cv::Mat curr = imread(WX2CV(inFile.GetFullName()), cv::IMREAD_COLOR);
cv::Mat currG;
cv::cvtColor(curr, currG, cv::COLOR_BGR2GRAY);
cv::Mat flow;
double polySig = polyN * 1.2 / 8.0;
cv::calcOpticalFlowFarneback(currG, prevG, flow, pyrScale, pyrLevs, winSize,
iterations, polyN, polySig, flags);
cv::Mat normFlow = NormalizeFlow(flow);