Revision history [back]

it looks like you copied the signature from findHomography().

findEssentialMat(p1,p2,FM_RANSAC, 1, 0.99,output);  // <-- all params from the 3rd on are wrong

so they just could not find the signature you called

CV_EXPORTS Mat findEssentialMat( InputArray points1, InputArray points2, double focal = 1.0, Point2d pp = Point2d(0, 0), 
                                 int method = CV_RANSAC, 
                                 double prob = 0.999, double threshold = 1.0, OutputArray mask = noArray() );