Hover to enlarge

Hi all. Hopefully this is an easy and quick one that I just cant figure out.

I am using a number of images on a number of slides to compliment the text, however I wish for the images to to be enlarged, under the control of the learner, so the learner can see them clearer and in more detail when the mouse moves over the image.

I know I can enlarge the image by using the Zoom Region function operated by a few simple triggers, or by having multiple images where one hides and another appears when a trigger is clicked; but I really wish for there to be more control for the user to look at specifics of the images. I want the mouse pointer to be the focal point which enlarges and for the learner to be able to hover over a specific area and for that area to be larger.

Any thoughts.

Thanks in advance.