High Dynamic Range Research Papers (original) (raw)

Recorded neural data are frequently corrupted by large amplitude artifacts that are triggered by a variety of sources, such as subject movements, organ motions, electromagnetic interferences and discharges at the electrode surface. To prevent the system from saturating and the electronics from malfunctioning due to these large artifacts, a wide dynamic range for data acquisition is demanded, which is quite challenging to achieve and would require excessive circuit area and power for implementation. In this paper, we present a high performance Delta-Sigma modulator along with several design techniques and enabling blocks to reduce circuit area and power. The modulator was fabricated in a 0.18-µm CMOS process. Powered by a 1.0-V supply, the chip can achieve an 85-dB peak signal-to-noise-and-distortion ratio (SNDR) and an 87-dB dynamic range when integrated over a 10-kHz bandwidth. The total power consumption of the modulator is 13 µW, which corresponds to a figure-of-merit (FOM) of 45 fJ/conversion step. These competitive circuit specifications make this design a good candidate for building high precision neurosensors.

- by and +1
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- High Dynamic Range, Data Converters(pipeline/sigma-Delta ADCs), Analog to Digital Conversion, Sigma-Delta A/D Converters

Recent high dynamic range (HDR) display devices provide significantly greater output brightness and dynamic range compared to conventional display technology. A possible concern for the extended use of HDR displays is the potential to cause visual fatigue. Furthermore, ambient illumination has a significant effect on the perception of the imagery displayed, and its impact on user preferences for brightness and contrast must be understood.

- by Adar Pelah
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- Perception, Animation, High Dynamic Range, Facial expressions

We envision cobotic infinitely-variable transmissions (IVTs) as an enabling technology for haptics and prosthetics that will allow for increases in the dynamic range of these devices while simultaneously permitting reductions in actuator size and power requirements. Use of cobotic IVTs eliminates the need to make compromises on output flow and effort, which are inherent to choosing a fixed transmission ratio drivetrain. The result is a mechanism with enhanced dynamic range that extends continuously from a completely clutched state to a highly backdrivable state. This high dynamic range allows cobotic devices to control impedance with a high level of fidelity. In this paper, we discuss these and other motivations for using parallel cobotic transmission architecture in prosthetic devices.

- by Michael Peshkin
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- Robotics, Biomedical Engineering, Electronics, Kinetics

This paper analyzes the gain – noise – linearity partitioning in multi-standard radio receivers embedding baseband analog signal conditioning. The presented novel gain partitioning strategy tailored towards multi-standard radio receivers optimally mitigates the extreme reception conditions specific to the wireless environment. Based on a first order system level analysis, the paper develops a standard independent methodology that drives the gain partitioning strategy and enables the designer to handle efficiently the large amount of information from the envisaged wireless standards. The receiver gain is split between an RF front-end embedding programmable gain and a high-dynamic range Variable Gain Amplifier (VGA). As the receiver NF and IIP3 change with the RF front-end gain, we proposed a generic algorithm to find the optimal gain partitioning between the receiver's two variable gain blocks.

- by Mircea Bodea and +1
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- High Dynamic Range, Front end
- by Oguz Akyuz
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- High Dynamic Range Imaging, High Dynamic Range, Noise reduction, Image Enhancement

We have previously described methodology that makes it possible to genetically encode a wide array of unnatural amino acids in both prokaryotic and eukaryotic organisms. Here, we report the systematic optimization of a Saccharomyces cerevisiae expression system for the production of mutant proteins containing unnatural amino acids. Modifications include significant increases in both the expression levels of the orthogonal Escherichia coli amber suppressor tRNA CUA and cognate aminoacyl-tRNA synthetase (aaRS) pair, and expression of the target protein gene using a strong transcriptional promoter, optimized codons and elevated plasmid copy numbers. With this new system, a number of unnatural amino acids, including the photocrosslinkers p-benzoylphenylalanine and p-azidophenylalanine, and the chemically reactive amino acids, p-acetylphenylalanine and p-propargyloxyphenylalanine, were incorporated into human superoxide dismutase (hSOD) in yeast in good yields (maximally ∼6-8 mg/l of culture in most cases). Mass spectrometric analysis of the hSOD mutants was performed with high dynamic range using multiple reaction monitoring that provided new insights into the factors that control the fidelity of unnatural amino acid incorporation.

