Abstract: Local image feature extractors that select local maxima of the determinant of Hessian function have been shown to perform well and are widely used. This paper introduces the negative local ...

(-2 * (x - a) / sigma * exp_sin_function(x, a, sigma, omega) + omega * exp(-(x - a)^2 / sigma) * cos(omega * (x -a))) # main second derivative (1d) exp_sin_second ...