JP2010204379A - Map display device and map display method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a map display device allowing a user to obtain positional relation with a reference point and operate this device simply. <P>SOLUTION: In this map image display device, the user performs zoom-out operation in linking with scroll operation inputted to display the reference point within a screen if a user performs the scroll operation while keeping a magnification and the reference point becomes out of the screen (or the predetermined region within the screen) when the user inputs the scroll operation. Alternatively, the user may perform tilt operation for tilting a map image in the interlocking relationship with the scroll operation to display the reference point within the screen. It is also preferable that the user performs both of zoom-out operation and tilt operation to display the reference point within the screen. In this case, it is preferable that the user enlarges a tilt angle gradually while distance on a map between a current position (center of screen) and the reference point is short and performs the zoom-out operation while keeping the tilt angle constant after this distance reaches a predetermined distance. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a map display device and a map display method.

  In recent years, map data distribution services have become widespread, and opportunities for using map navigation on computers have increased. Since the map is larger than the viewport which is the display area of the display, in order to obtain information outside the viewport, it is necessary to perform a combination of operations such as scrolling and zooming.

  The scrolling of the map is generally performed by a drag operation, a click operation of a direction movement icon, or a press operation of a cursor key. Further, map zooming (zoom-in and zoom-out) is generally performed by a mouse wheel operation or a slider bar operation on the screen (Patent Document 1).

  Scrolling (panning) and zooming can be regarded as camera operations such as horizontal control (pan = scroll) and vertical control (zoom) of the camera overlooking the map from above. In addition to panning and zooming, there are tilt operations for controlling the vertical tilt of the camera. A technique for applying a tilt operation to document navigation is also known (Non-Patent Document 1). By tilting, it is possible to display content in a distant area without panning or zooming operations.

  In addition, a method of interlocking zoom with scrolling has been proposed (Non-Patent Document 2). In this method, the product of scroll speed and screen scale is controlled to be constant, and zoom-out processing is automatically performed when scrolling at high speed. By this method, it is possible to obtain a viewport that can easily grasp the big picture while preventing the screen from becoming unclear.

Japanese Patent Laid-Open No. 2000-316881

Guiard, Y., Chapuis, O., Du, Y., and Beaudouin-Lafon, M .: Allowing camera tilts for document navigation in the standard GUI: a discussion and an experiment, Proc.AVI '06, pp.241- 244, 2006. Igarashi, T. and Hinckley, K .: Speed-dependent automatic zooming for browsing large documents, Proc.UIST '00, pp. 139-148, 2000.

  A method of obtaining a target viewport by independently performing operations such as scrolling, zooming, and tilting needs to be performed while frequently switching a plurality of operations.

When such operations are performed independently, there is a risk of losing sight of the current location during a scrolling operation or zooming operation while repeating these operations. In particular, when performing a zoom operation, it may be difficult to grasp the correspondence before and after zooming. Therefore, for example, when you want to search for a destination or get directions to the destination while keeping the departure place in the viewport, the departure point is taken off the screen against the user's will. Can cause cognitive problems.

  Moreover, even if each operation itself is simple, since it is necessary to change them frequently, operation is complicated and becomes a burden for a user. In recent years, direct pointing environments using fingers or stylus have become widespread, especially on mobile devices, etc. In such an environment, the main operation is scrolling by dragging, and the zooming operation is performed with a slider bar or zoom button For this reason, switching between scrolling and zooming is not smooth and requires complex operations.

  In Non-Patent Document 2, since a plurality of camera operations are performed in conjunction with each other, the operation is simplified, and blurring during high-speed scrolling can be prevented. However, this technique does not facilitate the grasp of the relative positional relationship with the reference point.

  The present invention has been made in consideration of such problems, and an object of the present invention is to provide a map display technique that allows easy understanding of the positional relationship with a reference point and is easy to operate. .

  In order to achieve the above object, the present invention displays a map by the following means or processing.

