如何从网络摄像头持续捕获影像?
我想通过实验使用物体识别(也许使用Java媒体框架)。
我想创建两个线程:
一个线程:
- 节点1:捕获实时图像
- 节点2:将图像保存为“1.jpg”
- 节点3:等待5秒
- 节点4:重复...
另一个线程:
- 节点1:等待图像被捕获
- 节点2:使用“1.jpg”获取每个像素的颜色
- 节点3:将数据保存在数组中
- 节点4:重复...
这个 JavaCV 实现很好。
代码:
import org.bytedeco.javacv.*;
import org.bytedeco.opencv.opencv_core.IplImage;
import java.io.File;
import static org.bytedeco.opencv.global.opencv_core.cvFlip;
import static org.bytedeco.opencv.helper.opencv_imgcodecs.cvSaveImage;
public class Test implements Runnable {
final int INTERVAL = 100;///you may use interval
CanvasFrame canvas = new CanvasFrame("Web Cam");
public Test() {
canvas.setDefaultCloseOperation(javax.swing.JFrame.EXIT_ON_CLOSE);
}
public void run() {
new File("images").mkdir();
FrameGrabber grabber = new OpenCVFrameGrabber(0); // 1 for next camera
OpenCVFrameConverter.ToIplImage converter = new OpenCVFrameConverter.ToIplImage();
IplImage img;
int i = 0;
try {
grabber.start();
while (true) {
Frame frame = grabber.grab();
img = converter.convert(frame);
//the grabbed frame will be flipped, re-flip to make it right
cvFlip(img, img, 1);// l-r = 90_degrees_steps_anti_clockwise
//save
cvSaveImage("images" + File.separator + (i++) + "-aa.jpg", img);
canvas.showImage(converter.convert(img));
Thread.sleep(INTERVAL);
}
} catch (Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
Test gs = new Test();
Thread th = new Thread(gs);
th.start();
}
}
这里还有一篇有关JavaCV配置的文章
你可以修改代码,定期保存图像并进行其他任何你想要的处理。
我之前创建了一个通用的Java库,可以使用PC摄像头拍照。该API非常简单,不会有过多的功能,可以独立运行,还支持其他网络摄像头驱动程序,如OpenIMAJ、JMF、FMJ、LTI-CIVIL等,以及一些IP摄像头。
项目链接:https://github.com/sarxos/webcam-capture
示例代码(拍照并保存为test.jpg):
Webcam webcam = Webcam.getDefault();
webcam.open();
BufferedImage image = webcam.getImage();
ImageIO.write(image, "JPG", new File("test.jpg"));
它也可以在Maven Central Repository中找到,或者作为单独的ZIP包提供,其中包含所有必需的依赖项和第三方JAR文件。
myron = new JMyron();
myron.start(imgw, imgh);
myron.update();
int[] img = myron.image();
这与gt_ebuddy使用JavaCV的答案有关,但我的视频输出质量要高得多。我还添加了其他一些随机的改进(例如在按下 ESC 和 CTRL + C 时关闭程序,并确保正确关闭程序使用的资源)。
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.image.BufferedImage;
import javax.swing.AbstractAction;
import javax.swing.ActionMap;
import javax.swing.InputMap;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.KeyStroke;
import com.googlecode.javacv.CanvasFrame;
import com.googlecode.javacv.OpenCVFrameGrabber;
import com.googlecode.javacv.cpp.opencv_core.IplImage;
public class HighRes extends JComponent implements Runnable {
private static final long serialVersionUID = 1L;
private static CanvasFrame frame = new CanvasFrame("Web Cam");
private static boolean running = false;
private static int frameWidth = 800;
private static int frameHeight = 600;
private static OpenCVFrameGrabber grabber = new OpenCVFrameGrabber(0);
private static BufferedImage bufImg;
public HighRes()
{
// setup key bindings
ActionMap actionMap = frame.getRootPane().getActionMap();
InputMap inputMap = frame.getRootPane().getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW);
for (Keys direction : Keys.values())
{
actionMap.put(direction.getText(), new KeyBinding(direction.getText()));
inputMap.put(direction.getKeyStroke(), direction.getText());
}
frame.getRootPane().setActionMap(actionMap);
frame.getRootPane().setInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW, inputMap);
// setup window listener for close action
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.addWindowListener(new WindowAdapter()
{
public void windowClosing(WindowEvent e)
{
stop();
}
});
}
public static void main(String... args)
{
HighRes webcam = new HighRes();
webcam.start();
}
@Override
public void run()
{
try
{
grabber.setImageWidth(frameWidth);
grabber.setImageHeight(frameHeight);
grabber.start();
while (running)
{
final IplImage cvimg = grabber.grab();
if (cvimg != null)
{
// cvFlip(cvimg, cvimg, 1); // mirror
// show image on window
bufImg = cvimg.getBufferedImage();
frame.showImage(bufImg);
}
}
grabber.stop();
grabber.release();
frame.dispose();
}
catch (Exception e)
{
e.printStackTrace();
}
}
public void start()
{
new Thread(this).start();
running = true;
}
public void stop()
{
running = false;
}
private class KeyBinding extends AbstractAction {
private static final long serialVersionUID = 1L;
public KeyBinding(String text)
{
super(text);
putValue(ACTION_COMMAND_KEY, text);
}
@Override
public void actionPerformed(ActionEvent e)
{
String action = e.getActionCommand();
if (action.equals(Keys.ESCAPE.toString()) || action.equals(Keys.CTRLC.toString())) stop();
else System.out.println("Key Binding: " + action);
}
}
}
enum Keys
{
ESCAPE("Escape", KeyStroke.getKeyStroke(KeyEvent.VK_ESCAPE, 0)),
CTRLC("Control-C", KeyStroke.getKeyStroke(KeyEvent.VK_C, KeyEvent.CTRL_DOWN_MASK)),
UP("Up", KeyStroke.getKeyStroke(KeyEvent.VK_UP, 0)),
DOWN("Down", KeyStroke.getKeyStroke(KeyEvent.VK_DOWN, 0)),
LEFT("Left", KeyStroke.getKeyStroke(KeyEvent.VK_LEFT, 0)),
RIGHT("Right", KeyStroke.getKeyStroke(KeyEvent.VK_RIGHT, 0));
private String text;
private KeyStroke keyStroke;
Keys(String text, KeyStroke keyStroke)
{
this.text = text;
this.keyStroke = keyStroke;
}
public String getText()
{
return text;
}
public KeyStroke getKeyStroke()
{
return keyStroke;
}
@Override
public String toString()
{
return text;
}
}
快来看看吧!
