Image vs Pcolor

Hi all,

I'm thinking of adding image support to octplot by implementing the
image object. Currently octplot supports surface data (but only
viewable from above in 2D using pcolor). Since I never did any image
processing/viewing I would appreciate input on the differences between
displaying a matrix as an image and displaying it as a surface. Also
what would be the most important features to implement in an image
object (i.e. what should I implement first)

Thanks
Shai