JP4771459B2 - Color elevation slope map creation system and color elevation slope map creation method - Google Patents

Description

  The present invention relates to a color elevation slope map creation system and a color elevation slope map creation method that are configured so that the degree of slope and the difference in elevation in a region to be measured can be determined visually and simultaneously.

  Interpretation of the topography may be necessary to take regional development, environmental conservation, and disaster prevention measures. Here, in general, terrain is a form of undulation of the ground surface, and its features are its location (expressed by plane coordinates x, y, and altitude z) at one point, and the direction and slope of the slope. Can be recognized in the direction. Further, in a region having a certain area, the topography can be recognized by continuity in a three-dimensional space of a combination of a change in slope direction and a change in slope.

  The terrain interpretation is to perform terrain classification according to the purpose by grasping the features of the undulations on the ground surface. Information necessary for interpretation of topography includes slope slope, change in slope, slope direction, slope strike, point altitude, point planar position, and distance / position relationship between multiple points. In order to carry out quantitatively, it is desirable that these are presented with as little distortion as possible.

  The following three types of methods are known as methods for obtaining information necessary for interpretation of topography.

(1) A method for visually recreating a virtual solid A pair of planar images with different viewpoints created by the central projection method, such as aerial photographs, or a pair of planar images obtained by subjecting a topographic map to image processing by the oblique projection method Is used to construct a virtual solid in the visual field using the parallax of the naked eye. Altitude was assigned to hue by creating a parallax for the left and right eyes using the difference in refraction angle of each wavelength by the microprism, creating a visual that looks red in the foreground and blue in the foreground. There is also a technique for reproducing a virtual solid from a planar image. In these methods, it is possible to reproduce a three-dimensional effect similar to a state of actually viewing a three-dimensional image, and to enhance the three-dimensional effect by adjusting the parallax effect.

(2) Method for individually presenting information necessary for terrain interpretation This is a method for reading terrain features on a two-dimensional plane by individually presenting terrain quantities describing the undulations of the ground surface. (A) The inclination diagram shows the degree of inclination at an arbitrary point by a numerical value or symbol, or a continuous amount such as hue or brightness. Non-Patent Document 1 shows an attempt to create an inclination map from an inclination calculated from DEM data and use it for terrain interpretation. Similarly, (b) the tilt azimuth map shows the tilt direction at an arbitrary point replaced with numerical values or symbols, hue, brightness, and the like.

  (C) The slope orientation diagram shows the direction of the intersection line drawn by the horizontal plane intersecting the slope at an arbitrary point replaced with a numerical value or symbol, hue, brightness, and the like. The altitude map shows the altitude value at an arbitrary point replaced with a numerical value or a symbol. Altitude values are replaced with hue, brightness, etc., and displayed step by step is called an advanced stage chart. (D) Of the altitude maps, those obtained by drawing lines with the same altitude values drawn at regular intervals are called contour maps, and the slope direction is represented by the direction of the contour lines simultaneously with the altitude values.

(3) Method of obtaining a three-dimensional effect in a pseudo manner by generating unevenness (a) On a two-dimensional plane, obtaining a three-dimensional effect based on information on altitude values is based on information on changes in altitude values over a certain distance. It is difficult to do alone. However, a technique for obtaining a stereoscopic effect by combining information on changes in altitude values over a certain distance and information for determining unevenness has recently been developed. As a method to obtain information on unevenness of topography, a method of expressing the undulations of the ground surface with shading caused by setting a light source in an arbitrary direction, and expressing the ground (underground) line-of-sight angle between a certain distance of convex parts and concave parts There is a method for calculating the above-ground (underground) opening. In addition, there is a method of generating a trend surface that intersects the undulating terrain, calculating the positive / negative of the difference in elevation between the surface and the ground surface, and distinguishing and visualizing the concave portion and the convex portion.

  (B) As a diagram expressing a three-dimensional effect on a two-dimensional plane based on these methods, there is a hillshade diagram created with a light source in a certain direction. Further, in Non-Patent Document 2, the difference between the value obtained by applying a low-pass filter to the undulation of the ground surface and the actual elevation value is assigned to hue and saturation, and the reflection luminance generated by the light source in the vertical direction is assigned to lightness and transmitted. A synthesized Yin Yang diagram is shown.

  By the way, with regard to expressing the terrain three-dimensionally, for example, Patent Document 1 discloses that the terrain is expressed by fusing the altitude data and the shaded map data of the imaging area to image data such as aerial photographs. It is described.

