在 OpenCV 中绘制图像几何形状的 Java 程序

原文:https://www . geesforgeks . org/Java-program-to-draw-geometric-shapes-on-images-in-opencv/

Java 中的 OpenCV 库包含一个名为Improc的类，该类提供了各种方法，如 resize() 、wrap 仿射() 、 filter2D 来处理输入图像。我们将在这里使用 javax.swing 包。*javax . swing包为 java swing API 提供类，如 JButton、JTextField、JTextArea、JRadioButton、JCheckbox、JMenu 、jcolorcooser、等。这里涉及到的 java 概念是 Swing 类和抽象窗口工具包，如下所述:***

【摇摆类】 *: 这里我将解释一下 javax.swing 包的所有类，这些类将在后面的程序中使用:***

  • *javax.swing.ImageIcon :类 ImageIcon 是从图像绘制图标的图标界面的实现。*
  • 类 JFrame* 是一种继承了 java 的容器。JFrame 的工作方式类似于主窗口，其中添加了标签、按钮、文本字段等组件来创建图形用户界面*
  • *javax.swing.JLabel :类 JLabel 用于显示短字符串或图像图标。*
  • *javax.swing.JMenu :类 JMenu 用于下拉菜单组件，从菜单栏中显示。*
  • *javax.swing.JMenuBa r:类 JMenuBar 用于在窗口或框架上显示菜单栏。它可能有几个菜单。*
  • *javax . swing . JMenuItem:JMenuItem类表示菜单中的实际项目。菜单中的所有项目都应该从类或其子类中派生出来。*

我们还需要在程序中使用抽象窗口工具包(AWT) 。它是 Java 基础类的一部分。我在这里简单描述一下 AWT* 。*

抽象窗口工具包 (AWT) 是一个用于创建图形用户界面的 Java 包。 AWT* 的特点包括:*

  • 一组本机接口组件
  • 一个健壮的事件处理模型
  • 图形和图像工具，包括形状、颜色和字体类
  • 布局管理器，用于不依赖于特定窗口大小或屏幕分辨率的灵活窗口布局
  • 数据传输类，用于通过本机平台剪贴板进行剪切和粘贴

*程序:在 OpenCV 中在图像上绘制几何形状的步骤***

  1. 创建一个项目并添加 OpenCV* 库*
  2. 创建包
  3. 创建一个类
  4. 创建一个名为“图像”的文件夹，并放置一个。jpg 或。png* 文件在里面。*
  5. 在 java 文件中编写以下代码。

*样本输入图像:***

*步骤 1: 创建一个项目并添加 OpenCV 库***

  • 点击文件>新建> Java 项目。
  • 为您的项目命名，并在如下图所示的 JRE 和项目布局*选项下勾选必要的选项。在这里，我已经将这个项目命名为 OpenCVShape。*
  • 标记选项后，单击下一步。

  • 之后，转到同一对话框中的“库”选项。单击类路径->添加外部罐子。
  • 从本地机器添加 opencv.jar 文件或者可以下载 opencv.jar* 文件。*

  • 添加完 jar 文件后，展开类路径选项，点击原生库位置:(无)，点击编辑*。*

  • 选择外部文件夹……*浏览选择包含 OpenCV 库的文件夹(如 Windows 下的 C:\opencv\build\java\x64)。点击完成。*

*第二步:创建包***

  • 右键点击 src* 。转到新建→包。*
  • 将出现一个对话框。将包裹名称输入 com.pkg ，点击完成*。*

*第三步:创建类***

  • 右击 com.pkg .转到新建→类。
  • 将出现一个对话框。键入类的名称。我把它命名为 OpenCVShape。
  • 勾选必要的选项，点击完成*。*

*第四步:创建一个名为“images”的文件夹，放一个。jpg 或。png 文件在里面。***

  • 右键*–点击项目名称(在本例中为 OpenCVShape)。转到新建- >文件夹。键入文件夹的名称(图片)并点击确定。***
  • 放一张扩展名为的图片。jpg 或。png* 在这个文件夹里。*

*第五步:在 java 文件中编写以下代码***

一*实现:计算上述步骤，得到不同的几何形状，如下例所示:***

  1. 线条
  2. 长方形
  3. 环
  4. 省略

*例 1:画线***

Java 语言(一种计算机语言，尤用于创建网站)

***// Java Program using openCV to draw lines

package com.pkg;

// Importing abstract windows toolkit classes
import java.awt.EventQueue;
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;

// Importing Swing classes 
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;

// Importing OpenCV modules
import org.opencv.core.Core;
import org.opencv.core.Mat;
import org.opencv.core.MatOfByte;
import org.opencv.core.Scalar;
import org.opencv.core.Size;
import org.opencv.imgcodecs.Imgcodecs;
import org.opencv.imgproc.Imgproc;

public class OpenCVShapes extends JFrame {

    Mat image;
    Mat tempImage;

    JLabel imageView;

    // Menu for save image
    private JMenuBar mb;
    private JMenu menu;
    private JMenuItem saveMenuItem;

    private Point originPoint;
    public OpenCVShapes()
    {
        // Loading image from local directory 
        image = Imgcodecs.imread("images/sample_image.png");

        // Method to view setup
        setUpView();

        // Loading image to jlabel
        loadImage(image);

        // Setting iframe property
        setSize(image.width(), image.height());
        setLocationRelativeTo(null);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setVisible(true);
    }

  // Method to load image 
    private void loadImage(Mat img)
    {
        final MatOfByte mof = new MatOfByte();
        Imgcodecs.imencode(".png", img, mof);

        final byte[] imageData = mof.toArray();