- by Shawn Chen
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- Genetics, Molecular Biology, Saccharomyces cerevisiae, High Dynamic Range

We have developed a numerical model of Small Target Motion Detector neurons, bio-inspired from electrophysiological experiments in the fly brain. These neurons respond selectively to small moving features within complex moving surrounds. Interestingly, these cells still respond robustly when the targets are embedded in the background, without relative motion cues. This model contains representations of neural elements along a proposed pathway to the targetdetecting neuron and the resultant processing enhances target discrimination in moving scenes. The model encodes high dynamic range luminance values from natural images (via adaptive photoreceptor encoding) and then shapes the transient signals required for target discrimination (via adaptive spatiotemporal high-pass filtering). Following this, a model for Rectifying Transient Cells implements a nonlinear facilitation between rapidly adapting, and independent polarity contrast channels (an 'on' and an 'off' pathway) each with center-surround antagonism. The recombination of the channels results in increased discrimination of small targets, of approximately the size of a single pixel, without the need for relative motion cues. This method of feature discrimination contrasts with traditional target and background motion-field computations. We improve the target-detecting output with inhibition from correlation-type motion detectors, using a form of antagonism between our feature correlator and the more typical motion correlator. We also observe that a changing optimal threshold is highly correlated to the value of observer ego-motion. We present an elaborated target detection model that allows for implementation of a static optimal threshold, by scaling the target discrimination mechanism with a model-derived velocity estimation of ego-motion.

- by Steven Wiederman
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- High Dynamic Range, Velocity Estimation, Biosensing, Target Detection

Rapid, reliable and objective estimations of leaf area index (LAI) are essential for numerous studies of atmosphere-vegetation interaction, as LAI is very often a critical parameter in process-based models of vegetation canopy response to global environmental change. This paper reviews current knowledge concerning the use of direct and indirect methods for LAI determination. The value of optical LAI measurements by means of hemispherical photography has already been demonstrated in previous studies. As clumping seems to be the main factor causing errors in indirect LAI estimation, we suggest that the use of a digital camera with high dynamic range has the potential to overcome a number of described technical problems related to indirect LAI estimation. Further testing and defining of a standardised field protocol for digital hemispherical photography is however needed to improve this technique to achieve the standards of an ideal device.

- by Marie Weiss and +2
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- Earth Sciences, Global Environmental Change, Biological Sciences, High Dynamic Range

High-dynamic-range (HDR) images are superior to conventional images. The experiments in this paper measure camera and human responses to calibrated HDR test targets. We calibrated a 4.3-log-unit test target, with minimal and maximal glare from a changeable surround. Glare is an uncontrolled spread of an image-dependent fraction of scene luminance in cameras and in the eye. We use this standard test target to measure the range of luminances that can be captured on a camera's image plane. Further, we measures the appearance of these test luminance patches. We discuss why HDR is better than conventional imaging, despite the fact the reproduction of luminance is inaccurate. in Scottsdale, Arizona. John J. McCann is with McCann Imaging, 161 Clafin St., Belmont, MA 02478; telephone/fax 617/484-7865, e-mail: mccanns@tiac.net. A. Rizzi is with the Universita degli Studi di Milano, Italy.

- by Alessandro Rizzi
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- High Dynamic Range, Retinex, Unit Testing

High Dynamic Range (HDR) images can represent the acquired scene with a greater dynamic range of luminance than classical Low Dynamic Range (LDR) ones. Despite the recent diffusion of some HDR camera models, HDR displays are not yet in the market. For this reason HDR images need to be adapted in order to be properly rendered through conventional devices. This operation mainly consists in a dynamic range compression realized by applying a Tone Mapping Operator (TMO). In this work, a new tone map algorithm, derived from the Contrast Limited Adaptive Histogram Equalization (CLAHE) technique, is presented. With respect to the original CLAHE, in the proposed implementation an adaptive contrast limit and a new strategy for the determination of local tone mapping functions have been introduced. The comparison between the obtained LDR images, and those produced by applying State of the Art TMOs, evidences how the main characteristic of the proposed algorithm is the ability to equally enhance visibility in both dark and bright areas. This could be, for example, a key feature in video surveillance applications and automotive safety camera systems.

