1. A method for inverse halftoning, comprising the steps of: a) building a template training set including at least one continuous-tone image and a corresponding halftone image; b) retrieving a full set of templates and a set of corresponding output values from the template training set; c) representing each of the retrieved templates as t and applying a partitioning function to each of the templates t, the partitioning function dividing an initial look-up table into N smaller look-up tables, wherein N is an integer; d) storing each of the templates t and the corresponding output values for the templates in a corresponding one of the smaller look-up tables, the corresponding one of the smaller look-up tables having a number equal to a result of the partitioning function; e) setting the output value stored in the corresponding one of the smaller look-up tables equal to an averaged output value; and f) defining an integer r as the number of the retrieved templates and performing an inverse halftoning operation having the steps of: retrieving the r retrieved templates simultaneously; and inverse halftoning the r retrieved templates, the inverse halftoning using the N smaller look-up tables, the input to the inverse halftoning being a halftone image and the output of the inverse halftoning being a continuous-tone image.