58
Piranha4 8K Camera Color User's Manual
03-032-20156-00
Teledyne DALSA
dataProcessing “Flat Field” Group
This group contains a number of features to correct image distortion due to lens vignetting and uneven
illumination:
1.
Flat field coefficients consist of an offset (FPN) and gain (PRNU) for each pixel
2.
These are the first user corrections applied to the image
3.
The flat field coefficients are saved and loaded with the user settings
Name
flatfieldCorrectionMode
Display Name ―Mode‖
Name Space
Custom
Visibility
Beginner
Access
Read-Write
Type
Enumeration
Values
―Off‖
- FPN and flat field coefficients disabled
―On‖
- FPN and flat field coefficients enabled
―Initialize‖
- Reset all FPN to 0 and all flat field coefficients to 1
―ScanDirectionControlled‖
- Different user set loaded depending on direction
Name
flatfieldScanDirectionReverseSet
Display Name " Select flatfield Correction Scan Direction Reverse Set‖
Name Space
Custom
Visibility
Beginner
Access
Read-Write
Type
Enumeration
Values
"UserSet1" to ―UserSet8‖
Name
flatfieldCorrectionAlgorithm
Display Name "Calibration Algorithm‖
Name Space
Custom
Visibility
Expert
Access
Read-Write
Type
Enumeration
Values
―Basic‖
Direct calculation of coefficients based on average line values and target.
First each color is flat fielded to its peak value and then the color gains
are used to achieve the target.
―LowPass‖
A low pass filter is first applied to the average line values before
calculating the coefficients. Use this algorithm if the calibration target is
not uniformly white or it is not possible to defocus the image. Because of
the low pass filter this algorithm is not able to correct pixel-to-pixel
variations and so it is preferable to use the ―Basic‖ algorithm.
