  In this paper a fast triangular mesh based registration method is proposed.
Having Template and Reference images as inputs, the template image is
triangulated using a content adaptive mesh generation algorithm. Considering
the pixel values at mesh nodes, interpolated using spline interpolation method
for both of the images, the energy functional needed for image registration is
minimized. The minimization process was achieved using a mesh based
discretization of the distance measure and regularization term which resulted
in a sparse system of linear equations, which due to the smaller size in
comparison to the pixel-wise registration method, can be solved directly. Mean
Squared Difference (MSD) is used as a metric for evaluating the results. Using
the mesh based technique, higher speed was achieved compared to pixel-based
curvature registration technique with fast DCT solver. The implementation was
done in MATLAB without any specific optimization. Higher speeds can be achieved
using C/C++ implementations.
