Photon Focus MV0 CMOSIS Series, User Manual, Page: 60 / 111

11 Image Data Processing
Column noise changes with different analog gain settings. The column FPN cor-
rection of the camera needs to be recalibrated when the analog gain setting is
changed.
11.2.3 Storing the calibration in permanent memory
After running the calibration procedure (see Section 11.2.2) the calibration values are stored in
RAM. When the camera is turned off, their values are lost.
To prevent this, the calibration values must be stored in flash memory. This can be done by
clicking on the property
ColCorrection_SaveToFlash (in category ColCorrection ). Wait until the
command has been finished, i.e.the property ColCorrection_Busy (category Correction /
ColCorrection ) is 0. ColCorrection_Busy can be updated by clicking on the property
ColCorrection_Update (in category Calibration ).
Storing the calibration in permanent memory overwrites the factory calibration.
11.3 Gain and Offset
There are three different gain settings on the camera:
Analog Gain Analog gain on the image sensor. Available values: x1, x1.6, x2.0, x2.6, x3.2 and
x4.0. Note that Digital Offset is applied after the Analog Gain .
Gain (Digital Fine Gain) Digital fine gain accepts fractional values from 0.01 up to 15.99. It is
implemented as a multiplication operation. Colour camera models only: There is
additionally a gain for every RGB colour channel. The RGB channel gain is used to
calibrate the white balance in an image, which has to be set according to the current
lighting condition.
Digital Gain
Digital Gain is a coarse gain with the settings x1, x2, x4 and x8. It is implemented
as a binary shift of the image data where ’0’ is shifted to the LSB’s of the gray values. E.g.
for gain x2, the output value is shifted by 1 and bit 0 is set to ’0’.
The resulting gain is the product of the three gain values, which means that the image data is
multiplied in the camera by this factor.
Digital Fine Gain and Digital Gain may result in missing codes in the output im-
age data.
A user-defined value can be subtracted from the gray value in the digital offset block. If digital
gain is applied and if the brightness of the image is too big then the interesting part of the
output image might be saturated. By subtracting an offset from the input of the gain block it
is possible to avoid the saturation.
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