DIP2-Enhancement(PointProcessing)

时间：2015-03-16 12:50:15 阅读：153 评论：0 收藏：0 [点我收藏+]

标签：

Image Enhancement

1.Reasons for doing this:

Highlighting interesting detail in images
Removing noise from images
Making images more visually appealing2

2. Two broad categories of image enhancement

Spatial domain techniques

- Direct manipulation of image pixels
Point processing
Neighbourhood operations

b. Frequency domain techniques

Manipulation of Fourier transform or wavelet transform of an image

2.1 Techniques in spatial domain

–Thresholding

–Logarithmic transformation

–Power law transforms

–Grey level slicing

–Bit plane slicing

–Logic operations

–Image subtraction

–Image averaging

a. Thresholding

 1 #include <opencv2\opencv.hpp>
 2 #include <iostream>
 3 #include <string>
 4 using namespace cv;
 5 using namespace std;
 6 int main()
 7 {
 8     IplImage* img; //声明IplImage指针
 9     //载入图像
10     img = cvLoadImage("C://Users//Administrator//Desktop//dip//moon.png",0) ;
11 
12     cvNamedWindow( "Image1", 1 );//创建窗口
13     cvShowImage( "Image1", img );//显示图像
14 
15     for(int row = 0; row<img->height; row++)
16     {
17         for (int col=0; col<img->width; col++)
18         {
19             if((unsigned char)(img->imageData[row*img->widthStep+col])>80)
20                 img->imageData[row*img->widthStep+col] = 255;
21             else
22                 img->imageData[row*img->widthStep+col] = 0;
23         }
24     }
25 
26         cvNamedWindow( "Image", 1 );//创建窗口
27         cvShowImage( "Image", img );//显示图像
28         cvWaitKey(0); //等待按键
29  
30         cvDestroyWindow( "Image" );//销毁窗口
31         cvDestroyWindow( "Image1" );//销毁窗口
32         cvReleaseImage( &img ); //释放图像
33         return 0;
34 }

结果：

技术分享

b. Logarithmic transformation

　　expression: s = c * log(1 + r)

 1 #include <opencv2\opencv.hpp>
 2 #include <iostream>
 3 #include <string>
 4 #include <math.h>
 5 #include <stdio.h>
 6 using namespace cv;
 7 using namespace std;
 8 int main()
 9 {
10     IplImage* img; //声明IplImage指针
11     //载入图像
12     img = cvLoadImage("C://Users//Administrator//Desktop//dip//light.png",0) ;
13 
14     cvNamedWindow( "Image1", 1 );//创建窗口
15     cvShowImage( "Image1", img );//显示图像
16     /*printf("%x",img->imageData[(img->height)*(img->widthStep)/2+(img->width)/2]);*/
17 
18     for(int row = 0; row<img->height; row++)
19     {
20         for (int col=0; col<img->width; col++)
21         {
22             //----------------关键代码在这儿----------------------
23                 (unsigned char)img->imageData[row*img->widthStep+col];
24                 img->imageData[row*img->widthStep+col] = (unsigned char)(20*(log(1+(double)img->imageData[row*img->widthStep+col])));
25         }
26     }
27 
28         cvNamedWindow( "Image", 1 );//创建窗口
29         cvShowImage( "Image", img );//显示图像
30 
31         
32         cvWaitKey(0); //等待按键
33         cout<<"hello";
34         /*printf("%x",img->imageData[(img->height)*(img->widthStep)/2+(img->width)/2]);*/
35  
36         cvDestroyWindow( "Image" );//销毁窗口
37         cvDestroyWindow( "Image1" );//销毁窗口
38         cvReleaseImage( &img ); //释放图像
39         return 0;
40 }

结果：

技术分享

注意：程序让图像显示出了更多细节，但是不知道为什么中间的255白点变成了0？

　　　Line16，32试图输出确切的灰度级，未果。。

c. Power law transforms　　

　　expression: s = c * r ^γ

 1 #include <math.h>
 2 #include <stdio.h>
 3 using namespace cv;
 4 using namespace std;
 5 int main()
 6 {
 7     IplImage* img; //声明IplImage指针
 8     //载入图像
 9     img = cvLoadImage("C://Users//Administrator//Desktop//dip//spine.png",0) ;
10 
11     cvNamedWindow( "Image1", 1 );//创建窗口
12     cvShowImage( "Image1", img );//显示图像
13     
14     for(int row = 0; row<img->height; row++)
15     {
16         for (int col=0; col<img->width; col++)
17         {
18             //----------------关键代码在这儿----------------------
19                 (unsigned char)img->imageData[row*img->widthStep+col];
20                 img->imageData[row*img->widthStep+col] = 8*pow((double)(unsigned char)img->imageData[row*img->widthStep+col],0.6);
21         }
22     }
23 
24         cvNamedWindow( "Image", 1 );//创建窗口
25         cvShowImage( "Image", img );//显示图像
26     
27         cvWaitKey(0); //等待按键
28         cvDestroyWindow( "Image" );//销毁窗口
29         cvDestroyWindow( "Image1" );//销毁窗口
30         cvReleaseImage( &img ); //释放图像
31         return 0;
32 }

