%%二維迭代硬閾值法（IHT）
%?function?Demo_CS_IHT（）
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%?the?DCT?basis?is?selected?as?the?sparse?representation?dictionary
%?instead?of?seting?the?whole?image?as?a?vector?I?process?the?image?in?the
%?fashion?of?column-by-column?so?as?to?reduce?the?complexity.
?
%?Author:?Chengfu?Huo?roy@mail.ustc.edu.cn?http://home.ustc.edu.cn/~roy
%?Reference:?T.?Blumensath?and?M.?Davies?“Iterative?Hard?Thresholding?for
%?Compressed?Sensing”?2008.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
?
%------------?讀入圖像?--------------
load?C:\Users\zkdn\Desktop\MATLABdata\I1\I1.mat
X=I1;
background=imopen（Xstrel（‘disk‘15））;%獲取背景信息
X=imsubtract（Xbackground）;%利用函數去除背景

X=double（X）;
[heightwidth]=size（X）;
?
?
%------------?形成測量矩陣和基本矩陣---------------
Phi=randn（floor（height/2）width）;??%?only?keep?one?third?of?the?original?data?
Phi?=?Phi./repmat（sqrt（sum（Phi.^21））[floor（height/2）1]）;?%?normalize?each?column
?
mat_dct_1d=zeros（512512）;??%?building?the?DCT?basis?（corresponding?to?each?column）
for?k=0:1:511
????dct_1d=cos（[0:1:511]‘*k*pi/512）;
????if?k>0
????????dct_1d=dct_1d-mean（dct_1d）;
????end;
????mat_dct_1d（:k+1）=dct_1d/norm（dct_1d）;
end
?
?
%---------?投影?---------
X_cs_1d=Phi*X;??????????%?treat?each?column?as?a?independent?signal
?
?
%--------?恢復使用iht?------------
sparse_rec_1d=zeros（heightwidth）;???????????
Theta_1d=Phi*mat_dct_1d;
s_ratio?=?0.2;
for?i=1:width
????column_rec=cs_iht（X_cs_1