JP 2001-005380 A Kamiya Izumi, Kuroki Kiichi, Tanaka Kohei, 2000, Interpretation of Topography and Geology Using Slope Map, Information Geology, Volume 11, Issue 9-22 Akiyama Yukihide, 2005, LiDAR 3D data micro-terrain representation method-Yin Yang map-Proceedings of the 2005 Joint Conference on Earth and Planetary Society, Y57-007

  In the method of terrain interpretation, in (1) the method of visually recreating a virtual solid, constructing the solid in the visual sense simultaneously gives a sense of perspective, and a uniform scale is obtained in the field of view. Therefore, there is a problem that it is difficult to perform quantitative measurement directly.

  In addition, in (2) the method of individually presenting information necessary for terrain interpretation as shown in Non-Patent Document 1, in general, the elevation value and the elevation value between a certain distance on a two-dimensional plane are indicated. It is difficult to obtain a stereoscopic effect only by visualizing the amount of change. For example, in an inclined view, since the inclination direction cannot be expressed only by the inclination angle, it is not possible to discriminate between an ascending slope and a descending slope, and it is not possible to obtain a complete uneven feeling only by the information.

  The same applies to the case of topographic maps using generally known contour lines. The contour lines simultaneously represent the slope direction by the direction and the degree of slope by the density of the drawing interval. However, the ridge and valley are often mistaken because it is not possible to distinguish whether the slope is ascending or descending only by the degree of slope, and the slope orientation has no effect of preventing inversion.

  In the case of a Laplacian diagram, sharp slope changes can be clearly expressed, and concave slopes and convex slopes can be identified. However, if the slope change is constant, the same expression can be used anywhere in the valley or ridge. Therefore, the position of the valley line or the ridge line may not be specified. As described above, the method (2) also has a problem that the topographic interpretation cannot be performed with high accuracy.

  Further, in (3) the method of obtaining a three-dimensional effect by generating unevenness as shown in Non-Patent Document 2, since the information indicating the altitude value itself is lacking, There is a problem that even if a level difference between local regions cannot be grasped and local unevenness is obtained, a sufficient three-dimensional effect including the overall height positional relationship cannot be obtained.

  In the topographic map described in Patent Document 1, the undulation state of the target area can be visually judged to some extent. However, there is a problem that it is difficult to visually determine the details of the degree of inclination in the target area and the elevation difference.

  The present invention solves the above-mentioned problems, and as means for interpreting and identifying features of the terrain, the terrain undulation and valley terrain / ridge terrain, distribution position / altitude are two-dimensionally planar, simultaneously and respectively. It is an object of the present invention to provide a color elevation slope map creation system and a color elevation slope map creation method that can be clearly identified.

For this purpose, the color elevation inclination map creating system of the present invention comprises data storage means for storing DEM data,
The assignment of colors to the data storage altitude value based on the DEM data stored in the unit, the color elevation view creating means color according to elevation values to create a color elevation view expressed in gradation color transition,
And gray-scale gradient diagram creating means for creating the allocation of the concentration gradient value to calculate a slope value based on the DEM data stored in the data storage means, the gray scale gradient diagram representing the slope value by shading,
Color elevation slope map creation means for creating a color elevation slope map by combining the color elevation map created by the color elevation map creation means and the gray scale slope map created by the gray scale slope map creation means; Have
The color elevation slope map creating means sets the opacity of the color elevation map and the opacity of the gray scale tilt map to be different from each other, and the color elevation map is compared with the opacity of the gray scale tilt map. The color elevation map and the gray scale slope map are combined with a small opacity value .

Further, the color elevation map creating means includes color enhancement means capable of adjusting a stretch width with respect to an elevation portion to be enhanced .

The gray-scale tilt diagram creating means includes a tilt emphasizing means capable of adjusting a stretch width for a tilted portion to be emphasized .

According to the color elevation slope map creation method of the present invention, the color elevation map creation means assigns a color to the elevation value based on the DEM data stored in the data storage means, and is expressed by a gradation color in which the color changes according to the elevation value. Creating a colored elevation map,
A step of calculating a slope value based on the DEM data stored in the data storage means, assigning a density to the slope value, and creating a gray scale slope chart expressing the slope value in shades by a gray scale slope map creating means; ,
The color elevation slope map creating means makes the opacity of the color elevation map different from the opacity of the grayscale slope map, and the color elevation map has an opacity different from that of the gray scale slope map. Combining the color elevation map and the gray scale slope map with a small opacity value;
A color elevation slope map is created by

Further, the present invention is characterized by having a step of adjusting the stretch width with respect to the altitude portion to be emphasized by the color emphasizing means .

