on saveImageWithItselfAsIcon(icon_image_file)
        -- save icon_image_file with itself as icon
        set icon_image_file_string to icon_image_file as string
        tell application "Image Events"
                launch
                set icon_image to open file icon_image_file_string
                save icon_image with icon
                close icon_image
        end tell
end saveImageWithItselfAsIcon

on copyIconOfTo(aFileOrFolderWithIcon, aFileOrFolder)
        tell application "Finder" to set f to aFileOrFolderWithIcon as alias
        -- grab the file's icon
        my CopyOrPaste(f, "c")
        -- now the icon is in the clipboard
        tell application "Finder" to set c to aFileOrFolder as alias
        my CopyOrPaste(result, "v")
end copyIconOfTo

on CopyOrPaste(i, cv)
        tell application "Finder"
                activate
                set infoWindow to open information window of i
                set infoWindowName to name of infoWindow
        end tell
        tell application "System Events" to tell process "Finder" to tell window infoWindowName
                keystroke tab -- select icon button
                keystroke (cv & "w") using command down (* (copy or paste) + close window *)
        end tell -- window 1 then process Finder then System Events
end CopyOrPaste

on run
        set icon_image_file to POSIX file "%s" as alias
        set dmg_file to POSIX file "%s" as alias

        my saveImageWithItselfAsIcon(icon_image_file)
        -- wait for virus scanner
        delay 2
        my copyIconOfTo(icon_image_file, dmg_file)
end run