您可以使用imgproc類的方法Polylines()在圖像上繪製多段線。下面是這個方法的語法。
polylines(img, pts, isClosed, color, thickness)
此方法接受以下參數&負;
mat−Amat表示要在其上繪製多段線的圖像的對象。
pts−AList包含類型爲MatOfPoint的對象的對象。
isClosed−布爾型參數,指定多段線是否閉合。
標量−A標量表示多段線顏色的對象。(BGR)
厚度−表示多段線厚度的整數;默認情況下,厚度值爲1。
類的構造函數接受類的對象。
MatOfPoint(Point... a)
Example
下面的程序演示如何在圖像上繪製多段線並使用JavaFX窗口顯示它。
import java.awt.image.BufferedImage; import java.io.ByteArrayInputStream; import java.io.InputStream; import java.util.ArrayList; import java.util.List; 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.MatOfPoint; import org.opencv.core.Point; import org.opencv.core.Scalar; import org.opencv.imgcodecs.Imgcodecs; import org.opencv.imgproc.Imgproc; public class DrawingPolyLines extends Application { Mat matrix = null; @Override public void start(Stage stage) throws Exception { // Capturing the snapshot from the camera DrawingPolyLines obj = new DrawingPolyLines(); 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 Polylines 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 ="E:/OpenCV/chap8/input.jpg"; Mat matrix = Imgcodecs.imread(file); List<MatOfPoint> list = new ArrayList(); list.add( new MatOfPoint ( new Point(75, 100), new Point(350, 100), new Point(75, 150), new Point(350, 150), new Point(75, 200), new Point(350, 200), new Point(75, 250), new Point(350, 250) ) ); // Drawing polylines Imgproc.polylines ( matrix, // Matrix obj of the image list, // java.util.List<MatOfPoint> pts false, // isClosed new Scalar(0, 0, 255), // Scalar object for color 2 // Thickness of the line ); // 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); } }
在執行上述程序時,您將得到以下輸出&負;