int? flags;? // signaling the contents of the matrix
int? dims;?? // dimensions
int? rows, cols;? // rows and columns
MatSize? size;? //
MatStep? step;? //

package org.mk.opencv;

import org.opencv.core.Core;
import org.opencv.core.CvType;
import org.opencv.core.Mat;
import org.opencv.highgui.HighGui;

public class DrawLine {

	public static void main(String[] args) {
		// 載入dll（必須先加載）
		System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
		Mat truth = new Mat(500, 500, CvType.CV_8UC3);

		byte[] line = new byte[truth.channels() * truth.width()];

		for (int i = 0; i < line.length; i++) {
			line[i] = 125;
		}
		truth.put(250, 0, line);

		HighGui.imshow("原圖", truth);
		HighGui.waitKey(0);

	}

}

package org.mk.opencv;

import org.opencv.core.Core;
import org.opencv.core.Mat;
import org.opencv.imgcodecs.Imgcodecs;

public class ImageShowAddCircle {
	public static void main(String[] args) {
		// 載入dll（必須先加載）
		System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
		// 將文件讀入為OpenCV的Mat格式。注意測試時，路徑不要包括中文
		Mat src = Imgcodecs.imread("D:\\opencv-demo\\1.jpg");
		if (src.dataAddr() == 0) {
			System.out.println("打開文件出錯");
		}
		ImageViewerAddCircle imageViewer = new ImageViewerAddCircle(src, "圖片上加圓圈");
		imageViewer.imshow();
	}
}

package org.mk.opencv;

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.Image;

import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JScrollPane;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.WindowConstants;

import org.mk.opencv.util.OpenCVUtil;
import org.opencv.core.Mat;
import org.opencv.core.Point;
import org.opencv.core.Scalar;
import org.opencv.imgproc.Imgproc;

public class ImageViewerAddCircle {
	private JLabel imageView;
	private Mat image;
	private String windowName;


	public ImageViewerAddCircle(Mat image) {
		this.image = image;
	}

	/**
	 * @param image      要顯示的mat
	 * @param windowName 窗口標(biāo)題
	 */
	public ImageViewerAddCircle(Mat image, String windowName) {
		this.image = image;
		this.windowName = windowName;
	}

	/**
	 * 圖片顯示，并使用opencv的ImgProc.circle在圖片上加兩個圓圈
	 */
	public void imshow() {
		setSystemLookAndFeel();
		//在圖上畫圓
		Imgproc.circle(image, new Point(50, 50), 40, new Scalar(255, 0, 0), 2);
		//在圖上畫另一個圓
		Imgproc.circle(image, new Point(50, 100), 80, new Scalar(0, 255, 0), 5);
		//展示畫了圓的圖像
		Image loadedImage = OpenCVUtil.matToImage(image);
		JFrame frame = createJFrame(windowName, image.width(), image.height());
		imageView.setIcon(new ImageIcon(loadedImage));
		frame.pack();
		frame.setLocationRelativeTo(null);
		frame.setVisible(true);
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);// 用戶點(diǎn)擊窗口關(guān)閉
	}

	private void setSystemLookAndFeel() {
		try {
			UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		} catch (InstantiationException e) {
			e.printStackTrace();
		} catch (IllegalAccessException e) {
			e.printStackTrace();
		} catch (UnsupportedLookAndFeelException e) {
			e.printStackTrace();
		}
	}

	private JFrame createJFrame(String windowName, int width, int height) {
		JFrame frame = new JFrame(windowName);
		imageView = new JLabel();
		final JScrollPane imageScrollPane = new JScrollPane(imageView);
		imageScrollPane.setPreferredSize(new Dimension(width, height));
		frame.add(imageScrollPane, BorderLayout.CENTER);
		frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
		return frame;
	}
}

package org.mk.opencv.util;

import java.awt.Image;
import java.awt.image.BufferedImage;
import java.awt.image.DataBufferByte;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
import java.io.File;

import org.apache.log4j.Logger;
import org.opencv.core.CvType;
import org.opencv.core.Mat;


public class OpenCVUtil {
	private static Logger logger = Logger.getLogger(OpenCVUtil.class);

	public static Image matToImage(Mat matrix) {
		int type = BufferedImage.TYPE_BYTE_GRAY;
		if (matrix.channels() > 1) {
			type = BufferedImage.TYPE_3BYTE_BGR;
		}
		int bufferSize = matrix.channels() * matrix.cols() * matrix.rows();
		byte[] buffer = new byte[bufferSize];
		matrix.get(0, 0, buffer); // 獲取所有的像素點(diǎn)
		BufferedImage image = new BufferedImage(matrix.cols(), matrix.rows(), type);
		final byte[] targetPixels = ((DataBufferByte) image.getRaster().getDataBuffer()).getData();
		System.arraycopy(buffer, 0, targetPixels, 0, buffer.length);
		return image;
	}


	public static BufferedImage matToBufferedImage(Mat matrix) {
		int cols = matrix.cols();
		int rows = matrix.rows();
		int elemSize = (int) matrix.elemSize();
		byte[] data = new byte[cols * rows * elemSize];
		int type;
		matrix.get(0, 0, data);
		switch (matrix.channels()) {
		case 1:
			type = BufferedImage.TYPE_BYTE_GRAY;
			break;
		case 3:
			type = BufferedImage.TYPE_3BYTE_BGR;
			// bgr to rgb
			byte b;
			for (int i = 0; i < data.length; i = i + 3) {
				b = data[i];
				data[i] = data[i + 2];
				data[i + 2] = b;
			}
			break;
		default:
			return null;
		}
		BufferedImage image2 = new BufferedImage(cols, rows, type);
		image2.getRaster().setDataElements(0, 0, cols, rows, data);
		return image2;
	}

	public static Mat bufferedImageToMat(BufferedImage bi) {
		Mat mat = new Mat(bi.getHeight(), bi.getWidth(), CvType.CV_8UC3);
		byte[] data = ((DataBufferByte) bi.getRaster().getDataBuffer()).getData();
		mat.put(0, 0, data);
		return mat;
	}
}

package org.mk.opencv;

import org.opencv.core.Core;
import org.opencv.core.Mat;
import org.opencv.core.Size;
import org.opencv.imgcodecs.Imgcodecs;
import org.opencv.imgproc.Imgproc;

public class Blur {
	public static void main(String[] args) {
		try {
			System.loadLibrary(Core.NATIVE_LIBRARY_NAME);

			Mat src = Imgcodecs.imread("D:/opencv-demo/1.jpg");
			if (src.empty()) {
				throw new Exception("no file");
			}

			Mat dst = src.clone();

			Imgproc.blur(src, dst, new Size(800, 600));
			Imgcodecs.imwrite("D:/opencv-demo/blur.jpg", dst);
		} catch (Exception e) {
			System.out.println("出錯啦:" + e);
		}
	}

}