JP6120736B2 - Map display device and character string display method on map - Google Patents

Description

  The present invention relates to a map display device and a character string display method on a map, and particularly suitable for use in an apparatus and method for displaying a character string along a shape line of an object included in a map according to set offset information. Is.

  A navigation device generally displays a character string such as a name along a curve or straight line representing the shape of a road / river / railroad line on a map, or a curve or straight line representing the shape of a facility such as a park. It has been broken. As a method for displaying a character string along such a shape line, each character is shifted to a position shifted by a predetermined offset amount based on the position of the start character or the position of an object such as a road / river / railway line / park. A technique for arranging characters is known.

  For example, with respect to the coordinates of the start character, there is a method in which the second and subsequent characters are arranged at the coordinates shifted by the calculated offset amount. In this method, since the shape element point of the object is used to determine the offset coordinates after the second character, each character is arranged on the shape line of the object as shown in FIG. Therefore, the character string is displayed in a state where it overlaps the object, and there is a problem that the visibility of the character string is deteriorated.

  Also, there is a method in which each character constituting the character string is uniformly shifted by a certain offset amount in a certain direction on the basis of the position of the object. According to this method, the character string is not displayed in a state where it overlaps the object. However, there is a problem that the distance between the object and the character string becomes non-uniform due to the relationship between the direction of the shape line of each object existing on the map and the direction of the uniform offset.

  That is, when the offset amount and the direction are uniformly fixed, a portion where the character string offset effect is hardly expected for the object as shown in FIG. 9A (the portion of the characters “A” and “B”). On the other hand, there is a problem in that a portion (character “E” portion) in which a gap is left between the object and the character string is generated. Further, as shown in FIG. 9B, there is a problem in that the spacing between the characters after the offset becomes uneven depending on the shape line of the object.

  On the other hand, the technique which devised so that a character string may become easy to see is proposed (for example, refer patent documents 1 and 2). In the map display device described in Patent Literature 1, when a character string is arranged and displayed along a corresponding object, the angle at which the character string is arranged on the screen is calculated, and the arrangement order of the character strings is determined according to the angle. Thus, for example, even when the map is rotated and displayed according to the traveling direction of the vehicle, the character string can be displayed in a natural and easy-to-read manner.

  Moreover, in the map display apparatus of patent document 2, it is a position along a traffic route for every character or every symbol which comprises the character symbol string shown by name information, and interference with another character symbol is carried out. The display position is determined at a position to be avoided, and characters or symbols are displayed at the determined position. Specifically, as shown in FIG. 7 of Patent Document 2, when a character or symbol constituting a road name is displayed along the slope of a line connecting the inflection points of the road, it interferes with the previous character or symbol. When doing so, the pixel range for displaying characters or symbols is moved to the next pixel range for display.

JP 2002-297025 A JP 2005-115174 A

  However, although the technique described in Patent Document 1 can always display a character string in a natural and easy-to-read arrangement order, special consideration is given to avoiding overlap between characters and objects or between characters. Not. Further, it is impossible to solve the problem that the distance between the object and the character string is not uniform or the distance between the characters is not uniform. Further, with the technique described in Patent Document 2, it is possible to avoid the overlap between characters and objects or between characters, but the problem that the intervals between characters are not uniform cannot be solved.

  The present invention has been made to solve such a problem, and there is a problem that characters and objects overlap or between characters, and the distance between the object and the character string is not uniform. It is intended to improve the visibility of the character string displayed along the shape line of the object, avoiding the problem that the character spacing becomes uneven or the character spacing is not uniform. .

  In order to solve the above-described problem, in the present invention, in a map display device that displays a character string offset along a shape line of an object included in a map, a reference arrangement position of a first character constituting the character string A segment setting unit for setting a segment between the first character and the reference arrangement position of the second character, and an angle for calculating an angle of the set segment with respect to a display reference line for determining the display direction of the second character A calculation unit and an offset calculation unit that obtains an offset direction and an offset amount of the character with respect to the object based on the calculated angle are provided.

  According to the present invention configured as described above, the offset direction and the offset amount of each character constituting the character string are obtained according to the angle of the line segment set according to the shape line of the object. Compared to the case where the direction and the offset amount are uniformly determined, it is possible to obtain appropriate offset information in accordance with the shape line of the object. Since the character string is displayed based on this appropriate offset information, there is no overlap between the character and the object, and there is no overlap between the characters. It is also possible to prevent the character spacing from becoming uneven. Thereby, the visibility of the character string displayed along the shape line of the object can be further improved.

