Search results for " Dynamic range"
showing 10 items of 24 documents
Real-time High Dynamic Range based on Multiple Non Destructive ReadOut during a Single Exposure
2017
This paper presents a new method based on Non Destructive Readout (NDRO) to improve multi-exposure High Dynamic Range (HDR) Imaging. A sequence of Low-Dynamic Range (LDR) images can then be acquired during a single exposure. The concept enables the latency between LDR images to be removed as well as the intrinsic ghost artifacts observed using state-of-art HDR systems based on multi-exposures. The method has been applied to improve the performances of HDR sensor based on logarithmic pixels. Using the NDRO method, a Short Wave InfraRed (SWIR) camera has been designed to produce HDR IR videos. A real-time HDR video stream generation is achieved based on GPU implantation.
Digital background calibration algorithm and its FPGA implementation for timing mismatch correction of time-interleaved ADC
2019
Sample time error can degrade the performance of time-interleaved analog to digital converters (TIADCs). A fully digital background algorithm is presented in this paper to estimate and correct the timing mismatch errors between four interleaved channels, together with its hardware implementation. The proposed algorithm provides low computation burden and high performance. It is based on the simplified representation of the coefficients of the Lagrange interpolator. Simulation results show that it can suppress error tones in all of the Nyquist band. Results show that, for a four-channel TIADC with 10-bit resolution, the proposed algorithm improves the signal to noise and distortion ratio (SN…
SAVU: A Statistical Approach for Uncertain Data in Dynamics of Axially Moving Materials
2012
In physics and engineering problems, model input is never exact. The effect of small uncertainties on the solution is thus an important question. In this study, a direct statistical-visual approach to approximate the solution set is investigated in the context of axially moving materials. The multidimensional probability distribution for the input uncertainties is assumed known. It is considered as a deterministic object, which is then mapped through the model. The resulting probability density of the model output is visualized. The proposed system consists of three non-trivial parts, which are briefly discussed: a multidimensional sampler, a density estimator, and a high dynamic range (HDR…
A 1.3 megapixel FPGA-based smart camera for high dynamic range real time video
2013
International audience; A camera is able to capture only a part of a high dynamic range scene information. The same scene can be fully perceived by the human visual system. This is true especially for real scenes where the difference in light intensity between the dark areas and bright areas is high. The imaging technique which can overcome this problem is called HDR (High Dynamic Range). It produces images from a set of multiple LDR images (Low Dynamic Range), captured with different exposure times. This technique appears as one of the most appropriate and a cheap solution to enhance the dynamic range of captured environments. We developed an FPGA-based smart camera that produces a HDR liv…
Smart camera design for realtime High Dynamic Range imaging
2011
International audience; 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…
HDR-ARtiSt: High Dynamic Range Advanced Real-Time Imaging System
2012
International audience; This paper describes the HDR-ARtiSt hardware platform, a FPGA-based architecture that can produce a real- time high dynamic range video from successive image acquisition. The hardware platform is built around a standard low dynamic range (LDR) 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 em- bedded image pre-processing capabilities including multiframe acquisition with various exposure times. Our approach consists of a hardware architecture with different algorithms: double exposure control during image capture, building of an HDR image by combining the…
A smart camera for High Dynamic Range imaging
2013
International audience; A camera or a video camera is able to capture only a part of a high dynamic range scene information. The same scene can be almost totally perceived by the human visual system. This is true especially for real scenes where the difference in light intensity between the dark areas and bright areas is high. The imaging technique which can overcome this problem is called HDR (High Dynamic Range). It produces images from a set of multiple LDR images (Low Dynamic Range), captured with different exposure times. This technique appears as one of the most appropriate and a cheap solution to enhance the dynamic range of captured environments. We developed an FPGA-based smart cam…
Inverse Tone Mapping Based upon Retina Response
2014
International audience; The development of high dynamic range (HDR) display arouses the research of inverse tone mapping methods, which expand dynamic range of the low dynamic range (LDR) image to match that of HDR monitor. This paper proposed a novel physiological approach, which could avoid artifacts occurred in most existing algorithms. Inspired by the property of the human visual system (HVS), this dynamic range expansion scheme performs with a low computational complexity and a limited number of parameters and obtains high-quality HDR results. Comparisons with three recent algorithms in the literature also show that the proposed method reveals more important image details and produces …
LDR Image to HDR Image Mapping with Overexposure Preprocessing
2013
International audience; Due to the growing popularity of High Dynamic Range (HDR) images and HDR displays, a large amount of existing Low Dynamic Range (LDR) images are required to be converted to HDR format to benefit HDR advantages, which give rise to some LDR to HDR algorithms. Most of these algorithms especially tackle overexposed areas during expanding, which is the potential to make the image quality worse than that before processing and introduces artifacts. To dispel these problems, we . present a new,LDR to HDR approach, unlike the existing techniques, it focuses on avoiding sophisticated treatment to overexposed areas in dynamic range expansion step. Based on a separating principl…
Twenty Years of Airborne Water Vapor and Total Water Measurements of a Diode Laser Based Photoacoustic Instruments
2020
We present relevant issues collected over twenty years of development and operation of an airborne water vapour / total water detector based on photoacoustic spectroscopy. The WaSulHygro instrument possesses high selectivity, short response time, and wide dynamic range, that are key requirements against trace gas measurement systems for applications in atmospheric sciences. Besides the major properties of WaSul-Hygro we discuss our efforts to develop a robust instruments that have proved its long-term reliability over the last fifteen years operating on-board a commercial aircraft within the framework of the CARIBIC project.2