JPH03224067A - Display control method for picture information - Google Patents

Abstract

PURPOSE:To magnify or reduce a desired display area without losing picture information by mapping the picture information which are not displayed via an inside area of a 1st window and an outside area of a 2nd window to an intermediate area between both areas when the inside display magnification of the 1st window is set larger than the outside display magnification of the 2nd window. CONSTITUTION:An image processing means 12 performs the mutual conversion between an XY coordinate system and a polar coordinate system, the mapping processing to the picture information, etc. A setting means 14 sets a window and the magnification in a display area of a display means 18. Then the picture information which are not displayed via an inside area of a 1st window and an outside area of a 2nd window are mapped in an intermediate area between both windows when the inside display magnification of the 1st window is set larger than the outside display magnification of the 2nd window. Then the inside picture information of the 1st window and the outside picture information of the 2nd window are continuously displayed via the picture information mapped in the intermediate area. Thus a desired display area is displayed with magnification or reduction with no less of the picture information.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a display control method for displaying image information such as map information on a display device such as a CRT (cathode ray tube). The present invention relates to a display control method for image information that maintains display continuity between the enlarged or reduced display area and the non-enlarged or reduced display area when a part of the area is enlarged or reduced.

[Prior Art] Mapping systems and the like that display image information such as residential maps and road maps on a display screen require a function to enlarge and display a desired area centered on a target object.

A common method for realizing such a display function is a zooming method in which the entire display area is enlarged at a predetermined magnification with the object at the center and displayed on the entire display screen.

In addition to this, there is also a method of adopting a multi-window system in which a display screen is provided with a window for displaying the overall view and a window for enlarging and displaying an area near the object in the overall view.

In the former method described above, while the vicinity of the object is displayed in an enlarged manner, the overall view is not displayed, and therefore the positional relationship of the object in the overall view cannot be displayed. In addition, although it is possible to recognize the positional relationship of objects according to the latter method, it is necessary to check the overall view and the enlarged view, and multiple windows occupy the limited display area of the display device. This is not an easy-to-read display method because it occupies the space.

In order to solve this problem, a window is set at a desired location on the displayed overall view, the image in this window is enlarged at a predetermined magnification, and then displayed overlaid on top of the overall view. A method has been proposed. This method will be explained with reference to FIGS. 7(A) and 7(B).

First, as shown in FIG. 7(A), in the window WA set in the display area of the display device, the buildings TI, T2
It is assumed that roads Ll and L2 are displayed. A window WB is set within the window WA, and the display magnification of the window WB is expanded to, for example, twice, with the center of the window WB as the center. As a result, Figure 7 (B)
As shown in , the image within the window WB is displayed enlarged twice.

[Problem to be Solved by the Invention] However, in FIG. 7(B) after the enlarged display, the building T2 that was displayed in the area within the window WB in FIG. 7(A) before the enlarged display is In addition, the connection between roads Ll and L2 is interrupted at the border between windows WA and WB.

That is, according to the conventional method described above, there is a drawback that by enlarging and displaying the image within the window WB, part of the image information existing within the window WB disappears. Therefore, especially in the case of image information such as maps, roads and buildings are displayed intermittently.
There was a drawback that the positional relationship between the enlarged object and its surroundings could not be clearly displayed. Note that in the conventional example described above, a case was shown in which the inside of window WB was enlarged and displayed without changing the display of the display area surrounded by windows WA and window WB. It is also possible to reduce the display area surrounded by the window WA and the window WB without changing the display magnification of the window WA and the window WB.

In this case as well, some image information in the area of window WA that exists around window W8 will be lost.
The same drawbacks as in the case described above arise.

Therefore, an object of the present invention is to provide a display control method for image information in which image information does not disappear when a desired display area is enlarged or reduced.

[Means for Solving the Problems] In the image information control method of the present invention, a first window and a second window surrounding the first window are set on a display area of a display device.

Next, when the display magnification in the first window is made larger than the display magnification outside the second window, image information that will not be displayed from the area inside the first window and the area outside the second window is transferred to the first window and the area outside the second window. The image is mapped to the intermediate area between the two windows.

Then, the image information inside the first window and the image information outside the second window are continuously displayed via the image information mapped to the intermediate area.

[Operation] According to the image information display control method of the present invention, when the display magnification within the first window is made larger than the display magnification outside the second window, the area within the first window and the area outside the second window are mapping image information that is no longer displayed from the area to an intermediate area between the first window and the second window;
Since the image information inside the first window and the image information outside the second window are displayed continuously via the image information mapped to the intermediate area, the desired display area can be expanded without losing the image information. Or you can zoom out.

