Desperation forced me to get into the world script writing (thought I had given up programing when I retired!!) and I have come up with two scripts which I now use on a regular basis, they can be down loaded from the URL below:
http://www.qdigital-astro.com/pixinsightscriptsThe two scripts are:
StarReduction
LargeScaleStructureEnhance
I am just doing the instruction/information sheets at the moment so these will a few days before they are finished.
Both scripts are designed to work on monochrome images although I have tested them on RGB images and they do give acceptable results, however, they are both intended to be used within the normal PI workflow after Dynamic Crop, DBE and initial stretching with HT, but before combining into RGB.
StarReductionDoes exactly what it says on the tin, it reduces the size of stars. The script can be run more than once to reduce the star size still further. It also has facilities to measure the mean FWHM and slightly sharpen the stars after reduction.
LargeScaleStructureEnhanceThis script will enhance faint large structures such as Integrated Flux Nebulae (IFN) which are very close to the noise floor and is based upon the workflow as developed by Rogelio Bernal Andreo and fully described in the article (page 97) in Robert Gendler's book Lessons From The Masters.
From a technical standpoint, and being very pedantic, just removing the stars from an image using Straton is not the same as actually splitting an image into its Large and Small Scale Structures. I therefore decided not to go the Straton route but to adopt Rogelio workflow as being a more correct approach. I may develop a Straton look-alike script but have not yet decided.
Default OperationWith the check boxes set to their default settings (Extract Large and Small scale checked, all others un-checked) the script will split the image into its Large (LSView) and Small (SSView) Scale structures and these become available for further processing. Rogelio recommends a slight HT stretch on the SSView and a more aggressive stretch on the LSView.
Re-combine the two images by using PixelMath with the expression LSView + SSView after they have been processed and re-stretch the final image, you can use Auto Stretch or STF to give you a rough idea of how much stretch it needs.
You will find that the LSView just doesn't look right and is blurred, this is quite normal as you are seeing an image that has no small strucuture detail.
Optional OperationOptionally you can let the script do the stretching of the LSView and SSView and then combine the two images into a final image, the LSView being stretched more aggressively than SSView. Complete the process by re-stretching this final image, you can use Auto Stretch or STF to give you a rough idea of how much stretch it needs. There is a choice of streching either view, both views or neither prior to creating the final image, this produces perfectly acceptable results, however, it is better to have direct control on the amount of stretching of the Large and Small scale views, and possibly perform other operations on them before re-combining using the Default Operation described above.
ExamplesMaster Ha image Dynamically Cropped, DBE and stretched with HT
[image Grayscale_Non_Linear.jpg]
Master Ha image after processing with LargeScaleStructureEnhance and one application of StarReduction.
[image Grayscale_Non_Linear_LSE_SR.jpg]
If you try either of these scripts I would appreciate some feedback and let me know of any problems or enhancements.
Regards,
Dave
