opencv java swing 图片灰度化 二值化

        <!-- https://mvnrepository.com/artifact/org.bytedeco.javacpp-presets/opencv -->
<dependency>
    <groupId>org.bytedeco.javacpp-presets</groupId>
    <artifactId>opencv</artifactId>
    <version>4.0.1-1.4.4</version>
</dependency>

 System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
        org.opencv.core.Mat grayImgMat = imread("src\\resource\\" + jTFimgName.getText(), IMREAD_GRAYSCALE);//读取为灰度图
        Imgcodecs.imwrite("src\\resource\\gray.png", grayImgMat);//保存mat对象为文件

ImageIcon grayIcon = new ImageIcon("src\\resource\\gray.png");
        grayIcon.setImage(grayIcon.getImage().getScaledInstance(320, 240, Image.SCALE_DEFAULT));//大小 可以自由设置        
        jLabGray.setIcon(grayIcon);