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90 lines
2.5 KiB
C++
90 lines
2.5 KiB
C++
/**
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* @file houghlines.cpp
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* @brief This program demonstrates line finding with the Hough transform
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*/
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#include "opencv2/imgcodecs.hpp"
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#include "opencv2/highgui.hpp"
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#include "opencv2/imgproc.hpp"
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using namespace cv;
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using namespace std;
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int main(int argc, char** argv)
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{
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// Declare the output variables
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Mat dst, cdst, cdstP;
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//![load]
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const char* default_file = "sudoku.png";
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const char* filename = argc >=2 ? argv[1] : default_file;
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// Loads an image
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Mat src = imread( samples::findFile( filename ), IMREAD_GRAYSCALE );
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// Check if image is loaded fine
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if(src.empty()){
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printf(" Error opening image\n");
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printf(" Program Arguments: [image_name -- default %s] \n", default_file);
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return -1;
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}
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//![load]
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//![edge_detection]
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// Edge detection
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Canny(src, dst, 50, 200, 3);
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//![edge_detection]
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// Copy edges to the images that will display the results in BGR
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cvtColor(dst, cdst, COLOR_GRAY2BGR);
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cdstP = cdst.clone();
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//![hough_lines]
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// Standard Hough Line Transform
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vector<Vec2f> lines; // will hold the results of the detection
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HoughLines(dst, lines, 1, CV_PI/180, 150, 0, 0 ); // runs the actual detection
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//![hough_lines]
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//![draw_lines]
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// Draw the lines
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for( size_t i = 0; i < lines.size(); i++ )
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{
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float rho = lines[i][0], theta = lines[i][1];
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Point pt1, pt2;
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double a = cos(theta), b = sin(theta);
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double x0 = a*rho, y0 = b*rho;
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pt1.x = cvRound(x0 + 1000*(-b));
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pt1.y = cvRound(y0 + 1000*(a));
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pt2.x = cvRound(x0 - 1000*(-b));
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pt2.y = cvRound(y0 - 1000*(a));
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line( cdst, pt1, pt2, Scalar(0,0,255), 3, LINE_AA);
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}
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//![draw_lines]
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//![hough_lines_p]
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// Probabilistic Line Transform
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vector<Vec4i> linesP; // will hold the results of the detection
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HoughLinesP(dst, linesP, 1, CV_PI/180, 50, 50, 10 ); // runs the actual detection
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//![hough_lines_p]
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//![draw_lines_p]
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// Draw the lines
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for( size_t i = 0; i < linesP.size(); i++ )
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{
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Vec4i l = linesP[i];
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line( cdstP, Point(l[0], l[1]), Point(l[2], l[3]), Scalar(0,0,255), 3, LINE_AA);
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}
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//![draw_lines_p]
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//![imshow]
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// Show results
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imshow("Source", src);
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imshow("Detected Lines (in red) - Standard Hough Line Transform", cdst);
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imshow("Detected Lines (in red) - Probabilistic Line Transform", cdstP);
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//![imshow]
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//![exit]
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// Wait and Exit
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waitKey();
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return 0;
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//![exit]
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}
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