Backing color and luminance nonuniformity compensation for linear image compositing
US5032901A · kind A · utility
Inventor
Key dates
| Filing date | Jun 28, 1988 |
| Grant date | Jul 16, 1991 |
| Priority date | — |
| Expiry date | Jun 28, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/75
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A linear image compositing system which corrects for nonuniform luminance and/or color of the colored backing without incurring the penalties of edge glow, edge darkening, loss of edge detail and other anomalies. A control signal is created directly proportional to the luminance of the colored backing and controls the level of the BG scene. Unless the control signal is corrected, the background scene will contain all the brightness and color variations occurring on the colored backing. Correction factors are developed by comparing the RGB video obtained from the backing before the subject is put in place, with the ideal values of RGB that would have been obtianed from a perfect backing. These correction factors correct the RGB video when the scene is scanned with the subject in place. The control signal, being zero in the subject area, may be used to inhibit the corrections in the subject area.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.