SW-2001Q-CL
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compensates for Pixel Response Non Uniformity (PRNU) for individual pixels.
The algorithm for compensation is different in No-Shutter mode and Shutter-Select mode.
If the operating mode is changed, an adjustment in the selected mode must be made. The
factory default is Shutter-Select mode.
Settings:
0=Off
1=Factory Setting (default)
2=User area
Associated functions:
Command PGR
Applicable modes:
All
7.25. Command PGR – Pixel Gain Correction and Store in User Area
This command initiates the pixel gain correction function, and stores the settings in the
user area.
Settings:
0= activate automatic process
Associated functions:
Command PGC must be set to 2
Note:
•
The image sensors must not be saturated when executing this function.
•
When executing this function, the exposure time and line rate should be the same as
when the camera is operated in the application.
Operating procedure for individual R, G and B channel shading correction:
1.
Before making adjustment,
approximately 30 minutes of warm up is required.
2.
Make sure the output signal is not saturated (<80% of full output is recommended)
3.
Set command PGC=2.
4.
Set command PGR to 0 to initiate shading correction.
5.
If desired, set command SDR to 0 or 1 to activate shading correction to correct the
shading caused by lens or lighting. When the shading correction is performed, the flat-
field correction must be activated before the shading correction is performed.
Principle of Pixel Gain (flat-field) correction (PRNU correction)
Pixel Response Non-Uniformity is, as the name implies, a non-uniformity of the response of
each individual pixel. This means that for a fixed light level each pixel will have a slightly
different output level (response).
To correct for PRNU, the camera’s internal correction circuit captures one or several lines
of data under non-saturated illuminated conditions (not more than 80% of maximum -
Max
Min
Multiply
by
Factor
> 1
Multiply
by
Factor
< 1
Before correction: Non-uniform response from
pixel to pixel
Average
