In image processing and video image compression

it is important to estimate the displacement between deformed image and its template.In this paper

we discuss some related methods and introduce an elastic matching

which is an image gradient based approach.First

a new quadratic error functional is proposed.The functional consists of two terms:one is matching error;the other is a smoothness constraint.Being different from Horn and Schunck’ optical flow method

the matching errors and smoothness constraint are explicitly defined on the displacement vector field instead of “flow field”.The functional by variational calculus leads to a set of elliptic partial differential equations

in particular

Poisson equations

which is possibly solved by numerical methods.Using finite difference method

our algorithm is effective for matching deformed image planes.It quickly converges to good estimates of displacement vector field

and is insensitive to additive noise.