In order to improve the output image quality of binary text and graphics (even for binary information that are buried within a document which also has gray level information), a gray level resolution enhancement anti-aliasing method (GRET) that uses feature extraction and a rule-based decision matrix for edge enhancement (anti-aliasing) with multi-level (LED) output printing capability in a electrophotographic system is described. A pipelined architecture (with a conflict resolution priority-sorting scheme in the decision matrix) was used to enable all the decision operations to be performed at the same time (for efficient high-speed operation) and was implemented in an ASIC. Further, a scalable multiple chip architecture with overlapping pixels at the end of the image segments was created to enable enhancement operation for wider width and higher speed printing.
Yee S. Ng, "Gray Resolution Enhancement Anti-aliasing Technology (GRET) for High Speed Printing" in Proc. IS&T Int'l Conf. on Digital Printing Technologies (NIP16), 2000, pp 810 - 813, https://doi.org/10.2352/ISSN.2169-4451.2000.16.1.art00097_2