This is the same process for most image editing applications.
I have found the Corel Draw Photo Shop the best for masking images.
The first step is to select the magic wand tool. The magic wand tool is the tool which will select similar pixels to where-ever you have selected with the tool. The tolerance will change how many pixels away from where you clicked the tool.

The mask will shown in red.

Click edit | copy. You can open the picture in a new window in Corel Draw. Alternatively you could invert the mask and change the background colour
