also a shape with a corner cut off as shown in FIG. There are also large outlines and small outlines. Furthermore, each contour may correspond to attribute data in the map (eg, private house, office building, park, school, etc.).

(1) The three-dimensional map creation method of the present invention is a method for determining the height of a facility in a map based on (a) (Claim 1). For example, the height of the facility is determined in proportion to the size and area of the contour. However, it is desirable to set an upper limit and a lower limit.
(2) The three-dimensional map creation method of the present invention is a method for determining the height of a facility in a map based on (a) and (b) (Claim 2).

  In this case, the height is determined by the size and area of the contour and the attributes of the facility. The height of the facility is changed in consideration of the size and area of the facility having the attribute, taking the invention of claim 1 into account. For example, when the area is large, the height is slightly increased. In order to prevent the same type of facility from always having the same height, several heights of the same type of facility may be set and selected from among them by a random number, an order, or the like.

(3) The method for creating a three-dimensional map of the present invention is a method for associating contours in a map with aerial photographs and obtaining the height of a facility in the map based on (c). ).
In this case, an aerial photograph is taken and the outline in the map is associated with the aerial photograph.
Then, the height of the facility in the map is determined based on the color of the aerial photograph of the portion corresponding to the outline. For example, if the color is a special color (ground color or plant color), the height is set to zero. Since the height of all facilities may not be determined by color alone, it is desirable to combine the inventions of claim 1 or claim 2 in this case.

(4) The three-dimensional map creation method of the present invention is a method for determining the color of the upper surface of the facility in the map based on (a). For example, if the size or area of the contour in the map is below a certain level, the color of the roof tile is used as a private house. If there is more than one, select them by random number or order. For those that could not be determined, it is desirable to determine the color by a random number, order, or the like.
(5) The three-dimensional map creation method of the present invention is a method of determining the color of the upper surface of the facility in the map based on (b) (Claim 5).

According to this, a color or color group determined by the facility attribute is assigned. For example, white, gray and beige are assigned to office buildings, green is assigned to parks, and earth colors are assigned to open spaces. When there are a plurality of colors, the color is determined by a random number or an order.
(6) The method for creating a three-dimensional map of the present invention associates the outline in the map with the aerial photograph, and then determines the color of the upper surface of the facility in the map based on (c) (Claim 6).

In this case, an area of the aerial photograph corresponding to the contour of the map is cut out and the color of the area is adopted as it is. If the area is not constant, the average value of the colors of all the pixels in the area, the color of the pixel at the center of gravity of the area, and the like are adopted.
(7) The three-dimensional map creation method of the present invention is a method for obtaining the color of the side of the facility in the map based on (a) (Claim 7).

If the size or area of the facility is about several m × several m, it is regarded as a private house, and is assigned in random number or order from white, gray, beige and the like.
(8) The three-dimensional map creation method of the present invention is a method for obtaining the color of the side of the facility in the map based on (b). In this case, a color or color group determined by the facility attribute is assigned. For example, white, gray, beige, etc. are assigned to office buildings. When there are a plurality of assigned colors, the color is determined by a random number or an order.
(9) The three-dimensional map creation method of the present invention is a method of associating the contour in the map with a stereo aerial photograph, and then obtaining the color of the facility side in the map based on (c1). (Claim 9).

In this case, a region of the stereo aerial photograph corresponding to the contour of the map is cut out, a surface that is nearly vertical is extracted from the region, and the color of the surface is used as it is. If the surface is not constant, the average value of the colors of all pixels on the surface, the color of the pixel at the center of gravity of the surface, and the like are employed.
(10) The method for creating a three-dimensional map of the present invention is a method for obtaining the color of the side face of the facility in the map based on (e).

In this case, the color of the upper surface of the already determined facility is adopted as it is. The RGB value may be changed somewhat.
(11) The three-dimensional map creation method of the present invention is a method for obtaining the pattern of the upper surface of the facility in the map based on (a) (claim 11). For example, if the size or area of the facility is about several tens of meters × several tens of meters, it is regarded as an office building and a concrete pattern is assigned. If the size or area of the facility is about several meters by several meters, it is considered a private house and a roof tile pattern is assigned.

