PixInsight Forum (historical)
PixInsight => Image Processing Challenges => Topic started by: LorenzoM on 2012 May 08 14:04:44
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Hello, i use this post to present my raw data and to invite anyone to do better than me.
To this link you can download raw fit, calibrated with bias and dark.
Unfortunately i have not flats.
http://dl.dropbox.com/u/59547074/Public%20Fits/NGC1333.fit
Enjoy it and good work!!!
The frames was been acquired under dark sky using a sbig ST2000 and a William Optics FLT98 F/5; attached my version.
I would you like to use this post also to talk about acquiring and processing of subjects with dust regions, mixed with riflection nebulas.
My problem in processing this kind of subjects is related to the weakness of dust and lightness of reflection regions.
To bring out dust is often necessary to perform three or more stretch, however reflection areas and stars will be burned.
I can apply a mask and so to do more stretches in regions with only dust applying a little heavy noise reduction, but the difficult is in creating the mask because dust has not defined edges and there is the risk to create an evident gap between background and dust itself.
There are particular attentions in acquiring light frames?
So how do you procede to process dust? I would like to collect some experiences about processing.
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Hi Lorenzo,
Could you please upload your single frames? This artifact can be processed during image integration.
Regards,
Vicent.
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Hello Lorenzo,
I am not very experienced with those dark Nebulas, but this is my attempt. I used a Mask from RangeSelection with this parameters:
P001.lowRange = 0.240000;
P001.highRange = 1.000000;
P001.fuzziness = 0.20;
P001.smoothness = 30.00;
No noise reduction because I don't linke the results...
CS TeeJay
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Hi Lorenzo
Here is my result ....
NGC1333
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Noise Reduction
1. MMT layer 1: S(t=1.25,s=1.00,a=0.00)
layer 2: S(t=0.70,s=1.00,a=0.00)
2. MorphTransf
morphol. median
Iter: 3 amount: 0.35
size 3; shape +
Stretching of image
3a. Masked Stretch
Iter: 75
target med: 0.080
3b. Masked Stretch
Iter: 125
target med: 0.080
4. HT RGB/K
shad: 0.0777
midt: 0.0150
Star Mask
5a. ATWT deleting all layers above 6 (incl.) from copy of original
image
5b. HT on Mask
shad: 0.07
midt: 0.15
5c. ATWT deleting layer 1 (blurring)
Large Scale Mask
6a. PixelMath
image(ngc1333) - 1.1*Star Mask
6b. CT (S-curve)
I: 0.060 O: 0.045
I: 0.270 O: 0.370
7. HDRMultiscaleTransf with Star Mask applied (prot. stars)
nb layers: 5
x lightness mask
8. CT with Large Scale Mask applied
I: 0.085 O: 0.200
I: 0.250 O: 0.430
Creation of Range Mask
9a. Lower lim: 0.50
upper lim: 1.00 smoothn:7.50 x invert
9b. CT I: 0.45 O: 0.25
10. ATWT with Range Mask applied
layer 2: +0.030
layer 3: +0.030
layer 4: +0.040
layer 5: +0.060
layer 6: +0.060
layer 7: +0.060
11. LocalHistEqual
kern r: 26
contr lim: 1.3
12. CT (S-curve)
I: 0.10 O: 0.08
I: 0.34 O: 0.40
---------------------------------------------------
and the image .....
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Thank you very much for taking up the challenge.
I will answer to every one!
First the image is just 3.5 hours, and was acquired under dark sky but with a lot of moisture so the signal is not really strong.
For this reason the processing with PI is quiet complicated, as i have just observed PI is an incredible software but just if you have a lot of signal, otherwise any tool amplifies the noise and finally it's difficult contain it with noise reduction.
Could you please upload your single frames? This artifact can be processed during image integration.
Yes i can, you can download single frames from here, frames are not calibrated so is included integrated bias and dark.
It's first time i hear image integration has an active part in processing, i am used to think it as a neutral step.
i am really courios...
http://dl.dropbox.com/u/59547074/Public%20Fits/NGC1333.rar
Thank you TeeJay for your attempt, in my opinion the result is not bad, but there is a little too noise so the very difficult step is precisely the noise reduction, so you have avoided the worst ;)
Thank you too Raymond, i think you have a little exaggerated the the background is patchy, the image has not so much signal to allow the use of so much tools.
And stars have gone out of control. Can you post an highest resolution? jpeg compression has ruined a lot the image.
