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Remote Sensing, GIS, Ecology, and Oddball Techniques

Archive for January, 2015

OpenDroneMap — Orthophotos and Textured Mesh (cont.)

Posted by smathermather on January 21, 2015

Schematic showing ODM processing chain

(Credit goes to Brandon Garman for the graphic above. It’s part of a very nice sUAS graphic he’s putting together at the moment.)

Following up on the earlier post on the addition of orthophotos and textured mesh to OpenDroneMap (FYI, one word, and not OpenDroneMaps) we have some more features in the pipeline. This is a deeper dive into architecture and future enhancements.

In the previous post, I talked about the addition of orthophotos and textured surface models as outputs. Those are currently being refined by the folks at Spotscale. In addition to that work, Spotscale is also adding the ability to include ground control points in the processing chain.

This will allow for the following:

  • imagery that doesn’t have onboard GPS to be used
  • refinement for datasets that do have onboard GPS, but have more accurate ground control points
  • use of ODM with balloons
  • kite aerial photography and other applications.

I am really excited by these enhancements. They lower the barrier to entry for a range of users, widen the use cases, and allow for fine refinements of the geometry / geography of ODM outputs.


The other thing in progress is the integration of Mapillary’s OpenSfM into the toolchain. This gets us a few things:

  • A modern SfM solution as an option at the front of the toolchain. The hope is this will improve the performance and quality of image matching. It will also allow us to take advantage of the solutions that Mapillary has developed and is developing for dealing with photo matching at scale and with a range of camera qualities, types, etc.
  • The ability to more easily use ground level imagery in the toolchain
  • Auto-correction of GPS ephemeris in the imagery using best available GPS ephemeris and structure from motion positioning (ala

This is huge. I expect between the work of Spotscale and Mapillary that, image smoothing / vignetting fixes aside, ODM will be on-par with any sUAS image processing software. Delivery and testing will tell, but stay tuned.

An initial schematic for how the OpenSfM and ODM can integrate now is below. In short order, OpenSfM will run as a submodule within OpenDroneMap, and we likely keep Bundler / vlsift for legacy sake.  When this happens, the schematic will simplify somewhat.

Schematic of workflow/interaction between ODM and OpenSfM


Posted in 3D, Bundler, Camera Calibration, FOSS4G, Image Processing, OpenDroneMap, Optics, Photogrammetry, PMVS | Tagged: , , , , , , , | Leave a Comment »

(Further) Refinements on the Tenor Guitar

Posted by smathermather on January 18, 2015

A couple more tenor guitar pictures.



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Refinements on the Tenor Guitar

Posted by smathermather on January 17, 2015

The following goes in reverse order and documents my current experiments in refining the top of the tenor guitar. No annotations this time, although I will say that the black filler is hide glue with pigment added — technically it’s “Old Brown Glue”, as it has longer open time than my traditional hide glue. I use it here both for filler and as a glue / filler.




















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OpenDroneMap — Humanitarian uses of outputs

Posted by smathermather on January 12, 2015

OpenDroneMap Logo


In response to a recent query about OpenDroneMap, I’m writing a quick summary here, and then a brief write-up on how it could relate to humanitarian response / crisis mapping applications, as discussed in my Deep Dive session at International Conference of Crisis Mappers in New York, this past November.  Ahem. The summary:

OpenDroneMap: Open Source Toolkit for processing Civilian Drone Imagery

“OpenDroneMap is an Open Source Toolkit for processing Civilian Drone Imagery. As small unmanned aerial systems have dropped in price and become readily affordable, software for making meaningful geographic data from civilian drones has not. Until now.

“OpenDroneMap is fully Free and Open Source postprocessing tool for highly overlapping unreferenced imagery, turning unstructured data (simple photos) into structured geographic data such as colorized point clouds, digital surface models, textured digital surface models, and highly detailed orthophotography.

The project can be found at”

So, cool stuff. But what does that mean? What do we really get at the end of the day, so to speak, at least within the context of crisis response. To answer this question, I’ll divide this into two categories — goodies we get now and goodies we will get later as the project matures.

Products we get now from OpenDroneMap:

  1. Point Cloud
  2. Textured Mesh
  3. Up to 1-2cm (or so) orthophotos

What can we do with 2cm imagery in the crisis response context? My colleagues at ICCM addressed this question:

  • Structural Mapping
  • Logistics and Supply Planning
  • Count People — IDPs, Protests
  • Identify Equipment / Weaponry
  • Finding people (search and rescue)
  • Finding Animals (conservation)

Products we get later from OpenDroneMap (as the project matures and adds features):

As to future products from the toolchain we will derive the following:

  • 4cm Terrain / Surface Models
  • Off-Nadir Imagery

Again, drawing from the brainstorming at ICCM:

4cm Terrain / Surface Models yield us:

  • Off-road route planning
  • Hydrology / innundation estimation
  • Damage assessment — rubble volume estimation
  • Agricultural Planning

Off-Nadir Imagery:

  • Forensics
  • Damage Assessment (useful for building especially which often won’t show damage on roof)
  • Context for video footage


The UAViators site lists the following (complementary and otherwise related to the above) uses of UAVs to support humanitarian efforts:

Together, these teams work collaborate to facilitate various uses of UAVs to support humanitarian efforts. These include:   

  • Rapid assessment of disaster damage to building infrastructure
  • Rapid assessment of powerlines and other electricity infrastructure
  • Identify usable roads and transportation infrastructure
  • Identify useful areas for humantiarians to set up base camp
  • Aerial support for road clearance activities
  • Estimate population displacement
  • Identify temporary shelters
  • Identify best locations to set up new temporary shelters
  • Survey impact of disaster on agriculture, farmland
  • Search and Rescue
  • Identifying whether radio transmitters/comms on the ground still work

Posted in 3D, Bundler, Camera Calibration, Conference, FOSS4G 2014, Image Processing, International Conference of Crisis Mappers, OpenDroneMap, Optics, Photogrammetry, PMVS | Tagged: , | Leave a Comment »

Lasers in Lutherie.

Posted by smathermather on January 2, 2015

More lasers in lutherie… . Now I’m just getting lazy with some of this work that could easily be done with a bandsaw and hand plane… . Sorry about the poor lighting.

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