Optimizing flight planning for calibration (or Self Calibration of Cameras from Drone Flights, part 4)

The problem with typical approaches to scaling up data collection just take a standard flight path and do it a lot of times. This compounds error over the space it’s done in, which with really large data sets results in a notable bowl in the data due to incorrect lens calibration estimates. There are several fixes: If possible, fly with a fixed lens like Sensefly’s … Continue reading Optimizing flight planning for calibration (or Self Calibration of Cameras from Drone Flights, part 4)

Shaded elevation model in green and purple

Self Calibration of Cameras from Drone Flights (part 3)

Background I have been giving a lot of thought to sustainable ways to handle self calibration of cameras without undue additional time added to flights. For many projects, I have the luxury of spending a little more time to collect more data, but for larger projects, this isn’t a sustainable model. In a couple of previous posts (this one and this one), we started to … Continue reading Self Calibration of Cameras from Drone Flights (part 3)

Self Calibration of Cameras from Drone Flights (part 2)

(Modified excerpt from the OpenDroneMap docs) In a previous post on camera calibration, we discussed the possibility of setting up calibration flights that have the following characteristics: non-parallel (converging) flightlines of 20° with a 5° forward facing camera (assuming 0° is nadir). With OpenDroneMap’s –camera parameter, we can thus import camera models from a calibration flight and use that in a more efficiently flown “traditional” … Continue reading Self Calibration of Cameras from Drone Flights (part 2)

Self Calibration of Cameras from Drone Flights

(Modified excerpt from the OpenDroneMap docs) Calibrating the Camera Camera calibration is a special challenge with commodity cameras. Temperature changes, vibrations, focus, and other factors can affect the derived parameters with substantial effects on resulting data. Automatic or self calibration is possible and desirable with drone flights, but depending on the flight pattern, automatic calibration may not remove all distortion from the resulting products. James … Continue reading Self Calibration of Cameras from Drone Flights

Follow-up (#1) for Camera Calibration in POV-Ray (Porro-Koppe Principle in Virtual)

Ok, so projecting an image isn’t hard at all in POV-Ray.  I’m not sure what I was thinking.  In my first post on camera calibration in POV-Ray, I suggested that we could analytically solve for lens and topographic distortion in POV-Ray.  I haven’t gotten far as I don’t have a work project to take advantage of this yet, but I projected a false color infrared … Continue reading Follow-up (#1) for Camera Calibration in POV-Ray (Porro-Koppe Principle in Virtual)

19th Century Camera Calibration for Remote Sensing in PovRay (or Porro-Koppe Principle in Virtual)

A complete analytic solution for geometric distortions in remote sensing (ahem, ignoring atmosphere, of course) Ok, so here is another thought experiment. This time, it will take a few months before I have time to write the code for this, but maybe the thought experiment will inspire someone. A major problem of photogrammetry, remote sensing, and computer vision is correction of lens distortion. Thanks to … Continue reading 19th Century Camera Calibration for Remote Sensing in PovRay (or Porro-Koppe Principle in Virtual)