before/after comparison

[gabrieli]

Since some people liked the prom image, I thought it would be interesting to show what the raw stacked tiff looked like before it was transformed by some more aggressive than usual processing into the final posted image.

Looking at how hopeless the stacked tiff appeared, I'm sure that I've tossed away many useable files in the past
that could have given acceptable results before I learned what I know now about processing in AstraImage5.
I only toss the file after processing attempts don't work well. Since the processing is a bit over the top and produces noise, I often have to run the processed tiff through NeatImage.

The final image was cropped a bit and the blocking disc was added in PS.

I always record in 16 bit mode. I find it allows more processing before artifacts show up. In some cases, it reduces banding especially in the "sky" around the sun.

Lou

comparison.png (474.83 KiB) Viewed 489 times

[MAURITS]

I know what you mean Lou with "how hopeless the stacked tiff appeared".
The processing what you have done is SUBLIEME.

[EGRAY_OBSERVATORY]

Hi Lou, quite amazing how the fine detail of the final processed image has evolved from the TIFF.
I've made a note of that processing program and will try it out.

Thanks for sharing
Terry

[H-Alpha]

Lou you are making miracles!!!!!
Congratulations and thanks so much for sharing!
Will try to download and use the software you mentioned.
Amazing work!
All the best,
Alexandros

[RodAstro]

That is one beautiful prom and image Lou
Brilliant bit of processing to bring it out.
Do you use deconvolution at any point in the process?

Rod

[DeepSolar64]

It's amazing what good processing will do!

[gabrieli]

For Rod and others that want to play with this method:

I use AstraImage(on a Mac Pro under Wineskin), Photoshop, and NeatImage( if noise is an issue) for this technique. The tools used are Wavelets, Unsharp Mask, and denoising. You can try Wavelets and Unsharp mask in other applications as well. I don’t usually use deconvolution.

I use this method to rescue bad looking stacked tiffs. Not all poor tiffs can be rescued. You can't tell until you run the steps.

I start off with a 16 bit stacked tiff and import it into Astra image.

Then, I apply wavelets with medium and large strengths set to maximum.

After that, I apply Unsharp mask with a radius of 2 or 3 pixels and strength set to maximum.

Then I go back to wavelets and set the large slider to 0 and increase the medium slider slowly until I see noise or artifacts and then pull back a bit. There may be unavoidable noise at this stage.

Then levels are used to bring out dim details, increase the contrast and darken the “sky”.

When you save (tiff 16 bits) be sure you choose 16 bits since higher bit levels might not be recognized
in Photoshop or NeatImage.

I sometimes use Photoshop Layers to enhance selected areas of the image.

Then I examine the image for noise. If noise is a problem, I import the tiff into NeatImage.

NeatImage has a free trial version which will process a tiff but outputs only jpeg images (which is the format posted on Solarchat anyway).

Note that Astra Image 5 has wavelets, many types of sharpening, gamma, levels, and many other features that might not be required.


Lou

[Montana]

Wow!! that is a huge amount of detail to come from the fuzz, quite amazing really. I think I would have given up
I've never got AstraImage to work very well as it is so slow I get bored waiting to see what changes a little tweak makes, so never get anywhere. I have always had better results from ImPPG. But this is certainly miraculous

Alexandra

[gabrieli]

Hi, Alexandra

There are many shades of grey in a high bit depth image that most screens can't display and the eye can't notice. Software can exaggerate the differences so that they can be seen.

The only part of AstraImage that is slow is deconvolution even though it has a quick preview. I stopped using it for that reason as well in favour of wavelets and other methods.

Lou

[p_zetner]

Thanks for presenting your workflow, Lou.
The results are amazing with no signs of artifacts whatsoever.
Cheers.
Peter