数字图像处理中对图像进行压缩，保存，显示等一系列操作，源码已经可以运行

clc clear all close all %% 图像读取、显示和保存 I=imread('2.jpg'); I=double(I); [nrow,ncol]=size(I) figure imshow(uint8(I)) %取子图像和均匀采样 I_s=I(1:200,1:300); I_s=I(1:2:end,1:2:end); figure imshow(uint8(I_s)) %% 图像缩放 I=imread('2.jpg'); I=double(I); [nrow,ncol]=size(I) figure imshow(uint8(I)) size_s=[200,200] %使用matlab函数 I_s=imresize(I,size_s,'bilinear'); figure imshow(uint8(I_s)) I=I_s; size_b=[nrow,ncol] %重写缩放函数 ratio=size_s./size_b; I_resize=zeros(size_b); for row=1:size_b(1) for col=1:size_b(2) %bilinear y=row*ratio(1); x=col*ratio(2); x1=floor(x); x2=ceil(x); y1=floor(y); y2=ceil(y); if(y==0) y=1; elseif(y>size_s(1)) y=size_s(1); end if(x==0) x=1; elseif(x>size_s(2)) x=size_s(2); end if(y1==0) y1=1; elseif(y1>size_s(1)) y1=size_s(1); end if(x1==0) x1=1; elseif(x1>size_s(2)) x1=size_s(2); end if(y2==0) y=1; elseif(y2>size_s(1)) y2=size_s(1); end if(x2==0) x2=1; elseif(x2>size_s(2)) x2=size_s(2); end if(x1==x2) I_R1=I(y1,x1); I_R2=I(y2,x1); else I_R1=(x2-x)/(x2-x1)*I(y1,x1)+(x-x1)/(x2-x1)*I(y1,x2); I_R2=(x2-x)/(x2-x1)*I(y2,x1)+(x-x1)/(x2-x1)*I(y2,x2); end if(y1==y2) I_P=I_R1; else I_P=(y2-y)/(y2-y1)*I_R1+(y-y1)/(y2-y1)*I_R2; end I_resize(row,col)=I_P; end end figure imshow(uint8(I_resize))