5 ms·

You can do this yourself crudely from any airplane window. Before you get too high, take two pictures of the same target (building or mountain) within 1 or 2 s

by 205guy 7y ago

You can do this yourself crudely from any airplane window. Before you get too high, take two pictures of the same target (building or mountain) within 1 or 2 seconds (try both, so 2 pairs of photos, because it depends on your altitude). Then open the 2 pictures in an app where they are overlaid and you can switch between them quickly (I use irfanview on Windows--still after all these years). Each eye will pick up elements of the corresponding right and left photo, giving an approximation of 3D. https://en.wikipedia.org/wiki/Wiggle_stereoscopy https://en.wikipedia.org/wiki/Wiggle_stereoscopy If you got 2 good pictures (good subject at the right altitude and separation) you could put them into a stereoscopic program and create a nice stereogram (either red-blue colored or side-by-side, depending on your preferred viewing device). What the software in the article does is compute all the parallax from multiple images to give essentially a 3D scan of the landscape. It has been theoretically possible for a long time, maybe this is one of the first to do it successfully in practice.

Nition 7y ago
Man, that default example there is terrible. The "street in Cork" is pretty good. That old gif of the T-Rex from The Lost World is always a good example[1] but I suppose it's probably not licenced the right way for Wikipedia. [1] https://i.imgur.com/DDce0hO.gif https://i.imgur.com/DDce0hO.gif
- saagarjha 7y ago
  The street in Cork looks strangely toy-like. Kinda like a tilt-shifted photo, but without the tilt-shifting.
  - roywiggins 7y ago
    Probably because you don't get that much parallax in real life, but you would if it were the size of a small model.
  - smcl 7y ago
    Reminds me of the bouncing, dancing scenery from Bowser's Kingdom in the Super Mario Oddyssey: https://www.youtube.com/watch?v=PnT8w10euCk&t=57m0s https://www.youtube.com/watch?v=PnT8w10euCk&t=57m0s (should start at 57 minutes 0 seconds)
- itronitron 7y ago
  This would be a very neat effect in a horror movie, like a monster running out of the shadows toward the viewer, and would probably work well as the colors are often desaturated in the darker scenes.
  - mrguyorama 7y ago
    In theaters you'd run into the problem of only have 24 frames per second to deal with.
moron4hire 7y ago
I used to do this with just my smartphone (and the default photo editing apps ok my phone). It's quite easy to make an image that fuses well, but it's quite hard to get a photo of human scale stuff that maintains scale correctly.
- 205guy 7y ago
  I suspect the default focal distance for smartphone cameras is a bit too wide-angle. I haven't tried recently, but zooming in a bit (say 1/4 to 1/3) would help, as would tracking the target (panning slightly so the main subject stays in the center). It all really depends on how close the subject is. You need to exaggerate the separation a little but not too much. In an airplane, the time between shots (and speed of course) determines the separation. If you're doing the same thing on the ground, it depends in how far your subject is, but you can step 1-2 feet sideways for your second shot. You just have to experiment to find what works. I have tried on an iPhone before, but the default "slide" between photos isn't fast enough to get the effect, so I had to download them to my PC. Maybe there's an iOS app for it now. Edited to add: I knew someone in the age of film who screwed 2 SLRs to a piece of wood about 16 inches apart, for 3d landscape photography. He used 2 mechanical remote shutter releases to make sure the photos were in sync. A similar rig with DLSRs and electronic remotes should be easy and more precise (to get same settings and synchronous release). I'm surprised I haven't seen it done yet.
satori99 7y ago
> maybe this is one of the first to do it successfully in practice. Photogrammetry software has been commercially available for a while. I played around with Agisoft photoscan [0] some time ago, and while the results were impressive, it did take a lot of human interaction to select the right source images and parameters. I think maybe The Army has automated this pipeline to go from drone camera -> 3d map without needing a human. [0] https://www.agisoft.com/ https://www.agisoft.com/
- 205guy 7y ago
  Exactly. I can't wait until I can do this with my own drone--though maybe I shouldn't hold my breath for the open source package because it seems to have military applications right now. There's a 1000-ft hill behind my house, and I thought it would be cool to get a 3D print of it. You can do this now with some online apps, based on the terrain model that you see in google maps. But the public data is "only" 30m resolution (https://en.wikipedia.org/wiki/Shuttle_Radar_Topography_Mission#Highest_Resolution_Global_Release https://en.wikipedia.org/wiki/Shuttle_Radar_Topography_Missi...), whereas this technique could probably make a 1m resolution.
  - DanAtC 7y ago
    Depending on where you live, the USGS may already have LIDAR data for your area: https://usgs.entwine.io/ https://usgs.entwine.io/
  - samplatt 7y ago
    >Exactly. I can't wait until I can do this with my own drone--though maybe I shouldn't hold my breath for the open source package because it seems to have military applications right now. I produce 3D models from photogrammetry from drones for the Engineering & Construction industry in Australia. The free software to use is VisualSFM. I recommend flying your drone over your target in a sort of 4-circle Venn diagram, with the overlapping center the actual subject you want to scan. Have the drone pointing inward to the center of each circle while flying, the camera being at a ~55deg angle. You're essentially circle-strafing in 4 circles with a little overlapping bit in the middle. Take video footage of the whole trip and extract individual frames... can't remember if VisualSFM does that for you or not.

