Unlike Windows, it is very easy to take screen shots of selected area of the screen in Ubuntu. But I am researching how to have the following features when taking screen shots of the selected area:

(1) The final output should be automatically saved to a location, for example on the desktop. (This feature is available in Mac OSX)

(2) A filter (such as drop down shadow) should be automatically applied to the image.

The above should happen as soon as the selection is done, without poping up any dialogs and expecting any inputs from the user.