Smart camera design for realtime high dynamic range imaging

Many camera sensors suffer from limited dynamic range. The result is that there is a lack of clear details in displayed images and videos. This paper describes our approach to generate high dynamic range (HDR) from an image sequence while modifying exposure times for each new frame. For this purpose, we propose an FPGA-based architecture that can produce a real-time high dynamic range video from successive image acquisition. Our hardware platform is build around a standard low dynamic range CMOS sensor and a Virtex 5 FPGA board. The CMOS sensor is a EV76C560 provided by e2v. This 1.3 Megapixel device offers novel pixel integration/readout modes and embedded image pre-processing capabilities including multiframe acquisition with various exposure times, approach consists of a pipeline of different algorithmic phases: automatic exposure control during image capture, alignment of successive images in order to minimize camera and objects movements, building of an HDR image by combining the multiple frames, and final tonemapping for viewing on a LCD display. Our aim is to achieve a realtime video rate of 25 frames per second for a full sensor resolution of 1, 280 X 1, 024 pixels

Bioclimatic building design considering urban microclimate

International audienc

Bioclimatic building design considering urban microclimate

International audienc

Construction d’un fichier microclimatique urbain utilisable en STD

International audienc

Construction d’un fichier microclimatique urbain utilisable en STD

International audienc

Real-time ghost free HDR video stream generation using weight adaptation based method

International audienceTemporal exposure bracketing is a simple and low cost technique to generate a high dynamic range (HDR) images. This technique is widely used to recover the whole dynamic range of a scene by selecting the adequate number of low dynamic range (LDR) images to be fused. Temporal exposure bracketing technique is introduced to be used for static scenes and it cannot be applied directly for dynamic scenes since camera or object motion in bracketed exposures creates ghosts in the resulting HDR image. In this paper we propose a HDR algorithm modification to remove ghost artifact and we present a real-time implementation of this method on a smart camera (HDR video stream 1280 x 1024 at 60fps). We present experimental results to show the ghost removing efficiency of our implemented method

Behavior-dependent specialization of identified hippocampal interneurons.

A large variety of GABAergic interneurons control information processing in the hippocampal circuits governing the formation of neuronal representations. Whether distinct hippocampal interneuron types contribute differentially to information processing during behavior is not known. We employed a new technique for recording and labeling interneurons and pyramidal cells in drug-free, freely moving rats. Recorded parvalbumin-expressing basket interneurons innervated somata and proximal pyramidal cell dendrites, whereas nitric oxide synthase- and neuropeptide Y-expressing ivy cells provided synaptic and extrasynaptic dendritic modulation. Basket and ivy cells showed distinct spike-timing dynamics, firing at different rates and times during theta and ripple oscillations. Basket, but not ivy, cells changed their firing rates during movement, sleep and quiet wakefulness, suggesting that basket cells coordinate cell assemblies in a behavioral state-contingent manner, whereas persistently firing ivy cells might control network excitability and homeostasis. Different interneuron types provide GABA to specific subcellular domains at defined times and rates, thereby differentially controlling network activity during behavior