Abstract

An optical method to generate a family of color coded equidensities from a continuous tone input is presented. A halftone screen technique is used together with the method of theta modulation to encode each density slice independently. The resulting coded image is demodulated in a spatial filtering system using a polychromatic extended source. With a simple screen, the method allows the number of slices and their density levels to be adapted to the input to be processed while a color code can easily be added to the processed output.

© 1977 Optical Society of America

Nonlinear optical processing: analysis and synthesis

S. R. Dashiell and A. A. Sawchuk
Appl. Opt. 16(4) 1009-1025 (1977)

Optical logarithmic filtering using inherent film nonlinearity

Anthony Tai, Thomas Cheng, and F. T. S. Yu
Appl. Opt. 16(9) 2559-2564 (1977)

Nonlinear optical processing: nonmonotonic halftone cells and phase halftones

S. R. Dashiell and A. A. Sawchuk
Appl. Opt. 16(7) 1936-1943 (1977)

Equidensitometry by coherent optical filtering

H. K. Liu, J. W. Goodman, and J. L-H. Chan
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Nonlinear optical processing with halftones: accurate predictions for degradation and compensation

Ahmad Armand, Alexander A. Sawchuk, and Timothy C. Strand
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