1. A system for sensing an absolute position in two dimensions, comprising: a target having a two-dimensional target pattern; a sensor for capturing an image of a first subset of the target pattern; and a controller for generating a first image vector representing summations of rows of pixel values from the image, and a second image vector representing summations of columns of pixel values from the image, the controller configured to determine an absolute two-dimensional position of the first subset with respect to an origin of the target pattern based on the first and the second image vectors and a plurality of target vectors that represent the target pattern.