Quote:
Originally Posted by RickS
I really like the ability to use a noise estimate for weighting, Roger. It makes mixing mismatched data work quite well. I have even integrated a bunch of narrowband and RGB master frames to make a "superluminance" for a narrowband/RGB hybrid image.
You probably have too much data for it to be convenient, but if you want me to try a noise weighted integration so you can see the result just drop me a PM. [Whoops, just saw Andrew's offer after I hit the button to post my reply...]
Good luck!
Cheers,
Rick.
|
I've found CCDStack can normalize and then stack the exposures weighted according to their exposure time. This sounds very similar except it's basing the weighting on exposure time rather than actual SNR. I suspect there would be some difference in the results from the two methods but stacking weighted by exposure might not end up so bad/different. I will give it a try.
I'm yet to be sure CCDStack doesn't have a similar "weight by noise" feature.
Quote:
Originally Posted by algwat
Gidday ,
Try imageJ, create a stack of all the images.
use the drop menu selection image>>stacks>>Zproject.
Select either sum, average, medium, or maximum.
Adjust the contrast and brightness
drop menu selection image>>adjust>>bright-contrast.
Should be ok for Lum iimages, a bit tricky for RGB sets.
fin imageJ here, http://imagej.nih.gov/ij/index.html
kind regards, Alan |
Thanks for your input Alan. I'm hesitant to get stuck in to yet another stacking program though!
Learning PixInsight and now CCDStack has taken some time and brain power. I'll keep your idea of using imageJ in hand in case I refer back to it ...
Quote:
Originally Posted by alocky
No problems Roger- you could always stick them on a USB drive and leave it up a Perth obs - you can drive pixinsight in batch mode, so it's just a question of processing time. Very little user time involved.
But as Rick has suggested - a weighted average is absolutely the only way to combine data with varying signal to noise.
Cheers
Andrew.
|
Andrew the data transfer isn't an issue, I upload 4-6GB every day anyhow so a couple'a hundred mb isnt' an issue. It's more about being able to do it myself anytime ongoing which I'm sure you realise ... Looking for "weighting" and ways to stack images "weighted" by different metrics has given me somewhere to head. I'll see how I go.
