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Inverse nondecimated 2-D wavelet transform

`C = indwt2(W,TYPE,N)`

C = indwt2(W,TYPE)

C = indwt2(W,TYPE,N)

X = indwt2(W)

X = indwt2(W,'a',0)

X = indwt2(W,'ca',0)

`indwt2` performs a multilevel
nondecimated 2-D wavelet reconstruction starting from a multilevel
nondecimated 2-D wavelet decomposition. You can also use `indwt2` to extract coefficients from
a multilevel nondecimated 2-D wavelet decomposition.

`C = indwt2(W,TYPE,N)` computes
the reconstructed or the extracted components at level

A group of 2 chars

`'xy'`, one per direction, with`'x'`and`'y'`in the set`{'a','d','l','h'}`or in the corresponding uppercase set`{'A','D','L','H'}`), where`'A'`(or`'L'`) stands for low-pass filter and`'D'`(or`'H'`) stands for high-pass.The char

`'d'`(or`'h'`or`'D'`or`'H'`) specifies the sum of the components different from the low-pass one.

For extraction, the valid values for * TYPE* are
the same as above prefixed by

See `ndwt2` for more information
about the decomposition structure * W*.

`C = indwt2(W,TYPE)` is
equivalent to

`X = indwt2(W)`,

% Load original image. load noiswom % Decompose X at level 3 using db1. W = ndwt2(X,3,'db1'); % Reconstruct approximations at levels 1 to 3. A = cell(1,3); for k=1:3, A{k} = indwt2(W,'aa',k); end % Plot original image at the top and approximations % at the bottom. figure; colormap(pink(255)) subplot(2,3,2);image(X); for k=1:3 subplot(2,3,k+3);image(A{k}); end

% Reconstruct detail at level 1. D = indwt2(W,'d',1); % Display reconstructed detail at level 1. figure; colormap(pink(255));imagesc(abs(D))

% Compute reconstructed approximation and detail at level 1. A1 = indwt2(W,'aa',1); D1 = indwt2(W,'d',1); % Check that X = A1 + D1. E1 = X-A1-D1; err1 = max(abs(E1(:))) err1 = 2.6645e-013 % Compute reconstructed approximation and detail at level 2. A2 = indwt2(W,'aa',2); D2 = indwt2(W,'d',2); % Check that X = A2 + D2. E2 = X-A2-D2; err2 = max(abs(E2(:))) err2 = 2.5668e-013

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