  A map display device according to the present invention includes a display unit that displays a map image, a setting unit that sets an arbitrary point in the map as a reference point, an input unit that receives a scroll operation instruction from a user, and a scroll operation instruction. When the is input, zoom operation to change the magnification of the map and / or tilt operation to change the tilt of the map in conjunction with the input scroll operation so that the reference point is within the display area And a control means for performing.

  The setting of the reference point can be realized by any method. For example, when the user selects a part of the displayed map image, the point can be set as the reference point. In addition, the reference point can be set by receiving information for specifying the reference point such as latitude / longitude information, address, and place name. The reference point to be set is not limited to one, and a plurality of reference points may be set.

  Arbitrary methods can be adopted for the instruction of the scroll operation. For example, drag processing by an input device such as a mouse or a touch screen, click (selection) processing of a scroll instruction icon, pressing processing of a keyboard, a button, or the like can be operations for instructing a scroll operation.

  The control means performs a zoom operation and a tilt operation in conjunction with the input scroll operation so that the reference point is within the display area as described above. When the reference point goes out of the display area due to the scroll process input by the user, the control means performs the zoom operation and the tilt operation without input from the user. Since the reference point only needs to be within the display area, when there is an input of a scroll operation that causes the reference point to deviate from a partial area within the display area, the zoom and tilt operations are performed in conjunction with each other. Also good.

  Here, the zoom operation is an operation for changing the enlargement ratio (scale) of the map image displayed on the display means. When the image drawn in the viewport is considered to be an image obtained when a map is taken with a virtual camera, an operation to change the enlargement ratio of the camera, or a vertical position while maintaining the enlargement ratio It can be understood as an operation to move. The zoom operation includes zoom-out (reduction) and zoom-in (enlargement).

The tilt operation is an operation for changing the tilt of the map image displayed on the display means. When map drawing is considered as a video from a virtual camera, it can be regarded as a process of changing the tilt of the camera. When the tilt angle is increased, even distant objects in the shooting direction of the camera are displayed without zooming or scrolling.

  In the map display device according to the present invention, the zoom operation and the tilt operation are performed so that the reference point always falls within the display area. Therefore, the user always sets the relative positional relationship between the currently displayed position and the reference point. I can grasp. At that time, the user performs only a scroll operation instruction, and a zoom operation and a tilt operation for placing the reference point in the display area are automatically performed in conjunction with each other. Therefore, a simple and easy-to-understand operation is realized.

  In order to make the reference point fall within the display area by the zoom operation, the following method can be employed. That is, the control means in the present invention sets a predetermined area in the display area, and when only the input scroll operation is performed, the reference point is displayed at a position outside the predetermined area. In this case, it is preferable to perform a zoom-out operation in conjunction with the input scroll operation so that the reference point is displayed in the predetermined area.

  Thus, the zoom process is automatically performed so that the reference point is always displayed in the predetermined area in the display area only by inputting the scroll operation. The shape of the predetermined area may be arbitrary, but may be a circle whose center coincides with the center of the display area, for example.

  Further, in order to make the reference point fall within the display area by the tilt operation, the following method can be employed. That is, the control means in the present invention performs a tilt operation for providing a tilt angle corresponding to the distance between the reference point after the input scroll operation and the center point of the display area on the map. It is preferable to carry out together. The tilt angle is preferably gradually increased according to the distance between the reference point and the display area center point on the map.

  As a result, the tilt operation is performed in conjunction with the user so that the reference point is always displayed in the display area only by inputting the scroll operation.

  Here, when the reference point is within the display area by the tilt operation described above, if the required tilt angle is larger than the predetermined tilt angle, the tilt angle is kept at the predetermined tilt angle and zoomed out. It is preferable that the reference point be within the display area by the operation.

  As the tilt angle increases, the deformation of the map image also increases, and there is a problem that it becomes difficult for the user to recognize the map image. Therefore, when the tilt angle becomes larger than the predetermined tilt angle, the user can easily grasp the positional relationship by responding with the zoom-out operation without performing any further tilt operation.

