OpenCV绘制箭头线

可以使用imgproc类的arrowedLine()方法在图像上绘制箭头线。 以下是这种方法的语法 -

arrowedLine(Mat img, Point pt1, Point pt2, Scalar color)

该方法接受以下参数 -

mat - 表示要在其上绘制矩形的图像的Mat对象。

pt1 和 pt2 - 两个Point对象，表示要绘制的矩形的顶点。

color - 表示矩形颜色的标量对象(BGR)。

示例

以下程序演示如何在图像上绘制箭头线并使用JavaFX窗口显示它。

package yiibai.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);

}

}

执行上面示例代码，您将会看到以下结果 -