Polarimetric Multi-View Inverse Rendering

A polarization camera has great potential for 3D reconstruction since the angle of polarization (AoP) of reflected light is related to an object's surface normal. In this paper, we propose a novel 3D reconstruction method called Polarimetric Multi-View Inverse Rendering (Polarimetric MVIR) that effectively exploits geometric, photometric, and polarimetric cues extracted from input multi-view color polarization images. We first estimate camera poses and an initial 3D model by geometric reconstruction with a standard structure-from-motion and multi-view stereo pipeline. We then refine the initial model by optimizing photometric and polarimetric rendering errors using multi-view RGB and AoP images, where we propose a novel polarimetric rendering cost function that enables us to effectively constrain each estimated surface vertex's normal while considering four possible ambiguous azimuth angles revealed from the AoP measurement. Experimental results using both synthetic and real data demonstrate that our Polarimetric MVIR can reconstruct a detailed 3D shape without assuming a specific polarized reflection depending on the material.Comment: Paper accepted in ECCV 202

Neglected Tropical Diseases of the Middle East and North Africa: Review of Their Prevalence, Distribution, and Opportunities for Control

The neglected tropical diseases (NTDs) are highly endemic but patchily distributed among the 20 countries and almost 400 million people of the Middle East and North Africa (MENA) region, and disproportionately affect an estimated 65 million people living on less than US$2 per day. Egypt has the largest number of people living in poverty of any MENA nation, while Yemen has the highest prevalence of people living in poverty. These two nations stand out for having suffered the highest rates of many NTDs, including the soil-transmitted nematode infections, filarial infections, schistosomiasis, fascioliasis, leprosy, and trachoma, although they should be recognized for recent measures aimed at NTD control. Leishmaniasis, especially cutaneous leishmaniasis, is endemic in Syria, Iran, Iraq, Libya, Morocco, and elsewhere in the region. Both zoonotic (Leishmania major) and anthroponotic (Leishmania tropica) forms are endemic in MENA in rural arid regions and urban regions, respectively. Other endemic zoonotic NTDs include cystic echinococcosis, fascioliasis, and brucellosis. Dengue is endemic in Saudi Arabia, where Rift Valley fever and Alkhurma hemorrhagic fever have also emerged. Great strides have been made towards elimination of several endemic NTDs, including lymphatic filariasis in Egypt and Yemen; schistosomiasis in Iran, Morocco, and Oman; and trachoma in Morocco, Algeria, Iran, Libya, Oman, Saudi Arabia, Tunisia, and the United Arab Emirates. A particularly noteworthy achievement is the long battle waged against schistosomiasis in Egypt, where prevalence has been brought down by regular praziquantel treatment. Conflict and human and animal migrations are key social determinants in preventing the control or elimination of NTDs in the MENA, while local political will, strengthened international and intersectoral cooperative efforts for surveillance, mass drug administration, and vaccination are essential for elimination

Characterization of a reservoir in a south Algerian prospect using the instantaneous seismic attributes: efficiency and reliability of the instantaneous frequency parameter using the joint time-frequency analysis

Present day, exploration for oil and gas requires a combined effort based on the successful integration of the most part of geophysical methods for optimizing the location of data acquisition, identifying and evaluating the productive potential of unexplored regions or extending existing productive traps. Exploration seismology has been focussed on imaging the structural features of the Earth's subsurface. This approach is now commonplace in most seismic evaluation project due to the ability of this technique under favorable hypothesis to predict reservoirs properties (depth, lateral extension, discrimination between reservoir fluids ... ). However, after the fantastic software improvement, new robust processing tools (principally in signal processing techniques) have been developed for extracting indirect information provided by structure imaging. These new tools can significantly increase the probability of success associated with a given project. In this context, the success of direct hydrocarbons detection is primary due to the identification oflarge negative amplitudes known as bright spot which can define a necessary but not sufficient condition for identifying oil and gas pitfalls. Robust methods in volve computed and correlated sesimic attributes such as the instantaneous ones (intantaneous phase, instantaneous frequency, instantaneous amplitude, inversion polarity ... ) have enjoyed in many cases considerable suc cess for characterizing potential hydrocarbon traps. In the present work, we have precisely used a set of instantaneous attributes to characterize a reservoir located in a permit of the South Algerian Sahara.However, we take the following question: how about the efficiency and the reliability of each instantaneous seismic attribute ? To do this, the instantaneous frequency parameter has been selected because it provides a power indicator of the variations in the energy distribution of the sei smic signal, principally in a noisy environment. More recently, adapted signal processing tools are performed; one can cite the joint time-frequency analysis and its corollaries the Wigner-Ville Distribution, the Wigner bispectrum and the Pseudo-Wigner-Ville representation which are simultaneously tested in the present work on a noisy hyperbolic swept frequency signa

Transfer Phenomena During the Drying of a Shrinkable Product: Modeling and Simulation

International audienc

High repetition-rate sub-picosecond source of fibre-amplified vertical-external cavity surface-emitting semiconductor laser pulses

In this work we used a V-cavity VECSEL with InGaAs quantum-well-based gain and semiconductor saturable absorber mirror structures as described in S. Hoogland et al.(2005): an overall cavity length of 25 mm conferred a fundamental pulse repetition frequency of 5.9908 GHz, and the VECSEL emitted 1-ps pulses in a stable passively mode-locked train with 40 mW average power. Pulses from the VECSEL were then launched through a free space optical isolator into 2 m of Yb-doped fiber with an octagonal core and outer cladding diameters of 20 µm and 125 µm respectively (Liekki Yb 1200-20/125DC). The fiber was cladding-pumped by a 5-W fibre-coupled diode at 915 nm