圆的绘制
在OpenCV环境中,圆的绘制依赖于Imgproc.circle() 这个方法。该方法的一个构造方法如下:
circle(img, center, radius, color, thickness);
其参数解释如下:
- 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。
Java代码(JavaFX Controller层)
public class Controller{
@FXML private Text fxText;
@FXML private ImageView imageView;
@FXML public void handleButtonEvent(ActionEvent actionEvent) throws IOException {
Node source = (Node) actionEvent.getSource();
Window theStage = source.getScene().getWindow();
FileChooser fileChooser = new FileChooser();
FileChooser.ExtensionFilter extFilter = new FileChooser.ExtensionFilter("PNG files (*.png)", "*.png");
fileChooser.getExtensionFilters().add(extFilter);
fileChooser.getExtensionFilters().add(new FileChooser.ExtensionFilter("JPG Files(*.jpg)", "*.jpg"));
File file = fileChooser.showOpenDialog(theStage);
imageView.setImage(this.drawCircle(file.getPath()));
}
private WritableImage drawCircle(String filePath) throws IOException {
System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
// Source.
Mat src = Imgcodecs.imread(filePath);
// Draw a circle.
Imgproc.circle(src, new Point(218,120), 55, new Scalar(0,0,255), 2);
// Encode source into MatOfByte object.
MatOfByte matOfByte = new MatOfByte();
Imgcodecs.imencode(".jpg", src, matOfByte);
byte[] bytes = matOfByte.toArray();
InputStream in = new ByteArrayInputStream(bytes);
BufferedImage bufImage = ImageIO.read(in);
WritableImage writableImage = SwingFXUtils.toFXImage(bufImage, null);
return writableImage;
}
}
运行图: