Running OpenDroneMap
To use OpenDroneMap run the following command:
python run.py --project-path /path/to/project
Make sure your project directory contains a subdirectory called "images" where your images are contained.
Then sit back, grab a coffee and wait
By default, OpenDroneMap tries to use the photo's GPS exif data to georeference. If your photos doesn't have GPS information or you want better accuracy you have to specify a ground control point file and use the --odm_georeferencing-useGcp parameter when running the script. This post has some information about placing Ground Control Targets before a flight, but if you already have images, you can find your own points in the images post facto. It's important that you find high-contrast objects that are found in at least 3 photos, and that you find a minimum of 5 objects.
For example, in this image, I would use the sharp corners of the diamond-shaped bioswales in the parking lot:
You should also place/find the GCPs evenly around your survey area.
The gcp_list.txt file must then be created in the base of your project folder:
The format of the GCP file is simple. The header line is a description of the coordinate system: either a UTM specification written as "WGS84 UTM xx<N\S>" or a coordinate system definition in any format the GDAL library can understand. Link. We recommend using EPSG:n codes. Subsequent lines are the X, Y & Z coordinate in your coordinate system, your associated pixel and line number in the image, and the image name itself:
coordinate system description
x1 y1 z1 pixelx1 pixely1 imagename1
x2 y2 z2 pixelx2 pixely2 imagename2
x3 y3 z3 pixelx3 pixely3 imagename3
e.g. for the Langley dataset:
WGS84 UTM 10N
544256.7 5320919.9 5 3044 2622 IMG_0525.jpg
544157.7 5320899.2 5 4193 1552 IMG_0585.jpg
544033.4 5320876.0 5 1606 2763 IMG_0690.jpg
Given the recommendations above, your file should have a minimum of 15 lines after the header (5 points with 3 images to each point).
Note: if you use a GCP file, then the images in the images_resize folder in your project will have coordinates in the EXIF data.