wavethresh (version 4.7.3)

imwr.imwdc: Inverse two-dimensional discrete wavelet transform.

Description

Inverse two-dimensional discrete wavelet transform.

Usage

# S3 method for imwdc
imwr(imwd, verbose=FALSE, ...)

Value

A matrix, of dimension determined by the original data set supplied to the initial decomposition (more precisely, determined by the nlevelsWT component of the imwdc.object). This matrix is the highest resolution level of the reconstruction.

Arguments

imwd

An object of class imwdc. This type of object is returned by threshold.imwd and is a compress.imwd compressed version of an imwd object.

verbose

If this argument is true then informative messages are printed detailing the computations to be performed

...

other arguments to supply to the imwr function which is called after uncompressing the imwdc object.

RELEASE

Version 3.5.3 Copyright Guy Nason 1994

Author

G P Nason

Details

This function merely uncompresses the supplied imwdc.object and passes the resultant imwd object to the imwr.imwd function.

This function is a method for the generic function imwr for class imwdc.object. It can be invoked by calling imwr for an object of the appropriate class, or directly by calling imwr.imwdc regardless of the class of the object.

See Also

compress.imwd, imwd, imwd.object, imwr.

Examples

#
# Do a decomposition, thresholding, then exact reconstruction
# Look at the error
#

test.image <- matrix(rnorm(32*32), nrow=32)

# Test image is just some sort of  square matrix whose side length
# is a power of two.
#
max( abs(imwr(threshold(imwd(test.image))) - test.image))
# [1] 62.34
#
# The answer is not zero (see contrasting examples in the help page for
# imwr.imwd because we have thresholded the
# 2D wavelet transform here).