(12) The three-dimensional map creation method of the present invention is a method for obtaining the pattern of the upper surface of the facility in the map based on (b) (claim 12). For example, if the facility is an office building, a concrete pattern is assigned. If it is a private house, assign a roof tile pattern.
(13) The three-dimensional map creation method of the present invention is a method for obtaining the pattern of the upper surface of the facility in the map based on (e) (claim 13).

In this case, a pattern suitable for the color of the upper surface of the already determined facility is made in advance on the table and adopted from there. If there is more than one, it is determined using a random number or order.
(14) The three-dimensional map creation method of the present invention is a method for obtaining a side pattern of a facility in a map based on (a) (claim 14). For example, if the size or area of the facility is about several tens of meters × several tens of meters, it is regarded as an office building, and is assigned from a brick, concrete, marble or the like in random numbers or in order. If the size or area of the facility is about several meters by several meters, it is considered a private house and a soil wall pattern is assigned.
(15) The three-dimensional map creation method of the present invention is a method for obtaining a side pattern of a facility in a map based on (b) (claim 15).

For example, if the facility is an office building, it is assigned in random number or order from brick, concrete, marble, or the like. If it is a private house, assign a mud wall pattern.
(16) The three-dimensional map creation method of the present invention is the method according to any one of claims 7 to 10 which obtains a side pattern of a facility in the map based on (f). ).

  In this case, a pattern suitable for the color of the upper surface of the already determined facility is made in advance on the table and adopted from there. If there is more than one, it is determined using a random number or order.

  As described above, according to the three-dimensional map creation method of the present invention, the three-dimensional map data of the three-dimensional shape, color, or pattern of the facility is automatically created by using the two-dimensional plane data with the minimum storage data amount. be able to. Therefore, if three-dimensional computer graphics processing is performed using this three-dimensional map data, a realistic image can be seen.

Hereinafter, an embodiment of the present invention that creates 3D map data containing three-dimensional facility data using a personal computer will be described in detail with reference to the accompanying drawings.
1. Preprocessing of map data In order to handle each contour of map data as a polygon (polygon), the following preprocessing is performed.

(1) When map data is stored as a two-dimensional bitmap For example, the map data contained in the map file of the Geographical Survey Institute's “Numeric Map 10000 Comprehensive” is the site shape of the building (original image) Are stored as bitmap data.
In this pre-processing procedure, a polygon (polygon) that is as close as possible to the edge lines constituting the original image is determined, and at the same time, the map is divided into mesh units. Note that this processing is not necessary when polygonalization or meshing is performed on commercially available house map data or the like.

  This pre-processing procedure will be described with reference to a flowchart (FIG. 2). First, map data is read (step S1). Then, a closed curve, that is, a contour is identified, and an identification number is assigned (labeled) to each contour (step S2). At this time, the number of pixels in the portion surrounded by each contour (a pixel is a pixel, which corresponds to the area of the contour) and an average value of pixel coordinates (corresponding to the center of the contour) are obtained. Next, the vertex coordinates of the contour are extracted from 1 to N (N is a fixed natural number, and N = 4 will be described below) (step S3). Specifically, as shown in FIG. 3, lines are formed vertically and horizontally with reference to the center of the contour, and divided into four sections, and the pixels a to d farthest from the center are checked in each section.

The CPU (central processing unit) does not know in advance how many squares the contour is actually. However, since it is usually considered to be a polygon more than a quadrangle, for the time being, four vertex coordinates are obtained, and the vertex coordinates actually exceeding it are sequentially obtained in steps S4 and S5. is there.
In step S4, a deviation between the line B connecting the vertices and the edge line A constituting the original image is obtained. Specifically, as shown in FIG. 4, it is assumed that vertices a and b are obtained, and a line segment connecting the vertices a and b is B. The vertical distance between each pixel A1, A2, A3,... On the edge line A of the original image and the line segment B is measured, and it is determined whether each vertical distance is larger or smaller than a threshold value. If all are smaller than the threshold value, it is determined that it is not necessary to add a vertex, and the three-dimensional map creation process of step S6 is entered. If it is larger than the threshold value, the pixel having the longest vertical distance is newly added as a vertex (step S5). The new vertex ordering method is as follows. The new vertex is traced to both sides along the edge line A of the original image, and when reaching the already detected vertex, the new vertex is placed between the two already detected vertices. As described above, the contour of the original image can be a polygon whose number of vertices and vertex coordinates are known.

