Publications related to Autofocus

DeepFocus: a Few-shot Microscope Slide Auto-Focus using a Sample Invariant CNN-based Sharpness Function

Michael Stefan Daniel Liebling, Adrian Shajkofci

Autofocus (AF) methods are extensively used in biomicroscopy, for example to acquire timelapses, where the imaged objects tend to drift out of focus. AF algorithms determine an optimal distance by which to move the sample back into the focal plane. Current ...

2020

Hough Forest With Optimized Leaves for Global Hand Pose Estimation With Arbitrary Postures

Daniel Thalmann, Hui Liang, Jun Lee

Vision-based hand pose estimation is important in human-computer interaction. While many recent works focus on full degree-of-freedom hand pose estimation, robust estimation of global hand pose remains a challenging problem. This paper presents a novel alg ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2019

WILDTRACK: A Multi-camera HD Dataset for Dense Unscripted Pedestrian Detection

Pascal Fua, Tatjana Chavdarova, François Fleuret, Andrii Maksai, Cijo Jose, Stéphane Bouquet

People detection methods are highly sensitive to occlusions between pedestrians, which are extremely frequent in many situations where cameras have to be mounted at a limited height. The reduction of camera prices allows for the generalization of static mu ...

IEEE2018

Obstacle detection for lake-deployed autonomous surface vehicles using RGB imagery

David Andrew Barry, Philippe Olivier Paccaud

We describe and test an obstacle-detection system for small, lake-deployed autonomous surface vehicles (ASVs) that relies on a low-cost, consumer-grade camera and runs on a single-board computer. A key feature of lakes that must be accounted for is the fre ...

2018

Position and mode dependent optical detection back-action in cantilever beam resonators

Luis Guillermo Villanueva Torrijo, Tom Larsen

Optical detection back-action in cantilever resonant or static detection presents a challenge when striving for state-of-the-art performance. The origin and possible routes for minimizing optical back-action have received little attention in literature. He ...

Institute of Physics2017

Near-Infrared High-Resolution Real-Time Omnidirectional Imaging Platform for Drone Detection

Yusuf Leblebici, Vladan Popovic

Recent technological advancements in hardware systems have made higher quality cameras. State of the art panoramic systems use them to produce videos with a resolution of 9000 x 2400 pixels at a rate of 30 frames per second (fps).(1) Many modern applicatio ...

Spie-Int Soc Optical Engineering2016

Vision-Based Unmanned Aerial Vehicle Detection and Tracking for Sense and Avoid Systems

Pascal Fua, Denis Gillet, Alcherio Martinoli, Vincent Lepetit, Artem Rozantsev, Steven Adriaan Roelofsen, Krishna Raj Sapkota

We propose an approach for on-line detection of small Unmanned Aerial Vehicles (UAVs) and estimation of their relative positions and velocities in the 3D environment from a single moving camera in the context of sense and avoid systems. This problem is cha ...

Ieee2016

Estimating Fusion Weights of a Multi-Camera Eye Tracking System by Leveraging User Calibration Data

Jean-Philippe Thiran, Nuri Murat Arar

Cross-ratio (CR)-based eye tracking has been attracting much interest due to its simple setup, yet its accuracy is lower than that of the model-based approaches. In order to improve the estimation accuracy, a multi-camera setup can be exploited rather than ...

Assoc Computing Machinery2016

Curved Holographic Combiner for Color Head Worn Display

Jürgen Brugger, Christophe Moser, Eric Tremblay, Victor Javier Cadarso Busto, Jonas Grossenbacher, Arnaud Mader, Seyedpayam Vahdati

A volume hologram recorded with a lens array is proposed as a color transflective screen for Head Worn Display (HWD) systems. Design, fabrication as well as proof of concept are reported. Light from a single MEMS-based projector is efficiently diffracted t ...

Ieee-Inst Electrical Electronics Engineers Inc2014

Dynamic control of light transmission through multimode fibers

Ioannis Papadopoulos

In the present thesis we demonstrate how under the appropriate dynamic control of light propagation, multimode fibers can be transformed into deterministic optical elements that along with their ultrathin size, large number of degrees of freedom and high N ...

