Lossy Image Compression

clc; clear all; close all;

function out_put = btc_image(in_put,block_size)

X=imread('rice.png');

Y=imfinfo('rice.png');

K=input('Enter the 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');

disp('K=');

disp(K);

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);

        Mrmat=(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);

                Mrmat=(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

Image Compression Lossy