  In addition, this invention can be grasped | ascertained as a map display apparatus which has at least one part of the said means. Moreover, this invention can also be grasped | ascertained as the map display method containing at least one part of the said process, or the program which performs the method. Each of the above means and processes can be combined with each other as much as possible to constitute the present invention.

  According to the present invention, it is easy to grasp the positional relationship with the reference point, and a map display that is easy to operate is realized.

FIG. 1 is a diagram showing functional blocks of the map display device according to the first and second embodiments. FIG. 2 is a diagram for explaining a map scrolling operation. FIG. 3 is a diagram for explaining a map zooming operation. FIG. 4 is a diagram for explaining a screen area in which a reference point is always displayed in the first embodiment. FIGS. 5A and 5B are diagrams schematically illustrating the map image display process in the first embodiment. FIG. 6 is a flowchart showing the flow of map image display processing in the first embodiment. FIGS. 7A to 7C are diagrams illustrating an operation example of the map image display process in the first embodiment. FIGS. 8A to 8D are diagrams illustrating a map tilt operation. FIGS. 9A to 9C are diagrams for schematically explaining the map image display processing in the second embodiment. FIG. 10 is a flowchart showing the flow of map image display processing in the second embodiment. FIGS. 11A to 11C are diagrams illustrating an operation example of the map image display process in the second embodiment. FIGS. 12A and 12B are diagrams schematically illustrating a modification of the map image display process in the second embodiment. FIGS. 13A and 13B are views for schematically explaining a modification of the map image display process in the second embodiment. FIG. 14 is a diagram illustrating a configuration of a map image display system according to the third embodiment.

Exemplary embodiments of the present invention will be described in detail below with reference to the drawings.
(First embodiment)
<Constitution>
FIG. 1 is a diagram showing functional blocks of the map display device according to the present embodiment. The map display device includes an input unit 1 for inputting an instruction from a user, a map data storage unit 2 for storing map data, a map image creating unit 3 for creating a map image to be displayed from the map data, and the created map image. It is comprised from the display part 4 for displaying.

  For the input unit 1, for example, an input device such as a mouse, a keyboard, a trackball, a touch panel, or a touch pad can be employed. The display unit 4 may be a display device such as a liquid crystal display or a CRT display. In the present embodiment, a touch panel (touch screen) in which a liquid crystal panel and a position input device are combined is employed. An electromagnetic induction pen device is used for input to the touch panel. When the user performs a drag operation with the pen device, the map display is scrolled by the same distance as the drag distance. Moreover, by double-clicking an arbitrary point on the map, the point is set as a reference point (described later).

The map data stored in the map data storage unit 2 may be two-dimensional map data or three-dimensional map data. The map image creation unit 3 creates a map image based on the map data. Specifically, the map image creation unit 3 determines which area on the map is displayed, how much magnification (scale) is displayed, and how much tilt (tilt angle) is displayed. The map image is created accordingly. The map image creation unit 3 is realized by a computer CPU executing a program stored in a memory. Note that the map image creation unit 3 may be realized by cooperation of a plurality of computers, or may be realized by a dedicated hardware circuit.

<Create viewport>
Creation of a map image (viewport) can be considered as a process of photographing a map (map data) with a virtual camera in a three-dimensional space. That is, the map scroll operation can be regarded as a horizontal control (pan operation) of the camera overlooking the map from the sky, and the map zoom operation can be regarded as a vertical control (zoom operation) of the camera.

  FIG. 2 is a diagram for explaining the scroll operation using a metaphor of the camera. The scroll operation for changing the position of the map to be displayed with the magnification kept constant can be handled as a pan operation for moving in the horizontal direction while maintaining the height of the camera as shown in FIG. A map image when the camera is at position 21 is shown in FIG. 2B, and a map image when the camera is at position 22 is shown in FIG. Thus, the scroll operation for moving the map to the left on the screen can be regarded as a pan operation for moving the camera to the right. Since the virtual camera pan operation is a metaphorical explanation of the map scroll operation, the map scroll operation and the camera pan operation are treated as synonymous in the following description.

