Search results for "Video"

The impact of irreversible image data compression on post-processing algorithms in computed tomography

2020

PURPOSE: We aimed to evaluate the influence of irreversible image compression at varying levels on image post-processing algorithms (3D volume rendering of angiographs, computer-assisted detection of lung nodules, segmentation and volumetry of liver lesions, and automated evaluation of functional cardiac imaging) in computed tomography (CT). METHODS: Uncompressed CT image data (30 angiographs of the lower limbs, 38 lung exams, 20 liver exams and 30 cardiac exams) were anonymized and subsequently compressed using the JPEG2000 algorithm with compression ratios of 8:1, 10:1, and 15:1. Volume renderings of CT angiographies obtained from compressed and uncompressed data were compared using objec…

Low Complexity Image Compression using Pruned 8-point DCT Approximation in Wireless Visual Sensor Networks

2017

International audience; Since the transmission of the uncompressed image in the context of wireless visual sensor networks (WVSNs) consumes less energy than transmitting the compressed image, developing energy-aware compression algorithms are mandatory to extend the camera node's lifetime and thereby the whole network lifetime. The present paper studies a low-complexity image compression algorithm in the context of WVSNs. This algorithm consists of applying a pruning approach on a DCT approximation transform. The scheme is investigated in terms of computation cycles, processing time, energy consumption and image quality. Experimental works are conducted using the Atmel Atmega128 processor o…

A simple and efficient face detection algorithm for video database applications

2000

The objective of this work is to provide a simple and yet efficient tool to detect human faces in video sequences. This information can be very useful for many applications such as video indexing and video browsing. In particular the paper focuses on the significant improvements made to our face detection algorithm presented by Albiol, Bouman and Delp (see IEEE Int. Conference on Image Processing, Kobe, Japan, 1999). Specifically, a novel approach to retrieve skin-like homogeneous regions is presented, which is later used to retrieve face images. Good results have been obtained for a large variety of video sequences. Peer Reviewed

BlockSee: Blockchain for IoT video surveillance in smart cities

2018

The growing demand for safety in urban environments is supported by monitoring using video surveillance. The need to analyze multiple video-flows from different cameras deployed around the city by heterogeneous owners introduces vulnerabilities and privacy issues. Video frames, timestamps, and camera settings can be digitally manipulated by malicious users; the positions of cameras, their orientation and their mechanical settings can be physically manipulated. Digital and physical manipulations may have several effects, including the change of the observed scene and the potential violation of neighbors' privacy. To face these risks, we introduce BlockSee, a blockchain-based video surveillan…

TRECVID 2006 - An overview

2006

TRECVID 2005 - An Overview

2005

University Students as Composers of a Digital Video

2013

This paper introduces a university course in which digital video composing was used as a study method. The aim of the course was to empower future teachers to use digital and multimodal literacy practices in their own teaching. Students in education, 13 in total, participated in the course on digital literacies. The course achievement was measured with the task in which students composed a video in small-groups. The students’ videos were supposed to convince a pedagogical target group about the usefulness of a teaching method or need for a reform. In the last meeting, student’s videos were watched and the contents of the videos were discussed. The experiences on composing a digital video we…

Separating compound figures in journal articles to allow for subfigure classification

2013

Journal images represent an important part of the knowledge stored in the medical literature. Figure classification has received much attention as the information of the image types can be used in a variety of contexts to focus image search and filter out unwanted information or ”noise”, for example non–clinical images. A major problem in figure classification is the fact that many figures in the biomedical literature are compound figures and do often contain more than a single figure type. Some journals do separate compound figures into several parts but many do not, thus requiring currently manual separation. In this work, a technique of compound figure separation is proposed and implemen…

Parlons sécurité

2012

National audience; Les questions de sécurité publique sont au cœur de l’actualité française. En témoignent les lois d'orientation et de programmation pour la performance de la sécurité intérieure (dites LOPSI 1 et LOPPSI 2), le débat autour du fichier central d’identité biométrique ou encore celui sur la vidéosurveillance et les violences urbaines avec l’exemple anglais. Quels sont les enjeux et les réalités de la sécurité en France ? Pour sortir du brouhaha médiatique, « Entrez dans l’actu » vous présente l’éventail des informations en mesure de vous éclairer objectivement.

Computational imaging with a balanced detector

2016

Single-pixel cameras allow to obtain images in a wide range of challenging scenarios, including broad regions of the electromagnetic spectrum and through scattering media. However, there still exist several drawbacks that single-pixel architectures must address, such as acquisition speed and imaging in the presence of ambient light. In this work we introduce balanced detection in combination with simultaneous complementary illumination in a single-pixel camera. This approach enables to acquire information even when the power of the parasite signal is higher than the signal itself. Furthermore, this novel detection scheme increases both the frame rate and the signal-to-noise ratio of the sys…