Furthermore, it has the step which can adjust a stretch width with respect to the inclination part to emphasize by inclination emphasis means, It is characterized by the above-mentioned .

  As described above, according to the present invention, the degree of inclination in the area to be measured is displayed in gray scale, and the difference in elevation is displayed in color gradation, for example, rainbow color, so that it can be clearly determined visually.

  In addition, by using the color elevation slope map created in the present invention, it is possible to simultaneously detect the elevation of an arbitrary point and the degree of slope slope, or the change in slope, without losing the meaning of individual information at the same time. Can be grasped continuously. Therefore, it is possible to grasp the undulations of the terrain without the inversion of ridges and valleys and the error of the altitude position relationship. Also, altitude and slope values are stored separately and can be retrieved as numerical data.

  First, the basic configuration principle of the present invention will be described. On one two-dimensional plane, it is not easy to intuitively correctly recognize the undulations of terrain only by individual information based on changes in elevation values such as slope and Laplacian. In addition, the method of obtaining a three-dimensional effect in a pseudo manner by generating an uneven feeling cannot intuitively obtain a relatively wide difference in height, and is not sufficient as information necessary for interpretation of topography.

  However, terrain interpretation does not necessarily require a three-dimensional effect, and the continuity in the three-dimensional space of the combination of the change in slope direction and the change in slope is the degree of slope slope, change in slope degree, slope direction. It is only necessary to be able to recognize correctly from information such as the strike of the slope, the altitude of the point, the planar position of the point, and the distance / positional relationship between multiple points.

  Therefore, in the present invention, based on the method of selectively combining and presenting individual information necessary for terrain interpretation, the elevation value and the slope are synthesized, and the features of the terrain are intuitively grasped on a two-dimensional plane. A specific method for displaying a quantitative topographic amount on an orthographic projection image without distortion is presented.

  That is, in the present invention, a color elevation slope map is created by transmitting and synthesizing elevation data (altitude chart) assigned to hues and the like from numerical elevation data and gradient data (slope chart) assigned to density. Such a color elevation inclination map is created using a general-purpose computer system and GIS (Geographic Information System) software.

  4 to 18 are explanatory diagrams showing specific color elevation slope map creation according to the embodiment of the present invention. In FIG. 4, in data creation A, terrain is measured by laser scanning with an aircraft (Aa). DEM (Digital Elevation Model) data is created based on the topographical measurement Aa obtained by laser scanning (Ab). Note that existing data can be used as the DEM data.

  FIG. 5 shows the terrain measurement Aa by laser scanning in FIG. 4 in detail. As shown in FIG. 5, the position and attitude of the aircraft 23 in the X, Y, and Z3 axis directions are accurately tracked by the IMU (Inertial Measurement Device), the GPS artificial satellite 21, and the GPS ground reference station 22. Laser scanning 24 is performed on the measurement target area, and position data 25 on the ground surface is acquired and a digital image is acquired.

  As shown in FIG. 5, the laser measurement of the landform by the aircraft is characterized in that the measurement point directly indicating the altitude of the ground surface is obtained at a high density and surface, with about one point at intervals of several meters to 1 m or less. There is. Furthermore, depending on the difference in the reflection distance, a filtering process is performed to distinguish the one reflected from the tree or building from the group of nearby measurement points and the one reflected from the ground. A detailed terrain model very close to the height can be created. As a result, it has become possible to reproduce detailed terrain that could not be represented by conventional large-scale topographic maps and numerical elevation terrain models with coarse data intervals. In addition, it became possible to visualize minute terrain that was difficult to quantitatively express by aerial photo interpretation.

  Furthermore, such high-density three-dimensional numerical data can be easily converted into a bird's eye view, a reduction ratio can be changed, a shadow can be added, and terrain information can be quantitatively measured. Moreover, there is an advantage that the processing of the terrain expression according to the purpose is easy, and the basic data is good for terrain analysis.

  In FIG. 4B, primary processing (elevation / inclination visualization) is performed on the DEM data for visualization. Since altitude and slope are important factors when interpreting the topography, in the process B, a color elevation map is created (Ba) and a gray scale slope map is created (Bb). In this example, a topographic map around a certain volcano is created. The color elevation map represents different elevations with different color steps.

