OpenCV + Java（Android） 设置ROI

package com.mengchicmc; import org.opencv.core.*; import org.opencv.core.Point; import org.opencv.imgcodecs.Imgcodecs; import org.opencv.imgproc.Imgproc; import javax.swing.*; import java.awt.*; import java.awt.image.BufferedImage; import java.awt.image.DataBufferByte; import java.io.BufferedWriter; import java.io.File; import java.io.FileWriter; import java.io.IOException; import java.util.ArrayList; /** * Created by MengchiCMC on 2017-6-14. */ public class MatView { /** * Open a image file * * @param filePath the path of the image to open * @return image in the form of Mat * @throws Exception There is no image to open in this file path */ public static Mat openFile(String filePath) throws Exception { Mat image = new Mat(); image = Imgcodecs.imread(filePath); if (image.dataAddr() == 0) { throw new Exception("Couldn't open file"); } return image; } /** * Display Mat image * * @param image */ public static void imshow(Mat image) { imshow(image, image.cols(), image.rows(), ""); } public static void imshow(Mat image, String windowName) { imshow(image, image.cols(), image.rows(), windowName); } public static void imshow(Mat image, int width, int height) { imshow(image, width, height, ""); } public static void imshow(Mat image, int width, int height, String windowName) { if (image.dataAddr() != 0) { setSystemLookAndFeel(); JFrame jFrame = new JFrame(windowName); JLabel imageView = new JLabel(); final JScrollPane imageScrollPane = new JScrollPane(imageView); imageScrollPane.setPreferredSize(new Dimension(width, height)); // set window size jFrame.add(imageScrollPane, BorderLayout.CENTER); jFrame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE); Image loadedImage = Mat2BufferedImage(image); imageView.setIcon(new ImageIcon(loadedImage)); jFrame.pack(); jFrame.setLocationRelativeTo(null); jFrame.setVisible(true); } else { System.out.println("Mat is empty!"); } } private static 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(); } } /** * Transform picture type from Mat to BufferedImage * * @param matrix * @return */ public static Image Mat2BufferedImage(Mat matrix) { int type = BufferedImage.TYPE_BYTE_GRAY; if (matrix.channels() > 1) { type = BufferedImage.TYPE_3BYTE_BGR; // **B G R** } int bufferSize = matrix.channels() * matrix.cols() * matrix.rows(); byte[] buffer = new byte[bufferSize]; matrix.get(0, 0, buffer); // get all the pixels 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; } }