@inproceedings{Ostromoukhov:1996:ACF,
  optcitations = {Ostromoukhov:1995:AS},
  optnote = {},
  author = {Victor Ostromoukhov and Nicolas Rudaz and Isaac Amidror and P. Emmel
            and Roger D. Hersch},
  optkey = {},
  series = {SPIE Proceedings Series},
  optannote = {},
  editor = {G{\"u}nther J. Dausmann},
  url = {http://www.iro.umontreal.ca/~ostrom/publications/abstracts.html#Berlin96_Security},
  address = {Bellingham, Washington},
  localfile = {papers/Ostromoukhov.1996.ACF.pdf},
  publisher = {SPIE},
  doi = {http://dx.doi.org/10.1117/12.262419},
  optmonth = {},
  volume = {2951},
  booktitle = {Proceedings on Holographic and Diffractive Techniques},
  optstatus = {abstract pdf paper url},
  optnumber = {},
  title = {{A}nti-{C}ounterfeiting {F}eature of {A}rtistic {S}creening},
  abstract = {In a recent publication (Ostromoukhov95), a new image reproduction
              technique, artistic screening, was presented. It incorporates
              freely created artistic screen elements for generating halftones.
              Fixed predefined dot contours associated with given intensity
              levels determine the screen dot shape's growing behavior. Screen
              dot contours associated with each intensity level are obtained by
              interpolation between the fixed predefined dot contours. A
              user-defined mapping transforms screen elements from screen
              element definition space to screen element rendition space. This
              mapping can be tuned to produce various effects such as
              dilatations, contractions and non-linear deformations of the
              screen element grid. Although artistic screening has been designed
              mainly for performing the creation of graphic designs of high
              artistic quality, it also incorporates several important
              anti-counterfeiting features. For example, bank notes or other
              valuable printed matters produced with artistic screening may
              incorporate both full size and microscopic letters of varying
              shape into the image halftoning process. Furthermore, artistic
              screening can be used for generating screen dots at varying
              frequencies and orientations, which are well known for inducing
              strong moire effects when scanned by a digital color copier or a
              desktop scanner. However, it is less known that
              frequency-modulated screen dots have at each screen element size a
              different reproduction behavior (dot gain). When trying to
              reproduce an original by analog means, such as a photocopier, the
              variations in dot gain induce strong intensity variations at the
              same original intensity levels. In this paper, we present a method
              for compensating such variations for the target printer, on which
              the original security document is to be printed. Potential
              counterfeiters who would like to reproduce the original with a
              photocopying device may only be able to adjust the dot gain for
              the whole image and will therefore be unable to eliminate the
              undesired intensity variations produced by variable frequency
              screen elements.},
  year = {1996},
  pages = {126--133},
}