Banding Reduction

In some cases, images may suffer from a banding defect. This is usually caused by the sensor and calibration by darks, bias and flats do not improve the images.

The banding reduction window dialog has some parameters to optimize the processing:

Amount defines the strength of the correction. The higher the value, the stronger the correction.
Protect from Highlights will ignore bright pixels when the option is checked.
1/Sigma Factor will adjust the highlight protection. Higher value will give a better protection.
Vertical banding allows user to fix banding if bands are vertical.

Applying the following filter to the original image, with parameter values as shown in the illustration, gives a nice result free of banding.

This transformation can easily be applied to a sequence. You just have to define the transformation on the loaded image (with a sequence already loaded), then check the Apply to sequence button and define the output prefix of the new sequence (unband_ by default).

Siril command line

fixbanding amount sigma [-vertical]

Tries to remove the horizontal or vertical banding in the loaded image.
amount defines the amount of correction, between 0 and 4.
sigma defines the highlight protection level of the algorithm, higher sigma gives higher protection, between 0 and 5. Values of 1 and 1 are often good enough.
-vertical option enables to perform vertical banding removal, horizontal is the default

Siril command line

seqfixbanding sequencename amount sigma [-prefix=] [-vertical]

Same command as FIXBANDING but for the sequence sequencename.

The output sequence name starts with the prefix "unband_" unless otherwise specified with -prefix= option

Links: fixbanding