Screened images of 1-bit depth are common in the office market and in graphic-arts printing systems. Bitmapped screens are produced at the copier scanner, copy-dot scanners and in the Digital Front End (DFE) as “digital negatives.” Raster-once-output-many (ROOM) is an example of a digital negative. Such bilevel images are printer device specific. The bilevel image may be inappropriate for the printer in use and the original image may be unavailable.While inverse halftone is a common solution for repurposing screened images, it results in lower quality reproduction:• Inverse halftoning requires further density compensation for the requirements of the new printer.• Much of the original image information is lost in the depth to frequency conversion and inverse halftoning cannot reclaim the lost image data.• Rescreening a reverse-halftone image results in loss of high-spatial frequency image data.The goal of the algorithm described is to increase screen-repurposing performance and maintain high-frequency detail without inverting the 1-bit image to 8-bit.
Stephen K. Herron, "Repurposing Device-dependent Screens for Unintended Printers" in Proc. IS&T Int'l Conf. on Digital Printing Technologies (NIP17), 2001, pp 709 - 713, https://doi.org/10.2352/ISSN.2169-4451.2001.17.1.art00060_2