Images taken from different views of a planar object are
related by planar homography. Recovering the parameters
of such transformations is a fundamental problem in computer
vision with various applications. This paper proposes
a novel method to estimate the parameters of a homography
that aligns two binary images. It is obtained by solving a
system of nonlinear equations generated by integrating linearly
independent functions over the domains determined
by the shapes. The advantage of the proposed solution is
that it is easy to implement, less sensitive to the strength
of the deformation, works without established correspondences
and robust against segmentation errors. The method
has been tested on synthetic as well as on real images and
its efficiency has been demonstrated in the context of two
different applications: alignment of hip prosthesis X-ray images
and matching of traffic signs.