结果：c=8, γ=0.6 如下

技术分享

　　c=16, γ=0.4 如下

技术分享

　　c=20, γ=0.3 如下

技术分享

d. Grey level slicing

It is similar to thresholding

e. Bit plane slicing

f. Image subtraction

　　Application: Change Detection

　　　　•Tracking moving vehicles

　　　　•Tracking walking persons

　　　　•Change detections

Example1：

 1 #include <opencv2\opencv.hpp>
 2 #include <iostream>
 3 #include <string>
 4 #include <math.h>
 5 #include <stdio.h>
 6 using namespace cv;
 7 using namespace std;
 8 int main()
 9 {
10     IplImage* img; //声明IplImage指针
11     IplImage* img2; 
12     //载入图像
13     img = cvLoadImage("C://Users//Administrator//Desktop//dip//car.png",0) ;
14     img2 = cvLoadImage("C://Users//Administrator//Desktop//dip//cargone.png",0) ;
15     cout<<img->height<<endl;
16     cout<<img->width<<endl;
17     cout<<img2->height<<endl;
18     cout<<img2->width<<endl;
19 
20     cvNamedWindow( "OriginalImage", 1 );//创建窗口
21     cvShowImage( "OriginalImage", img );//显示图像
22 
23     cvNamedWindow( "OriginalImageCarGone", 1 );//创建窗口
24     cvShowImage( "OriginalImageCarGone", img2 );//显示图像
25     
26     for(int row = 0; row<img->height; row++)
27     {
28         for (int col=0; col<img->width; col++)
29         {
30             //----------------关键代码在这儿----------------------
31                 (unsigned char)img->imageData[row*img->widthStep+col];
32                 (unsigned char)img2->imageData[row*img->widthStep+col];
33 
34                 img->imageData[row*img->widthStep+col] = (255+(img2->imageData[row*img->widthStep+col])-(img->imageData[row*img->widthStep+col]))/2;
35         }
36     }
37 
38         cvNamedWindow( "ProcessedImage", 1 );//创建窗口
39         cvShowImage( "ProcessedImage", img );//显示图像
40     
41         cvWaitKey(0); //等待按键
42         cvDestroyWindow( "OriginalImage" );//销毁窗口
43         cvDestroyWindow( "OriginalImageCarGone" );//销毁窗口
44         cvDestroyWindow( "ProcessedImage" );//销毁窗口
45         cvReleaseImage( &img ); //释放图像
46         cvReleaseImage( &img2 ); //释放图像
47         return 0;
48 }

理想结果应该是这样：

可是我的却是这样：

在黑框里调试输出了两张图片的高和宽，竟然不一样！

老干妈的PPT有问题啊啊

Example2：

 1 #include <opencv2\opencv.hpp>
 2 #include <iostream>
 3 #include <string>
 4 #include <math.h>
 5 #include <stdio.h>
 6 using namespace cv;
 7 using namespace std;
 8 int main()
 9 {
10     IplImage* img; //声明IplImage指针
11     IplImage* img2; 
12     //载入图像
13     img = cvLoadImage("C://Users//Administrator//Desktop//dip//banana.png",0) ;
14     img2 = cvLoadImage("C://Users//Administrator//Desktop//dip//bananamove.png",0) ;
15     cout<<"img1:height:"<<img->height<<endl;
16     cout<<"img1:width:"<<img->width<<endl;
17     cout<<"img2:height:"<<img2->height<<endl;
18     cout<<"img2:width:"<<img2->width<<endl;
19 
20     cvNamedWindow( "OriginalImage", 1 );//创建窗口
21     cvShowImage( "OriginalImage", img );//显示图像
22 
23     cvNamedWindow( "OriginalImageCarGone", 1 );//创建窗口
24     cvShowImage( "OriginalImageCarGone", img2 );//显示图像
25     
26     for(int row = 0; row<img->height; row++)
27     {
28         for (int col=0; col<img->width; col++)
29         {
30             //----------------关键代码在这儿----------------------
31                 (unsigned char)img->imageData[row*img->widthStep+col];
32                 (unsigned char)img2->imageData[row*img->widthStep+col];
33 
34                 img->imageData[row*img->widthStep+col] = (255+(img2->imageData[row*img->widthStep+col])-(img->imageData[row*img->widthStep+col]))/2;
35         }
36     }
37 
38         cvNamedWindow( "ProcessedImage", 1 );//创建窗口
39         cvShowImage( "ProcessedImage", img );//显示图像
40     
41         cvWaitKey(0); //等待按键
42         cvDestroyWindow( "OriginalImage" );//销毁窗口
43         cvDestroyWindow( "OriginalImageCarGone" );//销毁窗口
44         cvDestroyWindow( "ProcessedImage" );//销毁窗口
45         cvReleaseImage( &img ); //释放图像
46         cvReleaseImage( &img2 ); //释放图像
47         return 0;
48 }