OpenCV2马拉松第15圈——边缘检測(Laplace算子，LOG算子)

C++: void Laplacian(InputArray src, OutputArray dst, int ddepth, int ksize=1, double scale=1, double delta=0, int borderType=BORDER_DEFAULT)

src – Source image. dst – Destination image of the same size and the same number of channels as src . ddepth – Desired depth of the destination image. ksize – Aperture size used to compute the second-derivative filters. See getDerivKernels() for details. The size must be positive and odd. scale – Optional scale factor for the computed Laplacian values. By default, no scaling is applied. See getDerivKernels() for details. delta – Optional delta value that is added to the results prior to storing them in dst . borderType – Pixel extrapolation method. See borderInterpolate() for details.

This is done when ksize > 1 . When ksize == 1 , the Laplacian is computed by filtering the image with the following  aperture:

#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/highgui/highgui.hpp"

using namespace cv;

int main( int, char** argv )
{

  Mat src, src_gray;
  int kernel_size = 3;
  const char* window_name = "Laplace Demo";

  src = imread( argv[1] );
  GaussianBlur( src, src, Size(3,3), 0, 0, BORDER_DEFAULT );
  cvtColor( src, src_gray, CV_RGB2GRAY );
  namedWindow( window_name, CV_WINDOW_AUTOSIZE );

  Mat dst, abs_dst;
  Laplacian( src_gray, dst, CV_16S, kernel_size);
  convertScaleAbs( dst, abs_dst );

  imshow( window_name, abs_dst );
  waitKey(0);
  return 0;
}

#include "opencv2/highgui/highgui.hpp"  
#include "opencv2/imgproc/imgproc.hpp"  
using namespace cv;   

int main( int, char** argv )  
{  
	Mat src,gray,Kernel;
	 
    src = imread( argv[1] );
    GaussianBlur( src, src, Size(3,3), 0, 0, BORDER_DEFAULT ); 
    cvtColor( src, gray, CV_RGB2GRAY );
    namedWindow("dstImage", 1);  

    Kernel = (Mat_<double>(3,3) << 1, 1, 1, 1, -8, 1, 1, 1, 1);
    Mat grad,abs_grad;
    filter2D(gray, grad, CV_16S , Kernel, Point(-1,-1));  
    convertScaleAbs( grad, abs_grad );
    
    imshow("dstImage", abs_grad);  
    waitKey();  
    return 0;  
} 

#include "opencv2/highgui/highgui.hpp"  
#include "opencv2/imgproc/imgproc.hpp"  
using namespace cv;   

int main( int, char** argv )  
{  
    Mat src,gray;
	 
    src = imread( argv[1] );
    GaussianBlur( src, src, Size(3,3), 0, 0, BORDER_DEFAULT ); 
    cvtColor( src, gray, CV_RGB2GRAY );
    namedWindow("srcImage", 1); 
    namedWindow("dstImage", 1);  

    Mat grad,abs_grad;
    Laplacian( gray, grad, CV_16S, 3);
    convertScaleAbs( grad, abs_grad );
    Mat sharpped = gray + abs_grad;

    imshow("srcImage", gray);
    imshow("dstImage", sharpped);  
    waitKey();  
    return 0;  
}