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 (2013-01-22 00:33:04)

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

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:


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:


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.