Multiresolution image synthesis for navigation

• US 20040125114A1
• Filed: 12/31/2002
• Published: 07/01/2004
• Est. Priority Date: 12/31/2002
• Status: Abandoned Application

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Chen, Toulin, Schmidt, Hauke, Lee, Aaron
• Application Number:
  US10/334,517
• Publication Number:
  US 20040125114A1
• Time in Patent Office: Days
• US Class Current: 345/629
• CPC Class Codes: G01C 21/3647 Guidance involving output of stored or live camera images or video streams

Abstract

A system providing three-dimensional visual navigation for a mobile unit includes a location calculation unit for calculating an instantaneous position of the mobile unit, a viewpoint control unit for determining a viewing frustum from the instantaneous position, a scenegraph manager in communication with at least one geo-database to obtain geographic object data associated with the viewing frustum and generating a scenegraph organizing the geographic object data, and a scenegraph renderer which graphically renders the scenegraph in real time. To enhance depiction, a method for blending images of different resolutions in the scenegraph reduces abrupt changes as the mobile unit moves relative to the depicted geographic objects. Data structures for storage and run-time access of information regarding the geographic object data permit on-demand loading of the data based on the viewing frustum and allow the navigational system to dynamically load, on-demand, only those objects that are visible to the user.

Claims

1. A method for creating a multiresolution image from a plurality of images, the plurality of images including a first image having a first resolution and a second image having a second resolution, the method comprising:

assigning first and second blending factors for the first and second resolutions of the plurality of images;

computing a weighted sum of the first image and the second image multiplied by their respective first and second blending factors; and

generating a multiresolution image based on the weighted sum of the first and second images.

2. The method of claim 1, wherein the plurality of images are images of a particular geographic area.

3. The method of claim 2, further comprising:

determining a distance between an observer and the geographic area; and

calculating the blending factor for the first and second resolutions based upon the distance between the observer and the geographic area.

4. The method of claim 3, wherein the plurality of images are satellite images of a geographic region.

5. The method of claim 3, further comprising:

calculating the distance between the observer and the geographic area is calculated in real time;

wherein the observer is a mobile unit.

6. The method of claim 5, further comprising:

repeatedly calculating the distance between the mobile unit and the geographic area; and

continuously updating the blending factors of the first and second resolutions based for each repetition of distance calculation.

7. The method of claim 5, further comprising:

modifying the blending factors for the first and second resolutions based upon a user-selected zoom value.

8. The method of claim 1, further comprising:

storing meta data concerning the plurality of images in an indexable format; and

accessing the plurality of images efficiently using an index data structure.

9. The method of claim 8, further comprising:

storing the meta data concerning the plurality of images separately from actual data of the plurality of images.

10. A method for creating a multiresolution image from a plurality of images, the plurality of images containing images of at least two resolutions, the method comprising:

collecting viewing parameters;

determining a viewing frustum from the viewing parameters;

determining visible image tiles based on the viewing frustum, the images tiles including images of at least two resolutions;

determining a blending factor for each of the at least two resolutions of the visible image tiles; and

generating a multiresolution image from a weighted sum of the image tiles multiplied by their respective resolution blending factors.

11. The method of claim 10, further comprising:

obtaining the visible images from at least one geo-database.

12. The method of claim 10, wherein the at least one geo-database includes at least one of satellite images, building textures, digital elevation models, and roadmap databases.

13. The method of claim 10, wherein the viewing parameters include a position and an orientation of a mobile unit navigating through a geographic environment.

14. The method of claim 13, further comprising:

calculating a viewing distance from the location of the mobile unit; and

determining blending factors for each of the at least two resolutions of the visible image tiles based on the calculated distance.

15. The method of claim 13, further comprising:

modifying the blending factors based upon a user-selected zoom value.

16. The method of claim 10, further comprising:

storing meta data concerning the visible image tiles in an indexable format; and

accessing the plurality of visible image tiles efficiently using an index data structure.

17. An article comprising a computer-readable medium which stores computer-executable instructions for causing a computer system coupled to a system memory to create a multiresolution image from a plurality of images, the plurality of images including a first image having a first resolution and a second image having a second resolution, the article further storing computer-executable instructions for causing a computer system coupled to a system memory to:

assign first and second blending factors for the first and second resolutions of the plurality of images;

compute a weighted sum of the first image and the second image multiplied by their respective first and second blending factors; and

generate a multiresolution image based on the weighted sum of the first and second images.

18. The article of claim 17, wherein the plurality of images are images of a particular geographic area.

19. The article of claim 18, further storing computer-executable instructions for causing a computer system coupled to a system memory to:

determine a distance between an observer and the geographic area; and

calculate the blending factor for the first and second resolutions based upon the distance between the observer and the geographic area.

20. An article comprising a computer-readable medium which stores computer-executable instructions for causing a computer system coupled to a system memory to create a multiresolution image from a plurality of images, the plurality of images containing images of at least two resolutions, the article further storing computer-executable instructions for causing a computer system coupled to a system memory to:

collect viewing parameters;

determine a viewing frustum from the viewing parameters;

determine visible image tiles based on the viewing frustum, the images tiles including images of at least two resolutions;

determine a blending factor for each of the at least two resolutions of the visible image tiles; and

generate a multiresolution image from a weighted sum of the image tiles multiplied by their respective resolution blending factors.

21. The article of claim 20, further storing computer-executable instructions for causing a computer system coupled to a system memory to:

store meta data concerning the visible image tiles in an indexable format; and

access the plurality of visible image tiles efficiently using an index data structure.