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waverec2

2-D wavelet reconstruction

    Description

    example

    x = waverec2(c,s,wname) performs a multilevel wavelet reconstruction of the matrix x based on the wavelet decomposition structure [c,s] and the wavelet specified by wname. See wavedec2.

    x = waverec2(c,s,wname) is equivalent to x = appcoef2(c,s,wname,0).

    x = waverec2(c,s,LoR,HiR) reconstructs x using the specified lowpass and highpass wavelet reconstruction filters LoR and HiR, respectively.

    Examples

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    Load an image.

    load woman

    Perform a level 2 wavelet decomposition of the image using the sym4 wavelet.

    wv = 'sym4';
    [c,s] = wavedec2(X,2,wv);

    Reconstruct the image from the wavelet decomposition structure.

    xrec = waverec2(c,s,wv);

    Check for perfect reconstruction.

    max(abs(X(:)-xrec(:)))
    ans = 2.0989e-10
    

    Input Arguments

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    Wavelet decomposition vector, specified as a real-valued vector. The vector c contains the approximation and detail coefficients organized by level. The bookkeeping matrix s is used to parse c. See wavedec2.

    Data Types: double

    Bookkeeping matrix, specified as an integer-valued matrix. The matrix s contains the dimensions of the wavelet coefficients by level and is used to parse the wavelet decomposition vector c. See wavedec2.

    Data Types: double

    Analyzing wavelet, specified as a character vector or string scalar.

    Note

    waverec2 supports only Type 1 (orthogonal) or Type 2 (biorthogonal) wavelets. See wfilters for a list of orthogonal and biorthogonal wavelets.

    Wavelet reconstruction filters, specified as a pair of even-length real-valued vectors. LoR is the lowpass reconstruction filter, and HiR is the highpass reconstruction filter. The lengths of LoR and HiR must be equal. See wfilters for additional information.

    Data Types: double

    Tips

    • If c and s are obtained from an indexed image analysis or a truecolor image analysis, x is an m-by-n matrix or an m-by-n-by-3 array, respectively.

      For more information on image formats, see the image and imfinfo reference pages.

    Extended Capabilities

    Version History

    Introduced before R2006a

    See Also

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