Search found 53 matches

by Dave_S
27 Feb 2022, 13:28
Forum: Image processing and analysis
Topic: Histogram Stretch
Replies: 5
Views: 1443

Re: Histogram Stretch

All sorted now :)
by Dave_S
26 Feb 2022, 22:01
Forum: Image processing and analysis
Topic: Histogram Stretch
Replies: 5
Views: 1443

Re: Histogram Stretch

Sum.
by Dave_S
26 Feb 2022, 20:24
Forum: Image processing and analysis
Topic: Histogram Stretch
Replies: 5
Views: 1443

Re: Histogram Stretch

I tried that Iver, but it didn't work, as once stacked, the data that I can recover from a single sub is lost, and I now find that adjusting the image intensity using the scroll, the resulting image view cannot be saved. What I am trying to do, as I always did back in the day, is to layer combine tw...
by Dave_S
26 Feb 2022, 15:23
Forum: Image processing and analysis
Topic: Histogram Stretch
Replies: 5
Views: 1443

Histogram Stretch

Can I apply a Histogram Stretch setting to a batch of images, as opposed to applying it to each image individually, and then saving each one before preprocessing (cal, alignment, and stacking etc) to produce a master image with the chosen Histogram Stretch setting? For example, I have a batch of 30 ...
by Dave_S
15 Feb 2022, 11:29
Forum: Image processing and analysis
Topic: What are these?
Replies: 11
Views: 2267

Re: What are these?

Hi Fabio Thanks for that, it is useful information. The fact that Sum + Sigma will deal with satellite 'streaks' is a very useful feature indeed, as these are a growing problem, year on year. Being slow is not a problem, as being retired, I have all the time in the world. :D I print off all these us...
by Dave_S
12 Feb 2022, 16:05
Forum: Image processing and analysis
Topic: What are these?
Replies: 11
Views: 2267

Re: What are these?

Hi Fabio

Yes, that does indeed also work. :)

Is there any preference for one method over the other, or is either method as good as the other?

Dave
by Dave_S
12 Feb 2022, 12:27
Forum: Image processing and analysis
Topic: What are these?
Replies: 11
Views: 2267

Re: What are these?

Success :) Stacking the light frames using Sigma + Sum, then applying average Darks, removes these "hot Pixel worms" from the final image. I don't profess to understand the mechanism involved, although I'm sure Fabio will, but it works. Whether using Sigma + Sum has any negative impact on the image,...
by Dave_S
12 Feb 2022, 12:05
Forum: Image processing and analysis
Topic: What are these?
Replies: 11
Views: 2267

Re: What are these?

A bit more info. Aligning and stacking (SUM) the light frames, no dark frame subtraction, then applying the Hot Pixel filter using the Bayer Matrix option (100% strength) to the stacked light frame, reduces the intensity of these "hot pixel worms", but does not remove them completely. Is there an op...
by Dave_S
12 Feb 2022, 11:40
Forum: Image processing and analysis
Topic: What are these?
Replies: 11
Views: 2267

Re: What are these?

Ok, I have downloaded a 30 day trial version of APP, but having had a quick look, it is a whole new learning curve, and not particularly user friendly. A headache in itself. I thought PixInsIght was bad enough :roll:

I'm hoping that I can resolve this issue with AA8, and can continue using it.
by Dave_S
12 Feb 2022, 10:43
Forum: Image processing and analysis
Topic: What are these?
Replies: 11
Views: 2267

Re: What are these?

I cannot see any trace of them in the individual subs, albeit if they are hot pixels, they would be no more than specks in an individual sub. It is not until they are stacked (SUM) that they become evident, either before, or after dark frame subtraction. The image shown here is aligned, stacked (SUM...
by Dave_S
12 Feb 2022, 10:23
Forum: Image processing and analysis
Topic: What are these?
Replies: 11
Views: 2267

Re: What are these?

Tried that, but no different.

I might try using Astro Pixel Processor, if there is a demo version available.
by Dave_S
12 Feb 2022, 09:43
Forum: Image processing and analysis
Topic: What are these?
Replies: 11
Views: 2267

Re: What are these?

Ok, I'll give that a try. I have just been averaging the dark frames. I seem to remember reading somewhere that no form of pre-processing should be applied to these CMOS dark frames. I wonder if that means doing nothing to them, i.e selecting "None" in the option menu, apart from stacking them? Don'...