Guidelines When Using Shading Correction - Basler A400K User Manual

Saving a Set of Shading Values to a File
When you generate a set of PRNU shading correction values, the values are placed in the
camera's volatile memory and they overwrite any shading values that are already in the memory.
The current set of values in the volatile memory is used immediately by the camera. Values placed
in the camera's volatile memory are lost if the camera is reset or the camera power is switched off.
A400k cameras can save the current PRNU values in the volatile memory to a file in the camera's
non-volatile memory. Files saved in the non-volatile memory are not lost at reset or power off. You
can save only one set of PRNU values to file in the non-volatile memory.
A save will take approximately two minutes.
You can save the current shading values to a file in the non-volatile memory by using 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 Create PRNU Shading Values File parameter in the
PRNU Shading Value File parameters group to save the PRNU shading set currently in the volatile
memory to a file in the non-volatile memory.
By Setting CSRs
You can save the current shading correction values to a file in the non-volatile memory by writing
values to the bulk data CSR for PRNU shading values.
Section 4.2.3
values to a file. Section

3.6.4 Guidelines When Using Shading Correction

When using the shading correction feature, make sure to take the following guidelines into
account:
• Any time that you make a change to the optics or lighting or if you change the camera's gain
setting, you must generate new set of PRNU shading values. Using an out of date PRNU
shading set can result in poor image quality.
• When you generate the DSNU and PRNU shading tables, correction values will be calcu-
lated for the pixels in the current area of interest only. If you change the AOI settings, you
need to generate new shading values.
Basler A400k
explains the bulk data CSRs and explains how to use the CSRs to save the shading
4.3.1 explains using read/write commands.
If you save the set of PRNU values to a file, enable the use of shading correction,
and save the current work set to your standard user set, the camera will automati-
cally load and use shading correction at next power on. Loading will take approxi-
mately 25 seconds. After 25 seconds, the camera will start image capture and be
able to receive commands.
DRAFT
Basic Operation and Features
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