Conventional halftoning methods such as error diffusion and ordered dithering are poorly suited to the compression of halftone images using the baseline fax compression schemes CCITT G3 and G4. This paper proposes an efficient and flexible solution for binary representation of mixed content documents using CCITT G3/G4 compression. The solution includes two variations which we refer to as FastFa...

A new halftone algorithm is described. The algorithm is designed for implementation on a parallel architecture in order to provide fast, progressive coding of moderate-resolution images. The design is based on a multiresolution, hierarchical, pyramidal structure. At each pyramid level, the binarized image is compared with the original, gray-tone image over a successively larger window of pixels...

Colour mixing by a halftoning process, as used for colour reproduction in graphic arts and many forms of digital hardcopy, is neither additive nor subtractive. Halftone colour reproduction with a given set of primary colours is heavily influenced not only by the colourimetric properties of the full-tone primaries, but also by effects such as optical and physical dot gain and the halftone geomet...

Undesired moiré patterns may appear in colour printing for various reasons. One of the most important reasons is interference between the superposed halftone screens of the different primary colours, due to an improper alignment of their frequencies or orientations. In this article we explain the superposition moiré phenomenon using a spectral model which is based on Fourier analysis. After exa...

We present a prediction model for digital printers and more specifically for electrophotographic devices. On the one hand, we propose an electrophotographic simulation model which estimates the microscopic structure of any printed toner layer based on its input halftone bitmap. Applying BOUGUER–BEER–LAMBERT’s law, the obtained spatial toner arrangement yields the spectral transmittance distribu...

The transmittance spectrum of halftone prints on paper is predicted thanks to a model inspired by the Yule-Nielsen modified spectral Neugebauer model used for reflectance predictions. This model is well adapted for strongly scattering printing supports and applicable to recto-verso prints. Model parameters are obtained by a few transmittance measurements of calibration patches printed on one si...

In this paper we propose the image segmentation incthod by the neural networks (NN) to extract text, continuous-tone and screened-halftone region in the document image. Each feature extractor for text, continuons-tone and screened-halftone is composed of the 3-layer NN which is upper part of 5-layer lio~irglass model NN; each hourglass model NN is trained by different learning samples which spe...

When a transparency printed with a first halftone color is deposited on top of a paper printed with a second halftone color, we obtain a third color that we are able to predict in both reflectance and transmittance modes, thanks to a spectral prediction model. The model accounts for the multiple reflections of light between the printed paper and the printed transparency, which are themselves de...

Moiré patterns often appear in the image obtained from scanning an image printed on a magazine or a newspaper. The patterns do not exist in the original printing but come from alias sampling of screened halftone pictures. A strategy to design a moiré suppression scanning procedure is proposed. Fourier analysis is presented for both the screening and the scanning processes, from which a formula ...

Digital watermarking has been widely used in copyright protection for digital images, but most of the watermarking algorithm can't resist print-and-scan process. Print-and-scan attack is a challenging problem for most of digital watermarks. A watermarking algorithm against print-and-scan attack based on PSO (Particle Swarm Optimization) is proposed in this paper. The watermark information is em...