imshow() : fill certain regions with a specific color.


I would like to ask you a way to fill certain regions with a specific motif
when running imshow(). I take the following example :

For certain value, instead of writing directly a numerical result, I would
like to fill my table with 'x'. For other specific values, with 'o'. How take
care of this with imshow, and how assign a specific color to such a specific
region ?

I saw something about the spy method. Do you think it's possible to use it
combined with the imshow() capabilities ?

I'm wondering also about the possibility to make logical 'or' on the data, in
the order to select an area to fill with a custom color.

Thank you very much.


David Kremer