  Once the map data is converted to polygons, the user divides the file into meshes (rectangles or squares divided by a certain latitude and longitude) using the mouse or keyboard while looking at the screen, and performs a 3D map creation process ( Step S6), storing in the storage medium. The size of the mesh is, for example, 50 m square, 250 m square, 1 km square, or the like. Note that the map data may be divided into mesh units before polygonizing the map data, and then performing a 3D map creation process (the same applies to (2) below).

(2) When map data is displayed on paper etc. In this case, scan the map with a scanner. Thereafter, polygonalized map data is obtained in the same manner as “(1) When map data is stored as a two-dimensional bitmap”. Then, similarly to the above, mesh division is performed and stored in the storage medium.
2. Aerial photo pre-processing
(1) When stereo images are not used Read aerial photographs with a scanner. Thereafter, the file is divided into mesh units and stored in a storage medium. This process is performed based on the same standard as the mesh division process in “1. Preprocessing of map data”. As a result, the map and the aerial photograph can be associated with each other in the same mesh. Note that the aerial photograph data is not polygonized.

(2) When using stereo images Scan the right-eye image and left-eye image with a scanner. Then, a well-known three-dimensional recognition process is performed to obtain aerial photo data including height information (Takeshi Aoiin, Tomoharu Nagao “Image Processing and Recognition”, Shoshodo, pp. 151-154, November 1992 First edition issued on the 25th). Thereafter, it is divided into meshes and stored in a storage medium. Polygoning is not performed.
3. 3D map creation process
(1) When aerial photographs are not used In this case, The height, color, and pattern of the facility are determined based on the polygonal map data in mesh units obtained in (1) or (2).

FIG. 5 is a block diagram showing a flow of processing for creating stereoscopic map data based on polygon map data.
The CPU reads the map data converted into polygons and temporarily stores it in the buffer memory (B1). Based on the stored map data, the height, color, and pattern of the facility are determined (B2, B3, B4). Further, the side pattern or the top pattern is determined based on the determined color.

What makes the decision
(g) Outline shape in polygon map
(a) Outline size or area in polygon map
(b) The attribute of the facility in the polygon map. Specifically, the “contour shape” in (g) is specified by how many polygons (number of vertices) form the contour. The “contour size or area” in (a) is specified by the number of pixels in the contour. The “facility attribute” in (b) is determined by the data if it is originally included in the map data. If it is not included in the map data, the user uses a mouse or keyboard while looking at the screen. Enter the attributes of one house, or specify the area with a mouse or the like in a densely populated house. However, since it takes time to input, it is possible not to use “facility attributes” as a factor of determination.

The decision criteria are as follows.
(1-1) Determination of facility height
(1-1-1) When the attributes of a building are not decided For example, when the contour shape is a square or a square, the length of one side of the square is the height of the building. This is based on the recognition that buildings are often cubic. When the number of contour vertices is larger than a certain number (complex shape), the height can be made constant.

Further, the size or area of the contour may be measured, and the height of the building may be proportional to the size or area. In this case, an upper limit stipulated by laws and regulations is set for each type of area such as the first type residential area. A lower limit may be provided.
Further, the obtained height can be changed by a random number or an order within a certain limit. If it is changed randomly, a natural feeling close to the actual landscape can be given to the viewer.

(1-1-2) When the attributes of a building are determined Also, when the attributes of a building are determined, the height of the building can be determined according to the attributes. For example, the height is about two stories for a private house, about five stories for an office building, about three stories for a school, and 0 meters for a park. Furthermore, the height of the building is varied within a certain range depending on the size or area of the contour. For example, if the school is a very large school, raise it to the height of a building.

