crystal.matrix
.
stretch(x, ...) stretch.default(x, power.stretch=0, stretch.fun=NULL) stretch.crystal.matrix(x, low.pass=T, power.stretch=0, stretch.fun=NULL)
crystal.matrix
.
stretch.image
is
TRUE
.
If
power.stretch=0
, then image is transformed
with
log(abs(x)+1)
.
Otherwise, the image is transformed with
(abs(x))^power.stretch
.
stretch.fun
.
If provided, then
power.stretch
will be ignored.
TRUE
the smooth/low-frequency coefficients
are scaled to have the same dynamic range as the
remaining coefficients.
Only for objects which inherit from class
wpt.2d
(2-D DWT and 2-D wavelet packet transforms).
x
.
Rescaling the gray levels is used to enhance the visual display of an image.