Timelapse software

Discussion in 'Digital Video' started by tillsbury, Nov 8, 2014.

  1. tillsbury macrumors 65816

    Joined:
    Dec 24, 2007
    #1
    I've been photographing my house relocation over the last year or two (photographs every 30 minutes in daytime, or 10 minutes when something interesting is going on). But I've been struggling to find something that can handle putting it together as a timelapse video.

    Even though my camera is mounted to a house, it moves both in the wind and throughout the day (presumably because of heat/sunlight on the mount). So the resulting video is jerky, and the images need aligning.

    There is a lot of stuff out there for panorama stitching, but very little for timelapse aligning. Fortunately, some of them can do both.

    I downloaded the Hugin tools, and PTGui, and AutopanoPro (trial versions) to see what they'd do. Autopano simply couldn't handle it, either dying when a hundred images are loaded or claiming that it'd finished but failing to do a decent job of the alignment.

    I have 10,000 photos (3kx2k) so far, and will have more before we're finished, so performance was an issue.

    Experimenting with 100 images to start with, Hugin got a good result but took an age (an hour or more) to provide it. It compares every photo with every other, so increasing the number of photographs increases the time geometrically. If you have forever, or a small number of photos, it will probably do the job though.

    PTGui (trial), however, did the 100 photos in a couple of minutes. I thought it had failed, but it had done a pretty good job. Maxed out retina iMac. Was using 8 threads some of the time (CPU load on 780%), but for a fair amount of the processing it is single-threaded.

    I sifted through my photos in Finder (Retina iMac means you can clearly see almost 1000 finder thumbnails at a time and thin out the duff ones), and then used Automator to remove the bottom strip on each photo that contains the time and date of the photo. This bottom strip is always in the same place, so it tends to confuse aligning software as that part of the image suggests it doesn't need adjusting. I couldn't find any part of any software that allows you to mask off control points outside a certain X or Y range -- that would be a very useful feature.

    The annoying element of removing the timestamps is that aligning software also puts the current time and date on its output files (of course). So if you remove the timestamps from the image too you can no longer see when the image was taken, either from its name or its file attributes. It would be very elegant if PTGui could 'touch' these images and put back the original file date/time on them.

    PTGui didn't like me throwing 5000 images at it (OSX ran out of file handles for the process), but I have now settled on giving it 1000 at a time. It takes just over an hour to align these 1000 images and write them out in original size (2560x1920) at 99% jpg quality. The same time it took Hugin to do 100.

    I then loaded these up into Final Cut Pro and merged them in the usual way as a compound clip of 1000 frames (by selecting the lot as an event, pressing E, then selecting all the frames and Control-D 1 Enter, then shift-Z to see the lot and create the clip. Works beautifully.

    So last night I put down my money for PTGui and the release version does it fine (the trial version puts watermarks on the images).

    I will load up each of the six or seven clips like this and should then be able to assemble them in FCPX (using translation as required if each group of clips isn't bang on line), and then as a final job cropping off the varying borders and rendering down to something like HD.

    Just putting this out there for others looking to try this. Autopano I couldn't get to handle this job, PTGui did it perfectly (for 79 euros), Hugin would probably do the job but take forever.
     
  2. Borntorun macrumors member

    Joined:
    Nov 15, 2011
    Location:
    Perth, Australia
    #2
    Have you tried image stabilization in FCPX on the "unaligned" photos?
     
  3. sevoneone macrumors 6502

    Joined:
    May 16, 2010
    #3
    This, or the stabilizer built into Motion, which allows you to manually set tracking points.
     
  4. tillsbury thread starter macrumors 65816

    Joined:
    Dec 24, 2007
    #4
    Image stabilisation in FCPX just doesn't make enough movement to get things to line up. It's more intended to smooth out jerkiness, whereas what you want in a timelapse is rock-solid positioning of the key elements (even where many other parts of the photograph are moving).

    I don't have Motion, but manually setting control points in several thousand photographs just wasn't on my to-do list.

    There are some tricks (such as manually setting all the lens parameters, keeping the first ten photographs the same on each batch of 1000 or so, making sure that you overlap each batch by 10 frames or more so that you can cross-dissolve the resulting clips to avoid any jumps, and tweaking rotation/scaling of each batch in FCPX by overlapping and setting opacity down), but otherwise it's fairly straightforward. There's still a good chunk of processing to do, but it's a start and my video is now pretty stable.

    There are a few wobbly bits in there, but as I find them I can manually adjust those particular frames (or just tip them out) to slowly improve the video. I'm not finished with the photography yet so the video is still a work-in-progress, but I'm fairly happy with where it's going.

    The big deal about long-term timelapses (particularly of one-off subjects) is that you don't get two chances to shoot. You have to go for a setting at the beginning and stick with it for a year or two. Everything else is post-production.
     
  5. Borntorun macrumors member

    Joined:
    Nov 15, 2011
    Location:
    Perth, Australia
    #5
    I understand exactly where you are coming from. I have done some short term time lapses (like in 8hrs compressed to 30-60s) for an industrial client of mine (he wanted to capture construction sequences for training purposes). I used what I call the "brute force" method: Rig up a standard video camera (not DSLR) and record 8hrs of normal footage, and speed it up in post.

    Of course, you deal with a mass of data - but it allows you to stabilize and colour correct the original footage before you speed it up. Or afterwards, depending on the situation.

    Of course, this would not work for a time lapse shot over many months.
     

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