33
10.1.7 Gamma Correction
With this feature, Baumer LXC cameras offer the possibility of compensating nonlinearity
in the perception of light by the human eye.
For this correction, the corrected pixel intensity (Y') is calculated from the original intensity
of the sensor's pixel (Y
original
) and correction factor
γ
using the following formula (in over-
simplified version):
Y' = Y
original
γ
10.1.8 Region of Interest (ROI) and Multi ROI
With this functions it is possible to predefine a so-called Region of Interest (ROI) or Partial
Scan. The ROI is an area of pixels of the sensor. After image acquisition, only the informa-
tion of these pixels is sent to the PC.
This functions is turned on, when only a region of the field of view is of interest. It is
coupled to a reduction in resolution and increases the frame rate.
The ROI is specified by following values:
▪ Region Selector Region 0 / Multi-ROI horizontal 1-8, Multi-ROI vertical 1-8
▪ Region Mode On/Off
▪ Offset X - x-coordinate of the first relevant pixel
▪ Offset Y - y-coordinate of the first relevant pixel
▪ Width
- horizontal size of the ROI
▪ Height - vertical size of the ROI
Notice
The values of the Offset X and Size X must be a multible of 32!
The step size in Y direction is 1 pixel at monochrome cameras and 2 pixel at color cam-
eras.
Notice
If defect pixels should exist in the first (mono cameras) or in the first two (color
cameras) rows or columns of a ROI, these cannot be corrected with the defect
pixel correction.
In this case you need to move or increase the ROI by a few
pixels.
The coordinates of defect pixels can be read out with the Camera Explorer
(Category: Control LUT).
Start ROI
End ROI
▲ Figure 14
Non-linear perception of
the human eye.
H - Perception of bright-
ness
E - Energy of light
H
E
0
◄ Figure 15
Parameters of the ROI.