Halftone patterns for arbitrary screen periodicities

A means of improving the ordered dither halftoning algorithm by the use of unconventional screen periodicities is discussed. It is shown that altering the periodicity matrix frequently shifts the location of the halftone spectral orders into a region of the Ω plane to which the human visual system is less sensitive. Consequently, optimal patterns for these periodicities exhibit a lower degree of false contours and textures and outperform traditional dither patterns. A few representative periodic tessellations that produce typical results are examined. It is also shown that the concepts introduced can be applied to the angled screens created by Holladay´s technique