Abstract

Usually, images and other signals are recorded on photographic media using either density modulation, as in ordinary photographs, or spatial pulse modulation, as in halftone image reproduction. This paper presents an analysis of a modulation technique that combines density and spatial modulation. It is shown that the technique studied can provide a large class of average-transmittance functions. This class includes linear, power, and logarithmic functions. Design formulas for screens that give these functions are derived. It is shown that the average-transmittance function of films exposed through a screen of this design is independent of film characteristics for a suitably chosen, film-dependent exposure range.

© 1978 Optical Society of America

Synthesis of average film transmission functions

Robert L. Everett
J. Opt. Soc. Am. 68(8) 1113-1118 (1978)

Halftone images: Spatial resolution and tone reproduction*

Olof Bryngdahl
J. Opt. Soc. Am. 68(3) 416-422 (1978)

Nonlinear optical processing with halftones: accurate predictions for degradation and compensation

Ahmad Armand, Alexander A. Sawchuk, and Timothy C. Strand
Appl. Opt. 26(6) 1007-1014 (1987)

Coherent optical analog-to-digital conversion using a single halftone photograph

H. K. Liu
Appl. Opt. 17(14) 2181-2185 (1978)

Halftone screen techniques for photographic film response shaping with application to optical processing of medical x-ray images

I. Glaser and H. H. Barrett
Appl. Opt. 18(13) 2294-2300 (1979)