c# - Capturing an image with Emgu - black image -

i'm newbie in emgu cv , major project i'm trying capture image webcam , show in image box, it's showing black image.

what wrong following code?

using system.collections.generic; using system.componentmodel; using system.data; using system.drawing; using system.linq; using system.text; using system.windows.forms; using emgu.cv; using emgu.cv.structure; using emgu.cv.ui; using emgu.util;  namespace windowsformsapplication7 {     public partial class form1 : form     {         private capture capture;          public form1()         {             initializecomponent();         }          private void form1_load(object sender, eventargs e)         {             if (capture == null)                capture = new capture();             image<bgr,byte> img=capture.queryframe();             imagebox1.image = img;                          }     } } 

i think there minor mistake.

use instead:

declare global variable:

capture capture = default(capture); 

put in load:

capture = new capture(0); control.checkforillegalcrossthreadcalls = false; system.threading.thread t = new system.threading.thread(grab);  t.start(); 

create sub grab , put in,

do {     imagebox1.image = capture.queryframe(); } while (true); 

cheers
shreyas