- by nicola adami
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- Visualization, High Dynamic Range Imaging, High Dynamic Range, Video Surveillance

We present a method of recovering high dynamic range radiance maps from photographs taken with conventional imaging equipment. In our method, multiple photographs of the scene are taken with different amounts of exposure. Our algorithm uses these differently exposed photographs to recover the response function of the imaging process, up to factor of scale, using the assumption of reciprocity. With the known response function, the algorithm can fuse the multiple photographs into a single, high dynamic range radiance map whose pixel values are proportional to the true radiance values in the scene. We demonstrate our method on images acquired with both photochemical and digital imaging processes. We discuss how this work is applicable in many areas of computer graphics involving digitized photographs, including image-based modeling, image compositing, and image processing. Lastly, we demonstrate a few applications of having high dynamic range radiance maps, such as synthesizing realistic motion blur and simulating the response of the human visual system.

- by Archana Pahurkar
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- Image Processing, Digital Image Processing, High Dynamic Range, Computer Graphic

We have developed an emissive high dynamic range (HDR) display that is capable of displaying a luminance range of 10,000cd/m 2 to 0.1cd/m 2 while maintaining all features found in conventional LCD displays such as resolution, refresh rate and image quality. We achieve that dynamic range by combining two display systems -a high resolution transmissive LCD and a low resolution, monochrome display composed of high brightness light emitting diodes (LED). This paper provides a description of the technology as well as findings from a supporting psychological study that establishes that correction for the low resolution display through compensation in the high resolution display yields an image which does not differ perceptibly from that of a purely high resolution HDR display.

- by Lorne Whitehead
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- Image Quality, High Dynamic Range, High Resolution, Low Resolution

A new wavelet-based image enhancement algorithm is proposed to improve performance of face detection in non-uniform lighting environment with high dynamic range. Wavelet transform is used for dimension reduction so that dynamic range compression with local contrast enhancement algorithm is applied only to the approximation coefficients. The normalized approximation coefficients are transformed using a hyperbolic sine curve which achieves dynamic range compression. Contrast enhancement is realized by tuning the magnitude of each coefficient with respect to its surroundings. The detail coefficients are also modified to prevent the edge deformation. Experimental results on the proposed algorithm show improvement on the performance of the Viola-Jones face detector when compared to other prominent enhancement techniques.

- by Praveen Sankaran and +1
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- Image Processing, Dimension Reduction, Face Detection, High Dynamic Range

Common mode (CM) currents are a major source of interference in electrical and electronic systems. Cable trays are often used to shield cables from unwanted CM electromagnetic interference, and their shielding characteristics are defined in terms of transfer impedance. We present the measurement and modeling of nonmagnetic U-shaped cable trays from 300 kHz to 30 MHz. A calibrated vector network analyzer in a screened environment is required for the high dynamic range measurements. We use method of moments simulations to determine the transfer impedance and mutual inductance within the interior region of a cable tray. We refined the modeling after detailed attention to the code. The computational and measured data are in good agreement. We propose the simulation as a means to predict the magnetic fields, mutual inductance, and transfer impedance associated with victim cable loops in the cross section of nonmagnetic cable trays to frequencies well beyond our studied range of 30 MHz.

- by Nolan Ebertsohn
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- Electromagnetic Interference, Magnetic field, High Dynamic Range, Cross Section

A classic photographic task is the mapping of the potentially high dynamic range of real world luminances to the low dynamic range of the photographic print. This tone reproduction problem is also faced by computer graphics practitioners who map digital images to a low dynamic range print or screen. The work presented in this paper leverages the time-tested techniques of photographic practice to develop a new tone reproduction operator. In particular, we use and extend the techniques developed by Ansel Adams to deal with digital images. The resulting algorithm is simple and produces good results for a wide variety of images.

- by Peter Shirley
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- Information Systems, High Dynamic Range, Computer Graphic, Digital Image

Communication receivers that utilize I/Q downconversion are troubled by amplitude and phase mismatches between the analog I and Q branches. These mismatches are unavoidable in practice and reduce the obtainable image frequency attenuation to the 20-40-dB range in practical receivers. In wideband multichannel receivers, where the overall bandwidths are in the range of several megahertz and the incoming carriers located at each other's mirror frequencies have a high dynamic range, the image attenuation of the analog front-end (FE) alone is clearly insufficient. In this paper, two novel blind low-complexity I/Q imbalance compensation techniques are proposed and analyzed to digitally enhance the analog FE image attenuation in wideband directconversion receivers. The proposed algorithms are grounded on the concept of circular or proper complex random signals, and they are, by design, able to handle the often overlooked yet increasingly important case of frequency-dependent I/Q mismatches. The first technique is an iterative one, stemming from adaptive filtering principles, whereas the second one is a moment-estimation-based block method. The performance of the algorithms is evaluated through computer simulations, as well as real-world laboratory signal measurement examples in practical multicarrier receiver cases. Based on the obtained results, the proposed compensation techniques can provide very good compensation performance with low computational resources and are robust in the face of different imbalance levels and dynamics of the received signals, as well as many other crucial practical aspects such as the effects of the communications channel and carrier synchronization.

