The Image Processing Toolbox™ provides functionality for applying geometric transformations to register images.
For control point registration, the
can infer the parameters for the following types of transformations,
listed in order of complexity.
'polynomial' (Order 2, 3, or 4)
The first four transformations,
'polynomial' are global transformations. In
these transformations, a single mathematical expression applies to
an entire image. The last two transformations,
'lwm' (local weighted mean),
are local transformations. In these transformations, different mathematical
expressions apply to different regions within an image. When exploring
how different transformations affect the images you are working with,
try the global transformations first. If these transformations are
not satisfactory, try the local transformations: the piecewise linear
transformation first, and then the local weighted mean transformation.
Your choice of transformation type affects the number of control
point pairs you need to select. For example, a nonreflective similarity
transformation requires at least two control point pairs. A polynomial
transformation of order 4 requires 15 control point pairs. For more
information about these transformation types, and the special syntaxes
they require, see
For information about the specific transformation types available
for intensity-based automatic image registration, see the
imregister function reference page.