Photon Focus MV1-D1312C CameraLink Series, User Manual

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4.2 Pixel Response
4.2.1 Linear Response
The camera offers a linear response between input light signal and output colour level. This
can be modified by the use of LinLog
®
as described in the following sections. In addition, a
linear digital gain may be applied, as follows. Please see Table 3.2 for more model-dependent
information.
Black Level Adjustment
The black level is the average image value at no light intensity. It can be adjusted by the
software by changing the black level offset. Thus, the overall image gets brighter or darker.
Use a histogram to control the settings of the black level.
4.2.2 LinLog
®
Overview
The LinLog
®
technology from Photonfocus allows a logarithmic compression of high light
intensities inside the pixel. In contrast to the classical non-integrating logarithmic pixel, the
LinLog
®
pixel is an integrating pixel with global shutter and the possibility to control the
transition between linear and logarithmic mode.
The images delivered by the camera in LinLog
®
mode will require special pro-
cessing by the user. Photonfocus is unable to provide support for this function.
In situations involving high intrascene contrast, a compression of the upper grey level region
can be achieved with the LinLog
®
technology. At low intensities each pixel shows a linear
response. At high intensities the response changes to logarithmic compression (see Fig. 4.10).
The transition region between linear and logarithmic response can be smoothly adjusted by
software and is continuously differentiable and monotonic.
G r e y
V a l u e
L i g h t I n t e n s i t y
0 %
1 0 0 %
L i n e a r
R e s p o n s e
S a t u r a t i o n
W e a k c o m p r e s s i o n
V a l u e 2
S t r o n g c o m p r e s s i o n
V a l u e 1
R e s u l t i n g L i n l o g
R e s p o n s e
Figure 4.10: Resulting LinLog2 response curve
4.2 Pixel Response 27