- by Lauri Anttila
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- Engineering, Technology, Adaptive Filtering, High Dynamic Range

We describe a single-chip radio receiver for VHF and UHF digital wide-area paging transmissions up to 500 MHz with FSK data rates up to 1200 Bd. All channel filtering is on-chip and the IC requires only 28 surface mounted external components and a quartz crystal to make a complete receiver. With -126-dBm sensitivity, 70-dB adjacent channel rejection, and 60-dB intermodulation immunity, it satisfies all known pager specifications, worldwide, using the POCSAG paging code.

- by Gwilym Luff
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- Microwave, Performance, High Dynamic Range, Process Design

This paper describes the design of a fully differential CMOS amplifier for clipping control circuit. The amplifier with specification of low settling time less than 5ns, high dynamic range above 90dB and low power supply of 3 volt is designed and realized in a 0.35 µm CMOS process with 3 volt power supply. Simulation confirm the presented design.

- by BEHNAM KARAMI
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- High Dynamic Range, Low Power, Power Supply

We propose a technique for fusing a bracketed exposure sequence into a high quality image, without converting to High dynamic range (HDR) first. Skipping the physically based HDR assembly step simplifies the acquisition pipeline. This avoids camera response curve calibration and is computationally efficient. It also allows for including flash images in the sequence. Our technique blends multiple exposures, guided by simple quality measures like saturation and contrast. This is done in a multiresolution fashion to account for the brightness variation in the sequence. The resulting image quality is comparable to existing tone mapping operators.

- by Frank Van Reeth
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- High Dynamic Range

A three-dimensional (3-D) imager is presented, capable of computing the depth map as well as the intensity scale of a given scene. The heart of the system is a two-dimensional array of single photon avalanche diodes fabricated in standard CMOS technology. The diodes exhibit low-noise equivalent-power high-dynamic range, and superior linearity. The 3-D imager achieves submillimetric precision at a depth-of-field

- by Edoardo Charbon
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- Quantum Physics, High Dynamic Range, Optical physics, Three Dimensional

In this paper the first step of a wide research program regarding analysis of lighting in working places, in order to inquire about effects on visual comfort, health, wellbeing and energy savings are presented. Today, we can assess that a light environment is proper and effective when: (1) photometric quantities reported on European Code EN 12464-1, such as for instance illuminances on task areas, UGR and Colour Rendering Indexes assume convenient values; (2) energy requirements for lighting do not exceed limit values reported in The European Code EN 15193. However, lit environments are much more complex especially when more than one visual task for the same work position is present and daylighting is available. In order to establish connections between results obtained from photometric measures and visual performance and comfort, statistic experimental surveys based on measures in field and questionnaires are needed. For this aim a school environment has been chosen as a case-study: in fact in school facilities, comfortable and efficient visual conditions for people with different ages and functions as students, teachers and office staff, should be achieved. In particular, it is in the classrooms that teachers and students spend most of their time and in which very different visual tasks are performed, as reading on desks and on blackboard, establishing visual communication between teacher and pupils, watching on maps on walls, etc. Besides in the classrooms there are always several task areas (at least one for each student's position), during the school hours lessons cannot be interrupted for long time and daylight levels can vary during the survey: for these reasons fast and at the same time accurate measures should be carried out. These experimental data are very important in order to design integrated daylighting-artificial lighting systems with good energy performances.

- by Laura Bellia
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- Engineering, Energy Efficiency Buildings, Visual Communication, High Dynamic Range

A high-gain, 43-Gb/s InP HBT transimpedance-limiting amplifier (TIALA) with 100-A pp sensitivity and 6 mA pp input overload current is presented. The circuit also operates as a limiting amplifier with 40-dB differential gain, better than 15-dB input return loss, and a record-breaking sensitivity of 8 mV pp at 43 Gb/s. It features a differential TIA stage with inductive noise suppression in the feedback network and consumes less than 450 mW from a single 3.3-V supply. The TIALA has 6-k (76 dB) differential transimpedance gain and 35-GHz bandwidth and comprises the transimpedance and limiting gain functions, an auto-zero dc feedback circuit, signal level monitor, and slicing level adjust functions. Other important features include 45-dB isolation and 800-mV pp differential output.

