Method and apparatus for pixel composition
US6034694A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 30, 1997 |
| Grant date | Mar 7, 2000 |
| Priority date | — |
| Expiry date | Jun 30, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T15/503
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The present invention provides a method and apparatus that permits the introduction of customized compositing techniques into an application by a developer. A Composite interface and a CompositeContext interface are defined. Custom compositing operations can be defined by implementing these interfaces. A Composite object provides a CompositeContext object that holds the state and performs the compositing work. Multiple CompositeContext objects can be created from one Composite object to maintain separate states in a multi-threaded environment. An object implementing the Composite interface can be set as rendering state on a graphics object that provides rendering methods. This allows arbitrary compositing rules to be used by a developer. In one implementation of the Composite and CompositeContext interfaces, an AlphaComposite class is defined. The AlphaComposite class implements common compositing rules, such as defined by Porter and Duff, for combining source and destination pixels to achieve blending and transparency effects with graphics and images.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.