Python interface

The project uses pycuda to provide a pure-python package available on PyPi

pip install farneback3d

Usage:

import farneback3d

... # create some numpy volumes vol0 and vol1 (can also be pycuda GPUArrays)

# set parameters for optical flow (parameters have the same meaning as in the OpenCV implementation)
optflow = farneback3d.Farneback(
        pyr_scale=0.8,         # Scaling between multi-scale pyramid levels
        levels=6,              # Number of multi-scale levels
        num_iterations=5,      # Iterations on each multi-scale level
        winsize=9,             # Window size for Gaussian filtering of polynomial coefficients
        poly_n=5,              # Size of window for weighted least-square estimation of polynomial coefficients
        poly_sigma=1.2,        # Sigma for Gaussian weighting of least-square estimation of polynomial coefficients
    )

# calculate frame-to-frame flow between vol0 and vol1
flow = optflow.calc_flow(vol0, vol1)

C++ interface

To be implemented…

Future plans

The current implementation uses a naive approach to perform the necessary convolutions. The algorithm could be sped up drastically by performing separable convolutions along each coordinate axis.

References