[R] image() with color key?

[Michael Jerosch-Herold]

Is there an "easy" way to plot a "color key" next to a color image (with
image() in graphics package)? The color key should also include a
numerical scale, so that the colors can be cross-referenced with image
intensity values. I see that levelplot has a facility for color keys,
but with image it seems less straightforward, i.e. generating a color
key is not an option in image().

Thank you!

Michael Jerosch-Herold