I'm working on a project and the goal is to have all images read with ImageIO. This seems to work for everything except GIF images (which display as a static image of the initial frame). I have seen other answers on Stack Overflow and from a thread on the Oracle forums but most require using Java's File class which I can't access due to the program's SecurityManager. I've been able to break the GIF down into an Image array and edit the metadata, but after stitching everything back together I can only display a single image.
Below is a SSCCE for the program:
import java.awt.Image;
import java.awt.Toolkit;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
public class GifRenderer {
public static void main(String[] args) throws Exception {
Image image = null;
byte[] imageByteArray = null;
try {
String location = "http://i.imgur.com/Ejh5gJa.gif";
imageByteArray = createByteArray(location);
// This works, but I'm trying to use ImageIO
//image = Toolkit.getDefaultToolkit().createImage(imageByteArray);
InputStream in = new ByteArrayInputStream(imageByteArray);
image = ImageIO.read(in);
} catch (IOException e) {
e.printStackTrace();
}
JFrame frame = new JFrame();
frame.setSize(300, 300);
JLabel label = new JLabel(new ImageIcon(image));
frame.add(label);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
// Constraint: This method simulates how the image is originally received
private static byte[] createByteArray(String urlString) throws IOException {
URL url = new URL(urlString);
ByteArrayOutputStream baos = new ByteArrayOutputStream();
InputStream is = null;
try {
is = url.openStream ();
byte[] byteChunk = new byte[4096];
int n;
while ( (n = is.read(byteChunk)) > 0 ) {
baos.write(byteChunk, 0, n);
}
} catch (IOException e) {
e.printStackTrace ();
} finally {
if (is != null) { is.close(); }
}
return baos.toByteArray();
}
}
Some constraints worth mentioning that might not be clear:
The image is originally received as a byte array
The image should be read by ImageIO
The final result should be an Image object
The File class can't be accessed
Given these constraints is there still a way to use ImageIO to display the GIF the same way Toolkit.getDefaultToolkit().createImage() would display the image?
I am trying to send continuous screenshots to another PC on same network.
I googled it also but i didn't find things relevant to me.
Below is my code of sender and receiver. Problem is only first image is being received and then struck.
If i turn on JFrame then not a single image is updating in JPanel. Please help me :-(
imagesender.java
import java.awt.*;
import java.awt.image.*;
import java.net.*;
import java.io.*;
import javax.imageio.*;
import javax.swing.*;
class imagesender
{
imagesender()throws Exception
{
Socket soc=new Socket("127.0.0.1",5555);
OutputStream os=soc.getOutputStream();
while(true)
{
try
{
Dimension dim=Toolkit.getDefaultToolkit().getScreenSize();
Rectangle rec=new Rectangle(dim);
Robot bot=new Robot();
BufferedImage image=bot.createScreenCapture(rec);
ImageIO.write(image,"jpeg",os);
System.out.println("Image Sent");
}
catch(Exception e)
{
System.out.println(e);
}
}
}
public static void main(String aerg[])throws Exception
{
new imagesender();
}
}
imagereciever.java
import java.awt.*;
import java.awt.image.*;
import java.net.*;
import javax.imageio.*;
import java.io.*;
import javax.swing.*;
class imagereciever extends JPanel
{
static BufferedImage image;
imagereciever()throws Exception
{
ServerSocket ss=new ServerSocket(5555);
Socket soc=ss.accept();
JFrame frame=new JFrame();
frame.setSize(500,500);
frame.setContentPane(this);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//frame.setVisible(true);
InputStream is=soc.getInputStream();
while(true)
{
try
{
image=ImageIO.read(is);
//this.repaint();
ImageIO.write(image,"jpeg",new File("C:\\Users\\Arpit Jindal\\Desktop\\screenshot.jpeg"));
System.out.println("Image Recieved");
}
catch(Exception e)
{e.printStackTrace()}
}
}
public static void main(String aerg[])throws Exception
{
new imagereciever();
}
public void paint(Graphics g)
{
super.paint(g);
g.drawImage(image,0,0,null);
}
}
imagereciever.java recieves one image and then gives this error infinite times and imagesender.java keeps on sending images:-
java.lang.IllegalArgumentException: image == null!
