Re: Problem closing images

Posted by Nathaniel Ryckman on Jun 27, 2011; 3:38pm
URL: http://imagej.273.s1.nabble.com/Problem-closing-images-tp3683887p3683888.html

It would help if you were able to give the whole stack trace. My guess is that this line is giving you the problem:

Image result = WindowManager.getCurrentImage().getImage();

From my experience, the getCurrentImage() command doesn't work very consistently. Maybe you could keep references of the images that you are opening up or encapsulate the getCurrentImage() command in a while loop that checks to see if the return value is valid.

strahli wrote

Hei everybody.

I'm working with ImageJ and Java for a month now. My task is it to read an Image every 10 seconds from a camera, compare it to a reference image and create a result Image (shows the differences). Means that I need to have 3 images open at once. I can repeat this process about 260 times until the <Out of memory> exception comes. My problem is that I tried to close the Images, but if I do this, I get another NullPointerException.

================================
My code is like this:

start timer
if (timerEvent) {
  loadNewPicture();
}

loadNewPicture{
  result = manipulate(refImage, snapshot);
  ...
}

manipulate (refImage, snapshot) {
  if (refWindow == null) {
    refWindow = new ImageWindow(refImage)
  } else {
    refWindow.setImage(refImage)
  }
  // the same for the snapshot

  // execution of some macros
  Image result = WindowManager.getCurrentImage().getImage();
  return result;
}

================================

My problem is that I tried to close the images or the windows but if I do this , I get an exception in the class "ImageWindow" at row 526 (method "windowActivated" line: setMenuBar(Menus.getMenuBar());).

Btw: the image size is ca.70 KB.

Has anybody a hint for me?

Thanks in advance,
strahli

EDIT: And I've searched the older topics, but I didn't really found a solution except for closing the images, windows and using the garbage collector, but I can't really adapt it to my programm without getting other problems.