数字图像处理——绘制灰度直方图（遍历每个像素点的方法）

╰半夏微凉° 2022-11-10 10:54 134阅读 0赞

直接上代码：

close all
    
    clear all
    
    clc
    
    I=imread('lena.png');
    
    row=size(I,1);
    
    column=size(I,2);%2→dimision
    
    N=zeros(1,256);
    
    for i=1:row
    
        for j=1:column
    
            k=I(i,j);
    
            N(k+1)=N(k+1)+1;%记录每个灰度值的像素数
    
        end
    
    end
    
    figure(1)
    
    subplot(1,1,1),imshow(I);
    figure(2)
    
    subplot(1,1,1),bar(N);

结果示例：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ1MjgxODA3_size_16_color_FFFFFF_t_70]  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ1MjgxODA3_size_16_color_FFFFFF_t_70 1]  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ1MjgxODA3_size_16_color_FFFFFF_t_70 2]![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ1MjgxODA3_size_16_color_FFFFFF_t_70 3]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ1MjgxODA3_size_16_color_FFFFFF_t_70]: /images/20221022/243105fb16d544f5a27d52bc936573e7.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ1MjgxODA3_size_16_color_FFFFFF_t_70 1]: /images/20221022/aa5bf673fade45129bed38fe6e3dfa96.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ1MjgxODA3_size_16_color_FFFFFF_t_70 2]: https://img-blog.csdnimg.cn/20210318161056870.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ1MjgxODA3,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ1MjgxODA3_size_16_color_FFFFFF_t_70 3]: /images/20221022/41241112ecce49cdb2fcc32611831345.png