Saving Dsnu And Prnu Shading Correction Values - Basler L800k User Manual

Operation and Features
7. Once 16 lines have been captured, the camera calculates the PRNU shading correction
values:
a) The camera uses the data from the 16 captured lines to calculate an average gray value
for each pixel in the line.
b) The camera finds the pixel with the highest average gray value in the line.
c) For each of the other pixels in the line, the camera determines the additional gain that
would be needed to make the pixel's average value equal to the average value for the
highest pixel.
d) The camera creates a set of PRNU shading correction values that contains the
calculated gain adjustments.
The set of PRNU values is placed in the camera's volatile memory. This set of values
overwrites any PRNU shading values that are already in the memory. The current set of
PRNU values in the volatile memory is used whenever PRNU is enabled.
Enabling PRNU Shading Correction
Once you have a set of PRNU shading values in place, you can enable and use PRNU shading
correction. With the PRNU correction feature enabled, the camera will use the set of PRNU
shading values to apply the appropriate gain adjustment to each pixel to correct for PRNU.
You can enable PRNU shading correction with the Camera Configuration Tool Plus (CCT+) or by
using binary read/write commands from within your own application to set the camera's control
and status registers (CSRs).
With the CCT+
With the CCT+ (see Section 4.1), you use the Shading Mode parameter in the Image
Enhancement parameters group to enable PRNU shading correction.
By Setting CSRs
You enable PRNU shading correction by writing a value to the Mode field of the Shading Mode
CSR (see page 4-39).
Section 4.2.2

3.9.1.4 Saving DSNU and PRNU Shading Correction Values

When you generate a set of DSNU shading correction values, the set is placed in the camera's
volatile memory and overwrites any existing values in the memory. The same is true when you
generate a set of PRNU shading values. The DSNU and PRNU shading values currently in the
volatile memory are used whenever shading correction is enabled.
Values in the camera's volatile memory are lost if the camera is reset or the camera power is
switched off. On L800
the volatile memory to a file in the camera's non-volatile memory. When you perform the process
to save the shading values, the DSNU values and the PRNU values currently in the volatile
memory are stored together as a complete set in a single file in the non-volatile memory. Files
saved in the non-volatile memory are not lost at reset or power off. You can save one complete
set of DSNU and PRNU shading values to a file in the non-volatile memory.
3-28
explains CSRs and Section
cameras, you can save the DSNU and PRNU shading values currently in
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Draft
4.3.1 explains using read/write commands.
BASLER L800
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