Tone correction method using a blending mask
US7280705B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 4, 2003 |
| Grant date | Oct 9, 2007 |
| Priority date | — |
| Expiry date | Oct 27, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N2209/046
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A digital imaging system includes an image sensor, a frame buffer and a tone correction circuit. The tone correction circuit computes tone corrected pixel data using one or more tone correction curves. In operation, tone corrected pixel data for a first pixel is computed by generating a pixel mask for an m×n neighborhood of pixels surrounding the first pixel, applying a blending mask of weight factors to the pixel mask and computing a selector value based on the pixel mask and weight factors associated with the blending mask. The selector value is used to derive a first tone correction curve for use to compute the tone corrected pixel data for the first pixel. The first tone correction curve can be selected from the multiple tone correction curves based on the selector value or it can be derived by blending multiple tone correction curves based on the selector value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.