www.pudn.com > SPIHT_bandelet.rar > btc_image01.m

%   Function Usage out_put = btc_image01(in_put,block_size) 
%   The function does Image Compession based On BLOCK TRUNCATION CODING 
%   out_put     :   Output Image 
%   in_put      :   Input Image 
%   block_size  :   Block Size for processing(2x2,4x4,8x8 so on) 
%   This function supports only Square Images whose height and width 
%   are a multiple of 2(TWO) 
%   DATE    07/04/2004 
%   TIME    11:05 AM     
%   MULTIMEDIA COMMUNICATION LAB 
%   VALLABHA VASANT HAMPIHOLI 
function out_put = btc_image(in_put,block_size) 
X=imread(in_put); 
Y=imfinfo(in_put); 
K=block_size; 
X1=double(X); 
y1=size(X); 
n=y1(1); 
m=y1(2); 
k=1;l=1; 
 
 
if (Y.ColorType=='grayscale') 
 
%                      IMAGE ENCODING 
 
% 
%                  FOR GRAY SCALE IMAGES  
% 
subplot(131),imshow(X),title('ORIGINAL'); 
for i=1:K:n 
    for j=1:K:m 
        tmp([1:K],[1:K])=X1([i:i+(K-1)],[j:j+(K-1)]); 
        mn=mean(mean(tmp)); 
        tmp1([i:i+(K-1)],[j:j+(K-1)])=tmp>mn; 
        Lsmat=(tmp=mn); 
        Lsmn=sum(sum(Lsmat)); 
        Mrmn=sum(sum(Mrmat)); 
        Mu(k)=sum(sum(Lsmat.*tmp))/(Lsmn+.5);k=k+1; 
        Mi(l)=sum(sum(Mrmat.*tmp))/Mrmn;l=l+1; 
    end 
end 
subplot(132),imshow(tmp1);title('ENCODED'); 
 
%                     IMAGE DECODING 
 
k=1;l=1; 
for i=1:K:n 
    for j=1:K:m 
        tmp21([1:K],[1:K])=tmp1([i:i+(K-1)],[j:j+(K-1)]); 
        tmp22=(tmp21*round(Mu(k)));k=k+1; 
        tmp21=((tmp21==0)*round(Mi(l)));l=l+1; 
        tmp21=tmp21+tmp22; 
        out_put([i:i+(K-1)],[j:j+(K-1)])=tmp21; 
    end 
end 
subplot(133),imshow(uint8(out_put));title('DECODED'); 
 
% 
%                   FOR COLORED IMAGES 
% 
 
elseif (Y.ColorType=='truecolor') 
    R=X(:,:,1); 
    G=X(:,:,2); 
    B=X(:,:,3); 
    %                   IMAGE ENCODING 
subplot(131),imshow(X),title('ORIGINAL'); 
for b=1:3 
    for i=1:K:n 
            for j=1:K:m 
                tmp([1:K],[1:K])=X1([i:i+(K-1)],[j:j+(K-1)],b); 
                mn=mean(mean(tmp)); 
                tmp1([i:i+(K-1)],[j:j+(K-1)],b)=tmp>mn; 
                Lsmat=(tmp=mn); 
                Lsmn=sum(sum(Lsmat)); 
                Mrmn=sum(sum(Mrmat)); 
                Mu(b,k)=sum(sum(Lsmat.*tmp))/(Lsmn+.5);k=k+1; 
                Mi(b,l)=sum(sum(Mrmat.*tmp))/Mrmn;l=l+1; 
            end 
    end 
end 
subplot(132),imshow(tmp1);title('ENCODED'); 
 
%                   IMAGE DECODING 
 
k=1;l=1; 
for b=1:3 
    for i=1:K:n 
            for j=1:K:m 
                tmp21([1:K],[1:K])=tmp1([i:i+(K-1)],[j:j+(K-1)]); 
                tmp22=(tmp21*round(Mu(b,k)));k=k+1; 
                tmp21=((tmp21==0)*round(Mi(b,l)));l=l+1; 
                tmp21=tmp21+tmp22; 
                out_put([i:i+(K-1)],[j:j+(K-1)],b)=tmp21; 
            end 
    end 
end 
 
subplot(133),imshow(uint8(out_put));title('DECODED'); 
 
 
else 
      
    errordlg('IMAGE TYPE NOT SUPPORTED'); 
     
end