1. An input device comprising: a display device comprising a first display region; a plurality of sensor electrodes configured for capacitive sensing, wherein the plurality of sensor electrodes overlap at least a portion of the first display region; and a processing system operatively connected to the plurality of sensor electrodes and configured to: output a placement guide graphic on the first display region, wherein the placement guide graphic provides alignment indication for a feature of an input object, and wherein the placement guide graphic comprises a trace outlining the feature of the input object; generate a pressure-gauge graphic based on pressure exerted on the input device by the input object, wherein the pressure-gauge graphic displays a plurality of pressures exerted by different regions of the input object on the input device; send the pressure-gauge graphic for display while the input object is still in contact with the input device; obtain, based on resulting signals received with at least one sensor electrode of the plurality of sensor electrodes, a first capacitive image comprising the input object; and authenticate a user based on at least the first capacitive image.