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Bo co mn Xl m thanh & hnh nh
ti:Vit chng trnh thc hin cn bng lc xm nh mu. Hin th
c tuyn cn bng, lc xm nh gc v nh kt qu. (lc xm hin thtrn 1 gc ca nh). Khng sdng hm imhist c sn trong Matlab.
GVHD:Ts. Nguyn Thanh Bnh
Nhm 1:
1. Dip Ngc Anh2. o Minh t3. Hong Cng Hiu4. Lm Hng Thanh5.Nguyn ThTuyt Trinh6.Nguyn Ngc Minh Th7.Nguyn Trang Kim Yn
I. Xy dng gii thut xl nh:Gm cc bc sau:
Bc 1: c nh, chuyn i nh mu gc thnh nh chc mc xm. Bc 2: Tnh sim nh c mt mc xm, xc nh hm mt phn
bxc sut.
Bc 3: Thc hin cn bng lc xm nh gc, to nh kt qusaukhi cn bng.
Bc 4: Thc hin v lc xm nh gc, lc xm nh cnbng, hin thnh gc v nh cn bng.
II. M phng gii thut trn Matlab:clear all;
% Buoc 1: Chuyen tu anh mau sang anh xam
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A=imread('1.jpg');
Anh_goc=rgb2gray(A);
% To cc bin cn thit
tong_so_pixels=size(Anh_goc,1)*size(Anh_goc,2);
in=[0:1:255]
nk_goc=zeros(256,1);
prk_goc=zeros(256,1);
sk=zeros(256,1);
sk_sao=zeros(256,1);
nk_kq=zeros(256,1);
Anhketqua=uint8(zeros(size(Anh_goc,1),size(Anh_goc,2)));
% Bc 2: Tnh sim nh c mt mc xm, hm mt phn bxc
sut
fori=1:size(Anh_goc,1)
forj=1:size(Anh_goc,2)
value=Anh_goc(i,j);nk_goc(value+1)=nk_goc(value+1)+1;
prk_goc(value+1)=nk_goc(value+1)/tong_so_pixels;
end
end
% Bc 3: Thc hin cn bng lc xm nh gc, to nh kt qusau cn
bngsum=0;
fori=1:size(prk_goc)
sum=sum+prk_goc(i);
sk(i)=sum;
sk_sao(i)=round(sk(i)*256);
end
fori=1:size(Anh_goc,1)
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forj=1:size(Anh_goc,2)
Anhketqua(i,j)=sk_sao(Anh_goc(i,j)+1);
end
end
fori=1:size(Anhketqua,1)
forj=1:size(Anhketqua,2)
value=Anhketqua(i,j);
nk_kq(value+1)=nk_kq(value+1)+1;
end
end
% Bc 4: Thc hin vlc xm nh gc, lc xm nh cn bng,
hin thnh gc v nh cn bng
h1=figure;
set(h1,'color','y');
subplot(2,1,1)
imshow(A);title('Anh goc')
subplot(2,1,2);
stem(nk_goc);
title('Luoc do xam Anh goc')
h2=figure;set(h2,'color','y');
subplot(2,2,1);
imshow(Anhketqua)
title('Anh sau can bang')
subplot(2,2,2) ;
stem(nk_kq);
title('Luoc do xam anh can bang')
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subplot(2,2,3)
plot(in,sk_sao);
title('Dac tuyen can bang');
III. Kt qum phng Matlab: nh mu gc v lc xm gc:
nh sau khi cn bng v lc xm cn bng:
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Nhn xt: So snh lc xm nh gc v nh sau cn bng, ta thy rrng gi trcc mc xm hin thtrong nh c tri u hn so vi
nh gc.
IV. Hng dn sdng GUI:1. Khi ng GUI theo cc bc sau: Khi ng MATLAB. Trong ca sComment Windowns g lnh guide v enter ta c giao
din mn hnh nh sau:
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Chn Tab Open Existing GUI mi GUI to:
GUI ca ti cn bng lc xm ny c thhin nh hnh di:
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2. Hng dn chy GUI: Click vo nt ANH MAU GOCload nh mu gc:
Click ANH XAM CUA ANH GOChin thnh chuyn sang nhchc mu xm v lc xm nh gc:
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Click nt ANH CAN BANGhin thnh sau cn bng lc xmsau cn bng:
Cui cng hin th c tuyn cn bng ta nhn nt DAC TUYENCAN BANG:
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