How to use different blending for stacks and pano?  

Share your tips and tricks here or get help with any Autopano Pro / Giga problem!
No bug reports (of any kind) in this forum!
no avatar
Michael Ezra
Member
 
Topic author
Posts: 233
Likes: 0 post
Liked in: 1 post
Joined: Thu Jan 26, 2006 3:43 pm
Location: New York
Info

How to use different blending for stacks and pano?

by Michael Ezra » Mon Jan 21, 2013 11:40 pm

I am trying to create a pano of the night sky. For each camera position I shot a stack of N frames, to blend them to reduce the noise.
If i understand correctly, to reduce the noise, I need to use Linear blending within the stack.
But to stitch the stacks together I would prefer Multiblend blending.

Question: is it possible to configure APG to do this in a single pass - Linear blend within stacks and then Multiblend of the staked results?
Thanks, michael
Last edited by Michael Ezra on Mon Jan 21, 2013 11:41 pm, edited 1 time in total.

User avatar
gkaefer
Member
 
Posts: 3549
Likes: 0 post
Liked in: 15 posts
Joined: Tue Jun 09, 2009 1:01 pm
Location: Salzburg
Info

by gkaefer » Tue Jan 22, 2013 12:31 am

Michael Ezra wrote:I am trying to create a pano of the night sky. For each camera position I shot a stack of N frames, to blend them to reduce the noise.
If i understand correctly, to reduce the noise, I need to use Linear blending within the stack.
But to stitch the stacks together I would prefer Multiblend blending.

Question: is it possible to configure APG to do this in a single pass - Linear blend within stacks and then Multiblend of the staked results?
Thanks, michael

Hi Michael,

please, please ... correct me if I'm wrong (I reall hope it...) but denoising is currently not part of possible workflows with autopano.
(Same with focusstacking...)

external programs can be used to denoise the images. the denoised images than can be loaded to autopano...
oloneo.com (HDR, denoising, relighning)
photoacute.com (HDR, denoising, superresolution, focusstacking)
zerenesystems.com (focusstacking - is via commandline addressable from autopano plugin->external stackin process)

Liebe Gruesse,
Georg
Last edited by gkaefer on Tue Jan 22, 2013 12:33 am, edited 1 time in total.

no avatar
Michael Ezra
Member
 
Topic author
Posts: 233
Likes: 0 post
Liked in: 1 post
Joined: Thu Jan 26, 2006 3:43 pm
Location: New York
Info

by Michael Ezra » Tue Jan 22, 2013 2:30 am

I think Linear blending is some form of averaging, I tried with a few 6400 ISO noisy images and result is much cleaner. This leads me to beleive that APG can be used for denoising via stacking. However, it would be even more useful if it allowed to chose the averaging function - to use median vs means, for example. I think this would lead to sharper results. DeepSkyStacker does something similar and leads to sharper results, but is very slow, compared to APG. My guess is that if APG were to support median blending for stacks it would lead to better quality render.

Alexandre/Kolor team, hope you are reading this - do you think this could be added to APG?

User avatar
ThomasV
Kolor Team
 
Posts: 300
Likes: 0 post
Liked in: 1 post
Joined: Mon Aug 27, 2012 1:12 pm
Info

by ThomasV » Thu Jan 24, 2013 10:07 am

Hello Michael,

As Georg mentionned, I think that the problem you're facing in really denoising. To have the best result, it need specialized algorithm. Linear blending through a stack is far from a denoising algorithm. So I don't think it will be added soon in Autopano.

Regards,
Thomas

no avatar
Michael Ezra
Member
 
Topic author
Posts: 233
Likes: 0 post
Liked in: 1 post
Joined: Thu Jan 26, 2006 3:43 pm
Location: New York
Info

by Michael Ezra » Sat Jan 26, 2013 6:09 pm

APG is already suitable for denoising of a stack with Linear blender:
http://www.autopano.net/wiki-en/action/view/Astronomy_stacker
http://www.autopano.net/wiki-en/action/view/Reducing_Random_Noise_from_Small_Sensors

I just want to be able to stitch multiple stacks together using multiblend with ghost remover, while stack to be stitched using linear blend.

no avatar
beetwo77
Member
 
Posts: 36
Likes: 0 post
Liked in: 0 post
Joined: Tue Aug 28, 2012 5:49 am
Info

by beetwo77 » Thu Jan 31, 2013 2:11 pm

Noise reduction through stacking requires no specialised algorithm. As Michael mentioned, it should occur simply by averaging out the random noise (i.e. linear image blending). I did some experimenting quickly with APG but could never get the image to look as it does when stacked in photoshop. I use the free Adobe DR Brown's Stackomatic to partly automate stacking in adobe camera raw / photoshop. If you can find no other solution, I would try this.

I have many panoramic images using image stacking to simulation very long exposure times but I have not tried it for astropanos! Here is a simple example case showing how effective stacking is at noise reduction. This is the comparison of a single RAW file at ISO3200, the same RAW with noise reduction (noise ninja) and the same image shot multiple times and stacked using median mode in photoshop. THe result is dramatic. Note my camera has TERRIBLE ISO performance:

Image
100_pct_Views by Beetwo77, on Flickr

This is a daylight pano. I did not have my remote to be able to shoot longer than 30 second exposures (with 10 stop filter) so I took 4 x 30 second exposures at each image location and stacked them to reduce noise and achieve the equivalent look of a 120 second exposure:

Image
Fenced_In_Stacked_Up by Beetwo77, on Flickr

I would be very interested to see APG offer more stacking options. I was wondering how hard would it be to write a stacking algorithm but really you want to do it in APG so you can use the APG control point detection to create and align your stack and the detect your pano across your stacks.


Who is online

Users browsing this forum: No registered users and 2 guests

cron