1. A method for determining a printhead misalignment of a printer comprising the steps of: a) printing a printhead alignment test pattern including a plurality of spaced-apart images at least partially aligned substantially along a printhead scan axis; b) moving a sensor along the printhead scan axis at a known speed over the plurality of images; c) obtaining sampled data points from the sensor at a known sampling rate; d) determining the locations along the printhead scan axis of the edges of the plurality of images using the sampled data points, the known speed of the sensor, and the known sampling rate; and e) calculating the printhead misalignment from the determined locations of the edges of the plurality of images.