  FIG. 3 is a diagram for explaining the zoom operation using a metaphor of the camera. The zoom operation for changing the enlargement ratio (scale) without changing the display position can be handled as a zoom operation for moving in the height direction while maintaining the horizontal position of the camera as shown in FIG. A map image when the camera is at position 31 is shown in FIG. 3B, and a map image when the camera is at a higher position 32 is shown in FIG. By changing the vertical distance of the camera, the enlargement ratio (scale) changes, and the enlargement ratio decreases (the scale increases) as the camera height increases. Thus, the zoom operation for changing the magnification (scale) of the map on the screen can be regarded as a zoom operation for moving the camera in the vertical direction. Since the virtual camera zoom operation is a metaphorical explanation of the map zoom operation, hereinafter, the map zoom operation and the virtual camera zoom operation are treated as synonyms.

<Map image creation process>
Hereinafter, map display processing in the present embodiment will be described with reference to FIGS. The map image creation unit 3 automatically performs a zoom operation so that the set reference point is always displayed on the screen when a scroll operation is instructed by the user. For example, as shown in FIG. 4, the map image is created so that the reference point O is always displayed in the circular area 42 having the radius R from the center P of the display area 41 of the display. Here, the distance r between the center P and the reference point O and the radius R of the circular area 42 are distances on the screen. By setting the radius R to about half of the short side of the display area 41, the circular area 42 can be made larger.

FIG. 5 is a diagram schematically illustrating a map image display method in which the reference point O is always displayed in the circular area 42. 5A and 5B are diagrams showing the relationship between the horizontal position of the camera and zoom processing. 5A shows the vertical height of the camera on the vertical axis, and FIG. 5B shows the enlargement ratio on the vertical axis. Here, the horizontal position of the camera indicates the distance on the map between the reference point O and the screen center P. As shown in FIGS. 5A and 5B, when the distance between the OPs is small, that is, when the reference point O is displayed in the circular area 42 even if only the scroll operation is performed while maintaining the enlargement ratio. Only the input scroll operation is performed, and the zoom operation is not performed. Conversely, if the reference point O deviates from the circular area 42 when only the scroll operation is performed while the enlargement ratio is maintained while the distance between the OPs is increased, the reference point O can be obtained by performing the zoom-out operation in conjunction. In the circular area 42. Incidentally, the horizontal distance L becomes the zoom-out processing is performed, the distance on the map corresponding to the length R on the screen in the initial magnification M _0.

  FIG. 6 is a flowchart showing the flow of map image display processing in the present embodiment. Details of the map image creation processing in this embodiment will be described with reference to FIG.

  First, a reference point O is set (S101). This may be performed by allowing the user to set a reference point via the input unit 1. A predetermined point may be adopted as the reference point. Hereinafter, the reference point O will be described as being displayed in the currently displayed map image.

  Next, an input of a scroll operation is received from the user (S102). The scroll operation is input by a drag operation by the pen device. The moving direction and moving distance of the drag operation are input to the map image creating unit 3 as inputs.

  The map image creation unit 3 displays the screen of the reference point O and the screen center P when it is assumed that the scroll operation is performed while keeping the current enlargement ratio constant according to the input scroll operation (drag operation). The distance r above is calculated (S103). At this stage, the map on the screen is not changed. Then, the distance r is compared with the radius R of the circular area 42 (S104).

  When the distance r is equal to or less than the radius R (S104-NO), the reference point O is displayed inside the circular area 42 even if the input scroll operation is performed. Therefore, the map image creation unit 3 performs only the input scroll operation (S106), and creates and displays a map image (S107).

  On the other hand, when the distance r is larger than the radius R (S104-YES), the reference point O is displayed outside the circular area 42 when only the input scroll operation is performed. Therefore, the map image creation unit 3 performs a zoom-out operation (S105) for setting the enlargement ratio to R / r (<1) times the current value in conjunction with the scroll operation (S106). Then, a map image is created and displayed (S107). Note that the zoom-out operation is processing based on the screen center P, and the point displayed on the screen center P does not change before and after zoom-out.