Further, the obtained height can be changed by a random number or an order within a certain limit. If it is changed randomly, a natural feeling close to the actual landscape can be given to the viewer.
(1-2) Determination of the color of the upper surface of the facility
(1-2-1) If the building attributes are not determined If the facility attributes are not set, the color of the top surface of the facility is determined by a random number or order. However, if the size or area of the outline is a small square of several meters, it is regarded as a private house and gray, red, blue, etc. close to the color of the roof are adopted.
Further, the obtained color can be changed within a certain range by a random number or an order.

(1-2-2) When the building attributes are determined If the facility attributes are set, the color is determined according to the facility attributes (eg, private house, office building, park, school, etc.). For example, in the case of a private house, gray, red, blue, etc. close to the color of the roof are adopted. Parks should be a mixture of green and earth colors, and office buildings should be cold concrete gray.
Further, the obtained color can be changed within a certain range by a random number or an order.
(1-3) Determination of the color of the side of the facility
(1-3-1) If the attributes of the building are not decided For example, if the outline shape is square or rectangular, it is considered as an office building and the side color of the facility is beige, gray, white, etc. . If the outline is small, it is considered a private house and light brown or the like is adopted.
(1-3-2) When building attributes are determined If the facility attributes are set, the color can be determined according to the attributes (eg, private house, office building, park, school, etc.) . For example, in the case of an office building, beige, gray or white is used as the color of the side of the facility. For a private house, light brown or the like is used. (1-4) Determination of the pattern on the top or side of the facility As an example of the pattern on the top or side of the facility, prepare bricks, stone walls, granite, brick walls with windows, stone walls with windows, etc. In FIG. 6, the example of the pattern of the brick wall with a window is shown.
(1-4-1) When the attributes of a building are not decided For example, the pattern of the upper surface or the side surface of the facility in the map can be determined based on the contour shape of the facility. When the shape of the contour is square or close to a square or when the contour is large, it is regarded as a building and a brick wall with a window, a stone wall with a window, or the like is used.

When determining the pattern of the upper surface or side surface of the facility according to the size or area of the facility, the pattern of the upper surface or side surface of the facility is determined based on a random number or order. However, if the size or area of the outline is a small one of several meters square, it is regarded as a private house and a roof tile pattern, a tin roof pattern, a mortar wall, a plaster wall, etc. are adopted.
(1-4-2) When the attributes of the building are fixed Also, if the attributes of the building are set, mortar walls, plaster walls, etc. for private houses, brick walls, stone walls with windows, marble for office buildings Adopt walls. When deciding the pattern of the top surface of the facility, if it is a private house, use a roof tile or tin roof pattern.

(2) When using aerial photographs that are not stereo images In this case, Along with the polygonal map data in mesh units obtained in (1) or (2), 2. The aerial photograph data in mesh units created by the aerial photograph pre-processing (when stereo images are not used) in (1) are used.
Explaining based on the block diagram (FIG. 7), polygon map data and aerial photograph data are read and temporarily stored in buffer memories (B5, B6). Based on the stored map data, the height, color, and pattern of the facility are determined (B7, B8, B9). Further, the side pattern or the top pattern is determined based on the determined color. What makes the decision
(g) the shape of the contour in the polygon map,
(a) the size or area of the contour in the polygon map,
(b) Facility attributes in the polygon map,
With
(c) The color of the aerial photograph corresponding to the outline in the aerial photograph map. The color of the aerial photograph corresponding to the contour in (c) is the average of the color data of the aerial photograph pixels in the portion corresponding to the contour in the polygon map using a well-known colorimetric method. It can be determined by the value.
(2-1) Determination of facility height
(2-1-1) If the building attributes are not determined If the “facility attributes” is not set, measure the size or area of the contour and make the height of the building proportional to the size or area. However, an upper limit and a lower limit are set. If the color of the aerial photograph is special, for example, green or red or yellow (ie, brown) with low saturation, the height is set to 0 assuming that it is forest or soil.
(2-1-2) When the building attributes are determined When the “facility attributes” are set, the height of the facility is roughly determined by the attributes, and varies slightly depending on the size and area of the facility. Furthermore, when the color of the aerial photograph of the part is special, for example, when the color is green or red or yellow with low saturation (that is, brown), it is regarded as forest or soil and the height is set to zero.
(2-2) Determination of the color of the upper surface of the facility
(2-2-1) When the attributes of the building are not decided Measure the color of the aerial photograph and adopt a color close to that color. When the colorimetric color gradation is finer than the color gradation to be determined, a conversion table is created that converts the colorimetric data within a certain range and converts them into one color. And adopt the color. Furthermore, the adopted color can be changed by a random number or order within a certain limit. If there is a variation in color, the person who sees the screen will feel close to the color of the actual landscape.