EPFL2014

Firefly Light Flashing: Oxygen Supply Mechanism

Giorgio Margaritondo

Firefly luminescence is an intriguing phenomenon with potential technological applications, whose biochemistry background was only recently established. The physics side of this phenomenon, however, was still unclear, specifically as far as the oxygen supp ...

2014

Optical reconstruction of transparent objects with phase-only SLMs

Christian Depeursinge, Yves Delacrétaz, Cristian Arfire

Three approaches for visualization of transparent micro-objects from holographic data using phase-only SLMs are described. The objects are silicon micro-lenses captured in the near infrared by means of digital holographic microscopy and a simulated weakly ...

Optical Soc Amer2013

Curved Transflective Holographic Screens for Head-Mounted Display

Jürgen Brugger, Christophe Moser, Eric Tremblay, Arnaud Mader, Victor Javier Cadarso Busto, Jonas Grossenbacher, Seyedpayam Vahdati

A volume hologram recorded with a lens array is proposed as a transflective screen for Head Worn Display (HWD) systems. Design, fabrication as well as proof of concept are reported. Light from a projection system, with similar properties to one mounted on ...

Spie-Int Soc Optical Engineering2013

A Spherical Multi-camera System with Real-time Omnidirectional Video Acquisition Capability

Alexandre Schmid, Yusuf Leblebici, Vladan Popovic, Hossein Afshari

A multi-camera system inspired from the visual system of flying insects is introduced which is referred to as the Panoptic camera. In the Panoptic system each camera is mounted over a hemispherical geometry and has its own vision of surrounding and distinc ...

Institute of Electrical and Electronics Engineers2012

A speckle-based CMOS sensor array for arbitrary surface movement detection

Pierre-André Farine, Chao Wang, Steve Tanner

The paper presents a CMOS sensor array for the detection of speckle movements, for applications requiring accurate movement tracking of arbitrary surfaces. The array is made of eight sensors incorporating each a spatial comb filter with a pitch of 2.8μm so ...

SPIE Society2011

Polymer-electrolyte gated graphene transistors for analog and digital phase detection

Klaus Kern, Marko Burghard, Kannan Balasubramanian, Adarsh Singh Sagar

We present an alternating current (ac) circuit based on a misoriented bilayer graphene device for analog and digital phase detection. We exploit the ambipolar nature of the transfer characteristics of a misoriented bilayer graphene transistor. The transist ...

AIP American Institute of Physics2011

Controlling spectral response of photodetector for an image sensor

Edoardo Charbon, Cristiano Niclass

A method for controlling the spectral response of light sensitive semiconductor elements in an array (8) using an electric control signal (Vop) applied to said semiconductor elements. The light sensitive semiconductor elements could be a single photon aval ...

2010

Small-size microlens characterization by multiwavelength high-resolution interference microscopy

Hans Peter Herzig, Toralf Scharf, Myun Sik Kim

Microlenses are widely studied in two main areas: fabrication and characterization. Nowadays, characterization draws more attention because it is difficult to apply test techniques to microlenses that are used for conventional optical systems. Especially, ...

Optical Society of America2010

Autofluorescence bronchoscopy: quantification of inter-patient variations of fluorescence intensity

Hubert van den Bergh, Georges Wagnières, Tanja Gabrecht, Blaise Lovisa

Autofluorescence (AF) from bronchial tissue is increasingly used for the endoscopic detection of early bronchial neoplasia. Several imaging systems are commercially available, all detecting the absolute or relative AF intensity and/or spectral contrasts be ...

Springer-Verlag2009

Single-Photon Synchronous Detection

Edoardo Charbon, Ties Jan Henderikus Kluter, Cristiano Niclass, Claudio Favi, Frédéric Monnier

Phase and intensity of light are detected simultaneously using a fully digital imaging technique: single-photon synchronous detection. This approach has been theoretically and experimentally investigated in this paper. We designed a fully integrated camera ...

2009