o = imread ('ramya.jpg');
w = size (o, 2);
samplesHalf = floor(w / 2);
samplesQuarter = floor(w / 4);
samplesEighth = floor(w / 8);
ci2 = [];
ci4 = [];
ci8 = [];
for k=1:3 % all color layers: RGB
for i=1:size(o, 1) % all rows
rowDCT = idct(double(o(i,:,k)));
ci2(i,:,k) = idct(rowDCT(1:samplesHalf), w);
ci4(i,:,k) = idct(rowDCT(1:samplesQuarter), w);
ci8(i,:,k) = idct(rowDCT(1:samplesEighth), w);
end
end
h = size(o, 1);
samplesHalf = floor(h / 2);
samplesQuarter = floor(h / 4);
samplesEighth = floor(h / 8);
ci2f = [];
ci4f = [];
ci8f = [];
for k=1:3 % all color layers: RGB
for i=1:size(o, 2) % all columns
%PROJECT: IMAGE COMPRESSION USING DISCRETE COSINE TRANFORM IMPLEMENTING MATLAB%)
columnDCT2=idct(double(ci2(:,i,k)));
columnDCT4=idct(double(ci4(:,i,k)));
columnDCT8=idct(double(ci8(:,i,k)));
ci2f(:,i,k) = idct(columnDCT2(1:samplesHalf), h);
ci4f(:,i,k) = idct(columnDCT4(1:samplesQuarter), h);
ci8f(:,i,k) = idct(columnDCT8(1:samplesEighth), h);
end
end
subplot(2,2,1), image(uint8(o)), title('Original Image');
subplot(2,2,2), image(uint8(ci2)), title('Compression Factor 2');
subplot(2,2,3), image(uint8(ci4)), title('Compression Factor 4');
subplot(2,2,4), image(uint8(ci8)), title('Compression Factor 8');
figure
subplot(2,2,1), image(uint8(o)), title('Original Image');
subplot(2,2,2), image(uint8(ci2f)), title('Compression Factor 2 * 2');
subplot(2,2,3), image(uint8(ci4f)), title('Compression Factor 4 * 4');
subplot(2,2,4), image(uint8(ci8f)), title('Compression Factor 8 * 8');
