data from window

[Dave]

Hi,
I am using an active x control that display an image on it window, i want to
get the image data into a byte buffer but the active x control dont expose
any function that fill a buffer with its images data, so can i get a window
data (the image on the window or any other drawing on it) by using its
handle only???
can i get the window image displaying on it by its hwnd even if the window
in not visible???

Thanks