<Operation example>
The operation of displaying a map image in the present embodiment will be specifically described with reference to FIG. FIG. 7A shows an initial state of the map display, and the reference point O is displayed at the screen center P. FIG. The enlargement ratio at this time is M ₀ . Consider a case where the user inputs a scroll operation that gradually moves the reference point O to the upper left from this state. First, as long as the moving distance on the screen is small, as shown in FIG. 7B, the scroll operation is performed while the enlargement ratio is constant. A circular area 71 in the figure is a circle having a radius R with the screen center P as the center. This circular area 71 is not actually displayed in the map image. Further, when the map is scrolled and the moving distance on the screen increases, a zoom-out operation is performed in conjunction with the scroll operation. Here, since the enlargement ratio is R / r times and the distance between OPs on the screen is made equal to the radius R, the reference point O is on the circumference of the circular region 71 when zooming out is involved. Is displayed.

<Action / Effect>
According to the map display device of the present embodiment, when a scroll operation is input, the zoom-out process is automatically performed in conjunction so that the reference point is always displayed on the screen. Therefore, the user can perform a search on the map, grasp a route, etc. while grasping the relative positional relationship with the reference point. In addition, the user only needs to input the scroll operation, and there is no need to switch between the scroll operation and the zoom operation as in the prior art.

  The map display device according to the present embodiment is preferably applicable to a route guidance system that performs route search to a destination and displays a route guidance map. In order to grasp the searched route, it is preferable that the route can be traced while the departure point is always displayed on the screen. In such a case, by setting the departure point as a reference point, the user can obtain information on the relative positional relationship with the departure point without being aware of the zoom operation, and at the same time simplifying the operation Cognitive burden is reduced.

<Modification>
In the above processing, in order to always display the reference point O on the screen, whether or not to perform the zoom process in conjunction with the distance on the screen between the reference point O and the screen center P is determined. is doing. However, the control for always displaying the reference point O on the screen may be realized by any other specific process. For example, when the distance on the map between the reference point O and the screen center P is equal to or smaller than a predetermined threshold value, only the scroll operation is performed, and when this distance is larger than the predetermined threshold value, zooming is performed in conjunction with the scroll operation. An out operation may be performed. Here, the threshold distance is the length on the map corresponding to the length R at the initial enlargement ratio (scale), and the enlargement ratio is the distance between the reference point O and the screen center P on the screen. If it is set as an enlargement ratio, the same map display as the embodiment described above is performed.

  In the above description, map control is performed such that the reference point O is always displayed in the circular area 42 centered on the screen center P, but the area where the reference point O is displayed is not limited to this. For example, the center of the circular area 42 is not necessarily the center of the screen. In this case, the zoom-out operation is performed so that the distance is constant on the screen between the reference point O and the center of the circular area 42. At this time, zooming out may be performed with the center of the circular area as a base point, and zooming out may be performed with other points (the screen center, the reference point O, etc.) as the base point. Further, the area where the reference point O is displayed can be an arbitrary shape such as a rectangular area in addition to the circular area. When the reference point O goes out of the area when only the input scroll operation is performed, it is easy to determine what zoom-out operation is performed to display the reference point O in the area. It can be calculated.

  In the above description, the enlargement ratio at zoom-out is R / r times, and the reference point O is displayed on the circumference of the circular region 42. However, the zoom-out may be performed larger. That is, the enlargement ratio may be smaller than R / r. In this case, when the zoom-out occurs, the reference point O is displayed not on the circumference of the circular area 42 but inside.

  Further, in the present embodiment, only the operation when the scroll operation is performed so that the reference point O moves away from the screen center is specified, and the operation when the scroll operation is performed so that the reference point O approaches the screen center. May be determined arbitrarily. That is, only the scroll operation may be performed while maintaining the enlargement ratio (in this case, the reference point O is displayed at a position closer to the center P from the circumference of the circular region 42), and in conjunction with the scroll operation. The zoom-in process may be performed so that the distance between the reference point O and the screen center P on the screen is constant (in this case, the reference point O is always displayed on the circumference of the circular region 42). ).