[Embodiment] FIG. 2 is a block diagram of a display control device in an embodiment of the image information display control method according to the present invention. Large-capacity storage means 10 consisting of hard disks and CDROMs
stores image information such as map information. Map information is
For example, the shapes of roads, rivers, buildings, etc. are expressed as vector data. The image processing means 12 performs a series of processing on the image information, that is, converts the image information read out from the storage means 1o from vector data to a bitmap.
It performs processing to develop into data, mutual conversion processing between the XY coordinate system and polar coordinate system, mapping processing for image information, etc. The frame buffer storage means 16 stores image information developed into bitmap data. Display means 18, such as a CRT, displays bitmap data input from frame buffer storage means 16. The setting means 14, which consists of a keyboard, a mouse, etc., is used by the user to give instructions to the image processing means 12 to set a window on the display area of the display means 18 and to set the display magnification. be.

FIG. 1 is a schematic flowchart illustrating an example of the present invention.

First, desired image information is searched and displayed on the display means 18 (step 20).

Next, the user sets a first window that specifies an area near the desired building that has been searched, and also sets a display magnification for displaying the area outside the first window in a reduced size (step 22).

Since the display magnification of the first window area and the external area of the first window has been set, the size of the second window surrounding the first window is set to an appropriate value (step 24).

By reducing the display area outside the first window, when the display magnification inside the first window becomes relatively larger than the display magnification outside the second window, the area inside the first window and outside the second window Image information that is no longer displayed from the area is mapped to an intermediate area between the first window and the second window (step 26).

The mapped image information is displayed in an intermediate area between the first window and the second window (step 28).

FIG. 3 is a detailed flowchart of an embodiment of the present invention;
4 (AI) to (A3) are coordinate diagrams showing the coordinate system (hereinafter referred to as world coordinate system) of the storage means 1o in this embodiment, and FIG. 4 (B1) to (B3) are display means in the same embodiment. 18 is a coordinate diagram showing 18 coordinate systems (hereinafter referred to as display coordinates).

Also, for easier viewing, Figures 4 (AI) to (A3)
and FIGS. 4(B1) to (B3) are shown on the same scale.

In this embodiment, the desired object is searched for, the area around this object is displayed at a relatively large magnification, and the surrounding area around this object is reduced and displayed at a smaller magnification than the above magnification. A case will be described in which the positional relationship of the entire object is displayed.

First, a third window W3 for displaying on the display area of the display device 18 is set from the setting means 14 (step 50), and the display magnification Z in this third window W3 is set.
For example, l is set to twice (step 52). next,
Desired image information, such as buildings and roads, is specified and search processing is executed (step 54). Since the search process is a commonly performed process, a description thereof will be omitted.

As a result, as shown in FIG. 4 (B1), the searched image information is displayed in the display area of window W3 at a display magnification of Zl.
is displayed (step 56). The world coordinate system corresponding to FIG. 4 (B1) is as shown in FIG. 4 (A1), and the third window W30 corresponds to the third window W3.
is set.

Display magnification Z1 of the third window W3 in the display coordinate system
is twice as large, so the third window W30 in the world coordinate system is half the size of the third window W3. Here, steps 50 to 56 above correspond to step 20 in FIG. 2.

Next, in the display area of the third window W3, the position and size of the first window W1 are set so as to surround the searched image information (step 58). The display magnification within this first window Wl is the above-mentioned Zl. Next, the display magnification Z2 of the display area between the third window w3 and the second window W2, which will be set in a later step so as to surround the first window W1, is set (step 60).

By setting the display magnification Z2 to a smaller value than the display magnification Z1 in the first window, in the display area between the second window W2 and the third window W3,
It becomes possible to reduce and display the peripheral area of the image displayed in the first window W1. Image processing means 12
sets a second window W2 of an appropriate size surrounding the first window W1 between the already set first window W1 and third window W3 (step 62).

This appropriate size is a size that allows the display in the intermediate area between the first window W1 and the second window W2 to be easily seen by the user. Next, the image processing means 12 erases the display area between the first window W1 and the third window W3 from among the image information displayed on the display means 18 (step 64). In other words, the storage contents corresponding to the display area to be erased are erased from the frame buffer storage means 16. The state of the display coordinate system at this point is shown in FIG. 4 (B2). Next, steps 58-62
The first to third windows W1 to W of the display coordinate system set in
3 is set in the world coordinate system as shown in FIG. 4 (A2) (step 66). for example,
If the display magnification Z2 of the display area between the second window W2 and the third window W3 in the display coordinate system is 0.5 times, then the second and third windows W in the world coordinate system
20, W2O is the second window W2 in the display coordinate system
and twice the size of the third window W3. Here, since the display magnification Zl of the first window W1 in the display coordinate system is twice, the size of the first window W10 in the world coordinate system is 0.5 times that of the first window W1. Further, in FIG. 4 (A2), H and S are the starting point and ending point of the image information. Here, steps 58-66 correspond to step 24 in FIG.

