Publications associées à Perspective (représentation)

Perspective Aware Road Obstacle Detection

Pascal Fua, Mathieu Salzmann, Krzysztof Maciej Lis, Sina Honari

While road obstacle detection techniques have become increasingly effective, they typically ignore the fact that, in practice, the apparent size of the obstacles decreases as their distance to the vehicle increases. In this letter, we account for this by c ...

2023

Detecting Anomalies and Obstacles in Road Scenes

Krzysztof Maciej Lis

We address the problem of segmenting anomalies and unusual obstacles in road scenes for the purpose of self-driving safety. The objects in question are not present in the common training sets as it is not feasible to collect and annotate examples for every ...

EPFL2023

Proofs, Circuits, and Communication

Mika Tapani Göös

We survey lower-bound results in complexity theory that have been obtained via newfound interconnections between propositional proof complexity, boolean circuit complexity, and query/communication complexity. We advocate for the theory of total search prob ...

2022

Penalized denoising of vehicle trajectories collected by a swarm of drones

Nikolaos Geroliminis, Emmanouil Barmpounakis, Georgios Anagnostopoulos

Vehicle trajectory datasets collected in urban traffic environments with drones pose unique chal- lenges in terms of denoising due to extensive visual restrictions, perspective distortions and human- induced errors. This article taps into the unexplored po ...

2022

Human-Centered Scene Understanding via Crowd Counting

Weizhe Liu

Human-centered scene understanding is the process of perceiving and analysing a dynamic scene observed through a network of sensors with emphasis on human-related activities. It includes the visual perception of human-related activities from either single ...

EPFL2021

Discrete metal nanoparticles with plasmonic chirality

Jijun He

From a geometrical perspective, a chiral object does not have mirror planes or inversion symmetry. It exhibits the same physical properties as its mirror image (enantiomer), except for the chiroptical activity, which is often the opposite. Recent advanceme ...

Royal Society of Chemistry2021

Multi-View Triangulation: Systematic Comparison and an Improved Method

Peng Song

Triangulation is an important task in the 3D reconstruction of computer vision. It seems simple to find the position of a point in 3D space when its 2D perspective projections in multi-view images are given and the corresponding camera projection matrices ...

2020

Geometric and Physical Constraints for Drone-Based Head Plane Crowd Density Estimation

Pascal Fua, Mathieu Salzmann, Weizhe Liu, Krzysztof Maciej Lis

State-of-the-art methods for counting people in crowded scenes rely on deep networks to estimate crowd density in the image plane. While useful for this purpose, this image- plane density has no immediate physical meaning because it is subject to perspecti ...

IEEE2019

Closed-Form Solution to Disambiguate Defocus Blur in Single-Perspective Images

Sabine Süsstrunk, Majed El Helou, Marjan Shahpaski

Depth-from-defocus techniques suffer an ambiguity problem where depth planes on opposite sides of the focal plane have identical defocus. We solve the ambiguity by relying on the wavelength-dependent relationship between defocus and depth. We conduct a rob ...

2019

Solving the Depth Ambiguity in Single-Perspective Images

Sabine Süsstrunk, Majed El Helou, Marjan Shahpaski

Scene depth estimation is gaining in importance as more and more AR/VR and robot vision applications are developed. Conventional depth-from-defocus techniques can passively provide depth maps from a single image. This is especially advantageous for moving ...

2019

Robustness of Classifiers to Universal Perturbations: A Geometric Perspective

Pascal Frossard, Seyed Mohsen Moosavi Dezfooli, Alhussein Fawzi

Deep networks have recently been shown to be vulnerable to universal perturbations: there exist very small image-agnostic perturbations that cause most natural images to be misclassified by such classifiers. In this paper, we provide a quantitative analysi ...

2018

Embodiment Sensitivity to Movement Distortion and Perspective Taking in Virtual Reality

Henrique Galvan Debarba

Despite recent technological improvements of immersive technologies, Virtual Reality suffers from severe intrinsic limitations, in particular the immateriality of the visible 3D environment. Typically, any simulation and manipulation in a cluttered environ ...

EPFL2017

GDSP: A graphical perspective on the distributed storage systems

Michael Christoph Gastpar, Saeid Sahraei

The classical distributed storage problem can be modeled by a k-uniform complete hyper-graph where vertices represent servers and hyper-edges represent users. Hence each hyper-edge should be able to recover the full file using only the memories of the vert ...

2017

SHAPE: Linear-Time Camera Pose Estimation With Quadratic Error-Decay

Martin Vetterli, Adam James Scholefield, Alireza Ghasemi

We propose a novel camera pose estimation or perspective-n-point (PnP) algorithm, based on the idea of consistency regions and half-space intersections. Our algorithm has linear time-complexity and a squared reconstruction error that decreases at least qua ...

Ieee2016

Massive Open Online Courses: Current State and Perspective

Pierre Dillenbourg

10.4230/DagMan.4.1.1 ...

Schloss Dagstuhl--Leibniz-Zentrum fuer Informatik2014

Plenoptic Spherical Sampling

Pascal Frossard, Pierre Vandergheynst, Luigi Bagnato

We present a novel plenoptic sampling scheme that permits an efficient representation of the full light ray field in a space limited by a convex closed surface. We show that a convenient way to sample the light ray field around an observer consists in usin ...

2012

Sparse stereo image coding with learned dictionaries

Pascal Frossard, Ivana Tosic, Dimitri Palaz

This paper proposes a framework for stereo image coding with effective representation of geometry in 3D scenes. We propose a joint sparse approximation framework for pairs of perspective images that are represented as linear expansions of atoms selected fr ...

2011

Analysis of Multiview Omnidirectional Images in a Spherical Framework

Zafer Arican

With the increasing demand of information for more immersive applications such as Google Street view or 3D movies, the efficient analysis of visual data from cameras has gained more importance. This visual information permits to extract some crucial inform ...

EPFL2010

IA Generative Model for True Orthorectification

Pascal Fua, Christoph Strecha

Orthographic images compose an efficient and economic way to represent aerial images. This kind of information allows to measure two-dimensional objects and relate these to Geographic Information Systems. This paper deals with the computation of a true ort ...

2008

Surface extraction and flattening for anatomical visualization

Laurent Saroul

In the last years, three-dimensional (3D) medical imaging techniques have taken an increasing importance in patient care and medical research. Volume images provide medical specialists with a direct access to the interior of a patient's body and reduce the ...

EPFL2006