  In the present embodiment, the case where there is one reference point has been described as an example, but it is not necessary to limit the number of reference points to one. The reference point can be set by an input from the user, and two or more reference points may be set. Even when a plurality of reference points are set, the enlargement ratio for displaying all the reference points in the screen can be easily obtained from the relationship between the distance between the screen center P and each reference point.

(Second Embodiment)
In the present embodiment, in conjunction with the scroll operation, control is performed so that the reference point is displayed on the screen by performing not only the zoom-out operation but also the tilt operation. Since the basic configuration of the map display device according to the present embodiment is the same as that of the first embodiment, description of overlapping parts is omitted, and different parts are mainly described.

<Tilt operation>
The tilt operation is an operation for changing the tilt of the map image displayed on the screen. FIG. 8 is a diagram for explaining the tilt operation using a camera metaphor. The operation for changing the tilt of the map image can be regarded as control for operating the tilt in the vertical direction of the virtual camera (tilt operation) as shown in FIG. In the tilt operation in this embodiment, control is performed so that the center point of the screen does not move. Therefore, more precisely, as shown in FIG. 8 (b), it should be expressed as an operation of relatively rotating the camera and the map (ground) around the point where the camera is projected on the ground. Such control is called a tilt operation.

  FIG. 8C shows a map image when there is no tilt (tilt angle 0 degree), and FIG. 8D shows a map image when there is tilt. In FIG. 8D, the upper direction of the screen is the tilt direction. As shown in FIGS. 8C and 8D, by performing a tilt operation, an object in a distant area can be displayed without scrolling or zooming.

<Map image creation process>
Hereinafter, map image display processing in the present embodiment will be described with reference to FIGS. FIG. 9 is a diagram schematically illustrating the map image display process in the present embodiment. FIG. 9A is a diagram showing the horizontal position, vertical height, and tilt angle of a virtual camera. FIGS. 9B and 9C are diagrams respectively showing a tilt angle and an enlargement ratio (scale) with respect to the horizontal position of the virtual camera. Here, the horizontal position of the camera indicates the distance on the map between the reference point O and the screen center P. As shown in the figure, when the distance between the OPs is small, the tilt angle is gradually increased with the scroll operation (increase in the distance between the OPs). When the distance between the OPs is larger than a predetermined threshold L (distance at which the tilt angle becomes θ _MAX ), the zoom-out operation is performed with the tilt angle fixed at θ _MAX . Note that the threshold value L and the maximum tilt angle θ _MAX are values determined in advance as values at which the reference point O always falls within the display area (viewport).

  FIG. 10 is a flowchart showing the flow of map image display processing in the present embodiment. Details of the map image display processing in the present embodiment will be described with reference to FIG.

  First, a reference point O is set (S201). And the input of scroll operation is received from a user (S202). The processing so far is the same as in the first embodiment.

The map image creation unit 3 calculates a distance d on the map between the reference point O and the screen center P after the input scroll operation (S203). At this stage, the map on the screen is not changed. Then, the distance d is compared with a predetermined threshold value L. If the distance d is equal to or less than the threshold value L (S204-YES) is carried out in conjunction with tilting (S205) a scroll operation (S207) to the tilt angle and _{θ = θ MAX × d / L} . In this case, the zoom operation is to remain magnification M ₀ not performed. Then, a map image is created and displayed (S208).

On the other hand, when the distance d is larger than the threshold value L (S203-NO), it is necessary to set the tilt angle θ to be equal to or greater than the maximum tilt angle θ _{MAX if the} reference point is to be placed in the display area only by the tilt operation. come. Therefore, the zoom-out operation (S206) in which the tilt angle θ is θ _MAX and the enlargement ratio is M = M ₀ × L / d is performed in conjunction with the scroll operation (S207). Then, a map image is created and displayed (S208).