It is a block diagram which shows the function structural example of the map display apparatus by this embodiment. It is a figure for demonstrating operation | movement of the character string display part by this embodiment. It is a figure which shows an example of the table information which the offset calculating part of this embodiment memorize | stores. It is a figure for demonstrating operation | movement of the character string display part by this embodiment. It is a figure for demonstrating operation | movement of the character string display part by this embodiment. It is a flowchart which shows the operation example of the map display apparatus by this embodiment. It is a figure for demonstrating other operation | movement of the character string display part by this embodiment. It is a figure for demonstrating the conventional problem. It is a figure for demonstrating the conventional problem.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram illustrating a functional configuration example of the map display device according to the present embodiment. As shown in FIG. 1, the map display device of this embodiment includes a map data storage unit 1, a map display unit 2, and a character string display unit 3 as its functional configuration. Moreover, the character string display part 3 is provided with the line segment setting part 31, the angle calculating part 32, the offset calculating part 33, and the display control part 34 as the concrete function structure.

  Each of the functional blocks 2 and 3 can be configured by any of hardware, DSP (Digital Signal Processor), and software. For example, when configured by software, each of the functional blocks 2 and 3 is actually configured with a computer CPU, RAM, ROM, and the like, and is stored in a recording medium such as RAM, ROM, hard disk, or semiconductor memory. Is realized by operating.

  The map data storage unit 1 stores map data necessary for map display and route search. The map data includes a drawing unit composed of various data necessary for map display and a road unit composed of data necessary for various processes such as map matching, route search, and route guidance.

  In addition, the drawing unit includes background layer data necessary for displaying roads, rivers, railway lines, various facilities, etc. (hereinafter collectively referred to as “objects”), road names, river names, railway lines. And character layer data necessary to display various names such as names and facility names (hereinafter collectively referred to as “object names”).

  The map display unit 2 displays a map including an object on the display 10 based on the background layer data among the map data stored in the map data storage unit 1. The character string display unit 3 displays the shape line (curve or straight line) of the object on the map displayed by the map display unit 2 based on the character layer data among the map data stored in the map data storage unit 1. Along with the object name string.

FIG. 2 is a diagram for explaining the operation of the character string display unit 3. Hereinafter, a specific functional configuration of the character string display unit 3 will be described with reference to FIG. The line segment setting unit 31 includes a reference arrangement position of the first character and a reference of the second character that constitute the character string of the object name (consisting of three characters 22 _{-1 to} 22 _{-3 in} the example of FIG. 2). A line segment is set between the position and the position.

Here, the reference arrangement position refers to the arrangement position of characters when displaying characters on the shape line of the object without offset. For example, as shown in FIG. 2, the positions of the center points of the characters 22 _{-1 to} 22 _-3 when the characters 22 _{-1 to} 22 _-3 are arranged so that the center points overlap the shape line 21 of the object. Is a reference arrangement position. In the present embodiment, each of the characters 22 _{-1 to} 22 _-3 is an upright character with a rotation angle of 0 degrees.

In the example of FIG. 2, the first character and the second character are characters that are not adjacent to each other in the character string. Specifically, the first character is the first character 22 _-1 constituting the character string, and the second character is the last character 22 _-3 constituting the character string. Segment setting unit 31 sets a line segment 23 between the reference position of the first character 22 _-1 of the reference position and the final character 22 _-3.

The angle calculation unit 32 calculates the angle of the line segment 23 set by the line segment setting unit 31 with respect to the display reference line 24 of the second character (final character 22 ₋₃ ). Here, the display reference line 24 is a reference line for determining the display direction of characters, and the characters are displayed in a direction parallel to the display reference line 24. In the case of an upright character, the display reference line 24 is always a line parallel to the X axis of the display. As shown in FIG. 2, in the present embodiment, the angle calculation unit 32 calculates the angle θ with the line segment 23 clockwise with respect to the display reference line 24.

  Based on the angle θ calculated by the angle calculation unit 32, the offset calculation unit 33 obtains offset information that is an offset direction and an offset amount of the character with respect to the shape line 21 of the object. The offset calculation unit 33 includes a table information storage unit that stores the angle θ of the line segment 23 with respect to the display reference line 24 and the character offset direction and offset amount as table information in association with each other.

