Radiometric calibration from a single image
US7463769B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 20, 2005 |
| Grant date | Dec 9, 2008 |
| Priority date | — |
| Expiry date | Dec 30, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T7/90
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Radiometric calibration of an image capture device (e.g., a digital camera) using a single image is described. The single image may be a color image or a grayscale image. The calibration identifies and analyzes edge pixels of the image that correspond to an edge between two colors or grayscale levels of a scene. Intensity distributions of intensities measured from the single image are then analyzed. An inverse response function for the image capture device is determined based on the intensity distributions. For a color image, the radiometric calibration involves calculating an inverse response function that maps measured blended colors of edge pixels and the associated measured component colors into linear distributions. For a grayscale image, the radiometric calibration involves deriving an inverse response function that maps non-uniform histograms of measured intensities into uniform distributions of calibrated intensities.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.