In this paper, we present an unsharp masking-based approach for
noise smoothing and edge enhancing in multichannel images. The
proposed structure is similar to the conventional unsharp masking
structure, however, the enhancement is allowed only in the direc-
tion of maximal change and the enhancement parameter is com-
puted as a nonlinear function of the rate of change. The proposed
scheme enhances the true details, limits the overshoot near sharp
edges and attenuates noise in flat areas. Moreover the use of the
control function eliminates the need for the subjective coefficient
used in the conventional unsharp masking technique.
