腻子粉20kg多少钱一袋:如何用MATLAB编写一个双线性插值的算法,用来放大缩小图象

%% 4.图像的缩放

% 思路：双线性插值
kV = 0.5; % 垂直缩放系数
kH = 0.5; % 水平缩放系数

% 读入图像
I = imread('D:\lena.bmp'); % 注意修改文件路径
II = double(I);

[m, n, r]=size(II);
OI=zeros(m*kV,n*kH, r);
rot=[kV 0 0;0 kH 0;0 0 1]; % 变换矩阵

for k=1:r
for i=1:m*kV
for j=1:n*kH
pix=[i j 1]/rot;
Y =pix(1)-floor(pix(1));
X =pix(2)-floor(pix(2));
% 边界处理
if pix(1) < 1
pix(1) = 1;
end
if pix(1) > m
pix(1) = m;
end
if pix(2) < 1
pix(2) = 1;
end
if pix(2) > n
pix(2) =n;
end
% 四个邻点
pix1 = [floor(pix(1))floor(pix(2))];
pix2 = [floor(pix(1))ceil(pix(2))];
pix3 = [ceil(pix(1))floor(pix(2))];
pix4 = [ceil(pix(1))ceil(pix(2))];
% 计算临近四个点的权重
w1 = (1-X)*(1-Y);
w2 = X*(1-Y);
w3 = (1-X)*Y;
w4 = X*Y;
% 按权重进行双线性插值
OI(i,j,k)=...
w1*II(pix1(1),pix1(2),k)+ ...
w2*II(pix2(1),pix2(2),k)+ ...
w3*II(pix3(1),pix3(2),k)+ ...
w4*II(pix4(1),pix4(2),k);
end
end
end
figure, imshow(uint8(II)), title('原图')
figure, imshow(uint8(OI)), title('缩放后')