US 11,778,334 B2
Method and a thermal camera having a microbolometer detector for capturing a sequence of image frames
Thomas Winzell, Lund (SE); and Jesper Bengtsson, Lund (SE)
Assigned to AXIS AB, Lund (SE)
Filed by Axis AB, Lund (SE)
Filed on Mar. 31, 2022, as Appl. No. 17/710,134.
Claims priority of application No. 21171561 (EP), filed on Apr. 30, 2021.
Prior Publication US 2022/0353402 A1, Nov. 3, 2022
Int. Cl. H04N 23/73 (2023.01); G06T 5/50 (2006.01); G08B 21/18 (2006.01); H04N 7/18 (2006.01)
CPC H04N 23/73 (2023.01) [G06T 5/50 (2013.01); G08B 21/182 (2013.01); H04N 7/18 (2013.01); G06T 2207/10016 (2013.01); G06T 2207/10048 (2013.01); G06T 2207/10144 (2013.01); G06T 2207/20224 (2013.01); G06T 2207/30232 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method for capturing a sequence of image frames in a thermal camera having a microbolometer detector, comprising:
capturing a first sequence of image frames with a shutter of the thermal camera being in a closed state and while switching an integration time of the microbolometer detector between a plurality of integration times according to one or more first repetitions of a temporal pattern of integration times,
capturing a second sequence of image frames with the shutter of the thermal camera being in an open state and while switching the integration time of the microbolometer detector between the plurality of integration times according to one or more second repetitions of the same temporal pattern of integration times, and
correcting, by subtraction, image frames in the second sequence that are captured when the integration time is switched to a particular position within the temporal pattern of integration times using image frames in the first sequence that are captured when the integration time is switched to the same particular position within the temporal pattern of integration times.