Standard matlab’s quiver function has axis origin in left bottom corner, however, images have origin in top left corner. To display optical flow vector field consistenly i use the following fucntion:

function [ output ] = quiver_flow( u, v )
%QUIVER_FLOW Displays quiver for optical flow 
%   SMatyunin2014

output = quiver( u, v, 0);
axis ij;