Publications associées à Simultaneous Geometric and Radiometric Calibration of a Projector-Camera Pair

Assessing Analytical Methods for the Rapid Detection of Lead Adulteration in the Global Spice Market

Lead adulteration of spices, primarily via Pb chromate compounds, has been documented globally as a growing public health concern. Currently, Pb detection in spices relies primarily on expensive and time-consuming laboratory analyses. Advancing rapid Pb de ...

AMER CHEMICAL SOC2022

Precise and accurate image-based measurements of optical material properties

Marjan Shahpaski

The appearance of objects is governed by how they reflect, transmit and absorb the light they receive. That, in turn, depends on the material's internal structure, surface structure, and viewing and illumination directions. Changes in those characteristics ...

EPFL2020

Aliasing mitigation in optical microscopy of dynamic biological samples by use of temporally modulated color illumination and a standard RGB camera

Michael Stefan Daniel Liebling, Christian Jaques

Significance: Despite recent developments in microscopy, temporal aliasing can arise when imaging dynamic samples. Modern sampling frameworks, such as generalized sampling, mitigate aliasing but require measurement of temporally overlapping and potentially ...

SPIE Society of Photo-optical Instrumentation Engineers2020

Spinning operators and defects in conformal field theory

Marco Meineri

We study the kinematics of correlation functions of local and extended operators in a conformal field theory. We present a new method for constructing the tensor structures associated to primary operators in an arbitrary bosonic representation of the Loren ...

Springer Nature2019

Context-based Quality of Experience in Immersive Multimedia

Anne-Flore Nicole Marie Perrin

Since 1895, when the Lumière brothers came out with the projected cinematograph, motion pictures and more generally multimedia contents have considerably improved and are still experiencing a very dynamic development. Advances involved improving various mo ...

EPFL2019

Temporal Super-Resolution Microscopy Using a Hue-Encoded Shutter

Michael Stefan Daniel Liebling, Sylvain Calinon, Christian Jaques, Emmanuel Pignat

Limited time-resolution in microscopy is an obstacle to many biological studies. Despite recent advances in hardware, digital cameras have limited operation modes that constrain frame-rate, integration time, and color sensing patterns. In this paper, we pr ...

2019

Wide Gamut Spectral Upsampling with Fluorescence

Wenzel Alban Jakob

Physically based spectral rendering has become increasingly important in recent years. However, asset textures in such systems are usually still drawn or acquired as RGB tristimulus values. While a number of RGB to spectrum upsampling techniques are availa ...

2019

Magic Prints: Image-Changing Prints Observed under Visible and 365 nm UV Light

Petar Pjanic, Marjan Shahpaski

In this paper we propose a novel layered-printing method consisting of superposed visible cmy and invisible fluorescent ultraviolet (UV) rgb inks. Our approach can be used to generate a variety of visual color-alteration effects such as revealing two compl ...

I S & T-SOC IMAGING SCIENCE TECHNOLOGY2019

Color changing effects with cross-halftone prints on metal

Roger Hersch, Petar Pjanic

We propose new methods for creating color varying prints with classical cyan, magenta, yellow inks on a metallic substrate. We use a special crossline halftone with optimized surface coverages of the inks to create color prints on a metallic surface whose ...

2017

Color Representation in Deep Neural Networks

Sabine Süsstrunk, Martin Pierre Engilberge, Edo Collins

Convolutional neural networks are top-performers on image classification tasks. Understanding how they make use of color information in images may be useful for various tasks. In this paper we analyze the representation learned by a popular CNN to detect a ...

2017

A high sensitivity, low noise and high spatial resolution multi-band infrared reflectography camera for the study of paintings and works on paper

Marie Eve Pascale Didier

Background: Infrared reflectography (IRR) remains an important method to visualize underdrawing and compositional changes in paintings. Older IRR camera systems are being replaced with near-infrared cameras consisting of room temperature infrared detector ...

Biomed Central Ltd2017

JPEG XT: A Compression Standard for HDR and WCG Images [Standards in a Nutshell]

Touradj Ebrahimi, Philippe Hanhart

High bit depth data acquisition and manipulation have been largely studied at the academic level over the last 15 years and are rapidly attracting interest at the industrial level. An example of the increasing interest for high-dynamic range (HDR) imaging ...

Institute of Electrical and Electronics Engineers2016

Color Changing Prints on a Metallic Substrate

Petar Pjanic

Printing on a flat metallic substrate has gained popularity in recent years. The reflection of light on a specularly reflecting metallic substrate differs strongly from the reflection of light on a diffusely reflecting medium such as paper. Direct prints o ...

EPFL2016

Evaluation of Color Mapping Algorithms in Different Color Spaces

Touradj Ebrahimi

The color gamut supported by current commercial displays is only a subset of the full spectrum of colors visible by the human eye. In High-Definition (HD) television technology, the scope of the supported colors covers 35.9% of the full visible gamut. For ...

Spie-Int Soc Optical Engineering2016

Color reproduction, pattern hiding and image alternations with halftone prints on metal

Roger Hersch, Petar Pjanic

We propose new methods for creating color or achromatic images that are printed with classical cyan, magenta, yellow and a white diffusing ink on a metallic substrate. We optimize the surface coverages of the cyan, magenta, yellow and white inks in order t ...

2016

Gradient-Based Correction of Chromatic Aberration in the Joint Acquisition of Color and Near-Infrared Images

Sabine Süsstrunk, Yue Lu, Zahra Sadeghipoor Kermani

Chromatic aberration distortions, such as wavelength-dependent blur caused by imperfections in photographic lenses, have long been studied in color imaging. The problem becomes more challenging to solve in the case of color and near-infrared joint acquisit ...

Spie-Int Soc Optical Engineering2015

Joint Acquisition of Color and Near-Infrared Images on a Single Sensor

Zahra Sadeghipoor Kermani

In the past few years, fusing NIR and color images has been explored in general computational photography and computer vision tasks, where traditionally only color images are used. The additional information provided by the differences of light and scene r ...

EPFL2015

Multiscale guided deblurring: Chromatic aberration correction in color and near-infrared imaging

Sabine Süsstrunk, Yue Lu, Zahra Sadeghipoor Kermani

Chromatic aberration, caused by photographic lens imperfections, results in the image of only one spectral channel being sharp, while the other channels are blurred depending on their wavelengths difference with the sharp channel. We study chromatic aberra ...

2015

Semantic-Improved Color Imaging Applications: It Is All About Context

Sabine Süsstrunk, Albrecht Johannes Lindner

Multimedia data with associated semantics is omnipresent in today’s social online platforms in the form of keywords, user comments and so forth. This article presents a statistical framework designed to infer knowledge in the imaging domain from the semant ...

2015

Color Reproduction of Authenticable Luminescent Backlit Transmissive Color Images

Roger Hersch, Julien Alexandre Andres

We propose a method for creating authenticable color images under UV excitation backlight by printing an invisible luminescent white emissive ink layer on the verso side of a transmissive substrate and a classical cmy image on the recto side of the substra ...

Wiley-Blackwell2014