实时视频处理演示:
http://www.youtube.com/watch?v=D5mBt0kRYvk
你可以使用下面的源代码。只需每5秒钟使用MarvinImageIO.saveImage()保存一帧即可。
网络摄像头视频演示:
public class SimpleVideoTest extends JFrame implements Runnable{
private MarvinVideoInterface videoAdapter;
private MarvinImage image;
private MarvinImagePanel videoPanel;
public SimpleVideoTest(){
super("Simple Video Test");
videoAdapter = new MarvinJavaCVAdapter();
videoAdapter.connect(0);
videoPanel = new MarvinImagePanel();
add(videoPanel);
new Thread(this).start();
setSize(800,600);
setVisible(true);
}
@Override
public void run() {
while(true){
// Request a video frame and set into the VideoPanel
image = videoAdapter.getFrame();
videoPanel.setImage(image);
}
}
public static void main(String[] args) {
SimpleVideoTest t = new SimpleVideoTest();
t.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}
对于那些只想拍一张照片的人:
WebcamPicture.java
public class WebcamPicture {
public static void main(String[] args) {
try{
MarvinVideoInterface videoAdapter = new MarvinJavaCVAdapter();
videoAdapter.connect(0);
MarvinImage image = videoAdapter.getFrame();
MarvinImageIO.saveImage(image, "./res/webcam_picture.jpg");
} catch(MarvinVideoInterfaceException e){
e.printStackTrace();
}
}
}
webcam = Webcam.getDefault();
webcam.open();
if (webcam.isOpen()) { //if web cam open
BufferedImage image = webcam.getImage();
JLabel imageLbl = new JLabel();
imageLbl.setSize(640, 480); //show captured image
imageLbl.setIcon(new ImageIcon(image));
int showConfirmDialog = JOptionPane.showConfirmDialog(null, imageLbl, "Image Viewer", JOptionPane.YES_NO_OPTION, JOptionPane.QUESTION_MESSAGE, new ImageIcon(""));
if (showConfirmDialog == JOptionPane.YES_OPTION) {
JFileChooser chooser = new JFileChooser();
chooser.setDialogTitle("Save Image");
chooser.setFileFilter(new FileNameExtensionFilter("IMAGES ONLY", "png", "jpeg", "jpg")); //this file extentions are shown
int showSaveDialog = chooser.showSaveDialog(this);
if (showSaveDialog == 0) { //if pressed 'Save' button
String filePath = chooser.getCurrentDirectory().toString().replace("\\", "/");
String fileName = chooser.getSelectedFile().getName(); //get user entered file name to save
ImageIO.write(image, "PNG", new File(filePath + "/" + fileName + ".png"));
}
}
}
我曾在一个视频会议应用中使用了JMF,它在两台笔记本电脑上表现良好:一台带有集成式摄像头,另一台带有旧的USB摄像头。在使用之前需要安装和配置JMF,但一旦完成,您可以通过Java代码轻松访问硬件。
http://grack.com/downloads/school/enel619.10/report/java_media_framework.html
在Swing应用程序中,可以轻松使用Player。以下代码创建了一个基于Swing的电视捕获程序,视频输出显示在整个窗口中:
import javax.media.*;
import javax.swing.*;
import java.awt.*;
import java.net.*;
import java.awt.event.*;
import javax.swing.event.*;
public class JMFTest extends JFrame {
Player _player;
JMFTest() {
addWindowListener( new WindowAdapter() {
public void windowClosing( WindowEvent e ) {
_player.stop();
_player.deallocate();
_player.close();
System.exit( 0 );
}
});
setExtent( 0, 0, 320, 260 );
JPanel panel = (JPanel)getContentPane();
panel.setLayout( new BorderLayout() );
String mediaFile = "vfw://1";
try {
MediaLocator mlr = new MediaLocator( mediaFile );
_player = Manager.createRealizedPlayer( mlr );
if (_player.getVisualComponent() != null)
panel.add("Center", _player.getVisualComponent());
if (_player.getControlPanelComponent() != null)
panel.add("South", _player.getControlPanelComponent());
}
catch (Exception e) {
System.err.println( "Got exception " + e );
}
}
public static void main(String[] args) {
JMFTest jmfTest = new JMFTest();
jmfTest.show();
}
}