13 – Digital Halftoning

Publisher Summary This chapter deals with digital halftoning. In terms of photolithography, halftoning involved projecting light from the negative of a continuous-tone photograph, through a mesh screen, such as finely-woven silk, onto a photosensitive plate. Later versions of the halftoning process employed screens made of glass that were coated on one side by an opaque substance. Later still, the glass plate mesh was replaced altogether with a flexible piece of processed film, placed directly in contact with the unexposed lithographic film. This contact screen had direct control of the dot structure. The screen controlled the screen frequency, the dot shape, and the screen angle. This chapter discusses three types of halftonig—amplitude-modulated (AM) halftoning, frequency-modulated (FM) halftoning, and AM-FM hybrids. In AM halftoning, halftone screen has been replaced in digital printers with a raster image processor (RIP) that converts each pixel of the original image from an intermediate tone directly into a binary dot. In FM or stochastic screening techniques, dots of constant size but variably spaced according to tone, are available to digital printers. AM–FM hybrids produce dot clusters that vary according to tone in both their size and spacing.

[1]  Robert Ulichney,et al.  Digital Halftoning , 1987 .

[2]  Peter J. Diggle,et al.  Statistical analysis of spatial point patterns , 1983 .

[3]  Rodney L. Miller,et al.  Design of minimum visual modulation halftone patterns , 1991, IEEE Trans. Syst. Man Cybern..

[4]  Roger D. Hersch,et al.  Spectral analysis and minimization of moire patterns in color separation , 1994, J. Electronic Imaging.

[5]  F. Campbell,et al.  The effect of orientation on the visual resolution of gratings , 1966, The Journal of physiology.

[6]  Eric Renshaw,et al.  A practical guide to the spectral analysis of spatial point processes , 1996 .

[7]  Jan P. Allebach,et al.  Model-based halftoning using direct binary search , 1992, Electronic Imaging.

[8]  Daniel L. Lau,et al.  Green-noise digital halftoning , 1998 .

[9]  John F. Jarvis,et al.  A survey of techniques for the display of continuous tone pictures on bilevel displays , 1976 .

[10]  Keith T. Knox.  Error image in error diffusion , 1992, Electronic Imaging.

[11]  Peter Fink,et al.  Postscript Screening: Adobe Accurate Screens , 1992 .

[12]  M. S. Bartlett,et al.  The spectral analysis of two-dimensional point processes , 1964 .

[13]  Gonzalo R. Arce,et al.  Digital halftoning by means of green-noise masks , 1999 .

[14]  David Blatner,et al.  Real world scanning and halftones , 1993 .

[15]  Michel Goulard,et al.  Marked point process : using correlation functions to explore a spatial data set , 1995 .

[16]  Robert Ulichney,et al.  Dithering with blue noise , 1988, Proc. IEEE.