(2-2-2) When the attributes of the building are determined Also, when the attributes of the building are set, for example, in the case of a park, it is determined to be brown. If the color of the aerial photograph and the color determined by the building attributes are different, select one of the colors.
Furthermore, the adopted color can be changed by a random number or order within a certain limit. If there is a variation in color, the person who sees the screen will feel close to the color of the actual landscape.
(2-3) Determination of the color of the facility side
(2-3-1) When the attributes of the building are not fixed The color of the side of the facility in the map matches the color of the top surface of the facility corresponding to the contour in the map. However, if the size or area of the contour is small, it is regarded as a private house and selected from light brown, white, gray, and the like.
(2-3-2) When the attributes of the building are determined If the attributes of the facility are set, the color of the side should be determined according to the attributes (eg, private house, office building, park, school, etc.) You can also. For example, in the case of an office building, beige, gray or white is used as the color of the side of the facility. For a private house, light brown or the like is used. If the color of the side determined in (2-3-1) and the color determined by the building attributes are different, select one of the colors.
(2-4) Determination of the pattern on the top or side of the facility
Based on the color of the upper surface of the facility based on the aerial photograph described in (2-2), the pattern of the upper surface or side surface of the facility is determined. As the method, in addition to the method described in (1-4), the method described below can be adopted.

For example, in the case of preparing eight patterns on the side surface, the hue circle is divided into eight angles (magenta, red, orange, yellowish green, green, light blue, blue, purple) and is associated with each color. Designate the pattern. For example, if it is a color belonging to the red section, it is a brick pattern, and if it is a color belonging to the green section, it is a habit pattern. Then, by analyzing the RGB values and determining which category the color belongs to, the pattern is automatically selected.
(3) When using aerial photographs of stereo images In this case, Along with the polygonal map data in mesh units obtained in (1) or (2), 2. The aerial photograph data in mesh units created in the aerial photograph preprocessing (when stereo images are used) in (2) are used. Then, the height, color, and pattern of the facility are determined based on these map data.

What makes the decision
(g) the shape of the contour in the polygon map,
(a) the size or area of the contour in the polygon map,
(b) Facility attributes in the polygon map,
(c) In addition to the color of the aerial photograph corresponding to the outline in the aerial photograph map,
(d) the height of the part corresponding to the contour in the map determined from the stereo aerial photograph;
(c1) The color of the aerial photograph of the side of the part corresponding to the contour in the map. The height of the part corresponding to the contour in the map in (d) is taken out of the height data in the part corresponding to the contour in the polygon map, and their average, median, and maximum values are extracted. Any one of the minimum value and the like can be calculated and obtained.

The “color of the side surface of the part corresponding to the contour in the map” in (c1) is determined as follows. The height data in the portion corresponding to the contour in the polygon map is taken out, and the change rate of the height, that is, the gradient is obtained. When this gradient is larger than the threshold value, the part is regarded as a side surface. As the threshold value, for example, a value close to a right angle such as 80 ° or 85 ° from the horizontal plane is adopted.
(3-1) Determination of facility height
(3-1-1) When building attributes are not determined If `` facility attributes '' are not set, the height of the part corresponding to the contour in the map obtained from stereo aerial photographs is used as it is To do.

