Photographs must be converted to halftone format when they are prepared for print reproduction. To faithfully reproduce an image using halftone dots, the proper resolution must be chosen to match the end use of the printed product as well as the attributes of the process and materials that will be used to reproduce the image. One of the important considerations when making a halftone is screen ...

Most recent papers about visual cryptography for halftone images are dedicated to get a higher contrast decoded image. However, the hidden visual pattern often blends into the background image and leads to a confused image. In this paper, we propose an improved method for halftone image hiding. By using the proposed method, the background image can be eliminated and the hidden visual pattern ca...

A method of coding scanned documents containing halftone pictures, e.g. newspapers and magazines, for transmission purposes in prepress is proposed. The halftone screen is estimated and the grey value of each dot is found, thus giving a compact description. At the receiver the picture is re-screened. A new data structure and related algorithms for handling the digital screen without restriction...

Halftones, or periodic cluster dithers, are point-to-point, contone pixel to halftone dot, conversion processes. This paper describes an approach to achieving accurate halftone reproduction by using the errors caused during the scan conversion process without comparison to the source pixels and maintaining the point-to-point scan conversion paradigm. Two types of density errors encounter in the...

Image quality of halftone print is significantly influenced by optical characteristics of paper. Light scattering in paper produces optical dot gain, which has a significant influence on the tone and color reproductions of halftone print. The light scattering can be quantified by the Modulation Transfer Function (MTF) of paper. Several methods have been proposed to measure the MTF of paper. How...

Halftones are intended to produce the illusion of continuous images from binary output states, so the visibility of undesired halftone textures is an essential quality factor of halftone patterns. We propose a metric to predict the visibility of color halftone textures. The metric utilizes the human visual threshold function and contrast sensitivity functions (CSF) of luminance and chrominance....

Hexagons are widely observed as a packing or tiling geometry in nature, yet they appear to have been avoided in conventional halftone tiling. A goal of the present study is to understand the potential barriers that have prevented their use and present new halftone geometry options that overcome the issues while offering several potential benefits. While conventional halftone geometries often in...

We review the phenomena having an impact on the interaction between light, paper and color halftones. They comprise surface reflections and refractions at the air-paper interface, propagation of light within the paper, internal reflections at the paper-air interface, as well as ink spreading and trapping. We introduce basic notions from radiometry and optics, such as the definitions of radiant ...