Inverse curvelet transform fdct_wrapping, ifdct_wrapping

Following is test code for inserting watermark using curvelet transform(wrapping).Curvelet transform is invertible, hence results of forward transform and inverse should be same and hence get errors in extraction logic.However i am experiencing some problem.dont know where i am going wrong.Can someone help me. thanking in anticipation.

if true
clear all; 
close all; 
a=imread('sat55.jpg'); a=a(:,:,3); 
% a=resize_nbyn(a); 
b=mat2tiles(a,[64 64]); 
is_real=0; 
level=3; 
location=3; 
jnd=.2;
w=ones(16,22); 
w(1:8,1:22)=-1
C=fdct_wrapping((b{18,5}),is_real,1,4,8) ;
Ct = C; 
%modify coefficients 
%comment next 2 lines to compute without modifications 
add_coeff=abs(Ct{1,level}{1,location}).*(w*jnd) ;
Ct{1,level}{1,location}=Ct{1,level}{1,location}+add_coeff;
%take inverse 
tic; restored_img= uint8(abs(ifdct_wrapping(Ct,is_real,64,64))); toc;
%take forward 
tic; re_transform= fdct_wrapping(restored_img,is_real,1,4,8); toc; 
%compare the coefficients. should be same. 
abs(Ct{1,level}{1,location}-re_transform{1,level}{1,location})
end

[hadi gha]

i have same problem and i can't extract watermark. Can someone help us