Next, according to the display magnification Z2 between the second window W2 and the third window W3 in the display coordinate system set in step 60 above, the world coordinate system shown in FIG. The reduction process is performed as shown in A3) (step 68). Therefore, the first
~Third windows WIO~W30 each have a display magnification Z
2, for example, reduced by 0.5 times. Next, the image processing means 12 reads image information from the storage means 10 in units of line data (step 70). In this embodiment, image information is represented by only one line of data as shown in FIG. 4 (A2), but usually image information is composed of a large number of line data. Next, the read line data is reduced in accordance with the display magnification Z2 between the second window W2 and the third window W3 (step 72). Then, it is determined whether or not there is an intersection between the first to third windows Wl to W3 and the line data in the world coordinate system (step 74). If there is an intersection, the line data is divided for each intersection (step 76).

Then, the divided line data is displayed in the first window W.
1 and the second window W2 (step 78). For line data that is determined in step 74 to have no intersection with the window, the process proceeds to step 78, where it is determined whether or not it corresponds to an intermediate area. Next, the line data determined to correspond to the intermediate area in step 78 is subjected to intermediate area mapping processing, which will be described later, and is mapped to the intermediate area in the display coordinate system (step 80). The line data determined in step 78 to be outside the intermediate area is
is written to the frame buffer storage means 10 (step 82). Note that the image information corresponding to the display area within the first window Wl is held at the time of step 62, and in step 82, only the image information corresponding to the display area outside the first window Wl is stored in the frame buffer storage means 16. will be written to.

In the case of Fig. 4 (A3), the image information is line data H.
8, and this line data H3 is composed of intersection point P
It is divided by 1 to P5.

Therefore, the line date PIP2 corresponding to the intermediate area between the first window Wl and the second window W2
and P3P4 are mapped to the intermediate area in the display coordinate system as shown in FIG. 4 (R3), and become plp2 and p3p4. This mapping process will be described later. Note that each point H, S, PI to P5 in FIG. 4(A) corresponds to each point h+ "r p1+ p5 in FIG. 4(B). The steps 68 to 80 described above are the steps in FIG. 2
Corresponds to 6.

The image information thus written to the frame buffer storage means 10 is displayed on the display means 18, and a display corresponding to FIG. 4 (R3) is made (step 84).

Step 84 corresponds to step 28 in FIG.

As a result, the image information inside the first window and the image information outside the second window are displayed continuously via the image information mapped to the intermediate area between the first window W1 and the second window W2. Ru.

Next, an example of the intermediate region mapping process will be described in detail with reference to the flowchart of FIG. 5 and the coordinate diagrams of FIGS. 6(A) and 6(B).

FIG. 6(A) shows the world coordinate system, and FIG. 6(B) shows the display coordinate system. To simplify the explanation of the mapping process, the aspect ratio of the first window W1 and the second window W2 is 1:
1, and the center point of the mapping is the center point G of the first window W1 and the second window W2. Furthermore, when performing the mapping process, the coordinates are converted from the XY coordinate format to the polar coordinate format.

In polar coordinate conversion, the origin is the center point G, and the angle θ is the first window WIO and the second window W2.
The angle parallel to the horizontal axis of 0 is defined as 0°, and the counterclockwise direction is defined as the positive direction.

In FIG. 6(A), from the center point G to the first window W
The distance between the IO and the side of the second window W20 is xl
and x2, and the point to be mapped is P. center point G and point P
Let the intersections of the straight line connecting the first window WIO and the second window W20 be El and R2, respectively.

Further, the distances between the center point G and the points E1, E2, and P are R1, R2, and R, respectively. Also, if the angle of the point P seen from the center point G is θ, then the point P is expressed in polar coordinates (R, θ
) can be shown as In addition, each symbol R in FIG. 6(A)
, R1, R2, El, R2, P.

XI and X2 are the respective symbols r, rl, and
r2, el, e2. p, xi, x
2 respectively. For example, the point P to be mapped in FIG. 6(A) corresponds to the mapping point p in FIG. 6(B).

The mapping process is performed using the point P(R
, θ) as the point p(r+θ
). Even if mapping processing is performed, the proportional relationship on the line segment corresponding to the intermediate region remains unchanged, so (
1) The formula holds true.

