MATLAB抠图

poison matting matlab code
注：显示图像后，单击鼠标左键连出完全背景区域，双击左键结束；
图像改变后，再单击鼠标左键连出完全前景区域，双击左键结束。即可得到结果。
A=imread('ppmm2.bmp');
imshow(A);
hold on;

Threshold = 1;
UniBack=[0
0
255];

% choose background object, and B results into the Foreground Object and the
% Boundary Region
% choose the outer line of the boundary region. Single left click the mouse to specify vertice.Double left click or single right click to finish;
OuterBW = roipoly(A);
B(:,:,1) = immultiply(A(:,:,1),OuterBW);
B(:,:,2) = immultiply(A(:,:,2),OuterBW);
B(:,:,3) = immultiply(A(:,:,3),OuterBW);
Back(:,:,1) = immultiply(A(:,:,1),~OuterBW);
Back(:,:,2) = immultiply(A(:,:,2),~OuterBW);
Back(:,:,3) = immultiply(A(:,:,3),~OuterBW);
imshow(B);

% choose foreground object, and C results into a Circle of Interest
% choose the inner line of the boundary region. Single left click the mouse to specify vertice.Double left click or single right click to finish;
InnerBW = roipoly(B);
C(:,:,1) = immultiply(B(:,:,1),~InnerBW);
C(:,:,2) = immultiply(B(:,:,2),~InnerBW);
C(:,:,3) = immultiply(B(:,:,3),~InnerBW);
Fore(:,:,1) = immultiply(A(:,:,1),InnerBW);
Fore(:,:,2) = immultiply(A(:,:,2),InnerBW);
Fore(:,:,3) = immultiply(A(:,:,3),InnerBW);
imshow(C);

hold off;
RawAlpha = (double(OuterBW)+double(InnerBW))/2;

I = double(A);

% Method of "averaging" to get raw fore and background colors
for i = 1:size(RawAlpha,1)
for j = 1:size(RawAlpha,2)
RawFore(i,j,1)=0;
RawFore(i,j,2)=0;
RawFore(i,j,3)=0;
RawBack(i,j,1)=0;
RawBack(i,j,2)=0;
RawBack(i,j,3)=0;
if RawAlpha(i,j) == 1
RawFore(i,j,:)=Fore(i,j,:);
end;
if RawAlpha(i,j) == 0
RawBack(i,j,:)=Back(i,j,:);
end;
if RawAlpha(i,j) == 0.5
r=1;
while 1
TestFore = InnerBW(max(i-r,1):min(i+r,size(A,1)),max(j-r,1):min(j+r,size(A,2)));
if size(find(TestFore),1)
[i1, j1] = find(TestFore);
i2 = i1 + max(i-r,1) -1;
j2 = j1 + max(j-r,1) -1;
Rs = double(Fore(i2,j2,:));
Ds(:,1)=diag(Rs(:,:,1));
Ds(:,2)=diag(Rs(:,:,2));
Ds(:,3)=diag(Rs(:,:,3));
if size(Ds,1) == 1
RawFore(i,j,:) =Ds;
else
RawFore(i,j,:) = sum(Ds) / size(Ds,1);
end;
clear Ds;
break;
else
r=r+1;
end;
end;
r=1;
while 1
TestBack = ~OuterBW(max(i-r,1):min(i+r,size(A,1)),max(j-r,1):min(j+r,size(A,2)));
if size(find(TestBack),1)
[i1, j1] = find(TestBack);
i2 = i1 + max(i-r,1) -1;
j2 = j1 + max(j-r,1) -1;
Rs = double(Back(i2,j2,:));
Ds(:,1)=diag(Rs(:,:,1));
Ds(:,2)=diag(Rs(:,:,2));
Ds(:,3)=diag(Rs(:,:,3));
if size(Ds,1) == 1
RawBack(i,j,:) =Ds;
else
RawBack(i,j,:) = sum(Ds) / size(Ds,1);
end;
clear Ds;
break;
else
r=r+1;
end;
end;
end;
end;
end;

%此处没有用高斯滤波
Denorm = RawFore - RawBack;
%red channel
I1 = I(:,:,1);
Denorm1 = Denorm(:,:,1);

for i=1:size(Denorm1,1)
for j= 1: size(Denorm1,2)
if Denorm1(i,j)==0
Denorm1(i,j)=1;
end;
end;
end;

OldAlpha = RawAlpha;
NewAlpha = RawAlpha;
h1=0;
while 1
for i=1:size(OldAlpha,1)
for j=1:size(OldAlpha,2)
NewAlpha(i,j) = OldAlpha(i,j);
if RawAlpha(i,j) == 0.5
Roui = ((I1(i+1,j) + I1(i-1,j) - 2 * I1(i,j)) * Denorm1(i,j) - (I1(i+1,j) - I1(i,j)) * (Denorm1(i+1,j) - Denorm1(i,j)))/(Denorm1(i,j) * Denorm1(i,j));
Rouj = ((I1(i,j+1) + I1(i,j-1) - 2 * I1(i,j)) * Denorm1(i,j) - (I1(i,j+1) - I1(i,j)) * (Denorm1(i,j+1) - Denorm1(i,j)))/(Denorm1(i,j) * Denorm1(i,j));
Rou = Roui + Rouj;
NewAlpha(i,j) = (OldAlpha(i+1,j) + NewAlpha(i-1,j) + OldAlpha(i,j+1) + NewAlpha(i,j-1) - Rou) / 4;
if NewAlpha(i,j)<0
NewAlpha(i,j)=0;
end;
if NewAlpha(i,j)>1
NewAlpha(i,j)=1;
end;
end;
end;
end;
% imshow(uint8(NewAlpha*255));
DifferenceAlpha = abs(NewAlpha - OldAlpha);
OldAlpha = NewAlpha;
if sum(sum(DifferenceAlpha)) < Threshold
break;
end;
h1=h1+1;
end;
for i=1:size(A,1)
for j=1:size(A,2)
if OldAlpha(i,j)==0
NewImage(i,j,:)=UniBack';
else
NewImage(i,j,1)=UniBack(1)*(1-OldAlpha(i,j))+RawFore(i,j,1)*OldAlpha(i,j);
NewImage(i,j,2)=UniBack(2)*(1-OldAlpha(i,j))+RawFore(i,j,2)*OldAlpha(i,j);
NewImage(i,j,3)=UniBack(3)*(1-OldAlpha(i,j))+RawFore(i,j,3)*OldAlpha(i,j);
end;
end;
end;
figure,imshow(NewAlpha);
figure,imshow(uint8(NewImage));
figure,imshow(uint8(RawFore));
figure,imshow(uint8(RawBack));