计算机图像处理实验五：空间图像处理技术（MATLAB）

叁歲伎倆 2021-09-08 07:18 484阅读 0赞

> **【实验名称】**
> 
> 空间图像处理技术

> ** 【实验目的】**
> 
> １．熟悉使用MATLAB库函数fspecial、imfilter、imnoise、medfilt2；
> 
> ２．通过本次实验掌握图像空间滤波技术以及文字识别技术；

> **【实验内容】**
> 
> ![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDEwNzE0MA_size_16_color_FFFFFF_t_70][]![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDEwNzE0MA_size_16_color_FFFFFF_t_70 1][]
> 
>                                     图1                                                    图2
> 
> 1.  利用图1人物图像，通过库函数fspecial选择不同尺寸的平均滤波器，然后利用库函数imfilter进行滤波，观察滤波后的图像与滤波器大小的关系。
> 2.  利用图1人物图像，通过库函数imnoise对图像加噪音（椒盐噪音）。分别用5行5列的平均滤波器和中值滤波器，对加噪的图像滤波，对比结果进行分析比较。
> 3.  利用图2文字图像（该图像可从MATLAB中直接读取：I=imread('text.png');）从中选取字符a为模板（a=I(32:46,86:100);），通过滤波与阈值处理，识别出图像中的字符a。

> **【 实验代码】**
> 
> 题1
> 
>     clc;close all;
>     I=imread('实验5_Fig1.jpg');
>     imshow(I);
>     title('原图');
>     h1=fspecial('average',[5,5]);
>     h2=fspecial('average');
>     I1=imfilter(I,h1);
>     figure;
>     imshow(I1);
>     title('滤波器为[5,5]效果的图像');
>     % 选用默认的滤波器，即[3,3]
>     I2=imfilter(I,h2);
>     figure;
>     imshow(I2)
>     title('滤波器为[3,3]效果的图像');
> 
> 题2
> 
>     img=imnoise(I,'salt & pepper',0.02);
>     figure;
>     imshow(img);
>     title('加椒盐噪音处理后的图像');
>     % 5行5列滤波器处理
>     I3=imfilter(img,h1);
>     figure;
>     imshow(I3);
>     title('用5行5列的平均滤波器处理后图像');
>     % 中值滤波器处理
>     I4=medfilt2(img,[5,5]);
>     figure;
>     imshow(I4);
>     title('用中值滤波器处理后图像');
> 
> 题3
> 
>     img=imread('text.png');
>     img=double(img);
>     a=img(32:46,86:100);
>     figure;
>     subplot(1,3,1);
>     imshow(img);
>     title('原图');
>     subplot(1,3,2);
>     imshow(a);
>     title('截取字段的模板');
>     new_img=imfilter(img,a);
>     maxI=sum(a(:));
>     s=new_img==maxI;
>     IndexA=double(s);
>     [X,Y]=find(new_img==maxI);
>     num_a=length(X);
>     disp(['图像中a的个数:',num2str(num_a)]);
>     subplot(1,3,3);
>     imshow(IndexA);
>     title('经过字符模板处理后的');
>     [m,n]=size(a);
>     figure
>     for i=1:num_a
>         x=X(i);
>         y=Y(i);
>         IndexA((x-floor(m/2):x+floor(m/2)),(y-floor(n/2):y+floor(n/2)))=a;
>         imshow(IndexA);
>         hold on
>     end

>  **【运行结果】**
> 
> 题1
> 
> ![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDEwNzE0MA_size_16_color_FFFFFF_t_70 2][]![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDEwNzE0MA_size_16_color_FFFFFF_t_70 3][]![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDEwNzE0MA_size_16_color_FFFFFF_t_70 4][]
> 
> 题2
> 
> ![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDEwNzE0MA_size_16_color_FFFFFF_t_70 5][]![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDEwNzE0MA_size_16_color_FFFFFF_t_70 6][]![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDEwNzE0MA_size_16_color_FFFFFF_t_70 7][]
> 
> 题3
> 
> ![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDEwNzE0MA_size_16_color_FFFFFF_t_70 8][]
> 
> ![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDEwNzE0MA_size_16_color_FFFFFF_t_70 9][]
> 
>

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