Author Topic: SHOW ME THE NOISE AD GRADIENTS  (Read 2163 times)

Offline tdgm

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SHOW ME THE NOISE AD GRADIENTS
« on: 2016 December 17 11:30:43 »
Hello Everyone


Moved from Image Processing Challenge

I ave been using PixInsight for as while now and am starting to understand how to use the Noise Reduction processes as well as the background modelization  as well. I have followed video's and books as well. What I have not seen is visual examples of gradients and Noise. An example would be to see the background model of a specific image so people can actual where the gradients are. It would also be appreciated if I could see examples of noise in an image especially in background and in object of the image.

Lastly I have used the extract wavelets script but need a lot better explanation of what the noise is in each level (what is noise and what is not noise in each wavelet not written but a visual example.

If this has been done somewhere I have been umable to find this and could you direct me in the right direction


Thanks for any assistance  you could provide

steve

Offline pfile

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Re: SHOW ME THE NOISE AD GRADIENTS
« Reply #1 on: 2016 December 17 12:08:32 »
gradients (extreme example)


Offline pfile

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Re: SHOW ME THE NOISE AD GRADIENTS
« Reply #2 on: 2016 December 17 12:09:11 »
gradients, final result (not perfect but close enough)

Offline pfile

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Re: SHOW ME THE NOISE AD GRADIENTS
« Reply #3 on: 2016 December 17 12:22:35 »
noise


Offline pfile

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Re: SHOW ME THE NOISE AD GRADIENTS
« Reply #4 on: 2016 December 17 12:23:00 »
noise2

Offline pfile

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Re: SHOW ME THE NOISE AD GRADIENTS
« Reply #5 on: 2016 December 17 12:23:53 »
noise3


Offline tdgm

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Re: SHOW ME THE NOISE AD GRADIENTS
« Reply #6 on: 2016 December 17 13:32:45 »
Hello pfile

Thank you for responding. Just to clarify the noise images you sent were different scale layers or was it just total number of images? Obvious does not look like extract wavelet images so I am assuming they are just the amount of stacked images/ Just please clarify for me.

Steve

Offline pfile

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Re: SHOW ME THE NOISE AD GRADIENTS
« Reply #7 on: 2016 December 17 16:02:41 »
yeah sorry, had to leave right after posting those, the number in the filename is the # of 10-min frames thru a B filter on a 92mm f/5.5 telescope. you can see the noise in the outer arms of m33 decreasing as the frame count goes up, and the histogram taking a "real" shape instead of just a gaussian shape.

rob

Offline tdgm

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Re: SHOW ME THE NOISE AD GRADIENTS
« Reply #8 on: 2016 December 17 22:43:06 »

That helps

Thanks

Offline jkmorse

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Re: SHOW ME THE NOISE AD GRADIENTS
« Reply #9 on: 2016 December 20 14:32:55 »
Rob,

Can you share the settings you used for the DBE process.  I rarely get as detailed a final gradient image as the one you included.  Would love to see what settings you are using.

Thanks,

Jim
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Offline pfile

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Re: SHOW ME THE NOISE AD GRADIENTS
« Reply #10 on: 2016 December 20 15:27:06 »
i will have to go dredge up the project - all the images are from a presentation i gave some time ago. generally speaking i never have to tweak the DBE settings beyond increasing the tolerance and setting the mode to subtraction. i think all that's special here is the inclusion of so many points to pick up all the crazy stuff in that image (i think i am suffering from internal reflections induced by stray light and light pollution)

rob