This paper presents an experimental method and apparatus for producing spherical panoramas with high dynamic range imaging (HDRI). Our method is optimized for providing high fidelity augmented reality (AR) image-based environment recognition for mobile devices. Previous studies have shown that a pre-produced panorama image can be used to make AR tracking possible for mobile AR applications. However, there has been little research on determining the qualities of the source panorama image necessary for creating high fidelity AR experiences. Panorama image production can have various challenges that can result in inaccurate reproduction of images that do not allow correct virtual graphics to be registered in the AR scene. These challenges include using multiple angle photograph images that contain parallax error, nadir angle difficulty and limited dynamic range. For mobile AR, we developed a HDRI method that requires a single acquisition that extends the dynamic range from a digital negative. This approach that needs least acquisition time is to be used for multiple angles necessary for reconstructing accurately reproduced spherical panorama with sufficient luminance.

- by Akihiko SHIRAI
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- Computer Science, Digital Content, High Dynamic Range, Virtual Environment

- by Hiroe Li
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- Perception, Animation, Virtual Reality, High Dynamic Range

In: Air Monitoring and Detection of Chemical and Biological Agents (edited by J. Leonelli and ML Althouse). Society of Photo-Optical Instrumentation Engineers (SPIE). Vol. 3855. pp. 34-41. September 1999. ... A novel laser breakdown... more

- by Sergey Mirov
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- Environmental Monitoring, High Dynamic Range, Copper, Heavy Metal

This article report focuses on real-time image correction techniques that enable projector-camera systems to display images onto screens that are not optimized for projections, such as geometrically complex, colored and textured surfaces. It reviews hardware accelerated methods like pixel-precise geometric warping, radiometric compensation, multi-focal projection, and the correction of general light modulation effects. Online and offline calibration as well as invisible coding methods are explained. Novel attempts in super-resolution, high dynamic range and high-speed projection are discussed. These techniques open a variety of new applications for projection displays. Some of them will also be presented in this report.

- by Anselm Grundhöfer and +1
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- Computer Graphics, Augmented Reality, Super resolution, High Dynamic Range

New planar multijunction thermal converters (PMJTCs) with low-power coefficient and high dynamic range using CuNi44/BiSbTe thermocouples have been manufactured. In series connection with carefully evaluated range resistors for voltages up to 1000 V they result in ac-dc voltage transfer standards with known ac-dc voltage transfer difference at low frequencies, for which the voltage step-up procedure is not necessary anymore.

- by Rado Lapuh
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- Low Frequency, High Dynamic Range, Thin Film, Low Power

Computerized Tomography (CT) images are High Dynamic Range (HDR) images of the X-ray attenuation coefficients of the body's tissues. The inability to see abnormalities in tissues with marked differences in their X-ray attenuation coefficients, in a single CT window, poses a significant clinical problem in radiology. In order to provide proper contrast, which reveals all the required clinical details within each specifically imaged tissue, a single CT slice must be viewed by a radiologist four times: the first viewing focuses on the lung window; the second viewing focuses on the soft tissues window; the third viewing focuses on the liver window; and the fourth viewing focuses on the bone window. In order to enhance the ability to perform a complete diagnosis, while decreasing diagnostic time, we developed the BACCT (Biologically-based Algorithm for Companding CT images) method. Our algorithm compresses and expands (compands) the HDR CT image into a single, low dynamic range image. Before performing the companding procedure, unique processing is required which involves operations that enhance and stretch the image. The performance of our algorithm has been demonstrated on a large repertoire of CT body images. All the clinically required CT information is exposed in each CT slice in a single image. The algorithm compands the CT images in a fully automatic way. Collaborating radiologists have already tested the results of our algorithmic method, and reported that the images seem to provide all the necessary information. However, clinical tests for statistical reliability are still required.

- by Hedva Spitzer and +1
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- Algorithms, Body Image, High Dynamic Range, X Rays

Many real-world scenes contain a dynamic range that exceeds conventional display technology by several orders of magnitude. Through the combination of several existing technologies, new high dynamic range displays, capable of reproducing a range of intensities much closer to that of real environments, have been constructed. These benefits come at the cost of more optically complex devices; involving two image modulators, controlled in unison, to display images. We present several methods of rendering images to this new class of devices for reproducing photometrically accurate images. We discuss the process of calibrating a display, matching the response of the device with our ideal model. We then derive series of methods for efficiently displaying images, optimized for different criteria and evaluate them in a perceptual framework.

