I started with Map Warper (warper.geothings.net) but i found that manually warping in photoshop (just using the distort tool) yielded much better results, and was actually faster. This is mainly because of the kinds of images (and scales) you get from balloon mapping. See:
http://www.flickr.com/photos/jeffreywarren/sets/72157623196104469/ Thanks for the link - i'll take a look. I'd been using SIFT but haven't fiddled with it enough to know how to rectify against control imagery. It does a pretty good job for stitching, of course - though it doesn't accommodate images at different scales that well - something which happens a lot with balloon imagery. <http://www.flickr.com/photos/jeffreywarren/sets/72157623196104469/>Best, Jeff On Wed, Feb 17, 2010 at 2:40 PM, Marc Pfister <[email protected]> wrote: > There’s some or all of the functionality in GRASS, OSSIM, E-FOTO, and the > NASA Vision Workbench. Making it all work as a webservice sounds tough to > me. > > > > I think you’ll also have some challenges it that you probably only have low > resolution and quite possibly low accuracy orthoimagery to control against, > coarse (if any) DEMs, and a camera with a short focal length, no fiducials > or calibration report. I wonder if simple warping will get you just about as > far in terms of accuracy. > > > > At Random Hacks of Kindness I started on some code that used SIFT to try to > match UAV photos to control imagery and generate a GCP list that could be > fed into gdalwarp. The UAV imagery did have some rough GPS positioning that > limited the search space for the SIFT algorithm. It’s still (argh) > unfinished, but you can see the start here: > > > > http://github.com/drwelby/UAV-Ortho > > > > -Marc Pfister > > > > > > > > *From:* [email protected] [mailto: > [email protected]] *On Behalf Of *Jeffrey Warren > *Sent:* Wednesday, February 17, 2010 8:36 AM > *To:* [email protected]; [email protected] > *Subject:* [OAM-talk] open source orthorectification for > grassrootsmapping.org > > > > Hi all - I'm looking for an open source way to do automated > orthorectification as a web service to support > http://grassrootsmapping.org balloon/kite mapping imagery. > > > > Something that would generate GCPs and stitch imagery, and (even better) > perhaps generate tiles. > > > > I'm a bit new to rectification, any suggestions? > > > > Thanks, > > Jeff >
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