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97 lines
3.3 KiB
Java
97 lines
3.3 KiB
Java
/**
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* @file HoughLines.java
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* @brief This program demonstrates line finding with the Hough transform
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*/
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import org.opencv.core.*;
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import org.opencv.core.Point;
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import org.opencv.highgui.HighGui;
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import org.opencv.imgcodecs.Imgcodecs;
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import org.opencv.imgproc.Imgproc;
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class HoughLinesRun {
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public void run(String[] args) {
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// Declare the output variables
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Mat dst = new Mat(), cdst = new Mat(), cdstP;
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//! [load]
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String default_file = "../../../../data/sudoku.png";
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String filename = ((args.length > 0) ? args[0] : default_file);
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// Load an image
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Mat src = Imgcodecs.imread(filename, Imgcodecs.IMREAD_GRAYSCALE);
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// Check if image is loaded fine
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if( src.empty() ) {
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System.out.println("Error opening image!");
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System.out.println("Program Arguments: [image_name -- default "
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+ default_file +"] \n");
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System.exit(-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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Imgproc.Canny(src, dst, 50, 200, 3, false);
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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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Imgproc.cvtColor(dst, cdst, Imgproc.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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Mat lines = new Mat(); // will hold the results of the detection
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Imgproc.HoughLines(dst, lines, 1, Math.PI/180, 150); // 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 (int x = 0; x < lines.rows(); x++) {
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double rho = lines.get(x, 0)[0],
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theta = lines.get(x, 0)[1];
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double a = Math.cos(theta), b = Math.sin(theta);
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double x0 = a*rho, y0 = b*rho;
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Point pt1 = new Point(Math.round(x0 + 1000*(-b)), Math.round(y0 + 1000*(a)));
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Point pt2 = new Point(Math.round(x0 - 1000*(-b)), Math.round(y0 - 1000*(a)));
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Imgproc.line(cdst, pt1, pt2, new Scalar(0, 0, 255), 3, Imgproc.LINE_AA, 0);
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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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Mat linesP = new Mat(); // will hold the results of the detection
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Imgproc.HoughLinesP(dst, linesP, 1, Math.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 (int x = 0; x < linesP.rows(); x++) {
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double[] l = linesP.get(x, 0);
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Imgproc.line(cdstP, new Point(l[0], l[1]), new Point(l[2], l[3]), new Scalar(0, 0, 255), 3, Imgproc.LINE_AA, 0);
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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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HighGui.imshow("Source", src);
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HighGui.imshow("Detected Lines (in red) - Standard Hough Line Transform", cdst);
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HighGui.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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HighGui.waitKey();
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System.exit(0);
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//! [exit]
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}
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}
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public class HoughLines {
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public static void main(String[] args) {
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// Load the native library.
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System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
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new HoughLinesRun().run(args);
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}
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}
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