Adive over image functions:

Question

Hello,
I wondered if anyone could advice.
I am writing a program which finds the threshold of an greyscale image, by threshold I mean using maths to calculcate what is the foregound and background pixels in the image.
The threshold selected is often to high or low, so I added buttons to allow the user to change the value which in a grayscale image would be between 0-255.
When the the user changes the threshold, more or less of the image is considered foreground or background. At the moment I have stored these values in any array.
My question is, could any one think of a way of to display the orginal image in a label, and display the threshold pixels on top so we can still lightly see the orginal image, then when we change the threshold we see what is being regarded as foregound
I only need advice.
Thanks

Answer 1

Extend the label then draw over the top
Skeleton code
public class myLabel extends Jlabel
   Image foreImage
   myLabel(Icon icon, Image foreImage)
      super(icon);
      this.foreImage=foreImage;
   public void setForeImage(Image foreImage)
      this.foreImage=foreImage;
      repaint();
   public void paint(Graphics _g)
      paintComponent(_g);
      Graphics2D g=(Graphics2D)_g;
      g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 0.5f));
      //draw the processed image;
      paintBorder(g);
}When the tresh hold changes process the image then call setForeImage to update the foreground image.
This should be all you need to do.
Bamkin