by 205guy 7y ago

Nition 7y ago

Man, that default example there is terrible. The "street in Cork" is pretty good. That old gif of the T-Rex from The Lost World is always a good example[1] but I suppose it's probably not licenced the right way for Wikipedia. [1] https://i.imgur.com/DDce0hO.gif https://i.imgur.com/DDce0hO.gif

saagarjha 7y ago
The street in Cork looks strangely toy-like. Kinda like a tilt-shifted photo, but without the tilt-shifting.
- roywiggins 7y ago
  Probably because you don't get that much parallax in real life, but you would if it were the size of a small model.
- smcl 7y ago
  Reminds me of the bouncing, dancing scenery from Bowser's Kingdom in the Super Mario Oddyssey: https://www.youtube.com/watch?v=PnT8w10euCk&t=57m0s https://www.youtube.com/watch?v=PnT8w10euCk&t=57m0s (should start at 57 minutes 0 seconds)
itronitron 7y ago
This would be a very neat effect in a horror movie, like a monster running out of the shadows toward the viewer, and would probably work well as the colors are often desaturated in the darker scenes.
- mrguyorama 7y ago
  In theaters you'd run into the problem of only have 24 frames per second to deal with.

moron4hire 7y ago

I used to do this with just my smartphone (and the default photo editing apps ok my phone). It's quite easy to make an image that fuses well, but it's quite hard to get a photo of human scale stuff that maintains scale correctly.

205guy 7y ago
I suspect the default focal distance for smartphone cameras is a bit too wide-angle. I haven't tried recently, but zooming in a bit (say 1/4 to 1/3) would help, as would tracking the target (panning slightly so the main subject stays in the center). It all really depends on how close the subject is. You need to exaggerate the separation a little but not too much. In an airplane, the time between shots (and speed of course) determines the separation. If you're doing the same thing on the ground, it depends in how far your subject is, but you can step 1-2 feet sideways for your second shot. You just have to experiment to find what works. I have tried on an iPhone before, but the default "slide" between photos isn't fast enough to get the effect, so I had to download them to my PC. Maybe there's an iOS app for it now. Edited to add: I knew someone in the age of film who screwed 2 SLRs to a piece of wood about 16 inches apart, for 3d landscape photography. He used 2 mechanical remote shutter releases to make sure the photos were in sync. A similar rig with DLSRs and electronic remotes should be easy and more precise (to get same settings and synchronous release). I'm surprised I haven't seen it done yet.

satori99 7y ago

> maybe this is one of the first to do it successfully in practice. Photogrammetry software has been commercially available for a while. I played around with Agisoft photoscan [0] some time ago, and while the results were impressive, it did take a lot of human interaction to select the right source images and parameters. I think maybe The Army has automated this pipeline to go from drone camera -> 3d map without needing a human. [0] https://www.agisoft.com/ https://www.agisoft.com/

205guy 7y ago
Exactly. I can't wait until I can do this with my own drone--though maybe I shouldn't hold my breath for the open source package because it seems to have military applications right now. There's a 1000-ft hill behind my house, and I thought it would be cool to get a 3D print of it. You can do this now with some online apps, based on the terrain model that you see in google maps. But the public data is "only" 30m resolution (https://en.wikipedia.org/wiki/Shuttle_Radar_Topography_Mission#Highest_Resolution_Global_Release https://en.wikipedia.org/wiki/Shuttle_Radar_Topography_Missi...), whereas this technique could probably make a 1m resolution.
- DanAtC 7y ago
  Depending on where you live, the USGS may already have LIDAR data for your area: https://usgs.entwine.io/ https://usgs.entwine.io/
- samplatt 7y ago
  >Exactly. I can't wait until I can do this with my own drone--though maybe I shouldn't hold my breath for the open source package because it seems to have military applications right now. I produce 3D models from photogrammetry from drones for the Engineering & Construction industry in Australia. The free software to use is VisualSFM. I recommend flying your drone over your target in a sort of 4-circle Venn diagram, with the overlapping center the actual subject you want to scan. Have the drone pointing inward to the center of each circle while flying, the camera being at a ~55deg angle. You're essentially circle-strafing in 4 circles with a little overlapping bit in the middle. Take video footage of the whole trip and extract individual frames... can't remember if VisualSFM does that for you or not.