Nonuniformity correction of an imaging sensor using region-based

Details Nonuniformity correction of an imaging sensor using region-based Nonuniformity correction of an imaging sensor using region-based

1993-11-15

1995-11-28

Groody, James J.

Television

Responsive to nonvisible energy

Infrared

250332, H04N 533

Patent

active

054712408

ABSTRACT:
A scene based nonuniformity correction method (40) that computes and applies offset correction errors to a video signal corresponding to an image derived from a imaging sensor (11). A video signal derived from the sensor (11) is processed such that a vector representing offset correction terms is formed, and this vector is initially set to zero. Each element in this vector represents a correction term for a particular detector of the sensor (11). The vector is applied to each pixel of the image by a processor (13) as the pixels are read from the sensor (11). To measure the offset error, the image is separated into vertically oriented regions, each comprising a plurality of channels. The average of each channel within a region is computed (42), and a set of region vectors is foraged, such that there is one region vector for each region. Each region vector is then globally high-pass filtered and then edges larger than a predefined threshold are detected (43), and marked (44). Then, each region vector is further separated into sub-regions (45). The isolated sub-regions are locally high-pass filtered. In one embodiment, the correction terms for each vertical region vector are averaged together, resulting in a single correction vector (48). The correction terms calculated for each vertical region may also be applied individually to each detector of the sensor (11). In this second embodiment, the offset level error in each region for each channel is calculated (49), wherein the offset level error at boundary edges is undefined. The correction terms corresponding to a region are applied as the detector (11) scans the scene and views a portion corresponding to that particular region. The correction terms are smoothed at region boundaries to eliminate noise due to boundary transitions.

REFERENCES:
patent: 4712010 (1987-12-01), Alm
patent: 4719350 (1988-01-01), Alm
patent: 4975864 (1990-12-01), Sendall et al.
patent: 5302824 (1994-04-01), Prager

Affiliated with

Also associated with

Rating

Nonuniformity correction of an imaging sensor using region-based does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Nonuniformity correction of an imaging sensor using region-based, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Nonuniformity correction of an imaging sensor using region-based will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2016565