<Operation example>
The operation of displaying a map image in the present embodiment will be specifically described with reference to FIG. FIG. 11A shows an initial state of the map display, and the reference point O is displayed at the screen center P. FIG. At this time, the enlargement ratio is M ₀ and the tilt angle is 0 degree. A circle 1101 indicates a circle with a radius L centered on the reference point O on the map. This circle 1101 need not actually be displayed as a map image.

  When the user inputs a scroll operation for moving the reference point O to the upper left in this state, a tilt operation for tilting the map is performed in conjunction with the scroll operation while the movement distance on the map is smaller than the threshold value L. . The direction of tilt is matched with the direction from the screen center P toward the reference point O. By this tilt operation, the depth direction (P → O direction) can be stored in the viewport farther.

When the distance d becomes larger than the threshold value L, the zoom-out operation with the tilt angle θ fixed at θ _MAX and the enlargement ratio of M ₀ × L / d is performed in conjunction with the scroll operation. With this zoom-out operation, the reference point O is displayed on the screen even if a scroll operation is performed.

<Action / Effect>
According to the map display device of this embodiment, when a scroll operation is input, the tilt process and the zoom-out process are automatically performed in conjunction so that the reference point is always displayed on the screen. Therefore, the same effect as the first embodiment can be obtained.

  According to the method of placing the reference point in the screen by tilting operation, it is easy to grasp the relative positional relationship between the reference point and the center of the screen, particularly when the distance between the reference point and the screen center is small. On the other hand, increasing the tilt angle increases the distortion of the map and makes it difficult to see. Therefore, a restriction on the maximum tilt angle is provided for the tilt angle, and if the reference point cannot be accommodated within the screen even with the maximum tilt angle, the zoom out is used. This makes it possible to easily grasp the relative positional relationship between the reference point and the current position when the current position is close or far.

<Modification>
The combination of tilt operation and zoom-out operation is not limited to the above method, and various methods can be employed. For example, as shown in FIG. 12, when the distance between the reference point and the center of the screen is within the distance L _{1 at} which the reference point can be displayed in the viewport without performing the tilt operation and the zoom-out operation, the input is performed. Scroll only. Thereafter, if the distance L ₂ within which can be accommodated a reference point in the viewport only tilt operation, keep the reference point only tilting in the viewport. After the tilt angle distance of the reference point and the screen center becomes L ₂ or reaches the maximum tilt angle may correspond zoom-out operation.

  Further, the tilt operation and the zoom-out operation do not have to be performed independently, and both may be performed in conjunction with each other. For example, as shown in FIG. 13, when the distance between the reference point and the screen center is larger than the threshold value L, the zoom-out operation may be performed and the tilt angle may be gradually decreased. As a result, a map image with a vertical viewpoint can be obtained in accordance with zoom-out, so that a map image with less deformation can be obtained.

  Further, the method of determining the tilt angle linearly with the distance between the reference point and the screen center as described above is merely an example. For example, a non-linear relationship may be used instead of a linear relationship. Also in the present embodiment, similarly to the first embodiment, control may be performed so that the reference point is within a predetermined area (for example, the circular area 42 (FIG. 4)) in the screen. In this case, a tilt angle necessary for displaying the reference point in the predetermined area after the scroll operation may be employed. This tilt angle may be stored in advance as a function of distance, or may be calculated and calculated whenever necessary. If the tilt angle required to display the reference point within the predetermined area is larger than the maximum tilt angle, it is necessary to zoom out while keeping the maximum tilt angle so that the reference point is within the predetermined area. If the zoom-out rate is calculated, the same control as described above can be realized.

  Also, depending on the scroll direction, an image that is difficult to see may be obtained when the tilt operation is performed. For example, when a scroll operation for moving the reference point in the lower direction of the screen is performed, if the moving direction of the reference point is the tilt direction, a map image with a strange camera angle is obtained and recognition becomes difficult. Therefore, when scrolling downward, the control may be performed so that the reference point is within the screen by interlocking with the zoom operation without including the tilt operation. That is, it is also preferable to switch the control for keeping the reference point within the screen according to the scroll direction.

