content: set this_file to choose file
  try
  	tell application "Image Events"
  		-- start the Image Events application
  		launch
  		-- open the image file
  		set this_image to open this_file
  		-- get dimensions of the image
  		copy dimensions of this_image to {W, H}
  		-- determine the letterbox area
  		set crop_W to W
  		-- calcluate the 16:9 proportions
  		set crop_H to (W * 9) / 16
  		-- perform action
  		crop this_image to dimensions {crop_W, crop_H}
  		-- save the changes
  		save this_image with icon
  		-- purge the open image data
  		close this_image
  	end tell
  on error error_message
  	display dialog error_message
  end try