Undefined function 'wprec2' for input arguments of type 'double'.

I applied wpdec2 (Wavelet Packet transform) on a color image with size 512 * 512. It generates a subtree then I applied wpcoef to get it coefficients. On these coefficients I created blocks and apply DCT and inverse of DCT and blocks. Then i applied wprec2 after reverse process of block. Then i got a error as given below:

Undefined function 'wprec2' for input arguments of type 'double'.

Please help to troubleshoot this problem.

Answer 1

[dpb]

Without the actual code sequence we can't tell but the doc for wprec2 says it expects a wavelet packet tree object.

If you've munged on the output of wpdec2 to produce some output array of double, then you've broken the contract between the two of the forward/reverse transform.

All wprec2 promises is that it will reproduce X from the output of wdec2 operating on X

[Balkar Singh]

clear all;

img = imread('Image9.png');

T = wpdec2(img,6,'db5');

Tree_cfs = read(T,'allcfs');

X = wpcoef(T);

blksize=[8,8];

blk1 = our_blkproc(X,blksize);

dct_data = zeros(8,8,size(blk1,3));

for i=1:size(blk1,3)

dct_data(:,:,i) = dct2(blk1(:,:,i));

end

dct_data_inv = zeros(8,8,size(blk1,3));

for i=1:size(blk1,3)

dct_data_inv(:,:,i) = idct2(dct_data(:,:,i));

end

final_data = our_blkproc_rev(dct_data_inv);

final_data = reshape(final_data,1,[]);

x1 = wprec2(final_data);

I tried this code