M27- Resurrected with PI
Posted 07 April 2013 - 10:47 PM
Color is very difficult on this target. Did I go overboard? Comments welcome.
Higher res at 2x2 bin
Below is the old version done in 2009, I believe.
Posted 11 April 2013 - 09:13 PM
Posted 12 April 2013 - 12:00 AM
Posted 12 April 2013 - 12:14 AM
So the second time around, I did not push the saturation while combining. I did use curves to boost saturation later.
I deleted the image at the first link. Unfortunately I cannot edit my post any more.
Erik, The soft teal was done inelegantly and as you can see the effect on other parts of the image is quite drastic - clipped back ground, no star color etc.
Appreciate the feedback.
Posted 12 April 2013 - 08:35 AM
Posted 12 April 2013 - 11:13 AM
Posted 12 April 2013 - 11:41 AM
The only option I have is Extract CIE L* (lightness) not CIE Y (Luminance) When I extract lightness and run LGRB combine unchecking RGB, it tells me it can't run on grayscale images.
Posted 12 April 2013 - 07:59 PM
* After calibration, registration, integration and running DBE, I extracted the lightness component (CIE L*). This is what I referred to as L. The original image is the LRGB image.
* Did Atrous Wavelet Noise reduction on both L and LRGB.
* Did a custom Richardson Lucy Deconvolution on the L component: http://www.manuelj.c...1767553866&a...
* Individually stretched and did HDR Multiscale transform on each component.
* Combined components after this step, using the usual LRGB combination procedure. For the latest M27 image I set the midpoint of the L histogram at 48 and that of the LRGB at 43 during combination to get a boost in saturation. Here's a link to Harry's Tutorial on this step: http://www.harrysast...d.com/lrgb.HTML
* Morphological transformation to reduce star size. If you do this on the L and LRGB components separately, make sure you use the same setting or you could end up with halos.
* Local Contrast Enhancement. If you do LHE without star size reduction, the large bright stars will be too bold.
* From this point on do whatever processing you usually do. I did a little more saturation boost, slight tweak to the color, 2x2 binning and then some Unsharp Mask.
Hope this helps. I hope to try similar steps on other images soon.