opencv学习笔记4 边缘检测

浅浅的花香味﹌ 2023-06-04 03:54 13阅读 0赞

### 一。边缘检测的一般步骤 ###

1.滤波 2.增强 3.检测

### 二。canny ###

void Canny(InputArray image,OutputArray edges, double threshold1, double threshold2, int apertureSize=3,bool L2gradient=false )

![1615707-20190911182056309-55959986.png][]

1     Mat src = imread("E:/test.jpg");
     2     Mat blur,gray,edge;
     3     Mat dst(src.rows, src.cols, src.type());
     4     cvtColor(src, gray, CV_BGR2GRAY); //转换为灰度图
     5     GaussianBlur(gray, blur, Size(3, 3), 0, 0); //降噪
     6     Canny(blur, edge, 200, 100); //边缘检测
     7     dst = Scalar::all(0);
     8     src.copyTo(dst, edge); //edge作掩码将src拷贝到dst
     9     imshow("src", src);
    10     imshow("canny detect", dst);
    11     waitKey();
    12     return 0;

![1615707-20190911184819518-998261674.png][]

### 三。sobel ###

void Sobel (  
InputArray src,//输入图  
OutputArray dst,//输出图  
int ddepth,//输出图像的深度  
int dx,  
int dy,  
int ksize=3,  
double scale=1,  
double delta=0,  
int borderType=BORDER\_DEFAULT );  
![1615707-20190911185252121-1379919004.png][]

1     Mat grad_x, grad_y;
    2     Mat src = imread("E:/test.jpg",0);
    3     Sobel(src, grad_x, src.depth(), 1, 0,3); //x方向梯度
    4     Sobel(src, grad_y, src.depth(), 0, 1, 3);//y方向梯度
    5     imshow("grad_x", grad_x);
    6     imshow("grad_y", grad_y);

![1615707-20190911191823622-598969168.png][]

### 四。Laplacian ###

void Laplacian(InputArray src,OutputArray dst, int ddepth, int ksize=1, double scale=1, double delta=0, intborderType=BORDER\_DEFAULT );

![1615707-20190911191352470-345220368.png][]

1     Mat src = imread("E:/test.jpg");
    2     Mat dst;
    3     Laplacian(src, dst, src.depth(),3,1,0 );
    4     imshow("src", src);
    5     imshow("dst", dst);
    6     waitKey();

![1615707-20190911191656880-1655878615.png][]

### 五。scharr滤波器 ###

void Scharr(  
InputArray src, //源图  
OutputArray dst, //目标图  
int ddepth,//图像深度  
int dx,// x方向上的差分阶数  
int dy,//y方向上的差分阶数  
double scale=1,//缩放因子  
double delta=0,// delta值  
intborderType=BORDER\_DEFAULT )// 边界模式

1 Mat grad_x, grad_y;
    2     Mat src = imread("E:/test.jpg", 0);
    3     Scharr(src, grad_x, src.depth(), 1, 0, 1, 0, BORDER_DEFAULT); //和sobel类似
    4     Scharr(src, grad_y, src.depth(), 0 , 1, 1, 0, BORDER_DEFAULT); 
    5     imshow("grad_x", grad_x);
    6     imshow("grad_y", grad_y);

![1615707-20190911192304488-1764932706.png][]

转载于:https://www.cnblogs.com/sclu/p/11508206.html

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