MATLAB处理灰度图的四个实验

%高四位变成0
close all;clear all; clc;
%I=imread('lena_gray_256.tif');
I=imread('cameraman','tif');
I=double(I);
J=I;
row=size(J,1);
column=size(J,2);
for i=1:row
    for j=1:column
        if J(i,j)>15
           % x=dec2bin(I);
            n=bitshift(J(i,j),4,8);
            m=bitshift(n,-4,8);
            J(i,j)=m;
        end
    end
end
figure;
subplot(121);imshow(uint8(I));
subplot(122);imshow(uint8(J));
            
%低四位变成0
close all;clear all; clc;
%I=imread('lena_gray_256.tif');
I=imread('cameraman','tif');
I=double(I);
J=I;
row=size(J,1);
column=size(J,2);