java 中 mat 转 bufferimage

可以通过以下代码将 Mat 转换为 BufferedImage：

import java.awt.image.BufferedImage;
import org.opencv.core.CvType;
import org.opencv.core.Mat;
import org.opencv.imgproc.Imgproc;

public class MatToBufferedImage {

    public static BufferedImage matToBufferedImage(Mat mat) {
        
        // Convert the Mat object to an array
        int type = BufferedImage.TYPE_BYTE_GRAY;
        if (mat.channels() > 1) {
            type = BufferedImage.TYPE_3BYTE_BGR;
        }
        int bufferSize = mat.channels() * mat.cols() * mat.rows();
        byte[] buffer = new byte[bufferSize];
        mat.get(0, 0, buffer);

        // Create a BufferedImage
        BufferedImage image = new BufferedImage(mat.cols(), mat.rows(), type);

        // Fill the BufferedImage with the image data from the Mat object
        image.getRaster().setDataElements(0, 0, mat.cols(), mat.rows(), buffer);

        return image;
    }

    public static void main(String[] args) {
        
        // Load an image using OpenCV
        Mat mat = Imgcodecs.imread("path/to/image.jpg");

        // Convert the Mat object to a BufferedImage
        BufferedImage image = matToBufferedImage(mat);

        // Display the image
        JFrame frame = new JFrame();
        JLabel label = new JLabel(new ImageIcon(image));
        frame.getContentPane().add(label, BorderLayout.CENTER);
        frame.pack();
        frame.setVisible(true);
    }
}

其中，`matToBufferedImage` 方法将 Mat 对象转换为 BufferedImage 对象。如果 Mat 对象是单通道的，那么 BufferedImage 的类型为 `TYPE_BYTE_GRAY`，否则为 `TYPE_3BYTE_BGR`。