OpenCV绘制圆形
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小牛编辑
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2023-03-14
可以使用org.opencv.imgproc
包的相应方法在图像上绘制各种形状,如圆形,矩形,线条,椭圆,多段线,凸起,多段线,多段线。
可以使用imgproc
类的circle()
方法在图像上绘制一个圆形。 以下是这种方法的语法 -
circle(img, center, radius, color, thickness)
该方法接受以下参数 -
- mat - Mat对象,表示要在其上绘制圆的图像。
- point - 代表圆中心的
Point
对象。 - radius - 表示圆的半径的整型变量。
- scalar - 表示圆的颜色的标量对象(BGR)。
- thickness - 表示圆的厚度的整数; 默认情况下,厚度值为
1
。
示例
以下程序演示如何在图像上绘制圆形并使用JavaFX窗口进行显示。
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 DrawingCircle extends Application {
Mat matrix = null;
@Override
public void start(Stage stage) throws Exception {
// Capturing the snapshot from the camera
DrawingCircle obj = new DrawingCircle();
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 Circle 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/sample.jpg";
Mat matrix = Imgcodecs.imread(file);
//Drawing a Circle
Imgproc.circle (
matrix, //Matrix obj of the image
new Point(230, 160), //Center of the circle
100, //Radius
new Scalar(0, 0, 255), //Scalar object for color
2 //圆线的厚度
);
// 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);
}
}
在执行上述程序时,您将得到以下输出 -