Can you say which global information you want? For "image" do you want the html representation of the problem?
You can use the "render problems" button on the individual homework set page of the editor to display the images of all of the problems in the set.
You can also use the library browser to inspect all of the homework problems defined in a set definition file whether that set definition file has been imported into the course or not.
Except for the image it might be easier to extract the information you want (using a script) from the .def file for the homework set than from webwork itself.
Is any of this helpful? I may not understand what you are trying to do.