RBG images for later phtogrammetric work

Is there a way to extract the exterior orientations from the trajectory from the images collected? This would be a game changer as both laser and RBG images could then be used for later photogrammetric work and othomosaics produced from the R2A pointcloud.

This is what the big boys do and I’m sure its possible since the PCPainterGL seems to be using exterior orientation data from the trajectory to project the images for the the colorization process.

@laserboy we are working to build that into PCPainter. But, in the meantime, we have a stand-alone script you can use:

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Awesome.

Thanks Alex. Will test that out tomorrow.

Thanks for the reply on a Sunday!

I’ve been able to import the camera image positions as a file into Pix4d from my Greenvalley lidar unit, but its not a simple process. The Pix results came out very good however.

A test run of this script shows that it does exactly what’s on the label, it writes the lat/long/height to the EXIF data of each image.

This is OK for standard workflows, but it could potentially be a very important part of the complete data that we could generate from the unit. For a directly georeferenced dataset that was captured at 40% side lap, we do not have enough overlap for aerial triangulation and should have a separate file with each image orientation (exterior orientation). This is what is normally collected from larger systems from Leica, etc.

Thus we can then process orthomosaics fairly easily since we have:

  • a pre-generated pointcloud
  • a pre-calibrated camera
  • a file of exterior orientations

While aerial triangulation is possible at the 60% sidelap point, we are then going to be recreating a pointcloud that has already been done (via the laser) and are open to inaccuracies from the bundle adjustment. Not to mention that we will be both wasting time in the field by flying such a dense grid and in the office by processing the same dataset in a variety of ways.

Lets hope this is fairly easy to implement since the coordinates of each event marker seem to be interpolated from the script and that it now needs to be extended to the OPK information. Obviously this can not be written to the EXIF tags since none exist for that information and that a separate ASCII file would have to be generated.

@laserboy We completely agree. PCpainter is already doing a process of direct georeferencing using the complete intrinsic and extrinsics of the camera. The latest version of PCpainter products a CSV file with the location and attitude information for the use in direct georeferencing!

It’s in pre-release right now and we are testing it now. I’ll write back when then latest PCpainter includes this new functionality natively.

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Whoa! Sounds like you guys are far ahead of the curve already!

Looking forward to the new release.

Any update on this release? We utilize this information regularly in our Orthos since we are capturing photo/lidar at the same time. On linear missions, this info is critical to a solid process.

The new PCPainter spits out a CSV file with exterior orientations. We have successfully used this in a single test flight but not in production just yet.

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This was done with the Greenvalley V70 lidar + camera. The images were processed in Pix4d using the camera position file. It was lot of processing (200 GB total), but the results are very good.
If someone has a better way, please let me know

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