  The color elevation map is, for example, a gradation color where the high elevation portion Bx is red, the intermediate elevation portion By is yellow, the low elevation crater bottom Bz is blue, and the elevation between them is red-yellow-blue Is displayed. Secondary processing C for emphasizing and displaying the altitude zone and the slope zone is performed on the color elevation map created by the primary processing. This process creates a color elevation map Ca in which the altitude zone and the slope zone are highlighted. Secondary processing is done to facilitate visual interpretation of the terrain by changing the range of hue, saturation, brightness, etc. that are colored according to the elevation in the color elevation map created by the primary processing. . For example, a color changing process is performed in which the color of a high altitude portion is changed from red to another color. Note that the secondary processing can be omitted depending on the situation.

  In the color elevation slope map synthesis D, the color elevation map Ba obtained by the primary process B or the secondary process C and the gray scale slope map Bb are synthesized. In the gray scale inclination map Bb, the density is expressed deeply in a terrain having a steep inclination, for example, a portion of Br. As described above, the color elevation slope map Da is created as a result of combining the color elevation chart and the gray scale slope chart.

  This altitude slope map Da shows the target topography, in this example, the topography near the volcano, where the altitude and slope are chromatic and achromatic, for example, not only the three primary colors, but also the rainbow colors and gray including the intermediate colors. Since the scale is displayed, the features of the terrain can be clearly grasped visually compared to the conventional monochrome or single-color terrain map. Therefore, even if you are not an expert in terrain interpretation, you can intuitively interpret changes in elevation and slope.

  FIG. 6 is an explanatory diagram illustrating an example of creating a color elevation slope map for a target area different from that in FIG. 4. In FIG. 6, in data creation A, terrain is measured by laser scanning with an aircraft (Ac). In this example, it is assumed that mountainous landform interpretation is performed. DEM data is created based on the topographic measurement Aa of the laser scanner (Ad). Based on the DEM data Ad, a hillshade map Ae and a contour map Af are created.

  In B of FIG. 6, primary processing (elevation / inclination visualization) is performed on the DEM data. In this process, a color elevation map (Ba) and a gray scale slope map (Bb) are created as in the example of FIG. Color stage altitude map Ba The high altitude mountain area is displayed in red (Bx), the middle altitude area in yellow (By), and the low altitude river in blue (Bz). Yes. In the gray scale inclination diagram Bb, the density of the steep portion (Bw) is increased. From the gray scale inclination chart Bb, a ground opening figure Bc, an underground opening figure Bd, a Laplacian figure Be, and an inclination division chart Bf are created. Details of these figures will be described later. In FIG. 6, the secondary processing C is not performed on the color elevation map Ba, but the color elevation slope map synthesis C is performed using the color elevation map Ba and the gray scale slope map Bb.

  The color elevation slope map Ca created in the process C displays the target terrain in, for example, a gray scale in which the elevation is a color gradation and the slope is in the range of 0 to 50 degrees. In the process E, it is combined with various topographical analysis maps. That is, the color elevation map Ba, the hillshade map Ae, the ground opening map Bc, the underground opening map Bd, the Laplacian map Be, and the slope division map Bf are combined as appropriate. By this process, for example, elevation + slope band emphasis map Ea and elevation + Laplacian diagram Eb are created. In the process F, a terrain interpretation map Fa is created. The terrain interpretation map Fa is created by using the color elevation slope map Ca, the elevation + tilt zone enhancement chart Ea, the elevation + Laplacian chart Eb, and the like. This terrain interpretation map Fa is obtained by determining the type of terrain according to the cause from the slope of the slope, the direction of the slope, and the like, and the result of interpretation after the landslide is entered. Details of the topographic interpretation map Fa will be described later.

  FIG. 7 is an explanatory diagram showing an example of an inclined section diagram Bf created in the primary processing B of FIG. The inclination division diagram Bf is calculated by calculating the inclination angle from the DEM data and color-coding the angle. The slope division map Bf performs stepwise color coding according to the slope angle of the terrain.

  8 to 16 show various terrain analysis maps created based on the DEM data in FIG. 6, and the same terrain as the color elevation map Ba in FIG. 6 is displayed with different themes. Among these, the examples in FIGS. 8 to 10 are numerical values of terrain quantities such as shaded relief maps and slope maps, which are expressed by shading or color, or a combination of these with other terrain quantities.

  FIG. 8 shows a hillshade map Ae. The shaded relief map Ae is a diagram showing such a state because a shade corresponding to the relief of the topography is expressed when the light source is applied to the three-dimensional topography from a certain direction. Shaded relief maps are easy to understand when interpreting geology and topography, and are easy to understand intuitively. In addition, there is an advantage that the lineament can be clearly recognized. FIG. 9 shows a contour map Af.

