Add a WDR algorithm to do global tone mapping. Global tone mapping is
used to increase the perceived dynamic range of an image. The typical
effect is that in areas that are normally overexposed, additional
structure becomes visible.
The overall idea is that the algorithm applies an exposure value
correction to underexpose the image to the point where only a small
number of saturated pixels is left. This artificial underexposure is
then mitigated by applying a tone mapping curve.
This algorithm implements 4 tone mapping strategies:
- Linear
- Power
- Exponential
- Histogram equalization
Signed-off-by: Stefan Klug <stefan.klug@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
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