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sarxos / webcam-capture

The goal of this project is to allow integrated or USB-connected webcams to be accessed directly from Java. Using provided libraries users are able to read camera images and detect motion. Main project consist of several sub projects - the root one, which contains required classes, build-in webcam driver compatible with Windows, Linux and Mac OS, which can stream images as fast as your camera can serve them (up to 50 FPS). Main project can be used standalone, but user is able to replace build-in driver with different one - such as OpenIMAJ, GStreamer, V4L4j, JMF, LTI-CIVIL, FMJ, etc.
http://webcam-capture.sarxos.pl
MIT License
2.26k stars 1.11k forks source link

Want to getImage() without webcam.open() #556

Open josephraj2k16 opened 6 years ago

josephraj2k16 commented 6 years ago

hi sarxos,Iam using your webcam-capture in my play project and thanks for the code.I already opened my webcam feed using some html tags and look like this image

now when I want to take a snap using this code:

val webcam = Webcam.getDefault() 
if (webcam != null) {
  println("Webcam: " + webcam.getName())
  webcam.open()
} else {
  println("No webcam detected");
  val x1= "failure"
}
ImageIO.write(webcam.getImage(), "PNG",new File("D:/folder1/1.png"))
val x="Image captured from Webcam"

It cant able to take snap because the webcam is already opened and here also im trying to open it again using "webcam.open()".When I delete the line "webcam.open()" it throws a error as "[IllegalArgumentException: image == null!]".Is there any way to take snap without using open() function??

sarxos commented 6 years ago

Hi @josephraj2k16, you should be able to do that with the following code:

if (webcam != null) {
  println("Webcam: " + webcam.getName())
  if (!webcam.isOpen()) {
    webcam.open()
  }
} else {
  println("No webcam detected");
  val x1= "failure"
}

This should do the trick as well, set when you application is started:

static {
  Webcam.setAutoOpenMode(true);
}

Then you do not have to call open. This solution, however, have some side-effect - you lost control over the webcam open/closed state.

Webcam webcam = Webcam.getDefault();
if (webcam != null) {
  println("Webcam: " + webcam.getName())
  ImageIO.write(webcam.getImage(), "PNG",new File("D:/folder1/1.png"))
} else {
  System.out.println("No webcam detected");
}
josephraj2k16 commented 6 years ago

I did as u said,I had set the Auto open mode as true,and deleted the webcam.open(),now it says that execution exception:[WebcamException: Cannot execute task] on this line =>ImageIO.write(webcam.getImage(), "PNG",new File("D:/folder1/1.png"))

image

sarxos commented 6 years ago

Can you provide whole stack trace?

josephraj2k16 commented 6 years ago

here is the whole code:(scala doesnt has the keyword "static" so i took off static for autoopenmode()

val in = hello.bindFromRequest in.fold( errors => { BadRequest(views.html.index(errors)) }, name => {

                    Webcam.setAutoOpenMode(true);
                    val webcam = Webcam.getDefault 
                    if (webcam != null) {
                              println("Webcam: " + webcam.getName)
                             // webcam.open()
                    }
                   else {
                            println("No webcam detected")        
                   }
                   ImageIO.write(webcam.getImage(), "PNG",new File("D:/folder1/"+name+".png"))
                   val x="Image captured from Webcam"
                   Ok(views.html.welcome(x))
            })

}

josephraj2k16 commented 6 years ago

I have a breakthrough in this!!!! I ran your code separately,i had a response like :[warn] c.g.s.w.d.b.WebcamDefaultDevice - Different size obtained vs requested - [176x144] vs [160x120]. Setting correct one. New size is [160x120]

Is this the reason why we cant have the solution??

sarxos commented 6 years ago

@josephraj2k16,

The response you are writing about is just a warning. It will not cause exception in your solution. The reason behind previous exception is different.

Can you try with a different approach and open webcam before it's served by bind request? Try this:

val webcam = Webcam.getDefault 
webcam.open();

val in =  hello.bindFromRequest
   in.fold(
                errors => { 
                  BadRequest(views.html.index(errors))
                },
                name => {
                        if (webcam != null) {
                                  println("Webcam: " + webcam.getName)
                        }
                       else {
                                println("No webcam detected")        
                       }
                       ImageIO.write(webcam.getImage(), "PNG",new File("D:/folder1/"+name+".png"))
                       val x="Image captured from Webcam"
                       Ok(views.html.welcome(x))
                })
  }
reginavaleria96 commented 6 years ago

I have similar question with similar case. My code:

public void capture(String path) throws IOException {
        Webcam.setAutoOpenMode(true);
        Webcam webcam = Webcam.getDefault();
        if (webcam != null) {
            System.out.println("Webcam: " + webcam.getName());
            webcam.setViewSize(new Dimension(640, 480));
            // webcam.open();
            BufferedImage image = webcam.getImage();
            ImageIO.write(image, "JPG", new File(path));
            System.out.println("Captured & Saved");
            // webcam.close();
        } else {
            System.out.println("No webcam detected");
        }
    }

the stack trace:


com.github.sarxos.webcam.WebcamException: Cannot execute task
    at com.github.sarxos.webcam.WebcamProcessor$AtomicProcessor.process(WebcamProcessor.java:72)
    at com.github.sarxos.webcam.WebcamProcessor.process(WebcamProcessor.java:140)
    at com.github.sarxos.webcam.WebcamTask.process(WebcamTask.java:46)
    at com.github.sarxos.webcam.ds.cgt.WebcamOpenTask.open(WebcamOpenTask.java:20)
    at com.github.sarxos.webcam.Webcam.open(Webcam.java:271)
    at com.github.sarxos.webcam.Webcam.open(Webcam.java:232)
    at com.github.sarxos.webcam.Webcam.isReady(Webcam.java:745)
    at com.github.sarxos.webcam.Webcam.getImage(Webcam.java:613)
    at com.regina.thesis.tools.Camera.capture(Camera.java:21)
    at com.regina.thesis.servlet.Capture.doGet(Capture.java:41)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:624)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:218)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:110)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:506)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:962)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:445)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1115)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:637)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:318)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Unknown Source)
Caused by: com.github.sarxos.webcam.WebcamException: Cannot start native grabber!
    at com.github.sarxos.webcam.ds.buildin.WebcamDefaultDevice.open(WebcamDefaultDevice.java:330)
    at com.github.sarxos.webcam.ds.cgt.WebcamOpenTask.handle(WebcamOpenTask.java:38)
    at com.github.sarxos.webcam.WebcamProcessor$AtomicProcessor.run(WebcamProcessor.java:81)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    ... 1 more

My guess is that the library cannot detect the webcam as being open/turned on. Do you have any suggestion for my case?

sarxos commented 6 years ago

Hi @reginavaleria96, I already addressed your issue in #594. Your problem is not caused by missing webcam.open().

stefan-reich commented 6 years ago

So is it possible to use the same webcam in multiple processes? I thought you couldn't do that.