Lippmann Photography: A Signal Processing Perspective

Lippmann (or interferential) photography is the first and only analog photography method that can capture the full color spectrum of a scene in a single take. This technique, invented more than a hundred years ago, records the colors by creating interference patterns inside the photosensitive plate. Lippmann photography provides a great opportunity to demonstrate several fundamental concepts in signal processing. Conversely, a signal processing perspective enables us to shed new light on the technique. In our previous work, we analyzed the spectra of historical Lippmann plates using our own mathematical model. In this paper, we provide the derivation of this model and validate it experimentally. We highlight new behaviors whose explanations were ignored by physicists to date. In particular, we show that the spectra generated by Lippmann plates are in fact distorted versions of the original spectra. We also show that these distortions are influenced by the thickness of the plate and the reflection coefficient of the reflective medium used in the capture of the photographs. We verify our model with extensive experiments on our own Lippmann photographs.Comment: 12 pages, 18 figures, to be published in Transactions in Signal Processin

Arbitrage transnational et droit international général (2016)

National audience[No abstract

Development of a hyperspectral camera

The audiovisual communications laboratory (lcav.epfl.ch) is looking for students for the development of an interferential hyperspectral camera, as part of a semester project. It involves building, testing and improving, in collaboration with the scientific and technical team, a portable prototype based on a principle already successfully tested on an optical table. The ideal candidates would be trained in mechanics, electronics, embedded systems or optics

Guessing the fingerings from musical recordings

Synopsis: This project is about using musical recordings of string instruments to determine on which strings notes have been played. It includes the study of the spectral content of the recordings and the development of a robust classification algorithm. LCAV20170911 Level: BS, MS Description: In a string instrument such as a guitar or a violin, most notes and some chords can be played using different fingerings. The art of establishing fingering patterns being a key component of the mastery of string instruments, knowing the ones that were used to play musical recordings will push the limits in musical studies and training. The goal of this project is to build a digital audio device capable of detecting the string(s) used to play each note (chord) in a recording of such an instrument, thus bringing the user one step closer to knowing the fingerings. Musicians choose their fingering according to different criterions. On one hand, the choice of the finger which stops the string on the fingerboard is primarily dictated by technical and physiological reasons. On the other hand, the choice of the instrument’s string on which the note is played, while also depending on the above aspects, is mostly based on the seeked tone quality. Indeed, different strings have different timbral and loudness ranges, transient behaviour, and harmonicity. Furthermore, the fingering of a music piece is globally optimized in order to enhance phrasing, harmony and consistency while maintaining execution complexity at a reasonable level. The student will start by getting familiar with the subject and the project’s current state, which includes a database of samples of single notes played on a guitar and an inharmonicity-based classification algorithm. The quality of both the dataset and the algorithm should be determined with respect to quantitative criterions for robust string discrimination that should be established. The improved algorithm will then be extended towards at least one of these directions: unfretted instruments (e.g. violin) polyphony (intervals and chords) sequences of notes (melodies) Deliverables: project report Functional python code for classification Prerequisites: The student should have knowledge in basic acoustics, signal processing, linear algebra and python coding. Ideally, he/she has strong interest in music or practices it. Type of Work: 50% theory and 50% programming <br

Arbitrage transnational et droit international général (2013)

National audienceà veni

Arbitrage transnational et droit international général

Jacob Patrick, Latty Franck, Nanteuil Arnaud de. Arbitrage transnational et droit international général. In: Annuaire français de droit international, volume 61, 2015. pp. 857-909

ARBITRAGE D'INVESTISSEMENT ET DROIT INTERNATIONAL GÉNÉRAL (2017)

International audiencePour sa dixième livraison, la présente chronique change légèrement de nom. Son objet reste bien le même : il s'agit d'extraire des nombreuses décisions rendues chaque année par les tribunaux arbitraux compétents en matière d'investisse-ment 1 la substantifique moelle qui intéresse non pas le droit des investissements en particulier mais bien le droit international général 2. « Arbitrage transnational et droit international général » devient néanmoins « Arbitrage d'investissement et droit international général », ce pour diverses raisons. L'expression « arbitrage transnational » est liée au contexte du développement du contentieux relatif aux contrats d'États dans la seconde moitié du XX e siècle 3. Elle repose sur la nature mixte des parties à l'arbitrage (État et investisseur) et non sur son objet (l'investissement étranger). Si, en ce premier quart du XXI e siècle, les parties à ces arbitrages sont les mêmes (investisseur étranger, demandeur dans la quasi-totalité des cas

Arbitrage transnational et droit international général (2014)

National audienceà veni

Arbitrage d’investissement et droit international général

International audienc

Arbitrage transnational et droit international général (2016)

Jacob Patrick, Latty Franck, Nanteuil Arnaud de. Arbitrage transnational et droit international général (2016). In: Annuaire français de droit international, volume 62, 2016. pp. 587-650