        // Change image byte to image icon
        final ImageIcon icon = new ImageIcon(imageData);

      // Add icon to jlabel
        imageView.setIcon(icon);
    }

    private void setUpView()
    {
        setLayout(null);

        imageView = newJLabel();
        imageView.setBounds(0, 20, image.width(),
                            image.height());

        // Add mouse listener
        imageView.addMouseListener(new MouseAdapter() {
            @Override public void mousePressed(MouseEvent e)
            {
                super.mousePressed(e);

                // Storing location of mouse pressed
                originPoint = new Point(e.getX(), e.getY());
            }

            @Override
            public void mouseReleased(MouseEvent e)
            {
                super.mouseReleased(e);
                // when mouse release replace tempimage to
                // image
                image = tempImage.clone();
            }
        });

        // Adding another event mousemotionlstener
        imageView.addMouseMotionListener(
            new MouseMotionListener() {

                @Override
                public void mouseMoved(MouseEvent e)
                {
                    // TODO Auto-generate method stub
                }

                @Override
                public void mouseDragged(MouseEvent e)
                {
                    // Create temp image for drawing
                    tempImage = image.clone();
                    final Point point
                        = new Point(e.getX(), e.getY());

                    // NOW, DRAWING SHAPES

                    // 1\. Drawing line

                  // Color in bgr format
                    Imgproc.line(
                        tempImage, originPoint, point,
                        new Scalar(0, 0, 0),
                        5); 

                    loadImage(tempImage);
                }
            });

        add(imageView);

        // Adding menu
        mb = new JMenuBar();
        menu = new JMenu("file");
        saveMenuItem = new JMenuItem("save");
        menu.add(saveMenuItem);
        mb.add(menu);

        mb.setBounds(0, 0, image.width(), 20);
        add(mb);

        saveMenuItem.addActionListener(
            new ActionListener() {
                @Override
                public void actionPerformed(ActionEvent e)
                {
                    // TODO Auto-generated method stub
                    Imgcodecs.imwrite("images/ind1.png",
                                      image);
                }
            });
    }

    private JLabel newJLabel()
    {
        // TODO Auto-generated method stub
        return null;
    }

  // Main driver method
    public static void main(String[] args)
    {
        // Loading library
        System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
        EventQueue.invokeLater(new Runnable() {
            @Override public void run()
            {
                new OpenCVShapes();
            }
        });
    }
}***

*输出:***

*例 2: 绘制矩形***

Java 语言(一种计算机语言，尤用于创建网站)

***// Java Program using openCV to draw rectangles

package com.pkg;

import java.awt.EventQueue;
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;

import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;

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

public class OpenCVShapes extends JFrame {

    Mat image;
    Mat tempImage;

    JLabel imageView;

    // menu for save image
    private JMenuBar mb;
    private JMenu menu;
    private JMenuItem saveMenuItem;

    private Point originPoint;
    public OpenCVShapes()
    {
        // load image
        image = Imgcodecs.imread("images/sample_image.png");

        // view setup
        setUpView();

        // load image to jlabel
        loadImage(image);

        // set iframe property
        setSize(image.width(), image.height());
        setLocationRelativeTo(null);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setVisible(true);
    }

    private void loadImage(Mat img)
    {
        final MatOfByte mof = new MatOfByte();
        Imgcodecs.imencode(".png", img, mof);

        final byte[] imageData = mof.toArray();

        // change image byte to image icon
        final ImageIcon icon = new ImageIcon(imageData);
        // add icon to jlabel
        imageView.setIcon(icon);
    }

    private void setUpView()
    {
        setLayout(null);

        imageView = newJLabel();
        imageView.setBounds(0, 20, image.width(),
                            image.height());

        // add mouse listener
        imageView.addMouseListener(new MouseAdapter() {
            @Override public void mousePressed(MouseEvent e)
            {
                super.mousePressed(e);
                // store location of mouse pressed
                originPoint = new Point(e.getX(), e.getY());
            }

            @Override
            public void mouseReleased(MouseEvent e)
            {
                super.mouseReleased(e);
                // when mouse release replace tempimage to
                // image
                image = tempImage.clone();
            }
        });

        // add another event mousemotionlstener
        imageView.addMouseMotionListener(
            new MouseMotionListener() {
                @Override
                public void mouseMoved(MouseEvent e)
                {
                    // TODO Auto-generate method stub
                }

                @Override
                public void mouseDragged(MouseEvent e)
                {
                    // create temp image for drawing
                    tempImage = image.clone();
                    final Point point
                        = new Point(e.getX(), e.getY());

                    // here we will draw shapes

                    // draw rectangle
                    Imgproc.rectangle(
                        tempImage, originPoint, point,
                        new Scalar(255, 0, 0), 5);

                    loadImage(tempImage);
                }
            });

        add(imageView);

        // add menu
        mb = new JMenuBar();
        menu = new JMenu("file");
        saveMenuItem = new JMenuItem("save");
        menu.add(saveMenuItem);
        mb.add(menu);

        mb.setBounds(0, 0, image.width(), 20);
        add(mb);

        saveMenuItem.addActionListener(
            new ActionListener() {
                @Override
                public void actionPerformed(ActionEvent e)
                {
                    // TODO Auto-generated method stub
                    Imgcodecs.imwrite("images/ind1.png",
                                      image);
                }
            });
    }

    private JLabel newJLabel()
    {
        // TODO Auto-generated method stub
        return null;
    }

  // main driver method
    public static void main(String[] args)
    {
        // Loading library
        System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
        EventQueue.invokeLater(new Runnable() {
            @Override public void run()
            {
                new OpenCVShapes();
            }
        });
    }
}***

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