Color interpolator and horizontal/vertical edge enhancer using two line buffer and alternating even/odd filters for digital camera
US6628330B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 3, 1999 |
| Grant date | Sep 30, 2003 |
| Priority date | — |
| Expiry date | Nov 3, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2207/20192
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A digital-camera processor receives a stream of mono-color pixels in a Bayer pattern from a sensor. Two lines of the pattern are stored in a 2-line buffer. Red, Blue, and Green interpolators receive a 3×3 array of pixels from the 2-line buffer. The interpolators generate missing color values by interpolation. For green, horizontal interpolation is performed for odd lines, while vertical interpolation is performed for even lines. Horizontal and vertical interpolation is thus alternated with alternate lines. Edge detection is performed at the same time as interpolation, on the green pixels from the 2-line buffer. An edge-detection filter is multiplied by the green pixels in the 3×3 array from the 2-line buffer. Different edge-detection filters are used for odd and even lines. These filters are modified to detect edges running perpendicular to the direction of the green interpolation filter. Edges in the same direction as the interpolation filter are ignored. Thus blurring caused by the green interpolation does not affect edge detection. The result of the edge-detection filter is compared to two different threshold values, one for green and one for red and blue. When an ed…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.