It is a little off topic but I thought many of the forum goers might find the Photosynth to 3D process I've been working on useful for creating 3D models from aerial photos.  The process is pretty simple and FREE:

·         Gather images with a lot of overlap (like most of our aerial shots)

·         Upload the files to http://www.photosynth.net (or use the open source Bundler app http://phototour.cs.washington.edu/bundler/ )

·         Use this exporter to extract the point cloud http://pspcexporter.codeplex.com/

·         Use a product like Meshlab  http://www.meshlab.net/ (hard to get good results) or VrMesh Studio ( http://www.vrmesh.com/products/overview.asp  ) to generate a mesh surface from the point cloud.

 

Here are two examples from my work in Ecuador and West Texas:

https://www.youtube.com/user/mdwillis01#p/a/u/0/2-oK5lnNA-I

and

https://www.youtube.com/user/mdwillis01#p/u/6/nJgvLll57f0 (only part of this one was done with Photoysnth).

The images were captured from kite and balloon platforms but the same workflow should work for any series of photographs.

Also, here is a Google Earth file with some of the same data http://70.114.146.89/~mwillis/Puchara_Grande.kmz (~10 Mb).  My linux box connection is slow. It'll take a bit to download.

-Mark

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What's the flying time for the 600 photographs? Make and model of camera? Thanks.

Roger, The 410 photos covered an area of about 20 acres with the camera flying at about 40 meters above the ground.  The landscape was rugged, covered in cactus, thorny brush, and rattle snakes.  Much larger areas can be flown under better conditions or with the camera at a greater height.  My main focus was to document small archaeological features.  Flying t0o high would have lost a lot of detail in the imagery.  It's always a give and take in this regard.

I used a Canon A590 running CHDK.  You can find the specs of the camera at www.depreview.com

Hope that helps.

Hi Tommy.  Sorry for the slow reply.  Somehow I missed your message!

A (overly?) detailed explanation of the process is available at palentier.blogspot.com

Johny, the Hawkeye running ardupilot has been tested by a friend of mine with good results.  The Hawkeye is basically a powered kite.  It is able to fly very slowly allowing for good imagery overlap.  http://www.electricflights.com/

 

Thanks for the software suggestions.  I'm one of the few that was using GRASS in the early 1990s.  I should check it out again.

Mark,

 

I'm more interested on "near" ground imagery too.

 

Thanks for the info.

Hi Reto,

 

I will buy an APM soon to install on EasyStar model to capture aerial photos and then create a mosaic from them.

Could you explain me how can I make good DEM this way? (process, tools, etc.)

thanks in advance, Jaime

Brakar,

I had a look at the hypr3D and it looks impressive. Seems to sit somewhere between Photosculpt and Photosynth and produces results that are seemingly far superior to both. Can't wait to try it myself and see what we get, thanks for the link. What they seem to have resolved is the overall curvature in surfaces that both Photosculpt and Photosynth exhibit and their models of planar surfaces appears highly accurate. Very promising!

 

Cheers,

Mike

Many thanks for your detail explanation.  I will follow the instructions and buy you a cold beer later:)

I realize there has not been a lot of activity on this forum post for a while, but I would like to share some research with you regarding the attainable accuracies of Mark's Photosynth workflow. Please refer to a presentation I have given at a GIS conference

Hello, I also am an enthusiast of kite mapping, and not only. Unfortunately I struggle by doing it on my own. I have tried out, and keep using airplane and multicopter drones and kites with rigs. I also tried to recrute a friend of mine in developing o personal version of bundler, in a sense. I would like him to accomplish all that I need, him being the programmer. Try to put it all together in some sort of an app to run under fedora or ubuntu that should include georeferencing of point cloud after generating, stitching of images, orthorectification. meanwhile, I still am on my own and have to give him examples and data. So I kinda gathered some open source apps for generating the point cloud, the georeference it using a bit of script. Stitching I manage to do with ICE. But I have pb with this since it is open source and underdeveloped, it crashes frequently, or it limits the amount of data that can process. So I was wondering, what do you use for georeferencing the pointcloud and how do you drape the image stitch upon the 3D model and orthorectificate it?

Thanks for the sharing. Good info :-D

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