- by Archana Pahurkar
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- Image Processing, Image, High Dynamic Range, Displays

A Mueller polarimeter always comprises a polarization state generator (PSG) and a polarization state analyzer (PSA), whose configurations determine the modulation and analysis matrices W and A, involved in the linear relationship between the raw measurement matrix B and the Mueller matrix M of the sample under study. At constant noise in the raw data B, the noise in M is minimized when the condition numbers of both A and W are optimized wE. Compain et al., Rev. Sci. Instrum. 68 (1997) 2671 S. Tyo, Appl. Opt. 41 (2002) 619x. This result provides a quite general criterion for the optimization of instrument design. Typically, this optimization leads to PSG and PSA configurations, which may be difficult to calibrate accurately by usual procedures. This key issue is easily solved by the quite general eigenvalue calibration method wE. Compain et al., Appl. Opt. OT 38 (1999) 3490x. The usefulness of this approach for the development of innovative polarimeters is illustrated with two instruments. One of these comprises a photoelastic modulator and a division-of-amplitude prism, and features a high dynamical range over a broad spectrum, while the other, based on liquid crystal variable retarders, is better suited for imaging applications in the visible and the near infrared. ᮊ

- by Enrique Garcia-Caurel
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- Engineering, Technology, Near Infrared, High Dynamic Range

Propagation model tuning is a fundamental part of everyday GSM cellular engineering practice. The model tuning is usually accomplished through elaborate and costly tests based on CW measurements. This paper evaluates alternatives to CW testing where measurements are collected using GSM scanners and GSM high dynamic range receivers. The results of the analysis reveal that GSM receivers provide a viable alternative for CW tests in many practical situations. On the other hand, use of GSM scanners is affected by the co-channel and adjacent channel interference and therefore it is limited to cases of relatively low frequency reuse.

- by Nenad Mijatovic
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- Morphology, Low Frequency, High Dynamic Range, GSM

Eight high-dynamic-range image rendering algorithms were tested using ten high-dynamic-range pictorial images. A large-scale paired comparison psychophysical experiment was developed containing two sections, comparing the overall rendering performances and grayscale tone mapping performance respectively. An interval scale of preference was created to evaluate the rendering results. The results showed the consistency of tone-mapping performance with the overall rendering results, and illustrated that Durand and Dorsey's bilateral fast filtering technique and Reinhard's photographic tone reproduction have the best rendering performance overall. The goal of this experiment was to establish a sound testing and evaluation methodology based on psychophysical experiment results for future research on accuracy of rendering algorithms.

For many centuries artists have considered and depicted illumination in art, from the effect of sunlight on objects at different times of the day, of shadows and highlights as cast by the moon, through indirect light as that through an open window or the artificial light of the candle or firelight. The presentation will consider artists who were fascinated by the phenomena of natural and artificial illumination and how they were able to render the natural world as a form of dynamic range through pigment. Artists have been long aware of the psychological aspects of the juxtaposition of colour in exploiting the optical qualities and arranging visual effects in painting and prints. Artists in the 16th century were attempting to develop an extended dynamic range through multi-colour, wood-block printing. Artists working at the height of naturalist realism in the 17th through the 19th century were fascinated by the illusory nature of light on objects. The presentation will also consider the interpretation of dynamic range through the medium of mezzotint, possibly the most subtle of printing methods, which was used by printers to copy paintings, and to create highly original works of art containing a dynamic range of tones.

- by Carinna Parraman
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- Art History, Art, High Dynamic Range, Print History

A robust scheme is proposed to generate an anti-ghosting high dynamic range (HDR) image from a set of low dynamic range (LDR) images with different exposure times. Three major contributions of this paper are 1) a bi-directional prediction method; 2) an adaptive threshold for the classification of pixels; 3) Bayes estimator based methods for the on-line updating of predicted values and the synthesis of pixels to fill in the regions of moving objects to preserve their dynamic ranges. The proposed scheme is suitable for both static and dynamic scenes.

