R+G+B vs. gray, LCD projector

More depth on Gamma Poynton, Gamma and its disguises: The nonlinear mappings of intensity in perception, CRTs, film and video. SMPTE Journal, 1993,

Halftoning The problem with ink: it’s opaque Screening: luminance range is accomplished by printing with dots of varying size. Collections of big dots appear dark, small dots appear light. % of area covered gives darkness.

Halftoning references A commercial but good set of tutorials Digital Halftoning, by Robert Ulichney, MIT Press, 1987Digital Halftoning Stochastic halftoning

Color halftoning Needs screens at different angles to avoid moire moire Needs differential color weighting due to nonlinear visual color response and spatial frequency dependencies.

Halftone ink May not always be opaque Three inks can give 2 ^3 =8 distinct colors Visual system gives more since dot size, spacing, yields intensity, gives somewhat additive system Highly nonlinear. See Berns et al. The Spectral Modeling of Large Format Ink Jet PrintersThe Spectral Modeling of Large Format Ink Jet Printers

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