High dynamic range imaging implementation in scene monitoring under bad illumination

Unapređenje kvaliteta slike širenjem dinamičkog opsega u poslednje vreme se intenzivno koristi. Ovo za posledicu ima prisustvo znatno više detalja na slici, što je jako bitno u većini primena. Širenje dinamičkog opsega ima svoje granice i one su definisane fizičkim limitima senzora koji se koristi, tj. ograničenjima njegovog A/D konvertora. Kada je dinamički opseg scene značajno širi od dinamičkog opsega senzora, mnogi detalji neće biti adekvatno prikazani na slici. Međutim, ukoliko senzor inherentno podržava široki dinamički opseg, jasno se može uočiti da je snimljena slika kvalitetnija od one koja se dobija sa standardnog senzora...Improving image quality by expanding the dynamic range is extensively used recently. This results in the presence of significantly more details in the picture, which is very important for most applications. Expanding the dynamic range has its limits, and they are defined by the physical limits of sensor used, i.e. the limits of its A / D converter. When the dynamic range of the scene is significantly wider than the dynamic range of the sensor, many details will not be shown properly in the picture. However, if the sensor inherently supports wide dynamic range, it can be clearly noticed that the recorded image quality is higher than the one obtained with the standard sensors..

Nouvelle génération de systèmes de vision temps réel à grande dynamique

Cette thèse s intègre dans le cadre du projet européen EUREKA "High Dynamic Range - Low NoiseCMOS imagers", qui a pour but de développer de nouvelles approches de fabrication de capteursd images CMOS à haute performance. L objectif de la thèse est la conception d un système de visiontemps réel à grande gamme dynamique (HDR). L axe principal sera la reconstruction, en temps réelet à la cadence du capteur (60 images/sec), d une vidéo à grande dynamique sur une architecturede calcul embarquée.La plupart des capteurs actuels produisent une image numérique qui n est pas capable de reproduireles vraies échelles d intensités lumineuses du monde réel. De la même manière, les écrans, impri-mantes et afficheurs courants ne permettent pas la restitution effective d une gamme tonale étendue.L approche envisagée dans cette thèse est la capture multiple d images acquises avec des tempsd exposition différents permettant de palier les limites des dispositifs actuels.Afin de concevoir un système capable de s adapter temporellement aux conditions lumineuses,l étude d algorithmes dédiés à la grande dynamique, tels que les techniques d auto exposition, dereproduction de tons, en passant par la génération de cartes de radiances est réalisée. Le nouveausystème matériel de type "smart caméra" est capable de capturer, générer et restituer du contenu àgrande dynamique dans un contexte de parallélisation et de traitement des flux vidéos en temps réelThis thesis is a part of the EUREKA European project called "High Dynamic Range - Low NoiseCMOS imagers", which developped new approaches to design high performance CMOS sensors.The purpose of this thesis is to design a real-time high dynamic range (HDR) vision system. Themain focus will be the real-time video reconstruction at 60 frames/sec in an embedded architecture.Most of the sensors produce a digital image that is not able to reproduce the real world light inten-sities. Similarly, monitors, printers and current displays do not recover of a wide tonal range. Theapproach proposed in this thesis is multiple acquisitions, taken with different exposure times, to over-come the limitations of the standard devices.To temporally adapt the light conditions, the study of algorithms dedicated to the high dynamic rangetechniques is performed. Our new smart camera system is able to capture, generate and showcontent in a highly parallelizable context for a real time processingDIJON-BU Doc.électronique (212319901) / SudocSudocFranceF

Use of high dynamic range images for improved medical simulations

Here we describe the use of high-dynamic range lighting techniques to improve the rendering quality of real-time medical simulation systems. Specifically we show our method of extracting the lighting information from an actual endoscopic light probe used for surgery and how we apply this lighting information into a real-time rendering system based on OpenGL and using Shaders to improve the realism of the probe's lighting in the scene; with the consideration that it is the only light source in the simulation