samples/cpp/tutorial_code/ImgTrans/Sobel_Demo.cpp


Sample code using Sobel and/or Scharr OpenCV functions to make a simple Edge Detector

Sobel_Derivatives_Tutorial_Result.jpg
Sample screenshot

Check the corresponding tutorial 了解更多细节

#include <iostream>
using namespace cv ;
using namespace std ;
int main( int argc, char ** argv )
{
cv::CommandLineParser parser(argc, argv,
"{@input |lena.jpg|input image}"
"{ksize k|1|ksize (hit 'K' to increase its value at run time)}"
"{scale s|1|scale (hit 'S' to increase its value at run time)}"
"{delta d|0|delta (hit 'D' to increase its value at run time)}"
"{help h|false|show help message}" );
cout << "The sample uses Sobel or Scharr OpenCV functions for edge detection\n\n" ;
parser. printMessage ();
cout << "\nPress 'ESC' to exit program.\nPress 'R' to reset values ( ksize will be -1 equal to Scharr function )" ;
// First we declare the variables we are going to use
Mat image,src, src_gray;
Mat grad;
const 字符串 window_name = "Sobel Demo - Simple Edge Detector" ;
int ksize = parser. get < int >( "ksize" );
int scale = parser. get < int >( "scale" );
int delta = parser. get < int >( "delta" );
int ddepth = CV_16S ;
字符串 imageName = parser. get < 字符串 >( "@input" );
// As usual we load our source image (src)
image = imread ( samples::findFile ( imageName ), IMREAD_COLOR ); // Load an image
// Check if image is loaded fine
if ( image.empty() )
{
printf( "Error opening image: %s\n" , imageName.c_str());
return EXIT_FAILURE;
}
for (;;)
{
// Remove noise by blurring with a Gaussian filter ( kernel size = 3 )
GaussianBlur (image, src, Size (3, 3), 0, 0, BORDER_DEFAULT );
// Convert the image to grayscale
cvtColor (src, src_gray, COLOR_BGR2GRAY );
Mat grad_x, grad_y;
Mat abs_grad_x, abs_grad_y;
Sobel (src_gray, grad_x, ddepth, 1, 0, ksize, scale, delta, BORDER_DEFAULT );
Sobel (src_gray, grad_y, ddepth, 0, 1, ksize, scale, delta, BORDER_DEFAULT );
// converting back to CV_8U
convertScaleAbs (grad_x, abs_grad_x);
convertScaleAbs (grad_y, abs_grad_y);
addWeighted (abs_grad_x, 0.5, abs_grad_y, 0.5, 0, grad);
imshow (window_name, grad);
char key = (char) waitKey (0);
if (key == 27)
{
return EXIT_SUCCESS;
}
if (key == 'k' || key == 'K' )
{
ksize = ksize < 30 ? ksize+2 : -1;
}
if (key == 's' || key == 'S' )
{
scale++;
}
if (key == 'd' || key == 'D' )
{
delta++;
}
if (key == 'r' || key == 'R' )
{
scale = 1;
ksize = -1;
delta = 0;
}
}
return EXIT_SUCCESS;
}