(R2-R1): (R-R1) (r2-rl): (r-rl) (1)
Solving equation (1) for r, r= ((R-R1)(r2-r 1)) / (R2
-R1)+rl = (R-(XI/cosθ))((x2/cos
θ) - (xi/cos θ))/((X 2 / co
sθ)-(Xi/cosθ))+(xl/cosθ) = ((Rcos θ-XI) (x2-xi))/(
(X2-XI) cos θ) + (xi/cos θ)
(2) The mapping point p(r, θ) is obtained as shown in equation (2).

Equation (2) holds true when θ is in the following range.

−45°≦O≦45″ 1356≦θ≦2256 Also, when θ is in the following range, instead of formula (2), (
3) The mapping point p(r, θ) is determined based on the equation.

45″≦θ≦135°125°≦θ≦315' r=((Rsinf3-XI) (x2-xl))/
((X2-XI) sin θ) + (xi/sin θ)
(3) Next, intermediate region mapping processing will be explained with reference to the flowchart of FIG. First, data is converted from the XY coordinate format to the polar coordinate format (step 90). Then, the above-described mapping process is executed to map the points to be mapped onto the intermediate area, and data in polar coordinate format is calculated (step 92). The polar coordinate format data is again converted into XY coordinate format data (step 94). As described above, Figures 6 (A) and (B
) Mapping processing from point P to point p is executed. Therefore, the line data mapping process is performed by mapping the starting points and ending points defining each line data corresponding to the intermediate area, respectively, according to the flowchart of FIG. 5, and connecting the mapped starting points and ending points. For example, as shown in FIG. 4 (A3) and (B3) above, line data PIP2 and P3P corresponding to the intermediate area are
4 are mapped according to the intermediate region mapping process described above, and are mapped to line data plp2 and p3p4, respectively.

Further, in the above explanation, only the mapping of line data constituting a straight line has been explained, but since a curved line is also composed of a plurality of line data, mapping processing can be performed on a curved line in the same way as with a straight line.

Note that in the above-described embodiment, the data format of image information handled in processes other than intermediate area mapping processing is XY.
Although the coordinate format is used, the present invention is not limited to this. For example, the data format of the image information may be a polar coordinate format throughout all processing.

Furthermore, in the embodiment described above, a desired object is searched for and the vicinity of this object is displayed at a relatively large magnification, and at the same time, the surrounding area around this object is displayed at a higher magnification than the above magnification.
The positional relationship of the object as a whole was displayed by reducing the display at a JX magnification. However, on the contrary, it is also possible to perform the search process at a relatively low display magnification, set the first window near the desired object, and display the inside of the first window in an enlarged manner.

In this case as well, processing may be performed in substantially the same manner as in the embodiments already described. That is, by setting a second window that surrounds the first window, and enlarging the first window, image information that is no longer displayed from the area within the first window is transferred between the first window and the second window. It is sufficient to map it to an intermediate region.

[Effects of the Invention] As explained above, according to the image information display control method of the present invention, when the display magnification inside the first window is made larger than the display magnification outside the second window, the By mapping the image information that is no longer displayed from the area and the area outside the second window to the intermediate area between the first window and the second window, the image information inside the first window and the image outside the second window are Since the information is displayed continuously via the image information mapped to the intermediate area, a desired display area can be enlarged or reduced without losing the image information.

[Brief explanation of drawings]

FIG. 1 is a schematic flowchart showing an example of the present invention;
The figure is a block diagram of a display control device in an embodiment of the image information display control method of the present invention, and FIG. 3 is a detailed flowchart of the embodiment of the present invention.
3) is a coordinate diagram of the world coordinate system, Figure 4 (B1) to (B
3) is a coordinate diagram of the display coordinate system, FIG. 5 is a flowchart of intermediate area mapping processing, FIGS. 6(A) and (B) are coordinate diagrams for explaining intermediate mapping processing, and FIG. 7(A), (
B) is a coordinate diagram showing an example of a conventional display control method. Wl: First window in the display coordinate system W2: Second window in the display coordinate system W10: First window in the world coordinate system W20: Second window in the world coordinate system p: Point to be mapped in the display coordinate system P: World coordinates map points in the system

Claims (1)

[Scope of Claims] An image information display control method for displaying image information on a display area of a display means, and displaying image information in a window set on the display area at a predetermined display magnification, comprising: A first window and a second window surrounding the first window are set on the area, and when the display magnification inside the first window is set higher than the display magnification outside the second window, the inside of the first window is set. The image information that will no longer be displayed from the area and the area outside the second window is mapped to the intermediate area between the first window and the second window, and the image information inside the first window and the image information outside the second window are mapped. A method for controlling the display of image information, characterized in that the image information is continuously displayed via the image information mapped to the intermediate area.