  FIG. 3 is a diagram showing an example of the table information. In the example of FIG. 3, the offset amount in the X-axis direction and the offset amount in the Y-axis direction are stored in association with the angle θ. The offset amount is represented by the pixel amount of the display 10. The offset calculation unit 33 refers to the table information in FIG. 3 based on the angle θ calculated by the angle calculation unit 32 to obtain character offset information with respect to the shape line 21 of the object.

The display control unit 34 causes the character string to be offset and displayed along the shape line 21 of the object based on the offset information obtained by the offset calculation unit 33. In the present embodiment, the display control unit 34 applies and displays the offset information obtained by the offset calculation unit 33 to all the characters 22 _{-1 to} 22 _-3 .

  On the other hand, when the character string is composed of n characters, the first character and the second character are set to two characters every other character set with one character in between. May be. In this case, the line segment setting unit 31, the angle calculation unit 32, and the offset calculation unit 33 set the i-th character (1 ≦ i ≦ n−2) as the first character and the i + 2 character as the second character. And the offset information regarding the i + 1th character is sequentially obtained.

For example, when the character string is composed of five characters 22 _{-1 to} 22 _-5 as shown in FIG. 4, the line segment setting unit 31, the angle calculation unit 32, and the offset calculation unit 33 first set the first character The character 22 _-1 is set as the first character, the third character 22 _-3 is set as the second character, and offset information regarding the second character 22 _-2 is obtained. Next, the second character of a character _22-2 first letter, 4 th character 22 _-4 set to the second character to determine the offset information related to the character 22 _-3 of the third character. Further, the third character _22-3 is set as the first character, the fifth character _22-5 is set as the second character, and offset information relating to the fourth character _22-4 is obtained.

Note that the first character 22 _-1, before the first character 22 _-1 the first virtual character 22 _-x additionally arranged to, with its first virtual character 22 _-x, 1 character (first character 22 _- obtaining the offset information of the first character 22 _-1 by setting a line segment between the left second character in the character 22 disposed later _-2 between _1). Similarly, for the last character 22 _-5, after the final character 22 _-5 second virtual characters 22 _-y additionally arranged to, with its second virtual characters 22 _-y, 1 character (the last character 22 _{- 5)} set a line segment between the characters 22 _-4 fourth character disposed in front placed between the seek offset information of the last character 22 _-5.

In this way, even when the curvature of the shape line 21 of the object is relatively large as shown in FIG. 5, the characters 22 _{-1 to} 22 _-5 can be displayed with an offset in an appropriate direction and an appropriate amount. .

  FIG. 6 is a flowchart showing an operation example of the map display device according to the present embodiment configured as described above. The flowchart shown in FIG. 6 starts when the display of the map image is instructed by the user. First, the map display part 2 displays the map containing an object on the display 10 based on the data of a background layer among the map data memorize | stored in the map data storage part 1 (step S1).

  Next, the character string display unit 3 is configured to display one object existing on the map image displayed by the map display unit 2 based on the character layer data among the map data stored in the map data storage unit 1. A character string of the object name is provisionally arranged at the reference arrangement position along the shape line 21 (step S2). In this state, the line segment setting unit 31 sets a line segment between the reference arrangement position of the first character (for example, the first character) and the reference arrangement position of the second character (for example, the last character) ( Step S3).

  Next, the angle calculation unit 32 calculates the angle θ of the line segment set by the line segment setting unit 31 with respect to the display reference line 24 of the second character (step S4). Then, the offset calculation unit 33 refers to the table information in FIG. 3 based on the angle θ calculated by the angle calculation unit 32, thereby obtaining character offset information with respect to the object shape line 21 (step S5).

  Further, the display control unit 34 causes the character string to be offset and displayed along the shape line 21 of the object based on the offset information obtained by the offset calculation unit 33 (step S6). In the example shown in this flowchart, all characters constituting the character string are displayed with the same amount offset in the same direction.

  Thereafter, the character string display unit 3 determines whether there is another character string to be displayed on the currently displayed map image (step S7). If there is another character string, the process returns to step S2. On the other hand, when there is no other character string to be displayed, that is, when all character strings are displayed on the currently displayed map image, the processing of the flowchart shown in FIG. 6 ends.

