This invention is based on a new signal processing transform named Rao
Transform (RT) which was invented recently by the author of the present
invention. Forward RT provides a computationally efficient method and an
associated apparatus for computing the output signal of a Linear
Shift-Variant System (LSVS) from the input signal and a set of moment
parameters of the linear Shift-Variant Point Spread Function (SV-PSF)
that characterizes the LSVS. Inverse RT provides a computationally
efficient method and an associated apparatus for computing the input
signal or restored signal of an LSVS from the output signal and a set of
moment parameters of the linear SV-PSF that characterizes the LSVS. This
invention is useful in many applications including the restoration of
defocus blurred and motion blurred images recorded by a camera with a
linear SV-PSF. The apparatus include means for computing forward and
inverse RT coefficients.