可以使用imgproc
類的arrowedLine()
方法在影象上繪製箭頭線。 以下是這種方法的語法 -
arrowedLine(Mat img, Point pt1, Point pt2, Scalar color)
該方法接受以下引數 -
Mat
物件。Point
物件,表示要繪製的矩形的頂點。以下程式演示如何在影象上繪製箭頭線並使用JavaFX視窗顯示它。
package tw511.com;
import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.InputStream;
import javax.imageio.ImageIO;
import javafx.application.Application;
import javafx.embed.swing.SwingFXUtils;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.image.ImageView;
import javafx.scene.image.WritableImage;
import javafx.stage.Stage;
import org.opencv.core.Core;
import org.opencv.core.Mat;
import org.opencv.core.MatOfByte;
import org.opencv.core.Point;
import org.opencv.core.Scalar;
import org.opencv.imgcodecs.Imgcodecs;
import org.opencv.imgproc.Imgproc;
public class DrawingArrowedLine extends Application {
Mat matrix = null;
@Override
public void start(Stage stage) throws Exception {
// Capturing the snapshot from the camera
DrawingArrowedLine obj = new DrawingArrowedLine();
WritableImage writableImage = obj.LoadImage();
// Setting the image view
ImageView imageView = new ImageView(writableImage);
// setting the fit height and width of the image view
imageView.setFitHeight(600);
imageView.setFitWidth(600);
// Setting the preserve ratio of the image view
imageView.setPreserveRatio(true);
// Creating a Group object
Group root = new Group(imageView);
// Creating a scene object
Scene scene = new Scene(root, 600, 400);
// Setting title to the Stage
stage.setTitle("Drawing a line on the image");
// Adding scene to the stage
stage.setScene(scene);
// Displaying the contents of the stage
stage.show();
}
public WritableImage LoadImage() throws Exception {
// Loading the OpenCV core library
System.loadLibrary( Core.NATIVE_LIBRARY_NAME );
// Reading the Image from the file and storing it in to a Matrix object
String file ="F:/worksp/opencv/images/sample2.jpg";
Mat matrix = Imgcodecs.imread(file);
//Drawing a line
Imgproc.arrowedLine(
matrix, // Matrix obj of the image
new Point(10, 200), // p1
new Point(590, 200), // p2
new Scalar(0, 100, 255) // Scalar object for color
);
// arrowedLine(Mat img, Point pt1, Point pt2, Scalar color)
// Encoding the image
MatOfByte matOfByte = new MatOfByte();
Imgcodecs.imencode(".jpg", matrix, matOfByte);
// Storing the encoded Mat in a byte array
byte[] byteArray = matOfByte.toArray();
// Displaying the image
InputStream in = new ByteArrayInputStream(byteArray);
BufferedImage bufImage = ImageIO.read(in);
this.matrix = matrix;
// Creating the Writable Image
WritableImage writableImage = SwingFXUtils.toFXImage(bufImage, null);
return writableImage;
}
public static void main(String args[]) {
launch(args);
}
}
執行上面範例程式碼,您將會看到以下結果 -