  As described above in detail, according to the present embodiment, the offset direction and the offset amount of each character constituting the character string are determined according to the angle θ of the line segment 23 set in accordance with the shape line 21 of the object. Desired. Therefore, it is possible to obtain appropriate offset information in accordance with the shape of the shape line 21 as compared with the case where the offset direction and the offset amount are uniformly determined.

  Since the character string is offset and displayed based on this appropriate offset information, there is no overlap between characters and objects, and there is no gap between the objects and the character strings. It is also possible to prevent the characters from being unequally spaced from each other. Thereby, the visibility of the character string displayed along the shape line of the object can be further improved.

  In the above embodiment, the first character is set as the first character, the second character is set as the last character, and only one offset information is obtained and applied to all characters, and the first character Although the second character is set every other character and a plurality of pieces of offset information are obtained and applied to each individual character, the second pattern is described. However, these may be switched as appropriate.

Specifically, when the character string is composed of n characters, the line segment setting unit 31 and the angle calculation unit 32 set the first character as the first character and the last character as the second character. While determining the first angle θ ₁ when set, the j-th character (j is any one of the values satisfying 1 ≦ j ≦ n−2) is set as the first character and the j + 2th character A second angle θ ₂ when the character is set to the second character is obtained.

For example, when the character string is composed of five characters 22 _{-1 to} 22 _-5 as shown in FIG. 7, the line segment setting unit 31 and the angle calculation unit 32 set the first character 22 _-1 as the first character. And the first angle θ ₁ when the last character 22 _-5 is set as the second character is obtained. The line segment setting unit 31 and the angle calculation unit 32 set the first character 22 _-1 as the first character and the second character _22-3 when the third character 22 _-3 is set as the second character. Find the angle θ ₂ .

Next, the offset calculator 33 determines whether or not the difference between the first angle θ ₁ and the second angle θ ₂ is smaller than a predetermined value. If the angle difference is smaller than the predetermined value, the first pattern is applied to obtain offset information. That is, the offset calculation unit 33 determines the angle obtained by the line segment setting unit 31 and the angle calculation unit 32 by setting the first character 22 _-1 as the first character and the last character 22 _-5 as the second character. Based on θ, one offset information applied in common to all the characters 22 _{-1 to} 22 _-5 is obtained.

On the other hand, when the difference between the first angle θ ₁ and the second angle θ ₂ is equal to or greater than a predetermined value, the offset calculation unit 33 applies the second pattern to obtain offset information. That is, in the offset calculation unit 33, the line segment setting unit 31 and the angle calculation unit 32 set the i-th character (1 ≦ i ≦ n−2) as the first character and the i + 2 character as the second character. On the basis of the angle θ obtained by setting to the character, the offset information of the i + 1-th character is sequentially obtained.

As shown in FIG. 7, when the curvature of the shape line 21 of the object is relatively large, the difference between the first angle θ ₁ and the second angle θ ₂ is equal to or greater than a predetermined value, so the second pattern is applied. Thus, the offset information of each character 22 _{-1 to} 22 _-5 is obtained individually. On the other hand, as shown in FIG. 4, when the curvature of the shape line 21 of the object is relatively small, the difference between the first angle θ ₁ and the second angle θ ₂ is smaller than a predetermined value, so the first pattern To obtain offset information common to all the characters 22 _{-1 to} 22 _-5 . In the latter case, it is only necessary to obtain one piece of offset information common to all 22 _{-1 to} 22 _-5 , so that the calculation load can be reduced.

Here, the first angle θ ₁ when the first character is set as the first character and the last character is set as the second character, and the j-th character is set as the first character. The example in which the first pattern and the second pattern are switched based on the magnitude of the difference from the _second angle θ ₂ when the j + 2nd character is set as the second character has been described. It is not limited. For example, when the first character is set to the first character and the last character is set to the second character, the first line segment and the jth character are set to the first character and the j + 2nd character You may make it switch a 1st pattern and a 2nd pattern based on the magnitude | size of the angle which a 2nd line segment at the time of setting a character to a 2nd character.

  Moreover, although the said embodiment demonstrated the example which used the character displayed along the shape line of an object as an erect character, this invention is not limited to this. For example, characters may be rotated and displayed according to the offset direction obtained by the offset calculation unit 33. Specifically, it is possible to perform processing such as rotating the character in the same direction as the angle direction formed by the offset direction obtained by the offset calculation unit 33 and the display reference line 24.

  Moreover, although the said embodiment demonstrated the example which sets a 1st character and a 2nd character to every other 2 characters, this is only an example. That is, the first character and the second character may be set with an interval of two or more characters.

