Scene based nonuniformity compensation for starting focal plane arrays
US4975864A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 26, 1989 |
| Grant date | Dec 4, 1990 |
| Priority date | — |
| Expiry date | Jan 26, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N25/674
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Apparatus and methods for providing nonuniformity compensation of staring infrared focal plane array imaging systems, or other video imaging ssytem, or the like. The invention comprises a processor which implements nonuniformity compensation of the detectors comprising the array. The processor generates compensation terms that are stored in an offset term memory and which are subsequently combined with the output signals from the array. The processing accomplished by the present invention normalizes all detector elements in the array such that they all appear to respond to infrared energy in an identical manner. The processor comprises a median filter which selectively implements cross (X) shaped and plus (+) shaped filters. An antimedian calculator computes the antimedian of the output of the median filter. This value comprises the difference between the central pixel of a respective filter and the median value of all pixels in the cross (X) or plus (+) shaped filter. A third filter samples each of the signals from the detector array and compares them to a preset value indicative of an anticipated scene intensity level determined by the operator to provide an output signal indicat…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.