Abstract

Continuous-tone original picture information, such as a photograph or original art work, is put into a form suitable for halftone printing reproduction by raster-scan reading of the original to produce a varying video signal. The video signal is rendered suitable for writing in a high speed writer by continuously convolving (weighting, multiplying) said signal with stored halftone dot data (attenuation) signals obtained from a Read Only Memory, and applying the resultant treated signals, through a quantizer, to control a beam of radiation to expose a sensitive printing or recording medium to a halftone image pattern in which each dot is configured to provide optimum image information transfer to the reproduction medium. Simulations of the effects of conventional "bump" and "flash" exposures, and of other screenmodifying parameters, can be introduced as desired, and suitable apparatus combinations for performing all these operations are disclosed.