  In addition, each of the above-described embodiments is merely an example of implementation in carrying out the present invention, and the technical scope of the present invention should not be construed in a limited manner. That is, the present invention can be implemented in various forms without departing from the gist or the main features thereof.

DESCRIPTION OF SYMBOLS 1 Map data memory | storage part 2 Map display part 3 Character string display part 31 Line segment setting part 32 Angle calculation part 33 Offset calculation part 34 Display control part

Claims (8)

A map display unit for displaying a map including the object based on the map data;
A character string display unit that displays a character string along the shape line of the object on the map displayed by the map display unit;
The character string display section
A line segment setting unit for setting a line segment between the reference arrangement position of the first character and the reference arrangement position of the second character constituting the character string;
An angle calculation unit that calculates an angle of a line segment set by the line segment setting unit with respect to a display reference line that determines a display direction of the second character;
Based on the angle calculated by the angle calculation unit, an offset calculation unit for obtaining offset information that is an offset direction and an offset amount of characters with respect to the object;
A map display device comprising: a display control unit configured to offset and display the character string along the shape line of the object based on the offset information obtained by the offset calculation unit.   The offset calculation unit includes a table information storage unit that stores the angle of the line segment with respect to the display reference line, the offset direction, and the offset amount as table information in association with each other, and is calculated by the angle calculation unit. The map display device according to claim 1, wherein the offset information is obtained by referring to the table information based on the angle. The first character is a first character constituting the character string, the second character is a final character constituting the character string,
The map display device according to claim 1, wherein the offset calculation unit obtains offset information common to all characters constituting the character string. The first character and the second character are characters that are not adjacent to each other in the character string,
The map display device according to claim 1, wherein the offset calculation unit obtains offset information related to a character between the first character and the second character. When the character string is composed of n characters, the first character and the second character are two characters every other character set with one character in between,
The line segment setting unit, the angle calculation unit, and the offset calculation unit change the i-th character (1 ≦ i ≦ n−2) to the first character and the i + 2 character to the second character. 5. The map display device according to claim 4, wherein the map display device is set and offset information relating to the i + 1-th character is sequentially obtained. When obtaining the offset information related to the first character constituting the character string, a first virtual character is arranged before the first character, and the two characters arranged next to the first virtual character and the first character A line segment between the character and the eye is set by the line segment setting unit, and using the set line segment, the angle calculation unit and the offset calculation unit obtain offset information of the first character,
When obtaining the offset information relating to the final character constituting the character string, a second virtual character is arranged after the final character, and n−1 arranged before the second virtual character and the final character. A line segment is set between the character and the character by the line segment setting unit, and the offset information of the final character is obtained by the angle calculation unit and the offset calculation unit using the set line segment. The map display device according to claim 4, wherein When the character string is composed of n characters, the first character constituting the character string is set to the first character, and the last character constituting the character string is set to the second character. The first angle in the case is obtained by the line segment setting unit and the angle calculation unit, while the j-th character (j is any one of the values satisfying 1 ≦ j ≦ n−2) is used as the first character. And the second angle when the j + 2 character is set as the second character is determined by the line segment setting unit and the angle calculation unit,
When the difference between the first angle and the second angle is smaller than a predetermined value, the offset calculation unit sets the first character as the first character and sets the last character as the second character. If the difference between the first angle and the second angle is equal to or greater than a predetermined value, the i-th character (1 ≦ i ≦ n−2) is obtained. 2. The map display device according to claim 1, wherein the first character is set as the first character, the i + 2 character is set as the second character, and the offset information of the i + 1 character is sequentially obtained. . A method for displaying a character string along a shape line of an object included in a map displayed based on map data,
A first step in which a line segment setting unit of the map display device sets a line segment between a reference arrangement position of a first character and a reference arrangement position of a second character constituting the character string;
A second step in which an angle calculation unit of the map display device calculates an angle of a line segment set by the line segment setting unit with respect to a display reference line that determines a display direction of the second character;
A third step in which the offset calculation unit of the map display device obtains offset information that is an offset direction and an offset amount of the character with respect to the object based on the angle calculated by the angle calculation unit;
The display control unit of the map display device includes a fourth step of offsetting and displaying the character string along the shape line of the object based on the offset information obtained by the offset calculation unit. Character string display method on the feature map.

Images