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View Full Version here: : My reprocess of DP's 26th April data


iceman
16-05-2006, 06:45 AM
Hi all.

DP was kind enough to upload his great data from the 26th (http://www.iceinspace.com.au/forum/showthread.php?t=9991) for all of us to have a play with.

I had a quick play yesterday afternoon. My results are below.

To compare with Dave's process, here's a link to Dave's processed version (http://www.iceinspace.com.au/forum/showthread.php?t=9545&highlight=26th).

The data was great.. the image scale is huge! Due to the sheer size of it, it would probably warrant MAP processing on different features of the planet, and merge them all afterwards. If it was my image, i'd probably go back and do just that. Given the image scale, i'd probably agree with Dave's rating of 9/10 seeing. Though there's always room for improvement, so I'd probably rate it 8.5/10.

I started by splitting the BMP frames into separate R/G/B channels, and feeding them separately into registax.

For this exercise, I didn't do MAP processing. I only aligned on 1 feature; a 128px window centered on the blue festoon to the left and above of Io's shadow. I kept Io and the shadow out of the alignment frame due to their speed of orbit.

I used Gradient estimator in registax. I don't really pay any attention to what the % value is set at, as I just drag the slider when it's finished aligning to the point where the curve starts heading up. With this data, because the seeing was so good, and almost all frames were equally good, I left the slider at the far right and took all 500 ranked frames to the "Optimise" stage.

At the "Optimise" stage, I create reference frame (50 frames), and used wavelets 3@10 and 4@15, hit continue, and them optimise.

I stacked the best 110 frames by dragging the vertical slider down, as the graph was a nice curve, low on the left to high on the right.

Now I did something different. Usually at this step, I will do a medium wavelets process, followed by LR deconvolution of each channel and recombine in AstraImage.

But I didn't do that this time. I was reading an article somewhere, and combined with Janoskiss's insight into deconvolution, that said deconvolution should be done before wavelets.

So I saved the final stacked image from each channel, with no wavelet processing.

Into AstraImage, converted each channel to greyscale and did a LR deconvolution (12/2.5). Recombine and adjust R/B planes slightly. Save as TIFF.

Back into Registax with it, straight to wavelets tab (since it's a single image), and did some mild wavelets adjustment. Gamma curve adjust. Save as TIFF.

Into Photoshop with it, curves and levels adjust and slight unsharp mask.

That's it! I also resized down 75% for the second attachment, to see how it looks.

I'm quite pleased with the result of the new processing method. I plan to go back through my data of the 7th May and see what results I can get with similar processing, and compare to my original processed version.

I don't know if it's better or worse than DP's, but it is a bit different. The third attachment is DP's original.

Happy to hear your comments, and I look forward to seeing others efforts on the same data.

Many thanks to DP for letting me play with his data, it's fun to do when the weather is so bad and you don't have tracking anymore! :)

matt
16-05-2006, 07:39 AM
Very nice work, Mike. Also some very handy tips there.

I'll be doing my best to follow your process path when DPs vid arrives on disc, hopefully today.

I'll post my results ASAP.

Tis gonna be very nice to work with some good data.:)

Thanks again DP....

iceman
16-05-2006, 07:41 AM
Thanks Matt.

How come you can't download it, Matt? It's only 80meg ish :)

matt
16-05-2006, 08:02 AM
Mike.

Home is dial-up...

Girlfriend's place has broadband.

DP offered to send it "in a bag" ... I accepted;)

Couldn't wait til end o' week before heading over to GF's pad to get my hands on the data:rofl:

Lester
16-05-2006, 08:15 AM
Hi chaps,

Great thread, well done David :thumbsup: . I down loaded it yesterday= 90minutes but cannot open it, so I am a bit reserved to try again as my computer skills are very very basic.:newbie:

Will watch your results with interest.:astron:

Robert_T
16-05-2006, 08:31 AM
Hi Mike, great re-process on a great image. I can't really pick between them either, both are brilliant but different.

I'll have to try that reversal of deconvolution and wavelets and see what happens - ta!

cheers,

davidpretorius
16-05-2006, 09:59 AM
well done mike, i have tried the reverse process on this data, and did not see any noticeable effects.

i can see i need to take the "sheen" out of mine and less saturation to get the browns, brown and not more orange.

top stuff.

Hey Lester, i have put a link to winrar.exe for you to download to open up the compressed files. It is in the original thread