  FIG. 10 shows an inclination view Bb (0 to 50 degrees). The slope map Bb shows the degree of slope of the terrain, and the greater the slope, the darker the color. That is, it is a method of displaying the degree of inclination of the terrain represented by a numerical value converted into shades. In this way, by utilizing the fact that the slope map is numerical data, the range of shading can be selected and adjusted for subtle changes that are difficult to understand intuitively, and can be easily visualized in accordance with the slope category to be expressed.

  FIG. 11 shows an inclined band emphasis diagram Ea. The slope band emphasis diagram Ea is a color altitude tilt map superimposed with a gray scale tilt map. Using the tilt map Bb shown in FIG. 10, a tilt portion of 30 degrees or more was used for the altitude. It is the figure which selected and emphasized the hue from which color, saturation, and brightness differ.

  12 to 15 show opening diagrams. FIG. 12 is an example of the ground opening degree diagram Bc (distance 100 m), and FIG. 13 is an example of the ground opening degree diagram Bc ′ (distance 20 m). The opening of the ground represents the size of the sky that can be seen within a distance L from the point of interest. Generally, the point that protrudes from the surrounding area becomes larger, with larger values at the summit and ridge, The bottom of the valley shows a small value, and the protruding peaks and ridges are emphasized.

  FIG. 14 is an example of the underground opening diagram Bd (distance 100 m), and FIG. 15 is an example of the underground opening diagram Bd ′ (distance 20 m). The underground opening map is an index that represents the degree to which the sky is blocked by the ground surface, contrary to the ground opening map, and expresses the development of valley topography and the distribution and density of rivers. The underground opening map shows the area of the basement in the range of distance L when looking at the basement from the ground surface. In general, it becomes larger at the point where it is difficult to get into the basement. The ridge shows a small value and emphasizes depressions and valleys.

  16 and 17 show Laplacian diagrams. The Laplacian diagram represents the rate of change of slope, and is positive for concave terrain and negative for protruding terrain. In general, the absolute value increases at large terrain changes. The Laplacian diagram Be in FIG. 16 is created so that the convex portion (ridge, etc.) is red (Br) and the concave portion (valley, etc.) is blue (Bs). Further, the Laplacian diagram Gb of FIG. 17 is created so that the convex portion (ridge, etc.) is white (Bu) and the concave portion (valley, etc.) is black (Bv). Unlike the shaded figure, the Laplacian diagram has no direction to be emphasized, but a sharp edge with a tilt change is extracted, so that it is possible to express the state of mountain folds and a lineament.

  18 and 19 show examples of topographic interpretation maps created using color elevation slope maps. 18 shows a topographic interpretation map Fx with a contour map as the background, and FIG. 19 shows a topographic interpretation map with the same color elevation slope map Fb as in FIG. 18 and 19, (a) a rapid line, (b) a collapsed site, (c) a sliding cliff, (d) an alluvial cone, (e) a debris deposit, (f) a cliff cone gully, a landslide mass, ( g) The position of the terrace surface is indicated by a symbol.

  From FIG. 18 and FIG. 19, the topographic characteristics of the area are interpreted as follows. (B) Mountain streams with different degrees of erosion are distributed on the slopes of mountainous areas with a gentle slope as a whole. (B) Along the large river, there is a clear transition line (post-glacial erosion front) at a height of about 30m from the bed, and sediment movement is active on the slope immediately below. (C) The landslide topography in the center is divided into three small blocks. (D) The landslide topography in the center is accompanied by unclear sliding cliffs.

  Thus, it is possible to interpret the form of disaster occurrence from the topographic characteristics. The types of disaster occurrence that can be interpreted from the topographic map are: (a) Erosion from directly under the rapid line → Slope failure, (b) Flow of collapsed sediment from a highly eroded valley, (c) Slow sediment movement due to landslides, etc. It is.

  In FIG. 18, the altitude is represented by contour lines, but it is difficult to understand intuitively. On the other hand, in the example of FIG. 19, the elevation and inclination of the topographic map are displayed in a plurality of colors, for example, rainbow colors. For this reason, there is an advantage that it is possible to visually grasp the terrain situation that causes a disaster in the target area.

