Life Module Use

Notes from users, documentation addendums.

Life Module Use

Postby Guy » Thu Feb 02, 2017 9:40 am

Here are some notes relating to using this module. It is not the only way to use the module - please experiment and provide feedback.
Please let me know if anyone sees any errors or has any additional advice they think helpful so this post can be improved.
I will update this post as needed.
To see a full alphabetical list of module topics click here

Life Module

  • To bring back life into an image by remodelling uniform light diffraction. Removes the flatness that heavy processing can cause bringing back some of the 3d effects.
  • To lift objects from very noisy data or dense star fields
For a general overview see Life: Global Light Diffraction Remodelling of Large Scale Structures.

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.
The video 'StarTools: Lifting structures from heavy noise with the Life module' shows the use of Isolate preset with mask set: From the start to 5m27s.

When to use:
  • Towards the end of the workflow - usually just before using the Color module or the final Denoise
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

This is a way of using the module which should give good results in most cases:
Isolate preset - to push back noise/starfield
  • Select Isolate preset - this sets most of the controls to their optimum.
  • Set Strength - to adjust the impact of the Life module. Normally somewhere between 30-100% - use your judgement.
  • Set Saturation - Change this to adjust the amount of 'glow'.
Other Presets - to add 'life' to the image - increased glow and a more 3-dimensional effect.
  • Select Heavy, Medium or Less=More preset depending on the type and amount of effect needed.
  • Set strength - to adjust the impact of the Life module. Normally somewhere between 50-100% but can be less - use your judgement.
  • Set Saturation - Change this to adjust the amount of 'glow'.
  • When you are finished 'Keep' the result.
What result to look for:
  • Isolate Preset - objects should be lifted from the noise and background stars. Watch for halos around bright stars.
  • Shroud preset - The image should look brighter without background noise or starfields being more prominent.
  • Other presets - Images should look less flat and detail looks more 3-dimensional.

After Use:
  • Often followed by the Color module.
Special Techniques:

Push Back noise using the Isolate preset with a mask.
This is described in the video 'StarTools: Lifting structures from heavy noise with the Life module' from the start to 5m27s.
  • Open the Life module.
  • Create a mask which is initially clear but which you put green in the areas of detail you want to exclude.
    • for long thin wisps (e.g. veil) - create a trail of individual green pixels (Using Single Pixel Toggle Brush Mode) then use Grow until they join up and cover the whole area of detail.
  • Press 'Isolate' preset.
  • Increase 'Mask Fuzz' to 3-4.
  • Press 'Do'.
  • Press 'Keep' when happy with the result.
Description of Controls:

For general instructions on using mask see Mask
  • A mask can be used to selectively 'add life'.
  • The mask can be used in conjunction with the 'Isolate' preset to select the object(s) to be lifted.
  • Moderate - Applies a moderate application of the 'life' algorithm.
  • Heavy - A more aggressive application of the 'life' algorithm.
  • Less=More - Applies a light application of the 'life' algorithm.
  • Shroud - Helps brighten an image without emphasising background noise or starfields.
  • Isolate - Lifts objects from noisy data.
Inherit Brightness, Color
Sets whether brightness or colour information is preserved
  • Brightness
  • Color
  • Off
  • Default is Off (Moderate preset)
Glow Threshold
Sets how bright a pixel needs to be in order to be considered for diffraction.
  • Range is 0% to 100%.
  • Default is 12% (Moderate preset), 5% (Heavy), 4% (Less=More), 3% (Shroud), 0% (Isolate).
  • Setting a lower value will cause more pixels to be processed and so processing will take longer.
Output Glow Only
Set if only the calculated diffracted light (glow) is output.
  • Default is No
Sets the colour saturation level of the extracted diffracted light (glow) before it is combined with the original.
  • Default is 50%. Range is 0% to 500%.
  • Change this to adjust the amount of 'glow'.
Detail Preservation
Sets the way that Life preserves the detail in the parts of the image to be brightened.
  • Off - does not preserve any detail.
  • Min Distance to 1/2 Unity - uses the pixel that is closest to half unity.
  • Max Contrast - uses whatever pixel maximises contrast.
  • Linear Brightness Mask - uses a brightness mask that progressively masks out brighter values and uses the original values instead.
  • Linear Brightness Mask Darken - uses a brightness mask that progressively masks out brighter values. Only pixels that are darker than the original image are kept.
  • Default is 'Min Distance to 1/2 Unity' (Moderate & Heavy preset), Linear Brightness Mask (Less=More, Shroud & Isolate).
Detail Preservation Radius
Sets a filter radius that is used for smoothly blending processed and non-processed pixels, according to the algorithm specified.
  • Default is 20.0 pixels. Range is 1.0 pixel to 50.0 pixels.
Compositing Algorithm
This setting defines how the calculated diffraction glow is combined with the original image:
  • Screen - works like projecting two images on the same screen.
  • Power of Inverse - Combination based on Power of Inversed Pixels (PIP) function.
  • Multiply, Gamma Correct - multiplies foreground and background and then takes the square root.
  • Multiply, 2x Gamma Correct -
  • Default is 'Power of Inverse' (moderate), Screen (Heavy preset), Multiply, Gamma Correct (Less=More, Isolate), Multiply, 2x Gamma Correct (Shroud)
Controls the overall strength of the effect.
  • Range is 0% to 500%.
  • Default is 100% (for Moderate, Heavy, Isolate presets), 50% (Less=More), 75% (Shroud)
Airy Disk Sampling
Sets the number of samples in the Airy disk point spread function (PSF).
  • Default is 128 x 128 pixels. Range is 128 x 128, 256 x 256, 512 x 512 pixels.
  • Increasing this value will give a more accurate simulation but will take longer.
Airy Disk Radius
Sets the radius of the Airy disk point spread function (PSF) that is used to diffract the light.
  • Default is 8 pixels. Range is 0 pixels to 64 pixels.
  • There are subtle rings around the stars after processing. The way this looks can be adjusted using this setting.
Mask Fuzz
When using a mask, this sets the smoothness of the transition between masked and non-masked elements.
  • Default is 1.0 pixel. Range is 1.0 to 40.0 pixels.
  • Increase to make the transition smoother - values of 10 pixels are common.
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