  Further, in this embodiment, a tilt operation (FIG. 8B) in which the point displayed at the center of the screen does not change is adopted as the tilt operation. However, a tilt operation in which the point displayed at the center of the screen moves is employed. You may adopt. That is, instead of rotating the camera and the map (ground) relative to the point where the virtual camera is projected onto the ground (FIG. 8B), the camera and map (ground) are centered on the position of the virtual camera. ) May be employed (FIG. 8A). In this case, the tilt operation or zoom operation is not performed according to the distance between the reference point and the center of the screen, but the tilt operation or zoom operation is performed according to the distance between the reference point and the virtual camera horizontal position (referred to as the current position). A zoom operation may be performed.

  In the present embodiment, the case where there is one reference point has been described as an example, but it is not necessary to limit the number of reference points to one. The reference point can be set by an input from the user, and two or more reference points may be set. For example, even when a plurality of reference points are set, it is easy to calculate the enlargement ratio and tilt angle for displaying all the reference points on the screen from the relationship between the distance between the screen center P and each reference point. Can be sought.

(Third embodiment)
In the first and second embodiments, the case where the map image display device is configured by one computer has been described as an example. However, the present invention is configured by a plurality of computers connected via a network. A map image display system may be used.

  For example, as shown in FIG. 14, a client PC 1401 is connected to a map distribution server 1402 via a network such as the Internet, and information necessary for the client PC 1401 to display a map image or a map from the map distribution server 1402. It does not matter even if it is the composition which acquires. The client PC 1401 displays a map image and accepts a scroll operation input from the user. The input scroll operation is transmitted to the map distribution server 1402 as it is or in a different format. The map distribution server 1402 obtains map data from the map database 1403 and creates a map image by performing a zoom-out operation and a tilt operation in conjunction with the scroll operation in the same manner as in the first and second embodiments. Send to client PC 1401.

  The map distribution server 1402 does not create the map image, but transmits the original map data and the zoom-out operation and tilt operation information (magnification rate and tilt angle) to the client PC 1401. The client PC 1401 creates the map image itself. You may go by side.

1 Input unit 2 Map data storage unit 3 Map image creation unit 4 Display unit

Claims (6)

Display means for displaying a map image;
A setting means for setting an arbitrary point in the map as a reference point;
An input means for receiving a scroll operation instruction from the user;
A zoom operation that changes the map enlargement ratio or a tilt that changes the tilt of the map in conjunction with the input scroll operation so that the reference point is within the display area when a scroll operation instruction is input Control means for performing the operation or both of these operations;
A map display device comprising: The map display device according to claim 1,
When only the input scroll operation is performed, the control means zooms out together with the input scroll operation when the reference point is displayed at a position outside the predetermined area in the display area. An operation is performed so that the reference point is displayed in the predetermined area. The map display device according to claim 1,
The control means combines a tilt operation for adding a tilt angle corresponding to a distance on the map between the reference point after the input scroll operation and the center point of the display area together with the input scroll operation. A map display device characterized by performing. The map display device according to claim 3,
When the tilt angle reaches a predetermined threshold, the control means does not perform any further tilt operation, and zooms out to keep the distance on the display area between the reference point and the center point of the display area constant. A map display device characterized in that the operation is performed in conjunction with an input scroll operation. A map display method in a map display device comprising input means for receiving a scroll operation instruction from a user,
A setting process for setting an arbitrary point in the map as a reference point;
An input process for receiving a scroll operation instruction from the user;
A zoom operation that changes the map enlargement ratio or a tilt that changes the tilt of the map in conjunction with the input scroll operation so that the reference point is within the display area when a scroll operation instruction is input A control process to perform the operation or both of these operations;
The map display method characterized by including. In a computer having an input means for receiving a scroll operation instruction from a user,
A setting process for setting an arbitrary point in the map as a reference point;
An input process for receiving a scroll operation instruction from the user;
A zoom operation that changes the map enlargement ratio or a tilt that changes the tilt of the map in conjunction with the input scroll operation so that the reference point is within the display area when a scroll operation instruction is input A control process to perform the operation or both of these operations;
A program characterized by having executed.

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