Matlab code for robust optical flow -- Classic++ and Classic-NL -- as described in the IJCV paper "A Quantitative Analysis of Current Practices in Optical Flow Estimation and the Principles behind Them". This code is widely used as a baseline and starting point for "classical" flow methods. Matlab version of the "Black and Anandan" robust flow method: https://deqings.github.io/public_files/ba.zip Matlab version of "Horn and Schunck": https://deqings.github.io/public_files/hs.zip Original implementation from CVPR'2010 paper: https://deqings.github.io/public_files/cvpr10_flow_code.zip