Background a famous psychologists show that the second order variations extracted by the Laplacian operator are the most significant perceptually (Land and McCann 1971) a scalar function on a bounded domain is uniquely defined by its values on the boundary and its Laplacian in the interior The Poisson equation has a unique solution vcc可视计算研究中心• A famous psychologists show that the second￾order variations extracted by the Laplacian operator are the most significant perceptually (Land and McCann 1971) • A scalar function on a bounded domain is uniquely defined by its values on the boundary and its Laplacian in the interior. • The Poisson equation has a unique solution. Background 6