使用threshold()
方法将灰度图像转换为二进制值图像。以下是此方法的语法。
threshold(Mat src, Mat dst, double thresh, double maxval, int type)
该方法接受以下参数 -
Mat
对象。Mat
对象。THRESH_BINARY
和THRESH_BINARY_INV
阈值类型一起使用的最大值。通过将代码Imgproc.THRESH_BINARY
与值一起传递给其余参数,可以将灰度图像转换为二值图像。
以下程序演示如何将彩色图像作为二进制图像读取并使用JavaFX窗口显示。
package zyiz.net; 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 = "F:/worksp/opencv/images/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); } }
输入图像,假定以下是上述程序中指定的输入图像sample.jpg
。
在执行程序时,您将得到以下输出。