at javax.imageio.ImageTypeSpecifier.createFromRenderedImage(ImageTypeSpecifier.java:925)
at javax.imageio.ImageIO.getWriter(ImageIO.java:1592)
at javax.imageio.ImageIO.write(ImageIO.java:1520)
at imagereciever.<init>(imagereciever.java:26)
at imagereciever.main(imagereciever.java:37)
Your GUI completely ignores Swing threading rules, so I'm not surprised that it might be getting stuck. Suggestions:
Use a SwingWorker to do long-running background tasks such as reading in images. In your case, perhaps a SwingWorker<Void, BufferedImage> is what you want so that you can pass the BufferedImage to the GUI via the publish/process method pair. The Concurrency in Swing tutorial will tell you the details on how to use this tool.
Don't draw with the paint method.
Instead draw in the paintComponent method of a JPanel that is displayed in JFrame. Be sure to call the super's paintComponent method within your override.
Stop to consider -- do you really need images transmitted in this way as you're passing in a lot of information, perhaps more than is needed? Better would be to pass a data model over the socket and then recreate a view with the data, if possible.
Never blatantly ignore exceptions as your code is doing. At least catch the exception's stacktrace.
The example #MadProgrammer gave to me solved my problem. This is my new Code:-
imagesender.java
import java.awt.*;
import java.awt.image.*;
import java.net.*;
import java.io.*;
import javax.imageio.*;
import javax.swing.*;
class imagesender
{
imagesender()throws Exception
{
Socket soc=new Socket("127.0.0.1",5555);
OutputStream os=soc.getOutputStream();
while(true)
{
try
{
BufferedImage image=new Robot().createScreenCapture(new Rectangle(Toolkit.getDefaultToolkit().getScreenSize()));
ByteArrayOutputStream baos=new ByteArrayOutputStream();
ImageIO.write(image,"png",baos);
baos.close();
ObjectOutputStream oos=new ObjectOutputStream(os);
oos.writeObject(baos.size()+"");
os.write(baos.toByteArray());
//System.out.println("Image Sent");
}
catch(Exception e)
{
System.exit(1);
}
}
}
public static void main(String aerg[])throws Exception
{
new imagesender();
}
}
imagereciever.java
import java.awt.*;
import java.awt.image.*;
import java.net.*;
import javax.imageio.*;
import java.io.*;
import javax.swing.*;
class imagereciever extends JPanel
{
static BufferedImage image;
static Socket soc;
static InputStream is;
imagereciever()throws Exception
{
ServerSocket ss=new ServerSocket(5555);
soc=ss.accept();
is=soc.getInputStream();
JFrame frame=new JFrame();
frame.setSize(500,500);
frame.setContentPane(this);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
while(true)
{
try
{
ObjectInputStream ois=new ObjectInputStream(is);
int size=Integer.parseInt(ois.readObject().toString());
ByteArrayOutputStream baos=new ByteArrayOutputStream(size);
int sizeread=0,bytesin=0;
byte[] buffer=new byte[1024];
while(sizeread<size)
{
bytesin=is.read(buffer);
sizeread+=bytesin;
baos.write(buffer,0,bytesin);
}
baos.close();
ByteArrayInputStream bais=new ByteArrayInputStream(baos.toByteArray());
image=ImageIO.read(bais);
this.repaint();
}
catch(Exception e)
{
System.exit(1);
}
}
}
public static void main(String aerg[])throws Exception
{
new imagereciever();
}
public void paintComponent(Graphics g)
{
super.paintComponent(g);
g.drawImage(image,0,0,null);
}
}
HI guys I am experimenting with the use of JavaCV as I want to get to know how it works in order to include it's functionality in a project I have in mind. I have downloaded and set up OpenCV just like what the instructions said and I also have downloaded form bytedeco the JavaCV 1.0 jars that I need to include in my project.
