Page 1 of 1

Band Module Use (v1.5-v1.7-)

Posted: Mon Jan 30, 2017 9:46 am
by Guy
Here are some notes relating to using this module. It is not the only way to use the module and experimentation is encouraged.
Please let me know if anyone sees any errors or has any additional advice they think helpful.
These notes relate to StarTools versions 1.4 to 1.7.422
I will update this post as needed.

Band Module

Purpose:
  • To remove banding usually caused by sensor read noise.
Description:
For a general overview see Band: Banding Reduction
The module allows application of one of two algorithms to reduce vertical or horizontal banding.

Useful Sources
The Unofficial guide is also a good source of help. It relates to version 1.3.5 so there may have been some changes. The notes below relate to StarTools version 1.4.
There are general instructions for the use of the Band module here.

When to use:
  • Use if there is banding visible when you do the initial global stretch (AutoDev).
  • The Band module works best on linear data - but will attempt to compensate for any stretching.
  • Ideally it should be used after the initial global stretch (AutoDev) - but don't 'Keep' the result - and before the final global stretch (AutoDev or Develop).
  • The earlier you remove the banding, the fewer modules that will have to work with the 'tainted' data.
  • Experiment to see when it is most effective.
Example Workflow:
AutoDev-{Band/Lens}-Bin-Crop-Wipe-AutoDev(or Develop)-{As needed: Decon/Sharp/Contrast/HDR/Flux/Life}-Color-{Filter}-Denoise-{If needed: Layer/Magic/Heal/Repair/Synth}
Key: {...} optional modules

Method:
This is a way of using the module which should give good results in most cases:
  1. Set Orientation so that it matches the orientation of the banding your are trying to get rid of.
  2. Set Algorithm to 'Algorithm 1' (default) - If this does not improve the banding well then try 'Algorithm 2'
  3. 'Keep' the result when you are happy with it.
What result to look for:
  • The banding should be reduced significantly.
Ways of getting better results:
  • Using Bias sub-frames when stacking may get rid of the banding altogether.
After Use:
Start the main workflow.

Description of Controls:
Mask
  • The mask is not used in the Band module even though the button appears.
Orientation
Sets the orientation of the banding to be removed. Since this banding relates directly to the sensor the banding is always aligned with the sensor.
  • Vertical - removes vertical banding.
  • Horizontal - removes horizontal banding.
Algorithm
Specifies which banding-reducing algorithm to use.
  • Algorithm 1 - Usually gives best results.
  • Algorithm 2 - Is better than Algorithm 1 in certain circumstances.
Background Notes

When to use the Band Module
When to use the Band module is a little bit more care than many of the other modules.
The Band module is not currently Tracking aware - so ideally should be used either:
  • When tracking is off:
    • Before Tracking is turned on: Load image - say that it is modified - do the Banding reduction - then turn Tracking on and process as normal. See topic Band Module - where in workflow to use.
    • Before Tracking is turned off.
  • While the data is still linear (before final AutoDev or Develop module use).