Coherent motions, which represent coherent movements of massive individual particles, are pervasive in natural and social scenarios. Examples include traffic flows and parades of people (cf. Figs 1a and 2a). Since coherent motions can effectively decompose scenes into meaningful semantic parts and facilitate the analysis of complex crowd scenes, they are of increasing importance in crowd-scene ...

In this paper we present an original method mixing temporal and spectral processing to reduce the phasiness in the phase vocoder. Phasiness is an inherent artifact of the phase vocoder that appears when a sound is slowed down. The audio is perceived as muffled, reverberant and/or moving away from the microphone. This is due to the loss of coherence between the phases across the bins of the Shor...

Local features are widely used for content-based image retrieval and augmented reality applications. Typically, feature descriptors are calculated from the gradients of a canonical patch around a repeatable keypoint in the image. In this paper, we propose a temporally coherent keypoint detector and design e±cient interframe predictive coding techniques for canonical patches and keypoint locatio...

We have demonstrated a proof-of-principle experiment of reference-frame-independent phase coding quantum key distribution (RFI-QKD) over an 80-km optical fiber. After considering the finite-key bound, we still achieve a distance of 50 km. In this scenario, the phases of the basis states are related by a slowly time-varying transformation. Furthermore, we developed and realized a new decoy state...

Moving objects detection is a crucial step for video surveillance systems. The segmentation performed by motion detection algorithms is often noisy, which makes it hard to distinguish between relevant motion and noise motion. This article describes a new approach to make such a distinction using principal component analysis (PCA), a technique not commonly used in this domain. We consider a ten-...

Consistent belief functions represent collections of coherent or non-contradictory pieces of evidence, but most of all they are the counterparts of consistent knowledge bases in belief calculus. The use of consistent transformations cs[·] in a reasoning process to guarantee coherence can therefore be desirable, and generalizes similar techniques in classical logics. Transformations can be obtai...

Electron correlation microscopy (ECM) is a way to measure structural relaxation times, τ, of liquids with nanometer-scale spatial resolution using coherent electron scattering equivalent of photon correlation spectroscopy. We have applied ECM with a 3.5nm diameter probe to Pt57.5Cu14.7Ni5.3P22.5 amorphous nanorods and Pd40Ni40P20 bulk metallic glass (BMG) heated inside the STEM into the superco...

Establishing correspondence between features of a set of images has been a long-standing issue amongst the computer vision community. We propose a method that solves the multi-frame correspondence problem by imposing a rank constraint on the observed scene, i.e. rigidity is assumed. Since our algorithm is based solely on a geometrical (global) criterion, it does not suffer from issues usually a...

Maintaining a coherent percept of the visual scene while eye position continuously changes requires that saccades be accompanied by remapping of the visual environment. We studied saccadic remapping in patients with unilateral lesions in the intraparietal sulcus and healthy controls, using inhibition of return (IOR)-an inhibitory tag that enables efficient visual search. In healthy controls, IO...