I have started with an example program I found online that basically grabs and save images from a webcam. The code I have written is the following:
import org.bytedeco.javacpp.opencv_core.IplImage;
import org.bytedeco.javacv.CanvasFrame;
import org.bytedeco.javacv.Frame;
import org.bytedeco.javacv.FrameGrabber;
import org.bytedeco.javacv.VideoInputFrameGrabber;
import org.bytedeco.javacv.*;
import org.bytedeco.javacpp.*;
import static org.bytedeco.javacpp.opencv_core.*;
import static org.bytedeco.javacpp.opencv_imgproc.*;
import static org.bytedeco.javacpp.opencv_imgcodecs.*;
public class GrabberShow implements Runnable{
IplImage image;
CanvasFrame canvas = new CanvasFrame("Web Cam");
public GrabberShow(){
canvas.setDefaultCloseOperation(javax.swing.JFrame.EXIT_ON_CLOSE);
}
public void run(){
FrameGrabber grabber = new VideoInputFrameGrabber(0);
int i = 0;
try{
grabber.start();
IplImage img;
while(true){
img = grabber.grab();
if(img != null){
cvFlip(img, img, 1);
cvSaveImage((i++) + "-aa.img", img);
canvas.showImage(img);
}
}
}catch(Exception e){
e.printStackTrace();
}
}
public static void main(String[] args){
GrabberShow gs = new GrabberShow();
Thread th = new Thread(gs);
th.start();
}
}
This is a very straightforward and easy example. The problem I am experiencing can be found on the following lines:
img = grabber.grab();
and
canvas.showImage(img);
The problem I face is a Type Mismatch "Cannot convert from Frame to opencv_core.LplImage".
I have tried searching for this online but I was unable to locate a good answer about this. What I did found was the same example only. Does anyone have any ideas about this?
Need to stress out that this the first time I use openCV with Java. I have used it in the past to make and object tracking program but this was done with native openCV and using Python.
The code you have looks like it would probably work for javacv version 0.10. For 1.0 theFrameGrabber's returnFrame objects that then need to be converted to IplImage objects using a OpenCVFrameConverter.ToIplImage.
import org.bytedeco.javacpp.opencv_core.IplImage;
import static org.bytedeco.javacpp.opencv_core.cvFlip;
import static org.bytedeco.javacpp.opencv_imgcodecs.cvSaveImage;
import org.bytedeco.javacv.CanvasFrame;
import org.bytedeco.javacv.Frame;
import org.bytedeco.javacv.FrameGrabber;
import org.bytedeco.javacv.OpenCVFrameConverter;
import org.bytedeco.javacv.VideoInputFrameGrabber;
...
public class GrabberShow implements Runnable {
CanvasFrame canvas = new CanvasFrame("Web Cam");
public GrabberShow() {
canvas.setDefaultCloseOperation(javax.swing.JFrame.EXIT_ON_CLOSE);
}
public void run() {
FrameGrabber grabber = new VideoInputFrameGrabber(0);
OpenCVFrameConverter.ToIplImage converter = new OpenCVFrameConverter.ToIplImage();
int i = 0;
try {
grabber.start();
IplImage img;
while (true) {
Frame frame = grabber.grab();
img = converter.convert(frame);
if (img != null) {
cvFlip(img, img, 1);
cvSaveImage((i++) + "-aa.img", img);
canvas.showImage(frame);
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
GrabberShow gs = new GrabberShow();
Thread th = new Thread(gs);
th.start();
}
}
I also need to find a library which allows to implement the "chroma key" effect in Java. The video contains some part in green color, which is replaced which a picture during the rendering in order to create a new video.
I am linking my question with a similar question which was already answered but with uncomplete answer (Looking for Chromakey library in Java). Could you please specify how did you do to have something up and working so quickly? I have been unsuccessful for some months fighting against the same issue.
c00kiemon5ter pointed several resources:
JavaCV
JAI (Java Advanced Imaging API)
Java Image Processing Cookbook
Which one did work for you?
JavaCV contains lots of methods to process video streams.
This code should get you started: http://tech.groups.yahoo.com/group/OpenCV/message/59118 but it's probably too slow in Java. Try this approach:
Create a filter which turns all the green pixels into a mask (look for things that "select by color").
Use the mask to copy the background image into the video.
I would like to contribute with a piece of code which gave me quite good results. I wonder if I used the classes and methods that Aaron Digulla suggested.
Please note that in this case my video has black background, that is why I am replacing the black color with the background image. I expect to obtain better results when I can edit the video to have green background, because black color is more likely to be used within the video main characters and replacing wrong pixels causes a quite awful effect.
