Quote:
Originally Posted by naskies
Thanks Mike!  No offended at all, if anything I'm actually rather curious... I think I know the types of false-signal artefacts you're referring to; they're particularly infamous amongst the planetary imagers.
To the best of my knowledge, all the structures that I can see in the final result are visible in the raw screen-stretched-only stack (so they're "real" as far as I'm aware).
I've attached two crops with no processing. The first image is of a very high SnR region that has been linearly stretched (0, 0.5, 0.33) in PI, followed by 200% resampling using nearest neighbour for clarity. The second is of a very low SnR region in the background - linearly stretched (0, 0.5, 0.0125) and 200% resampled again. In both cases, there was *no* other processing - no wavelets, no multiscale processing, no sharpening, no deconvolution, etc applied.
When I compare the raw stretches to the final result - I can see the same fine structures in both. The "spotty background" is just noise from the depths of my CCD due to the extreme stretching (20 subs isn't really enough to smooth out the background given the amount of thermal noise I have with 60 min subs @ -10 deg C). At 86 hours, I'm definitely at the "diminishing returns" point of further data collection 
I think the "black magic" you refer to comes from PI's amazing ability to compress dynamic range. There's a huge amount of subtle detail in the Cat's Paw, but I think it tends to get swamped by the dynamic range. I'm very much a PI newbie though so it's sledge hammer strokes rather than fine tooth comb at this stage 
Anyway, thanks for your honest opinion. I'm curious what you think (or anyone else) after seeing the unprocessed crops?  |
Yeah ok.
I think, like what we saw with the various processing approaches taken on Berts free Eta Carina data a few months back, this is just a new
style of processing
...my eyes are slightly alarmed by it that's all, kind of
looks processed not that that is a bad thing of course, at times
pushing things is done to emphasise the extreme and that's ok, and I do this at times myself
Again very impressive looking and dramatic result
Mike