📅  最后修改于: 2020-11-23 03:38:22             🧑  作者: Mango
一种称为threshold()的方法用于将灰度图像转换为二进制图像。以下是此方法的语法。
threshold(Mat src, Mat dst, double thresh, double maxval, int type)
此方法接受以下参数-
垫–垫子对象表示输入图像。
dst-表示输出图像的Mat对象。
thresh-代表阈值的整数。
maxval-一个整数,表示与THRESH_BINARY和THRESH_BINARY_INV阈值类型一起使用的最大值。
type-表示转换类型的整数代码,例如,从RGB到灰度。
您可以通过将代码Imgproc.THRESH_BINARY及其值传递给其余参数,将灰度图像转换为二进制图像。
以下程序演示了如何将彩色图像读取为二进制图像并使用JavaFX窗口进行显示。
import java.awt.image.BufferedImage;
import org.opencv.core.Core;
import org.opencv.core.Mat;
import org.opencv.imgcodecs.Imgcodecs;
import org.opencv.imgproc.Imgproc;
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;
public class ColorToBinary extends Application {
@Override
public void start(Stage stage) throws Exception {
WritableImage writableImage = loadAndConvert();
// Setting the image view
ImageView imageView = new ImageView(writableImage);
// Setting the position of the image
imageView.setX(10);
imageView.setY(10);
// setting the fit height and width of the image view
imageView.setFitHeight(400);
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("Loading an image");
// Adding scene to the stage
stage.setScene(scene);
// Displaying the contents of the stage
stage.show();
}
public WritableImage loadAndConvert() throws Exception {
// Loading the OpenCV core library
System.loadLibrary( Core.NATIVE_LIBRARY_NAME );
// Instantiating the Imgcodecs class
Imgcodecs imageCodecs = new Imgcodecs();
// File input = new File("C:/EXAMPLES/OpenCV/sample.jpg");
String input = "C:/EXAMPLES/OpenCV/sample.jpg";
// Reading the image
Mat src = imageCodecs.imread(input);
// Creating the destination matrix
Mat dst = new Mat();
// Converting to binary image...
Imgproc.threshold(src, dst, 200, 500, Imgproc.THRESH_BINARY);
// Extracting data from the transformed image (dst)
byte[] data1 = new byte[dst.rows() * dst.cols() * (int)(dst.elemSize())];
dst.get(0, 0, data1);
// Creating Buffered image using the data
BufferedImage bufImage = new BufferedImage(dst.cols(),dst.rows(),
BufferedImage.TYPE_BYTE_GRAY);
// Setting the data elements to the image
bufImage.getRaster().setDataElements(0, 0, dst.cols(), dst.rows(), data1);
// Creating a Writable image
WritableImage writableImage = SwingFXUtils.toFXImage(bufImage, null);
System.out.println("Converted to binary");
return writableImage;
}
public static void main(String args[]) throws Exception {
launch(args);
}
}
假设以下是上述程序中指定的输入图像sample.jpg 。
在执行程序时,您将获得以下输出。