--
package transparentvideo;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Rectangle;
import java.awt.Toolkit;
import java.awt.image.BufferedImage;
import java.awt.image.FilteredImageSource;
import java.awt.image.ImageFilter;
import java.awt.image.ImageProducer;
import java.awt.image.RGBImageFilter;
import java.io.File;
import javax.media.Manager;
import javax.media.Player;
import javax.swing.ImageIcon;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
public class TransparentVideo
{
Player mediaPlayer;
JFrame invisibleFrame;
JFrame visibleFrame;
JLabel videoScreen;
JPanel offScreenVideo;
String backgroundImageFile="nature.jpg";
String videoFile="girl.mov";
public TransparentVideo()
{
invisibleFrame = new JFrame();
invisibleFrame.setSize(400, 400);
Container container=invisibleFrame.getContentPane();
offScreenVideo = getvidComp();
offScreenVideo.setPreferredSize(container.getSize());
offScreenVideo.setVisible(true);
container.add(offScreenVideo);
invisibleFrame.setVisible(true);
visibleFrame=new JFrame();
visibleFrame.setSize(container.getSize());
visibleFrame.setLocationRelativeTo(null);
videoScreen = new JLabel();
visibleFrame.getContentPane().add(videoScreen);
visibleFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
visibleFrame.setVisible(true);
invisibleFrame.setVisible(false);
try
{
while(true)
{
if(mediaPlayer.getState()==Player.Started)
reDraw();
Thread.sleep(100);
}
}
catch (Exception ex)
{
System.out.println(ex.getMessage());
}
}
public void reDraw()
{
BufferedImage bi=new BufferedImage(videoScreen.getWidth(), videoScreen.getHeight(),
BufferedImage.TYPE_INT_ARGB);
bi.getGraphics().drawImage(new ImageIcon(backgroundImageFile).getImage(), 0 , 0 ,
videoScreen.getWidth(), videoScreen.getHeight(), null);
BufferedImage screenShot = createImage((JComponent) offScreenVideo,
new Rectangle(invisibleFrame.getBounds()));
Image im = makeColorTransparent(new ImageIcon(screenShot).getImage(), Color.BLACK);
bi.getGraphics().drawImage(im, 0 ,0 , videoScreen.getWidth(), videoScreen.getHeight(), null);
videoScreen.setIcon(new ImageIcon(bi));
}
public static BufferedImage createImage(Component component, Rectangle region)
{
if (!component.isDisplayable()) {
Dimension d = component.getSize();
if (d.width == 0 || d.height == 0) {
d = component.getPreferredSize();
component.setSize(d);
}
layoutComponent(component);
}
BufferedImage image = new BufferedImage(region.width, region.height, BufferedImage.TYPE_INT_RGB);
Graphics2D g2d = image.createGraphics();
if (!component.isOpaque())
{
g2d.setColor(component.getBackground());
g2d.fillRect(region.x, region.y, region.width, region.height);
}
g2d.translate(-region.x, -region.y);
component.paint(g2d);
g2d.dispose();
return image;
}
public static void layoutComponent(Component component)
{
synchronized (component.getTreeLock())
{
component.doLayout();
if (component instanceof Container)
{
for (Component child : ((Container) component).getComponents())
{
layoutComponent(child);
}
}
}
}
public JPanel getvidComp()
{
Manager.setHint(Manager.LIGHTWEIGHT_RENDERER,true);
try
{
mediaPlayer = Manager.createRealizedPlayer(new File(videoFile).toURL());
mediaPlayer.realize();
mediaPlayer.prefetch();
JPanel video=new JPanel(new BorderLayout());
video.add(mediaPlayer.getVisualComponent()) ;
mediaPlayer.start();
return video;
}
catch( Exception d)
{
return null;
}
}
public static Image makeColorTransparent( Image im, final Color color)
{
ImageFilter filter = new RGBImageFilter()
{
public int markerRGB = color.getRGB() | 0xFF000000;
public final int filterRGB(int x, int y, int rgb)
{
Color c=new Color(rgb);
int red=c.getRed();
int green=c.getGreen();
int blue=c.getBlue();
//if(red<140 && green<140 && blue<140)
{
int alpha=Math.max(Math.max(red , green), Math.max(green, blue))*3;
c=new Color(red , green , blue , alpha>255 ?255 :alpha );
}
return c.getRGB();
}
};
ImageProducer ip = new FilteredImageSource(im.getSource(), filter);
return Toolkit.getDefaultToolkit().createImage(ip);
}
public static void main(String[] args) {
new TransparentVideo();
}
}
How can I continuously capture images from a webcam?
