[matlab 图像处理] 阈值分割(直方图自己算)

close all;%关闭所有窗口
clear;%清除变量的状态数据
clc;%清除命令行

wangpic=imread('lenargb.bmp');
figure;%打开一个新窗口
imshow(wangpic);
title('1 lena的原图');

wangpicgray=rgb2gray(wangpic);
figure;%打开一个新窗口
imshow(wangpicgray);
title('2lena的灰度图');

%直方图
figure;%打开一个新窗口
imhist(wangpicgray);
title('3lena由matlab直方图');

%直方图自己算
[width,height,bmsize]=size(wangpicgray);
myzjhist=zeros(256,1);
myquzhi=0;
for i=1:width
    for j=1:height
        myquzhi=wangpicgray(i,j);
        myzjhist(myquzhi+1,1)=myzjhist(myquzhi+1,1)+1;
    end
end  
figure;
plot(myzjhist);
title('4 lena自己计算直方图');

%阈值
[width,height,bmsize]=size(wangpicgray);
for i=1:width
    for j=1:height
        if wangpicgray(i,j)>140