20150602_multimedia_finalexam_pra

% DCT 1D

clear all
close all

N=8;
G = zeros(N,N);
alpha_u=1;

for u = 0:N-1
    for x = 0:N-1
        G(u+1,x+1) = alpha_u * cos(pi*u*(x+1/2)/N);
    end
end

figure(1);
for i=1:8
    subplot(4,2,i)
    bar(G(i,:))
end

%%%%%

%% DCT 2D

close all
clear all

N=8;
G=zeros(N,N,N,N);
alpha_u=1;
alpha_v=1;

for u = 0:N-1
    for v = 0:N-1
        for x = 0:N-1
            for y = 0:N-1
                G(u+1,v+1,x+1,y+1) = alpha_u * alpha_v * cos(pi*u*(x+1/2)/N) * cos(pi*v*(y+1/2)/N);
            end
        end
    end
end

figure(1);
for i=1:8
    for j=1:8
        subplot(8,8,(i-1)*8+j)
        imagesc(reshape(G(i,j,:,:),8,8))
    end
end


%%%%%%

%%%%%%

close all
clear all

N=8;
g=zeros(N,N);
t=linspace(0,pi,N); %cut 0~pi into N pieces

for i = 1:N
    g(i,:)=cos((i-1)*t);
end

G = zeros(N,N);
alpha_u=1;
n=1:N;

for i = 0:N-1
    for u = 0:N-1
        G(i+1,u+1) = sum(alpha_u.*g(i+1,:).*cos(u*pi/N*(n + 1/2)));
    end
end

figure(1)
for i=1:8
    subplot(4,2,i)
    bar(G(i,:));
end

%%%%%