I want to experiment with object recognition (by maybe using java media framework).
I was thinking of creating two threads
one thread:
Node 1: capture live image
Node 2: save image as "1.jpg"
Node 3: wait 5 seconds
Node 4: repeat...
other thread:
Node 1: wait until image is captured
Node 2: using the "1.jpg" get colors
from every pixle
Node 3: save data in arrays
Node 4: repeat...
This JavaCV implementation works fine.
Code:
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();
}
}
There is also post on configuration for JavaCV
You can modify the code and be able to save the images in regular interval and do rest of the processing you want.
Some time ago I've created generic Java library which can be used to take pictures with a PC webcam. The API is very simple, not overfeatured, can work standalone, but also supports additional webcam drivers like OpenIMAJ, JMF, FMJ, LTI-CIVIL, etc, and some IP cameras.
Link to the project is https://github.com/sarxos/webcam-capture
Example code (take picture and save in test.jpg):
Webcam webcam = Webcam.getDefault();
webcam.open();
BufferedImage image = webcam.getImage();
ImageIO.write(image, "JPG", new File("test.jpg"));
It is also available in Maven Central Repository or as a separate ZIP which includes all required dependencies and 3rd party JARs.
JMyron is very simple for use.
http://webcamxtra.sourceforge.net/
myron = new JMyron();
myron.start(imgw, imgh);
myron.update();
int[] img = myron.image();
Here is a similar question with some - yet unaccepted - answers. One of them mentions FMJ as a java alternative to JMF.
This kind of goes off of gt_ebuddy's answer using JavaCV, but my video output is at a much higher quality then his answer. I've also added some other random improvements (such as closing down the program when ESC and CTRL+C are pressed, and making sure to close down the resources the program uses properly).
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;
}
}
You can try Java Webcam SDK library also.
SDK demo applet is available at link.
I have used JMF on a videoconference application and it worked well on two laptops: one with integrated webcam and another with an old USB webcam. It requires JMF being installed and configured before-hand, but once you're done you can access the hardware via Java code fairly easily.
You can try Marvin Framework. It provides an interface to work with cameras. Moreover, it also provides a set of real-time video processing features, like object tracking and filtering.
Take a look!
Real-time Video Processing Demo:
http://www.youtube.com/watch?v=D5mBt0kRYvk
You can use the source below. Just save a frame using MarvinImageIO.saveImage() every 5 second.
Webcam video demo:
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);
}
}
For those who just want to take a single picture:
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();
}
}
}
I used Webcam Capture API. You can download it from here
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"));
}
}
}
http://grack.com/downloads/school/enel619.10/report/java_media_framework.html
Using the Player with Swing
The Player can be easily used in a Swing application as well. The following code creates a Swing-based TV capture program with the video output displayed in the entire window:
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();
}
}
Java usually doesn't like accessing hardware, so you will need a driver program of some sort, as goldenmean said. I've done this on my laptop by finding a command line program that snaps a picture. Then it's the same as goldenmean explained; you run the command line program from your java program in the takepicture() routine, and the rest of your code runs the same.
Except for the part about reading pixel values into an array, you might be better served by saving the file to BMP, which is nearly that format already, then using the standard java image libraries on it.
Using a command line program adds a dependency to your program and makes it less portable, but so was the webcam, right?
I believe the web-cam application software which comes along with the web-cam, or you native windows webcam software can be run in a batch script(windows/dos script) after turning the web cam on(i.e. if it needs an external power supply). In the bacth script , u can add appropriate delay to capture after certain time period. And keep executing the capture command in loop.
I guess this should be possible
-AD
There's a pretty nice interface for this in processing, which is kind of a pidgin java designed for graphics. It gets used in some image recognition work, such as that link.
Depending on what you need out of it, you might be able to load the video library that's used there in java, or if you're just playing around with it you might be able to get by using processing itself.
FMJ can do this, as can the supporting library it uses, LTI-CIVIL. Both are on sourceforge.
Recommand using FMJ for multimedia relatived java app.
Try using JMyron How To Use Webcam Using Java. I think using JMyron is the easiest way to access a webcam using java. I tried to use it with a 64-bit processor, but it gave me an error. It worked just fine on a 32-bit processor, though.