(3-1-2) When the attributes of the building are determined If the “facility attributes” are set, the height of the facility is determined according to the attributes, and slightly varies depending on the size and area of the facility. If the height determined from the aerial photograph and the height determined by the attributes of the building are inconsistent, either height is selected or the height between the two is calculated. Furthermore, when the color of the aerial photograph of the part is special, for example, when the color is green or red or yellow with low saturation (that is, brown), it is regarded as forest or soil and the height is set to zero.
(3-2) Determination of the color of the upper surface of the facility
Determine in the same way as described in (2-2).
(3-3) Determination of the color of the facility side
(3-3-1) When the attributes of the building are not fixed The color of the side of the facility in the map is the color of the aerial photograph of the side of the part corresponding to the contour in the map. When the colorimetric color gradation is finer than the determined color gradation, a conversion table is created to convert a certain range of colorimetric data into one color and use this table. And adopt the color. When the color of the side is distributed over a certain range, the average value is taken or the color of the center of gravity of the side is adopted.

(3-3-2) When building attributes are determined When the facility attributes are set, the color of the side should be determined according to the attributes (eg, private house, office building, park, school, etc.) You can also. For example, in the case of an office building, beige, gray or white is used as the color of the side of the facility. For a private house, light brown or the like is used. If the color of the side determined in (3-3-1) and the color determined by the building attributes are inconsistent, select one of the colors.
(3-4) Determination of the pattern on the top or side of the facility
Determine in the same way as described in (2-4).
4). 3D map data format Table 1 shows a storage format of a 3D map created based on the present invention.

表１で、施設番号とは、２次元地図に存在する１つ１つの輪郭の識別番号をいう。属性番号とは、各施設の属性（例：民家、オフィスビル、公園、学校など）を特定する番号である。輪郭頂点数は、例えば五角形なら５などとなる。輪郭頂点の座標は、当該地図メッシュの中での頂点の相対座標のことである。

In Table 1, the facility number refers to the identification number of each contour existing in the two-dimensional map. The attribute number is a number that identifies an attribute of each facility (eg, private house, office building, park, school, etc.). For example, the number of contour vertices is 5 for a pentagon. The coordinates of the contour vertex are relative coordinates of the vertex in the map mesh.

“Relative coordinates” refers to coordinates measured from the end of the mesh. Since the mesh itself is a rectangle or a square sectioned at a certain latitude and longitude as described above, the absolute position such as the north latitude and the east longitude can be specified based on the relative coordinates.
The ground clearance represents the height of the facility. The upper surface color means the color of the upper surface of the facility, and the side surface color means the color of each side surface of the facility. In either case, it may be represented only by brightness, may be represented by RGB values, may be represented by an XYZ color system, a Munsell color system, or may be represented by a color sample number. The side pattern number is a number that identifies a pattern (brick, stone wall, granite, brick wall with window, stone wall with window, etc.) on each side of the facility.

In addition, altitude data may be entered. By combining the altitude data and the ground height data, the absolute height of the facility can be determined.
5. Others After the height and color of the facility have been determined as described above, the facility can be shaded by fixing the position of the light source (sun).

In computer graphics, the surface color set for speedup is used as it is. However, with this method, if the color is the same as that of the adjacent surface, the boundary line disappears and the stereoscopic effect is lost. In order to prevent this, a normal light source is set, the angle between the ray and the surface of the object is calculated, and a shadow (tone difference) is added.
Also in the three-dimensional map creation method of the present invention, this method can be applied to add a shadow. Specifically, the angle of sunlight is set at a predetermined time, for example, noon, assuming an average latitude in Japan. In Tokyo, the angle is 55 ° from the zenith.

After obtaining the hue H, saturation S, and luminance I from the angle θ between the normal vector of the surface to be processed and the sunlight vector, and the RGB value of the surface, and adding a shadow according to the conversion formula Is determined. The following formula can be given as an example of the “conversion formula”.
I ′ = I [(1-cos θ) (1-k) / 2 + k]
Here, k is a luminance attenuation rate adjustment parameter, and its range is from 0 to 1.

  If such shading is performed and stored in the three-dimensional map data format, it is possible to display a shaded image in real time when displaying, and a stereoscopic image can be displayed at high speed. Can be displayed.

