System and method for labeling maps

• US 9,292,949 B2
• Filed: 04/01/2014
• Issued: 03/22/2016
• Est. Priority Date: 06/16/2003
• Status: Active Grant

• Current Assignee: Theodore J. Gelber
• Original Assignee: Theodore J. Gelber
• Inventors: Gelber, Theodore J.
• Primary Examiner(s): Brier, Jeffery A
• Application Number:
  US14/231,753
• Publication Number:
  US 20140210854A1
• Time in Patent Office: 721 Days
• Field of Search: 345/636, 345/672, 345/681
• US Class Current: 1/1
• CPC Class Codes: G06T 11/20 Drawing from basic elements, e.g. lines or circles
• CPC Class Codes: G06T 11/60 Editing figures and text; Combining figures or text
• CPC Class Codes: G09B 29/10 Map spot or coordinate position indicators; Map reading aids optical projection apparatus per se G03B

Abstract

A system and method for label placement is disclosed that achieves the twin goals of practical efficiency and high labeling quality by employing cartographic heuristics. A caller defines map and label properties. Then labels are pulled within a map boundary. Labels are next ordered by priority in descending importance. The order of testing labels is determined. Attempts are made to move overlapping labels. This is an iterative process; therefore there must be criteria that halt the procedure. Upon reaching an acceptable solution, the label properties are adjusted to reflect the new label placements.

Claims

1. A method for generating a solution for pulling a label within a boundary of a map utilizing a computer system comprising the computer implemented steps of:

determining, if the label is not wholly within the boundary of the map, a fraction of a label area that is inside the boundary of the map,

moving the label within the boundary of the map if;

(a) the fraction of the label area inside the boundary of the map is greater than a predetermined value,

(b) a distance of a movement of the label is less than a maximum movement permitted from an original position, and

(c) the movement would result in all vertices located within the boundary of the map, and then

outputting the solution to a caller,

wherein a boundary of the label is a convex polygon with pre-assigned properties including the original position, the vertices, a type of movement allowed, and the maximum movement permitted from the original position,

wherein the boundary of the map is a rectangle, and

wherein the determining, if the label is not wholly within the boundary of the map, the fraction of the label area that is inside the boundary of the map, comprises;

circumscribing a rectangle around the boundary of the label,

dividing the rectangle into a n by m grid of sub-rectangles,

testing a centroid of each sub-rectangle to determine if the sub-rectangle centroid is inside the label,

testing, if the centroid is inside the label, if the centroid is inside the boundary of the map, and

dividing a number of centroids both inside the label and inside the boundary of the map by a number of centroids inside the label.

2. The method of claim 1 wherein the movement of the label allowed is a vector type movement.

3. The method of claim 1 wherein the movement of the label allowed is a 2D type movement.

4. The method of claim 1 further comprising a computer implemented step of discarding the label after attempting to move the label within the boundary of the map if the label is not wholly inside the boundary of the map.

5. The method of claim 4 further comprising the computer implemented step of concluding that the label is wholly within the boundary of the map if all of the vertices are inside the map.

6. The method of claim 1 further comprising discarding the label unless the label is always at least partially within the boundary of the map.

7. The method of claim 1 further comprising discarding the label if the fraction of the label area inside the boundary of the map is less than a predetermined value;

wherein the boundary of the map is fixed relative to features within the boundary of the map;

wherein the boundary of the map is additionally fixed relative to the original position of the label;

and

wherein the features are not eliminated before the discarding.

15. A non-transitory computer storage medium storing computer executable instructions for performing the method of claim 1.

16. The medium of claim 15 wherein the movement of the label allowed is a vector type movement.

17. The medium of claim 15 wherein the movement of the label allowed is a 2D type movement.

18. The medium of claim 15 further comprising a computer executable instruction of discarding the label after attempting to move the label within the boundary of the map if the label is not wholly inside the boundary of the map.

19. The medium of claim 18 further comprising a computer executable instruction of concluding that the label is wholly within the boundary of the map if all of the vertices are inside the map.

20. The medium of claim 15 further comprising a computer executable instruction of discarding the label unless the label is always at least partially within the boundary of the map.

21. The medium of claim 15 further comprising a computer executable instruction of discarding the label if the fraction of the label area inside the boundary of the map is less than a predetermined value,

wherein the boundary of the map is fixed relative to features within the boundary of the map,

wherein the boundary of the map is additionally fixed relative to the original position of the label,

and

wherein the features are not eliminated before the discarding.

8. A computer system for generating a solution for pulling a label within a boundary of a map, said computer system comprising:

input means for inputting map data and label data,

memory means for storing the solution,

processor means responsive to a control program for generating digital signals

corresponding to the solution, the processor means being adapted to;

determining, if the label is not wholly within the boundary of the map, a fraction of a label area that is inside the boundary of the map,

moving the label within the boundary of the map if;

(a) the fraction of the label area inside the boundary of the map is greater than a predetermined value,

(b) a distance of a movement of the label is less than a maximum movement permitted from an original position, and

(c) the movement would result in all vertices located within the boundary of the map,

and then

outputting the solution to a caller,

wherein a boundary of the label is a convex polygon with pre-assigned properties

including the original position, the vertices, a type of movement allowed, and the

maximum movement permitted from the original position,

wherein the boundary of the map is a rectangle, and

wherein the determining, if the label is not wholly within the boundary of the map, the fraction of the label area that is inside the boundary of the map, comprises;

circumscribing a rectangle around a boundary of the label,

dividing the rectangle into a n by m grid of sub-rectangles,

testing a centroid of each sub-rectangle to determine if the sub-rectangle centroid is inside the label,

testing, if the centroid is inside the label, if the centroid is inside the boundary of the map,

dividing the number of centroids both inside the label and inside the boundary of the map by the number inside the label,

and then

outputting the solution to the memory means.

9. The system of claim 8 wherein the movement of the label allowed is a vector type movement.

10. The system of claim 8 wherein the movement of the label allowed is a 2D type movement.

11. The system of claim 8 further comprising the processor means being adapted to discarding the label after attempting to move the label within the boundary of the map if the label is not wholly inside the boundary of the map.

12. The system of claim 11 further comprising the processor means being adapted to concluding that the label is wholly within the boundary of the map if all of the vertices are inside the map.

13. The system of claim 8 further comprising the processor means being adapted to discarding the label unless the label is always at least partially within the boundary of the map.

14. The system of claim 8 further comprising the processor means being adapted to discarding the label if the fraction of the label area inside the boundary of the map is less than a predetermined value;

wherein the boundary of the map is fixed relative to features within the boundary of the map;

wherein the boundary of the map is additionally fixed relative to the original position of the label;

and

wherein the features are not eliminated before the discarding.