Method and apparatus for filtering and caching data representing images
US6738526B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 30, 1999 |
| Grant date | May 18, 2004 |
| Priority date | — |
| Expiry date | Jul 30, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G2340/10
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Methods and apparatus for displaying images, e.g., text characters, on display devices which have multiple separately controllable luminance elements per pixel are described. Multiple alpha values are generated per pixel, e.g., one per pixel sub-component. Filtering is then performed to generate a filtered alpha value for each pixel sub-component. The filtering operation uses as its input multiple alpha values, e.g., 5 per pixel. The alpha values used for the filtering operation may come from neighboring pixels. Accordingly, in the case where character glyphs are combined to form larger images, e.g., text strings, the filtering operation performed on glyph edge pixels depends on the content of a neighboring character glyph. In one embodiment unfiltered alpha values used to represent character glyphs are stored in a glyph cache. After caching, the unfiltered alpha values from multiple glyphs are combined and then the filtering operation is performed. To avoid repeated filtering of character glyphs, in another embodiment, character glyphs are padded along their vertical edges, filtered and then stored in the glyph cache. Glyphs are output from the cache as required and then combined …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.