  FIG. 1 is a block diagram showing an embodiment of the present invention, and corresponds to the processing of FIG. In FIG. 1, the control unit 1 of the color altitude inclination map creation system includes measurement data scanned by a laser scanner 2 mounted on an aircraft or the like, or a contour map 3 prepared in advance, or a stereo image measurement 4 of an aerial photograph. The DEM (Digital Elevation Model) data creation unit 5 creates DEM data (numerical elevation model) using (stereo image matching).

  From the created DEM data, the inclination and altitude of the target area are calculated and displayed. The existing DEM data 6 can also be used as the DEM data. The inclination calculation unit 7 calculates the inclination by differentiating the altitude values. Using the calculated slope, the slope display image creation unit 8 creates a slope chart in which grayscale brightness adjustment has been performed.

  On the other hand, the altitude display unit 9 creates a color stage chart in which the altitude is assigned to a hue or the like. In the color stage chroma chart, an appropriate hue is selected by the altitude-enhanced image creation unit 10 and the saturation and brightness are adjusted. The image composition unit 11 transmits and synthesizes the slope map in which the grayscale brightness is adjusted and the color elevation map in which the color is adjusted. A color elevation gradient (Elevation and Slope Angle: ELSA) is displayed on the display unit 12 for the image that has been transmitted and synthesized.

  Next, a color elevation inclination map is output by the output unit 13. The color elevation slope map of the present invention can be abbreviated as ELSA map (Elevation and Slope Angle Map). In addition, as demonstrated in FIG. 4, it is also possible to abbreviate | omit the highlight display of the altitude zone and inclination zone as secondary processing. In this case, the altitude-enhanced image creating unit 10 functions as an altitude image creating unit that adjusts appropriate hue, saturation, and brightness.

  Using DEM data, the secondary processing data described in FIGS. 8 to 16 is one of a hillshade map, an inclination map, a ground opening map, an underground opening map, a Laplacian map, or a plurality of them. The configuration for displaying and outputting can be arbitrarily selected. In FIG. 1, the output unit 13 that prints out the color elevation slope map is provided, but the output unit 13 is not an essential configuration. The display unit 12 is also an output means in a broad sense, and it may be sufficient to display a color elevation slope map.

  FIG. 2 is a block diagram showing a schematic configuration of the color elevation inclination map creating system according to the embodiment of the present invention. 2, the system 50 includes a CPU 51 that executes various operations and processes, an input unit 52 such as a keyboard and a mouse, and an output unit that displays the various topographic analysis maps described with reference to FIGS. Display) 53. As the output unit 53, a printer that prints the topographic map in color or monochrome on recording paper may be provided.

  It also has a RAM 54 for storing image space data. The data in the image space is a two-dimensional array composed of minute divided area cells (or pixels) for creating a raster data model using DEM data. The image space data is converted into the real world coordinate space of the RAM 54. Further, information on the real world coordinate space of the RAM 54 is displayed on the two-dimensional surface of the output unit (display) 53. Further, it has a ROM 55 storing a program for operating the system and a memory 56 storing DEM data.

  FIG. 3 is a flowchart showing a processing procedure of the color elevation inclination map creating method according to the embodiment of the present invention. In FIG. 3, the interpretation target / DEM data acquisition method is selected (S1). Next, DEM data is created by stereo image matching (S2), contour data (S3), and laser scanner measurement data (S4) in a symmetrical area (S6). Also, existing DEM data is extracted (S5).

  The altitude value of the target area is displayed (S7). In this process, color gradation is applied corresponding to the altitude value, and the color is a plurality of colors such as rainbow, but a single hue can also be selected. Next, the altitude zone display hue range is adjusted (S8). In this process, the hue and saturation are adjusted so that the hue to be colored corresponding to the altitude value matches the vision.

  The emphasis elevation band display suitability is determined (S9). If it is determined that there is display suitability (Y), the process proceeds to the next process. If the determination of the examination result is no display suitability (N), the altitude zone display hue range is adjusted again. Here, in normal processing, for example, if the topography with a high elevation is displayed in red, the topography with a low elevation in blue, and the topography with an intermediate elevation in yellow, the difference in elevation can be clearly determined visually. Therefore, the range is adjusted in order of red, yellow, and blue in order from high to low.

  By the way, the high altitude mountain is covered with green trees, so there is a visual green image at high altitude. Low roads and grounds are visually brown. Therefore, in the processing for determining the suitability for display of the emphasized altitude zone (S9), the range where the high altitude is initially displayed in red is replaced with green, and the lowland is replaced with blue to brown. You can also Through the above processing, a color elevation map is obtained from which three-dimensional information of the terrain with a natural feeling is obtained (S11).

