Generating, storing, and displaying graphics using sub-pixel bitmaps

• US 8,005,613 B2
• Filed: 07/29/2009
• Issued: 08/23/2011
• Est. Priority Date: 03/23/2004
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Google Inc. (Alphabet Inc.)
• Inventors: Rasmussen, Lars Eilstrup, Rasmussen, Jens Eilstrup
• Primary Examiner(s): Wang; Andrew
• Assistant Examiner(s): Chu; David H
• Application Number:
  US12/511,842
• Publication Number:
  US 20090287797A1
• Time in Patent Office: 755 Days
• Field of Search: None
• US Class Current: 701/208
• CPC Class Codes: G01C 21/367 Details, e.g. road map scale, orientation, zooming, illumination, level of detail, scrolling of road map or positioning of current position marker
• CPC Class Codes: G01C 21/3881 Tile-based structures
• CPC Class Codes: G06F 16/9537 Spatial or temporal dependent retrieval, e.g. spatiotemporal queries
• CPC Class Codes: G06Q 40/12 Accounting
• CPC Class Codes: G06T 11/40 Filling a planar surface by adding surface attributes, e.g. colour or texture
• CPC Class Codes: G06T 17/05 Geographic models
• CPC Class Codes: G06T 3/40 Scaling of whole images or parts thereof, e.g. expanding or contracting
• CPC Class Codes: G09B 29/003 Maps
• CPC Class Codes: G09B 29/004 Map manufacture or repair; Tear or ink or water resistant maps; Long-life maps printing processes for maps B41M3/02; by permanently attaching map sections to sheets B42B7/00
• CPC Class Codes: G09B 29/10 Map spot or coordinate position indicators; Map reading aids optical projection apparatus per se G03B
• CPC Class Codes: Y02A 90/10 Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation

Abstract

Techniques for generating, storing and displaying graphics on computer systems are disclosed. The type of graphics in particular are images, where the image can be defined as a set of areas, whether these areas are lines, geometric shapes, letters or other types of areas. The effect of using these methods is that graphics, such as digital maps, can be handled faster, with more flexibility and with higher display quality, both for screen use and for printing.

Claims

1. A sub-pixel bitmap tile serving system configured to serve tiles in response to requests from a user, comprising:

a plurality of front end tile servers for serving one or more sub-pixel bitmap tiles requested by a user;

a request distributor for distributing requests for sub-pixel bitmap tiles between the plurality of front end tile servers; and

a plurality of back end tile servers communicatively coupled with the plurality of front end tile servers, each back end tile server having access to the sub-pixel bitmap tiles, and configured to provide requested sub-pixel bitmap tiles to a corresponding front end tile server.

2. The system of claim 1 wherein the user uses a processing device to request sub-pixel bitmap tiles, and the system is configured to cache sub-pixel bitmap tiles on the processing device.

3. The system of claim 1 wherein the system is configured to pre-fetch sub-pixel bitmap tiles, so that tiles needed to draw a requested graphic represented by one or more sub-pixel bitmap tiles, as well as a number of sub-pixel bitmap tiles surrounding the requested graphic within a pre-determined distance, are served to a user.

4. The system of claim 3 wherein sub-pixel bitmap tiles associated with one or more zoom levels are also pre-fetched and served.

5. The system of claim 3 wherein the user uses a processing device to request sub-pixel bitmap tiles, and pre-fetched tiles are cached on the processing device.

6. The system of claim 3 wherein sub-pixel bitmap tiles that are least likely to be used, based on established criteria, are deleted from the cache.

7. The system of claim 3 wherein caching sub-pixel bitmap tiles includes caching a set of adjacent tiles in a single file, where index information associated with that file is stored separately.