Imaging apparatus
AssigneeAutoliv Development AB
InventorsTobias Höglund, Ognjan Hedberg, Peter Hall
Life of this patent
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Abstract
An imaging apparatus including an infrared video camera. The infrared video camera includes a sensor array operable to produce successive video images in the form of pixelated two-dimensional images. The imaging apparatus further comprises a processing arrangement operable to reduce or increase the overall brightness of an image in dependence upon the overall brightness of the pre-enhanced image and the overall brightness of the preceding enhanced image, so that the change in the overall brightness (DC-level) between the enhanced image and the preceding enhanced image is decreased.
Claims6
An imaging apparatus including an infrared video camera comprising a sensor array and operable to produce successive video images in the form of pixelated two-dimensional images, the imaging apparatus further comprising a processing arrangement operable to reduce or increase an overall brightness of an enhanced image in dependence upon an overall brightness of a pre-enhanced image and an overall brightness of a preceding enhanced image, so that a change in the overall brightness between the enhanced image and the preceding enhanced image is decreased to be less than a difference in overall brightness between the pre-enhanced image and the preceding enhanced image;
- wherein the output at time t is calculated using
- fout(x,y,t)=f(x,y,t)+γ·DCresidual(t) (1)
- where
- DCresidual(t)=DCout(t)−DCf(t) (2)
- DCf(t) being a mean brightness of the pre-enhanced image and
- DCout(t)=(1−λ)·DCout(t−1)+λ·DCf(t) (3)
- where γ is a parameter controlling a strength compensation and λ is a parameter determining an adaptation rate of the compensation.
An image enhancement method applicable to infrared video images characterised in that, for each video image received by a processor, an overall brightness of an enhanced image is reduced or increased by the processor in dependence upon an overall brightness of a pre-enhanced image and an overall brightness of a preceding enhanced image;
- wherein the output at time t is calculated using
- fout(x,y,t)=f(x,y,t)+γ·DCresidual(t) (1)
- where
- DCresidual(t)=DCout(t)−DCf(t) (2)
- DCf(t) being the mean of the pre-enhanced image and
- DCout(t)=(1−λ)·DCout(t−1)+λ·DCf(t) (3)
- where γ is a parameter controlling a strength compensation and λ is a parameter determining an adaptation rate of the compensation.
Dependencies are inferred from the claim text.