  On the other hand, based on the DEM data, the slope of the target area is calculated (S12). Next, the inclination is displayed with gray scale luminance (S13). Subsequently, the brightness range of the gradient display gray scale is adjusted (S14). With regard to the slope, the emphasized slope band display suitability is determined (S15). When the determination result is N, the process returns to S14 and the brightness range of the gradient display gray scale is adjusted again. If the determination result in S15 is Y, an enhanced grayscale tilt diagram is created (S17).

  A color elevation slope map (ELSA) is synthesized from the enhanced color elevation chart and the enhanced grayscale slope chart (S18). Next, a color elevation gradient (ELSA) is displayed on the display (S19). Subsequently, a color elevation inclination map is output and printed on a recording sheet (S20). Note that, as described with reference to FIG. 4, it is possible to omit the highlighting process of the altitude band and the inclined band as the secondary processing. In this case, the processing for determining the enhanced altitude zone display suitability (S9) and the processing for determining the emphasized slope band suitability (S15) are not performed.

  In the present invention, it has been found that a figure obtained by transparently synthesizing an altitude step color chart and an inclination amount map is effective for terrain interpretation, and has disclosed a specific method for transparently synthesizing a color elevation map and an inclination map. A specific method for the transmission composition of the color elevation map and the slope map is as follows.

(1) Transmission composition method The tilt map can be used alone for terrain interpretation, but the weakness is that the ridge valley may appear to be reversed. Therefore, the weak point can be compensated by synthesizing the altitude value as a color stage chart. Conventionally, since several types of images are multiplied and synthesized with an opacity of 100%, there has been a tendency to have a darker hue close to the primary color.

  The color elevation slope map of the present invention is displayed by combining the slope map (greyscale shading) with opacity adjusted to 100%, reducing the opacity of the high-level chromatic chart displayed in rainbow colors to 50%, etc. is doing. It is also possible to reduce the opacity of the tilt view, but in that case, the overall color becomes pale. Since changes in slope rather than elevation are more important for terrain interpretation, opacity is usually not adjusted in the slope map so that it can be clearly recognized visually. By increasing the transparency of the elevation map, it is possible to create a clear and clear color tone image from a hue close to the primary color.

(2) Programs used to create color elevation slope maps Conventional terrain interpretation maps are created using general-purpose image processing software. When two types of images (for example, a color elevation map and a slope map) are multiplied and synthesized by general image processing dedicated software, the opacity of one cannot be lowered. The color elevation slope map of the present invention was created using the raster transmission function of GIS software. By using this, it became possible to adjust the opacity in the range of 0 to 100% according to preference.

(3) Representation of altitude gradation In the present invention, seven hues are basically selected in order to finely express the difference in elevation, but depending on the preference, the hue of the color elevation map can be selected using image processing software. It is also possible to change the saturation and brightness. For example, a color elevation map that expresses the low part in red and the high part in green can be transparently combined with the slope map to obtain a natural three-dimensional appearance of the terrain, making it easy for people who are not familiar with terrain interpretation to understand the terrain. It becomes.

(4) Expression of inclination In the present invention, shade (grayscale) is basically selected for expression of the degree of inclination. However, if necessary, the end point of density can be changed using image processing software. Is possible. For example, when it is desired to finely express a gently inclined portion, a slight change in inclination that is difficult to be recognized by human vision can be visualized by adjusting the light and shade stretch width to that portion.

(5) Display of Quantitative Numerical Data The color elevation slope map of the present invention is a transmission composite as an image. Therefore, since it does not give an undulating feeling, the altitude value and the amount of inclination are individually stored as numerical data, and can be independently extracted as an image or numerical data as necessary.

(6) Transmission composition with a diagram other than the gradient diagram An image other than the gradient diagram can be used for a diagram with 100% opacity. It is also possible to express the Laplacian that emphasizes the slope conversion part of the ridge / valley with shades such as gray scale. Laplacian is generally said to be an indicator of the difference between an erosion zone and a sedimentation zone. For this reason, it is possible to grasp the altitude distribution in both areas by transmitting and synthesizing with the color elevation map, and it can be used in the field of disaster prevention such as sabo / land conservation projects and road disaster prevention projects.

  Next, other effective use of the color elevation inclination map of the present invention will be described. The color elevation slope map according to the present invention can be effectively used not only for terrain interpretation but also for matters requiring strict elevation information. With the disaster risk prediction map (hazard map) of floods and tsunamis, it is possible to grasp the flooded area and the altitude of the area where you currently live.

