PhotoSynth: Making semi 3D photo tours

PhotoSynth is a photo sharing web application provided by Microsoft that lets you upload your own photos of a place or event.  It then finds objects (like walls, floors, etc…) that match between your photos, then places your photos in a 3D virtual environment so that users can view your photos in a 3D space similar to the place where you took the photos.

Users can view your virtual 3D space either on the web at Microsoft’s PhotoSynth.com web site, or via a desktop application that they can download from Microsoft’s site.  The web site requires that the user has SilverLight installed.  If it’s not installed, they can install it in under a minute from the site.  Both interfaces (web and desktop) provide a nearly identical user experience.

Here’s a “synth” I made.  It took about 5 hours to take all the 1600+ photos:

If you want to make your own synth, here are some tips:

What you need:

Patience, diligence, and plenty of free time.  I took over 1600 photos in a 5-6 hour period.  Filled up my 2GB memory card TWICE, plus about 1/4 again.  Stopped after each fill up and copied to my Dad’s computer (in the house pictured in the synth) in Chattanooga and uploaded to my home computer in Knoxville, except the last batch, which I just brought home with me on the card.

Tips:

  • Decide on multiple points in a room or outside a building.
    • You can merge an inside project with an outside one if you take multiple photos from outside going inside.
  • Then take roughly 24 pictures at each point (left, right, front, back, and halfway between each)
  • then again, but down low.
  • then again, but up high, and make sure they all overlap.
  • Maybe one more set higher to get directly above.
  • The eye-level photos require the most.  As you go up or down, you’re zeroing in on the north or south pole of the visual sphere you’re in.  The top may only need one photo.  You probably don’t want any directly below to avoid getting your feet in them.  You could probably, if you’re really wanting it, stretch your arm way out and snap a pic of the ground after you step away from the spot you just covered.
  • The PhotoSynth software finds matches based on texture, so if you have smooth walls, it’ll have a tough time finding matches.
  • I recommend using a tripod if you’re inside to steady the shots (you don’t want to use a flash, but a flash will work… just looks cheesy).  Plus, your batteries will drain if you use a flash.  I took all 1600+ on one set of batteries (with power left over).
  • Be careful of getting yourself in the photos with reflective surfaces (mirrors, windows, glossy surfaces).  I found myself in the mirrors above the elevated book case in the great room photos and a few other places.  Avoiding your shadow in the sun is almost impossible.  I tried to stand in the shadow of trees and such, when they were available.  There’s even one in there of my Mom in her bathrobe in a distant mirror image (I won’t tell her if you don’t).
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  • When outside, if it’s bright, ditch the tripod because it’ll be faster without it and if the sun’s out, there’s plenty of light for the flash-less camera to gather enough light quickly so it won’t be blurred by your movement.  While inside, the tripod is a necessity.
  • You don’t have to be accurate, you just need coverage of your scene.
  • Make sure you blur license plates and anything personal you don’t want shared before you upload (like your bald spot in a ceiling mirror or your Mom in her bathrobe!).  Paint.net is plenty good for that.  Of course, I tell you this after the fact!
  • A decent synth has at least a couple hundred photos.
  • You’ll feel like a dork taking the pictures because you take photos of things like the ceiling, an unimportant corner, the floor, etc…, but what you’re really doing is filling in all the gaps so that your viewers get a complete view.  It’s not about preserving a "precious image of the light switch" or the bucket in the corner.  It’s about providing a complete scene.
  • Create an account on PhotoSynth (using your Windows Live account), click "create", and upload.  It does all the rest for you.

Tips for viewing:

  • I’m really disappointed in how clumsy and awkward the in-synth navigation is.  It’s not improved since the beta days years ago.
  • Occasionally, it’ll detect enough photo information around an object where it’ll let you do an actual 3D rotation (it’ll show curvy arrows).  You can control+click and slide the arrows, then you’ll see a 3D dot mesh of your scene that you can rotate around.
    • In my 2 synths, there’s one around the fireplace if you’re standing in the lower level right in front of it.
    • There’s also one outside between my van and the gargoyles at the entrance of the back yard around the left gargoyle, then another one near the roof over the gargoyles, and one that’s really hard to get to, just past that entrance on the side wall of the house, if you’re standing up by the hot tub.
  • When the PhotoSynth software generates your project, it tries to find matches to link all of your photos together.  Occasionally, if you missed some coverage that would have linked two areas together, it’ll create separate synth sub-projects.  You can’t visually navigate from one to the other, so you’ll have to go to the grid view:

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  • Here’s the gridview of my outside photosynth.  All photos grouped together are their own sub-synth.  In mine, you can see about 21 or so sub-synths.  The last row of images are individuals that couldn’t be matched at all.  So, you have to go to the grid view, then double or tripple click on any photo in a sub-synth to view that section.
  • When there’s a distant object in the background of many of your pictures (like lookout Mountain in many of mine), PhotoSynth will see that as something to connect photos that really shouldn’t have been connected.  As a result, you may be on the upper back deck, facing the city, click what seems like an adjacent picture, and wind up on the 2nd lower level on the other side of the house, by the gazebo, with Lookout mtn in the view.  It was "right", technically to find the matches in the backgrounds, but it hoses the navigation around the house because two scenes that are far apart get jumbled together because of the distant background objects.