GENERATING A MAP DISPLAY IMAGE

• US 20120038623A1
• Filed: 05/29/2008
• Published: 02/16/2012
• Est. Priority Date: 05/29/2008
• Status: Active Grant

• Current Assignee: TomTom Navigation B.V (TomTom NV)
• Original Assignee: TomTom Navigation B.V (TomTom NV)
• Inventors: Van Raamsdonk, Ewoud
• Granted Patent: US 9,852,709 B2
• Time in Patent Office: Days
• US Class Current: 345/419
• CPC Class Codes: G01C 21/3673 Labelling using text of road map data items, e.g. road names, POI names
• CPC Class Codes: G08G 1/0969 having a display in the form of a map
• CPC Class Codes: G09B 29/106 using electronic means
• CPC Class Codes: G09G 2320/028 by changing the viewing angle properties, e.g. widening the viewing angle, adapting the viewing angle to the view direction
• CPC Class Codes: G09G 2340/12 Overlay of images, i.e. displayed pixel being the result of switching between the corresponding input pixels
• CPC Class Codes: G09G 2340/125 wherein one of the images is motion video
• CPC Class Codes: G09G 5/00 Control arrangements or circuits for visual indicators common to cathode-ray tube indicators and other visual indicators image data processing or generation, in general G06T

Abstract

A method and apparatus are disclosed for generating a display image including a map view and linepiece information for example legible text and/or characters (e.g. alphanumeric) such as road names superposed on the map view. In at least one embodiment, the technique selects linepieces that are easy to read, by (i) selecting from a first subset of alphanumeric linepieces associated with information on the map, a second sub-set of the alphanumeric linepieces satisfying predetermined criteria including display angle; and (ii) including in the display image the second sub-set of alphanumeric linepieces. The first sub-set may be selected according to distance criteria.

Claims

1. A method of generating a display image including a map view and linepiece information superposed on the map view, the method comprising:

(a) selecting, from a first sub-set of linepieces, a second sub-set of linepieces according to display criteria including display angle; and

(b) including in the display image linepiece information from the second sub-set of linepieces.

2. The method of claim 1, wherein the step of selecting comprises:

(a1) projecting linepieces of the first sub-set into a display space;

(a2) determining a display angle of each linepiece projected in display space; and

(a3) selecting for the second sub-set each linepiece whose display angle lies in a selection range.

3. The method of claim 2, wherein the display angle is an angle of inclination with respect to a horizontal direction in display space.

4. The method of claim 3, wherein the selection range is defined by at least one threshold magnitude of angle with respect to said horizontal direction.

5. The method of claim 4, wherein the threshold magnitude of angle is between about 10°

and about 30°

.

6. The method of claim 5, wherein the threshold magnitude of angle is abut 20°

.

7. The method of claim 1, further comprising selecting the first sub-set of linepieces according to distance criteria with respect to a certain position.

8. The method of claim 7, wherein the distance criteria is a distance of the linepiece from a certain position selected from at least one of:

a viewing position from which the map view is generated, and a current position represented within the map view.

9. The method of claim 7, wherein the distance is not more than about 250 metres.

10. The method of claim 1, wherein the linepieces comprise road names for roads in the digital map.

11. The method of claim 10, wherein the road name is aligned with a representation of the road in display space.

12. The method of claim 1, wherein the map view is a three-dimensional perspective elevation.

13. An article of manufacture carrying or embodying a computer program which, when executed, causes a processor to perform the steps as defined in claim 1.

14. Apparatus for generating a display image including a map view and linepiece information superposed on the map view, the apparatus comprising:

(a) a device for selecting, from a first sub-set of linepieces, a second sub-set of linepieces according to display criteria including display angle; and

(b) a device for including in the display image linepiece information from the second sub-set of linepieces.

15. The apparatus of claim 14, further comprising a device for selecting the first sub-set of linepieces according to distance criteria with respect to a certain position.