Calmly i will apply your steps, but trying without ATWT and LocalHistEqual.
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Yes i can, you can download single frames from here, frames are not calibrated so is included integrated bias and dark.
It's first time i hear image integration has an active part in processing, i am used to think it as a neutral step.
i am really courios...
Anything is neutral in image processing but our mind. ;)
Will take a look.
Vicent.
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Ehi Vicent don't forget this post. You have thrown tha ball, now i am really curious ;)
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Hi Lorenzo,
It is very difficult to achieve good contrast in this image.
There goes my attempt:
(http://4.bp.blogspot.com/-KQ7rUS33d3o/T-IkIEeZV2I/AAAAAAAAAfU/owEdHCMPVOQ/s1600/integration1.png)
Details of processing
ImageCalibration, StarAlignment and ImageIntegration
(http://4.bp.blogspot.com/-H6zUUKHC7B8/T-IimFvU55I/AAAAAAAAAdk/JWh3oVZmhKc/s1600/Screenshot+from+2012-06-20+15:56:36.png)
Crop
(http://4.bp.blogspot.com/-w00EfaeRXac/T-IisTVCTFI/AAAAAAAAAds/0A1Ho5LAdNU/s1600/Screenshot+from+2012-06-20+15:56:54.png)
DBE. First duplicate the image to see where to put the samples and then use the instance over the original image.
(http://1.bp.blogspot.com/-NBu0nCR9VcQ/T-Ii0txVfZI/AAAAAAAAAd0/j85gn8Qb0MU/s1600/Screenshot+from+2012-06-20+15:59:46.png)
(http://3.bp.blogspot.com/-SKSfW69wuWU/T-Ii7HrFQpI/AAAAAAAAAd8/2ie8QWF3gJo/s1600/Screenshot+from+2012-06-20+16:00:29.png)
MaskedStretch and HT 1
(http://2.bp.blogspot.com/-V0r95Gz3a7k/T-Ii-W63ESI/AAAAAAAAAeE/ljOAAipsPrs/s1600/Screenshot+from+2012-06-20+16:02:25.png)
MaskedStretch and HT 2
(http://1.bp.blogspot.com/-SQq13vx3-YE/T-IjCqRbG6I/AAAAAAAAAeM/LDC8lXz17g8/s1600/Screenshot+from+2012-06-20+16:03:03.png)
MaskedStretch and HT 3
(http://3.bp.blogspot.com/-GSJ3DD62yxA/T-IjJ7wrZCI/AAAAAAAAAeU/dIg1EjfqC04/s1600/Screenshot+from+2012-06-20+16:03:31.png)
Noise Reduction whit MMT
(http://2.bp.blogspot.com/-sEm_VeuAdx4/T-IjOhKE9yI/AAAAAAAAAec/FkYVRsQgz7E/s1600/Screenshot+from+2012-06-20+16:04:18.png)
StarMask to protect stars and apply HDRMT twice
(http://2.bp.blogspot.com/-HHSRQ52qU2w/T-IjTPFvRpI/AAAAAAAAAek/n7yyV-M1-10/s1600/Screenshot+from+2012-06-20+16:05:26.png)
(http://2.bp.blogspot.com/-VTf8ULRzuDQ/T-IjetsE0_I/AAAAAAAAAes/87xjoLc1HK4/s1600/Screenshot+from+2012-06-20+16:05:52.png)
Range mask to noise reduction in the background
(http://2.bp.blogspot.com/-6DPGuDRTOQg/T-Ijp1yRSXI/AAAAAAAAAe0/pBNhou0tBOk/s1600/Screenshot+from+2012-06-20+16:07:11.png)
Invert the mask and ExponentialTransformation
(http://4.bp.blogspot.com/-Fy3F_haZTUw/T-IjwmxmbFI/AAAAAAAAAe8/eVm8cuJIIoU/s1600/Screenshot+from+2012-06-20+16:08:17.png)
Duplicate the image and use as mask to protect lights and apply LHE
(http://3.bp.blogspot.com/-4JaehaNjBQA/T-Ij8vJrkyI/AAAAAAAAAfE/pzeEn9H2O_Q/s1600/Screenshot+from+2012-06-20+16:09:36.png)
Noise reduction once again with ATWT
(http://4.bp.blogspot.com/-BXQ384YDh4g/T-Ij_VS1keI/AAAAAAAAAfM/z6OJFpk0wZ8/s1600/Screenshot+from+2012-06-20+16:15:05.png)
Saludos, Alejandro.