  In urban areas, color elevation slope maps can be created according to the altitude of buildings. The color elevation slope map in this case can be used for projects implemented based on building height information such as city planning. Furthermore, evacuation buildings have been proposed as tsunami evacuation measures, but it is also possible to examine which buildings are high and safe for flooded areas and visualize them visually on a plane.

  The embodiment of the present invention has been described above. The present invention is not limited to these embodiments, and can be implemented in various forms.

  As described above, according to the present invention, the color elevation slope map creation system and the color elevation slope map creation method are configured so that the degree of slope and the difference in elevation in the area to be measured can be visually determined clearly. Can be provided.

It is a block diagram which shows schematic structure of this invention. It is a block diagram which shows the system configuration | structure of this invention. It is a flowchart which shows the process sequence of this invention. It is explanatory drawing which shows embodiment of this invention. It is explanatory drawing which shows embodiment of this invention. It is explanatory drawing which shows embodiment of this invention. It is explanatory drawing which shows embodiment of this invention. It is explanatory drawing which shows embodiment of this invention. It is explanatory drawing which shows embodiment of this invention. It is explanatory drawing which shows embodiment of this invention. It is explanatory drawing which shows embodiment of this invention. It is explanatory drawing which shows embodiment of this invention. It is explanatory drawing which shows embodiment of this invention. It is explanatory drawing which shows embodiment of this invention. It is explanatory drawing which shows embodiment of this invention. It is explanatory drawing which shows embodiment of this invention. It is explanatory drawing which shows embodiment of this invention. It is explanatory drawing which shows embodiment of this invention. It is explanatory drawing which shows embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Control part of color elevation inclination map creation system, 2 ... Laser scanner, 3 ... Contour topographic map, 4 ... Stereo image matching (software), 5 ... DEM (Digital Elevation Model) Data creation unit, 6 ... existing DEM data, 7 ... inclination calculation unit, 8 ... inclination display image creation unit, 9 ... elevation display unit, 10 ... elevation emphasized image creation unit, 11 ... Image compositing section, 12... Display section, 13... (Color elevation slope map: ELSA) output section, 50... Color elevation slope map creation system, 51. Input unit, 53 ... output unit, 54 ... RAM, 55 ... ROM, 56 ... memory.

Claims (6)

Data storage means for storing DEM data;
The assignment of colors to the data storage altitude value based on the DEM data stored in the unit, the color elevation view creating means color according to elevation values to create a color elevation view expressed in gradation color transition,
And gray-scale gradient diagram creating means for creating the allocation of the concentration gradient value to calculate a slope value based on the DEM data stored in the data storage means, the gray scale gradient diagram representing the slope value by shading,
Color elevation slope map creation means for creating a color elevation slope map by combining the color elevation map created by the color elevation map creation means and the gray scale slope map created by the gray scale slope map creation means; Have
The color elevation slope map creating means sets the opacity of the color elevation map and the opacity of the gray scale tilt map to be different from each other, and the color elevation map is compared with the opacity of the gray scale tilt map. The color elevation slope map creating system characterized in that the color elevation chart and the gray scale slope chart are synthesized with the opacity of the image as a small value . The color elevation slope map creation system according to claim 1, wherein the color elevation map creation unit includes a color enhancement unit capable of adjusting a stretch width with respect to an altitude portion to be enhanced . The color altitude slope map creating system according to claim 1 or 2, wherein the gray scale slope map creating means includes a slope emphasis means capable of adjusting a stretch width with respect to a slope portion to be emphasized . A step of assigning a color to an elevation value based on the DEM data stored in the data storage means by the color elevation map creation means, and creating a color elevation map expressed by a gradation color in which the color transitions according to the elevation value;
A step of calculating a slope value based on the DEM data stored in the data storage means, assigning a density to the slope value, and creating a gray scale slope chart expressing the slope value in shades by a gray scale slope map creating means; ,
The color elevation slope map creating means makes the opacity of the color elevation map different from the opacity of the grayscale slope map, and the color elevation map has an opacity different from that of the gray scale slope map. Combining the color elevation map and the gray scale slope map with a small opacity value;
A method for creating a color elevation slope map, comprising: The method of claim 4, further comprising the step of adjusting a stretch width with respect to a height portion to be emphasized by a color enhancement means . 6. The color elevation slope map creation method according to claim 4, further comprising a step of adjusting a stretch width for the slope portion to be emphasized by the slope emphasis means.