It is the figure which displayed a part of map copied from the map database. It is a flowchart which shows a pre-processing procedure. It is a figure explaining the method of taking out the vertex coordinate of an outline. It is a figure explaining the process which calculates | requires the shift | offset | difference of the line B which connected the vertex, and the edge line A which comprises an original image. It is a block diagram which shows the flow of the process which produces 3D map data based on polygon map data. It is a figure which shows the pattern of the brick wall with a window attached to the upper surface or side surface of a plant | facility. It is a block diagram which shows the flow of the process which produces 3D map data based on polygon map data and aerial photography.

Explanation of symbols

A, B, C Outline in the map

Claims (16)

A 3D map creation method for creating 3D map data containing 3D facility data based on a map database,
A method for creating a three-dimensional map, comprising a step of determining a height of a facility in the map based on the following (a).
(a) Outline size or area in the map A 3D map creation method for creating 3D map data containing 3D facility data based on a map database,
A method for creating a three-dimensional map, comprising a step of determining the height of a facility in a map based on the following (a) and (b).
(a) Outline size or area in the map
(b) Attributes of facilities in the map A method for creating a 3D map based on a map database and an aerial photograph to create 3D map data containing 3D facility data,
A method for creating a three-dimensional map, comprising the step of associating an outline in a figure with an aerial photograph and then determining the height of a facility in the map based on the following (c).
(c) The color of the aerial photograph corresponding to the contour in the map A method for creating a three-dimensional map according to any one of claims 1 to 3,
A method for creating a three-dimensional map, comprising a step of determining the color of the upper surface of a facility in the map based on the following (a).
(a) Outline size or area in the map A method for creating a three-dimensional map according to any one of claims 1 to 3,
A method for creating a three-dimensional map, comprising a step of determining the color of the upper surface of a facility in the map based on the following (b).
(b) Attributes of facilities in the map A method for creating a three-dimensional map according to any one of claims 1 to 3,
Creating a three-dimensional map characterized by associating contours in the map with aerial photographs and then determining the color of the top surface of the facility in the map based on (c) below Method.
(c) The color of the aerial photograph corresponding to the contour in the map A method for creating a three-dimensional map according to any one of claims 1 to 3,
A method for creating a three-dimensional map, comprising a step of determining a color of a side surface of a facility in a map based on the following (a).
(a) Outline size or area in the map A method for creating a three-dimensional map according to any one of claims 1 to 3,
A method of creating a three-dimensional map, comprising a step of determining a color of a side surface of a facility in a map based on the following (b).
(b) Attributes of facilities in the map A method for creating a three-dimensional map according to any one of claims 1 to 3,
Creating a three-dimensional map characterized in that it includes a procedure for associating contours in a map with stereo aerial photographs and then determining the color of the side of the facility in the map based on (c1) below Method.
(c1) Aerial color of the side of the part corresponding to the contour in the map 5. The method includes the steps of associating the outline in the map with the aerial photograph and then determining the color of the facility side in the map based on (e) below: The three-dimensional map creation method according to claim 6.
(e) Color of the top surface of the facility in the determined map A method for creating a three-dimensional map according to any one of claims 1 to 3,
A method for creating a three-dimensional map, comprising a step of determining a pattern of an upper surface of a facility in a map based on the following (a).
(a) Outline size or area in the map A method for creating a three-dimensional map according to any one of claims 1 to 3,
A method of creating a three-dimensional map, comprising a step of determining a pattern of an upper surface of a facility in a map based on the following (b).
(b) Attributes of facilities in the map The method for creating a three-dimensional map according to any one of claims 4 to 6, further comprising a procedure for determining a pattern of the upper surface of the facility in the map based on the following (e).
(e) Color of the top surface of the facility in the determined map A method for creating a three-dimensional map according to any one of claims 1 to 3,
A method of creating a three-dimensional map, comprising a step of determining a side pattern of a facility in a map based on the following (a).
(a) Outline size or area in the map A method for creating a three-dimensional map according to any one of claims 1 to 3,
A method of creating a three-dimensional map, comprising a step of determining a side pattern of a facility in a map based on the following (b).
(b) Attributes of facilities in the map The method for creating a three-dimensional map according to any one of claims 7 to 10, further comprising a step of determining a side pattern of the facility in the map based on the following (f).
(f) The color of the facility's side in the determined map

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