pyvxl

Python wrapper for vxl using pybind11

Requirements

• pybind11 - You need to add the pybind11 repo as a submodule to your project (or install it into the OS)
• vxl

Cmake

pyvxl can be build standalone or as a module of an existing project.

Standalone

Whatever environment (your host or a docker container) you build pyvxl in will require these dependencies

• g++
• Python 3 development libraries (e.g. python3-devel)
• GeoTIFF development libraries (e.g. libgeotiff-devel)
• CMake 3.10.2 or newer
• Ninja (optional)

If you're not using ninja, replace "ninja" in the commands below with "make".

Using a virtualenv (recommended)

To avoid messing with your host machine, you can build pyvxl in a virtualenv

virtualenv -p python3 env
source env/bin/activate
mkdir build && cd build
cmake -DVXL_DIR=${VXL_DIR} -DPYBIND11_DIR=${PYBIND11_DIR} -G Ninja -DPYTHON_SITE=${YOUR_VIRTUALENV_SITE-PACKAGES} ..
ninja
ninja install

Not using virtualenv

If you're not going to use a virtualenv because you're in a docker, or your host machine (not recommended), then you can drop the PYTHON_SITE variable

mkdir build && cd build
cmake -DVXL_DIR=${VXL_DIR} -DPYBIND11_DIR=${PYBIND11_DIR} -G Ninja ..
ninja
ninja install

Contrib (Optional)

If you want to use any contrib module X, then add PYVXL_CONTRIB_MAKE_X=ON as a CMake option. To build all the contrib packages, use PYVXL_CONTRIB_MAKE_ALL=ON.

Also, these VXL build options should be set:

-DVXL_BUILD_CONTRIB="TRUE" -DVXL_BUILD_CORE_VIDEO="TRUE" -DVXL_BUILD_BRL="TRUE" 

Test your build

python3 -c "import vxl"

As part of your project

In your CMake file, just add

find_package(PythonLibs 3 REQUIRED)
add_subdirectory(${Your pybind11 dir})
add_subdirectory(${Your pyvxl dir})

Adding a new contrib module

To add a new contrib module xyz:

• Add xyz to the list of contrib_components in contrib/CMakeLists.txt
• Create a new directory contrib/xyz
• Add required files to new directory per the below

Required files for contrib module xyz are as follows:

CMakeLists.txt

project("pyvxl-contrib-xyz")
pyvxl_add_module(xyz)

pyxyz.h

#ifndef pyxyz_h_included_
#define pyxyz_h_included_

#include <pybind11/pybind11.h>

namespace pyvxl { namespace xyz {

void wrap_xyz(pybind11::module &m);

}}

#endif  // pyxyz_h_included_

pyxyz.cxx

#include "pyxyz.h"

namespace py = pybind11;

namespace pyvxl { namespace xyz {

void wrap_xyz(py::module &m)
{
  // wrapping code ...
}

}}

PYBIND11_MODULE(_xyz, m)
{
  m.doc() =  "Python bindings for the VXL contrib XYZ computer vision library";
  pyvxl::xyz::wrap_xyz(m);
}

__init__.py

from ._xyz import *