Align takes a really long time

[Tim]

Hello!
I've used Hugin in the past with pretty good success to create 360x180 panoramas but recently I've been having performance problems.

I'll start with system info:
- Windows 7 Home Premium 64-bit SP1
- CPU Intel i7 2600K
- 8GB RAM
- Video Card 1GB ATI AMD Radeon HD 6700 (not sure if this is relevant)
- Hugin version 2013.0.0.0d404a7088e6

In one situation I'm shooting a fairly large interior space, +/- 2 bracketed, using a Panosaurus 2.0 tripod head.  I've loaded my 55 images into Hugin (yes 55, I've already masked off the tripod in the nadir shot in Photoshop and don't feel like I need the other two exposures), masked of some areas, and used autopano-sift-c on different selections of photos to create control points.  I then aligned and it worked fine but wasn't perfect so I manually modified control points, optimized position/view/barrel, and went to align but it is taking quite a while.  It is definitely running because autooptimiser.exe is consuming a full CPU so it hasn't frozen.  The Optimizing Variables iterations are chugging right now at the 28th iteration but each iteration seems to take about twice as long as the last with the last taking 15-20 minutes.  The Average (rms) distance of iteration 27 was 1.43535468375691 and iteration 28 moved just to 1.43510034667803 so it isn't really doing much any longer.  I have 1526 total control points with mean error of 2.35 pixels and max 80.17.  Something to note is that before optimizing position/view/barrel I optimized using the Positions (incremental, starting from anchor) option and Hugin crashed.  I reloaded the pto and the position/view/barrel option ran fine.

Another series of shots that I was processing over the weekend I let run for over 30 hours and it still hadn't finished so I killed it and scrapped that series of photos (at least for now).

Does anyone have thoughts on what could cause this?  Could my configuration be screwy?  What causes Optimize Variables to stop?  Is it a set number of iterations?  Is there a way to make it stop after less than 1/100th of a unit changes between iterations or something?

Thanks,
Tim

[Tim]

I was able to find this similar post: https://groups.google.com/forum/#!searchin/hugin-ptx/long$20time/hugin-ptx/YpgrPnN5YB4/GKVaHnFMbtcJ

However there was no resolution to the performance problem, only a bug report to fix the unresponsive cancel button.

Also of note, in the last four hours I've gone from iteration 28 to iteration 31.  Woot!  :)

[Tim]

I ended up killing the process after about 36 hours at iteration 33 (only 2 iterations in the last ~30 hours).  Seems like a bug that it continues processing for so long to achieve such small gains.

[Brandan]

Hi there Tim,

I have never had one take as long as you are describing. I will often have 40-50 images in a project. The whole optimizing control points part tends to take less than a minute for me. What version of Hugin are you running?

Why do you use the align command a second time? If it is taking so long, why use it at all?

You can find the control points on the images tab and optimize everything on the optimize tab.(If you have 2012, on 2013 switch to expert and the settings are all on the photos tab) After optimizing the changes should be in the preview. As far as I know there is no reason to use the align button. It appears to be there for people who want a 3 step solution. With the bracketing it sounds like yours is far from a three step answer.


At this point I would try to go without using align and see if that solved your problem.

If align actually does something that is required someone please correct me.

I wonder if the bracketed photos are your problem. Have you tried a set with a single exposure? If that helps you could do all three exposures by themselves and then stitch them together or I hear a lot of people like to do that part in photoshop.

[Tim]

Hey Brandan,
Thanks for the response.  I'm running version 2013.0.0.0d404a7088e6.

Today I do align a second time because in the upper right corner of the Fast Preview window there is a message saying something like "control points changed, realignment needed" (sorry I'm not in front of Hugin now so that probably isn't the exact verbiage).  I'm using expert mode today and after I've modified my control points and optimized, I jump into Fast Preview to view the results and realign because of that little message in the corner.  I can try skipping the second alignment next time.

The funny thing is that I can never reliably reproduce the problem but it has happened on a few different projects.  After killing that running process, I jumped into the same pto (might have been a saved version from a bit earlier in my workflow), played around with control points, optimized, aligned and it ran just fine with perfect output.  I don't think it is due to the bracketed shots since after trying again it works fine.

If someone has a chance it still might be worth adding guard rails to make sure it doesn't run too long but probably not a very high priority.  Thanks again for the response.

[David W. Jones]

I get that message, too. Simply reopening a pano is enough to display
it. I ignore it!

--
David W. Jones
gnome...@gmail.com
wandering the landscape of god
http://dancingtreefrog.com

[Brandan]

On the 2012 version there is a button that you can click to update the preview. I do not see it in 2013, maybe we should put in a request for it again in future versions?

[Guy]

Ha! You should try this when you have 30698 control points. So far mine has taken about 78 hours with nothing else going on, and a devoted Samsung Notebook with Windows 8.1. Out of interest, I tried the exact same set of photos using Microsoft ICE, it took 15 minutes, and I had a load of background stuff going on at the same time. The results look really good, I was doing an extremely high focus 360 by 180 degree panorama and needed about 250 photos. I am yet to see the results from Hugin, but my best guess is that for pretty good quality result that can be achieved much faster, use a different software (Microsoft ICE is also free). 

Similar to your results, by the time I reached the 255 iteration for strategy 2, the difference was from 6.17328487072292 units to 6.17328283689973 units.

[David W. Jones]

On 06/27/2014 10:46 PM, Guy wrote:
> Ha! You should try this when you have 30698 control points. So far mine
> has taken about 78 hours with nothing else going on, and a devoted
> Samsung Notebook with Windows 8.1. Out of interest, I tried the exact
> same set of photos using Microsoft ICE, it took 15 minutes, and I had a
> load of background stuff going on at the same time. The results look
> really good, I was doing an extremely high focus 360 by 180 degree
> panorama and needed about 250 photos. I am yet to see the results from
> Hugin, but my best guess is that for pretty good quality result that can
> be achieved much faster, use a different software (Microsoft ICE is also
> free).

Microsoft ICE is not free. It requires purchasing Microsoft Windows. ;)

> Similar to your results, by the time I reached the 255 iteration for
> strategy 2, the difference was from 6.17328487072292 units
> to 6.17328283689973 units.

Since I really don't understand what those "units" really are, all I can
say is that refining them to such a small decimal value seems a little
silly ...