overlay image over image

[dkon]

Hi

I tried to search for this but can't seem to find something that works.

I am displaying an image 

img =pg.ImageItem(data)

self.plot.addItem(img)

I then want to overlay data on top of this

img2 = pg.ImageItem(data2)

self.plot.addItem(img2)

When I display the second one the plot is cleared. Is there a way I can overlay the second image?

Darren