Publications de Thomas Bugnon | EPFL Graph Search

Recovering Neugebauer colorant reflectances and Ink-spreading curves from printed color images

Spectral reflection prediction models, although effective, are impractical for certain industrial applications such as self-calibrating devices and online monitoring because their calibration requires specific color-constant calibration patches. Using the ...

Wiley-Blackwell2014

Constrained Acquisition of Ink Spreading Curves From Printed Color Images

Roger Hersch, Thomas Bugnon

Today's spectral reflection prediction models are able to predict the reflection spectra of printed color images with an accuracy as high as the reproduction variability allows. However, to calibrate such models, special uniform calibration patches need to ...

2011

Flexible and Robust Calibration of the Yule-Nielsen Model for CMYK Prints

Thomas Bugnon

Spectral reflection prediction models, although effective, are impractical for certain industrial applications such as self-calibrating devices and online monitoring because of the requirements imposed by their calibration. The idea emerged to make the cal ...

EPFL2011

Enhancing the Specular Effect of Metallic Color Prints by Reducing the Use of Yellow Ink

Roger Hersch, Thomas Bugnon, Andrea Maesani

The MetallicArt technique is used as a visual security feature to hide patterns in CMY images using an additional silver ink. The patterns are hidden under nonspecular viewing conditions and visible under specular viewing conditions. By varying the amount ...

2011

Deducing Ink Thickness Variations by a Spectral Prediction Model

Roger Hersch, Safer Mourad, Thomas Bugnon, Peter Amrhyn, Mathieu Brichon, Frédérique Crété

Most existing techniques for regulating the ink flow in offset presses rely oil density measurements carried out oil specially printed patches. In the present contribution. we develop a methodology to deduce ink thickness variations from spectral measureme ...

Wiley-Blackwell2009

Deducing Ink Spreading Curves from Reflection Spectra Acquired Within Printed Color Images

Roger Hersch, Thomas Bugnon, Mathieu Hébert, Mathieu Brichon

The Yule–Nielsen modified spectral Neugebauer model (YNSN) enhanced for accounting for ink spreading in the different ink superposition conditions provides accurate spectral predictions, but requires one to measure the reflectances of special halftone cali ...

2009

Spectral prediction model for variable dot-size printers

Roger Hersch, Thomas Bugnon

By printing a variable number of droplets onto the same pixel location, ink jet printers produce pixels at variable dot-sizes yielding several darkness levels. Varying the number of printed droplets affects the ink volume deposited onto the substrate. In t ...

2008

Simplified Ink Spreading Equations for CMYK Halftone Prints

Roger Hersch, Thomas Bugnon, Mathieu Brichon

The Yule-Nielsen modified spectral Neugebauer model enables predicting reflectance spectra from surface coverages. In order to provide high prediction accuracy, this model is enhanced with an ink spreading model accounting for physical dot gain. Traditiona ...

2008

Model-Based deduction of CMYK Surface Coverages from Visible and Infrared Spectral Measurements of Halftone Prints

Roger Hersch, Thomas Bugnon, Mathieu Brichon

The Yule-Nielsen modified Spectral Neugebauer reflection prediction model enhanced with an ink spreading model provides high accuracy when predicting reflectance spectra from ink surface coverages. In the present contribution, we try to inverse the model, ...

2007