Apparatus and method for black shading correction
US5548332A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 21, 1995 |
| Grant date | Aug 20, 1996 |
| Priority date | — |
| Expiry date | Apr 21, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N25/674
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A technique is disclosed for correcting black shading errors in a video camera. The technique involves calculating a horizontal correction waveform as a function of the average pixel values for the columns of a field. Next, a vertical correction waveform is calculated as a function of the average pixel values for the rows of a field. Then, calculation of a diagonal correction waveform as a function of the average pixel values along predetermined diagonals is performed. Finally, an input video signal representing real images is combined with the correction waveforms to produce a video output signal having substantially reduced black shading errors. Correction waveforms can be determined in any order.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.