Hi folks!

As I was assigned to do the preliminary about an interesting computer vision algorithm named Structure from Motion, so I am going be breaking the process down a bit as it can ease your process getting into SfM.

There are people who already implemented SfM algorithm in many languages such as MATLAB, C++, and Python. I have done some searches and found out that OpenSfM library is a potential library to be used mainly because it is an open-source project, so I can see how the code works.

Let’s get started with how to setup the library.

Building

This part is going to be about how to build the library from its source codes. First of all, we have to clone the project from GitHub using --recursive option.

git clone --recursive https://github.com/mapillary/OpenSfM

Then we need to make sure that the submodules are updated.

cd OpenSfM && git submodule update --init --recursive

Installing Dependencies

The main dependencies we have to install are:

1. OpenCV
2. OpenGV
3. Ceres Solver
4. NumPy, SciPy, Networkx, PyYAML, exifread

opensfm

If you only want to build the source codes to bin/ directory, it will automatically build all codes for you.

python3 setup.py build

Just in case that you need to install the opensfm package, then use install command through setup.py file.

python3 setup.py install

Troubleshooting

This section is dedicated to some issues you might be encountering during the setup process.

HTTP Server

As the library utilizes Python simeple HTTP server, in Python 3, you have to use this command instead of the indicated command in the document.

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#python3 -m SimpleHTTPServer
python3 -m http.server

Python Version

Running Python Scripts

On Linux, if you are running the OpenSfM scripts with your default python command, it is going to call your python, which means Python version 2 by default. So you have to change some files to make it works normally.

bin/opensfm

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#!/usr/bin/env python3
# the very first line, change it from `python` to `python3`

bin/opensfm_run_all

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# PYTHON=${2:-python}
PYTHON=${2:-python3}

Python Packages

pyproj

The required dependency of pyproj is cython, so just install it before installing pyproj.

pip3 install cython

The default remote url is sometimes unavailable, so you can use this link instead.

pip3 install git+https://github.com/jswhit/pyproj.git

Building Document

Sphinx

The document is written on the Sphinx tool and sphinx_rtd_theme. If you don’t have these packages, just install them through pip.

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pip3 install Sphinx
pip3 install sphinx_rtd_theme