R: Inverse two-dimensional discrete wavelet transform.

imwr.imwdc {wavethresh} | R Documentation

## Inverse two-dimensional discrete wavelet transform.

### Description

Inverse two-dimensional discrete wavelet transform.

### Usage

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

### 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.

### 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.

### 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.

### RELEASE

Version 3.5.3 Copyright Guy Nason 1994

### Author(s)

G P Nason

### 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).

[Package wavethresh version 4.6.8 Index]