122
Figure 16: Corresponding histogram after adapting saturation
1.18.2.3 Working With Gain And Black-Level Values Per Color Channel
In many low-lighting applications the gain needs to be increased to enhance the brighness of the images. However,
while the image brightness is increased, the black-level of the image is also increased, which in many cases should
be avoided. With the help of the GainOffsetKnee filter it is possible to correct/adjust the overall black-level as well
as the black-level per color channel, even when the gain is applied. Figure 1 shows the working principle of the
GainOffsetKnee filter.
Figure 1: The GainOffsetKnee filter working principle
The GainOffsetKnee filter is one of the image processing methods performed on the host. It allows you to adjust:
• The overall offset (i.e. overall black-level) of an image.
• The individual gain per color channel.
• The individual offset (i.e. individual black-level) per color channel.
MATRIX VISION GmbH