


Calculate optical flow using Lucas & Kanade. Fast, parallel code.
Note that the window of integration can either be a hard square window of
radius winN or it can be a soft 'gaussian' window with sigma winSig.
In general the soft window should be more accurate.
USAGE
[Vx,Vy,reliab]=optFlowLk( I1, I2, winN, ...
[winSig], [sigma], [thr], [show] )
INPUTS
I1, I2 - input images to calculate flow between
winN - window radius for hard window (=[] if winSig provided)
winSig - [] sigma for soft 'gauss' window (=[] if winN provided)
sigma - [1] amount to smooth by (may be 0)
thr - [3e-6] ABSOLUTE reliability threshold (min eigenvalue)
show - [0] figure to use for display (no display if == 0)
OUTPUTS
Vx, Vy - x,y components of flow [Vx>0->right, Vy>0->down]
reliab - reliability of flow in given window (cornerness of window)
EXAMPLE
% create square + translated square (B) + rotated square (C)
A=zeros(50,50); A(16:35,16:35)=1;
B=zeros(50,50); B(17:36,17:36)=1;
C=imrotate(A,5,'bil','crop');
optFlowLk( A, B, [], 2, 2, 3e-6, 1 );
optFlowLk( A, C, [], 2, 2, 3e-6, 2 );
% compare on stored real images (of mice)
load optFlowData;
[Vx,Vy,reliab] = optFlowLk( I5A, I5B, [], 4, 1.2, 3e-6, 1 );
[Vx,Vy,reliab] = optFlowCorr( I5A, I5B, 3, 5, 1.2, .01, 2 );
[Vx,Vy] = optFlowHorn( I5A, I5B, 2, 3 );
See also OPTFLOWHORN, OPTFLOWCORR
Piotr's Image&Video Toolbox Version 2.0
Copyright 2008 Piotr Dollar. [pdollar-at-caltech.edu]
Please email me if you find bugs, or have suggestions or questions!
Licensed under the Lesser GPL [see external/lgpl.txt]