1. An apparatus for estimating a position of one or more particles, the apparatus comprising: an imaging system; a detector, in optical communication with the imaging system, configured to detect an image of a plane; a memory, operably coupled to the detector, configured to store a representation of the image; and a processor, operably coupled to the memory, configured to: (a) perform a wavelet decomposition of an image of the plane to form a wavelet map of the image; (b) segment the wavelet map into multiple regions having intensity values above a predetermined threshold; and (c) estimate the location of a centroid of at least one region, the location of the centroid corresponding to the position of the particle in a first dimension and a second dimension of the plane.