1. A method that assesses character-rendering quality, the method comprising: transmitting a test-character set of test characters to a character-rendering device for rendering; intercepting digital pixel-based character maps for the test characters of the test-character set, used by the character-rendering device for rendering the test characters, to serve as an input-character set of input characters; capturing test characters rendered by the character-rendering device to serve as an output-character set of output characters; for each input character c i , generating and storing in a computer-readable memory one or more metrics that reflect differences between the input characters and the output characters; and outputting one or more indications of character-rendering quality based on the one or more metrics.