- by Ahmet Akyuz
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- High Dynamic Range Imaging, High Dynamic Range, Motion estimation, Object Detection

W-CDMA system require switched gain Low Noise Amplifier (LNA) with wide input dynamic range ICP1 in top of the receiver Front-End. This paper reports the design of an integrated switched gain LNA providing 1.65dB NF at 2140MHz with wide input ICP1=-10dBm in the high gain mode for 15.6 mW power supply. In the low gain mode operation, -11dB power loss

- by Didier Belot
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- High Dynamic Range, Quality Factor, Power Consumption, Low noise amplifier

A bright neutron source such as the Spallation Neutron Source (SNS) places extreme requirements on detectors such as the highly desirable characteristics of excellent 2-D spatial imaging and high dynamic range. Present imaging detectors have either shown position resolutions that are less than acceptable or they exhibit excessive paralyzing dead times due to the brightness of the source. Detectors that also exhibit high efficiency are necessary to ensure acceptable discrimination and satisfactory statistics. A detector concept known as MicroMegas (MicroMEsh GAseous Structure) has been developed at CERN in Geneva for high-energy physics charged-particle tracking applications and has shown great promise for handling high data rates with a rather low-cost structure. We are attempting to extend the MicroMegas detector concept to make it neutron sensitive by adding a neutron converter (10 B) to the structure and have designed a 1-D neutron strip detector which we are presently testing. In addition, we are performing research into the compatibility of various converter coatings. Our goal is to develop a manufacturable detector that could be scaled to a 1m 2 , 2-D array for use at the SNS and other facilities.

- by Vitaly Chepel
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- High Dynamic Range, Low Noise

Recently we proposed a wavelet-based dynamic range compression algorithm to improve the visual quality of digital images captured in the high dynamic range scenes with nonuniform lighting conditions. The fast image enhancement algorithm which provides dynamic range compression preserving the local contrast and tonal rendition is a very good candidate in aerial imagery applications such as image interpretation for defense and security tasks. This algorithm can further be applied to video streaming for aviation safety. In this paper the latest version of the proposed algorithm which is able to enhance aerial images so that the enhanced images are better then direct human observation, is presented. The results obtained by applying the algorithm to numerous aerial images show strong robustness and high image quality.

- by Vijayan Asari
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- Image Quality, Image Interpretation, Safety, High Dynamic Range

In high dynamic range (HDR) imaging, multiple photographs with different exposure times are combined into a radiance map, which reflects the radiance in real-life scenes. This involves recovering the response function of the imaging process. The technique proposed by Debevec and Malik is a well-known HDR image synthesis algorithm, but the computational complexity is relatively high, which limits the possible image size and the reconstruction quality. In this paper we present an improved joint optimization technique for estimating the camera response function (CRF) and the radiance map and a new sequential two-step optimization technique, which first estimates the CRF and then reconstructs the radiance map, resulting in better visual results and a higher SNR in remarkably less computation time.

We present a tone reproduction operator that preserves visibility in high dynamic range scenes. Our method introduces a new histogram adjustment technique, based on the population of local adaptation luminances in a scene. To match subjective viewing experience, the method incorporates models for human contrast sensitivity, glare, spatial acuity, and color sensitivity. We compare our results to previous work and present examples of our techniques applied to lighting simulation and electronic photography.

- by Holly Rushmeier
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- Computer Graphics, Image Processing, Visualization, Photography

This paper proposes an effective anomaly detection algorithm for a forward-looking ground-penetrating radar (FLGPR). One challenge for threat detection using FLGPR is its high dynamic range in response to different kinds of targets and clutter objects. The application of a fixed threshold for detection often yields a large number of false alarms. We propose a locally-adaptive detection method that adjusts the detection criteria automatically and dynamically across different spatial regions, which improves the detection of weak scattering targets. The paper also examines a spectrumbased classifier. This classifier rejects false alarms (FAs) by classifying each alarm location based on its spatial frequency-spectrum. Experimental results for the improved detection techniques are demonstrated by field data measurements from a US Army test site.

- by Timothy Havens
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- Ground Penetrating Radar, Anomaly Detection, High Dynamic Range, Adaptive Systems

This paper presents a robust and fast algorithm for automatically generating high dynamic range (HDR) images in presence of camera movement and moving objects. This scheme comprises five modules: 1) image alignment, 2) estimation of camera response function (CRF) in dynamic scenes, 3) moving object detection, 4) progressive image correction, and 5) construction of HDR images. The key advantage of the algorithm is the ability to generate HDR images without ghost artifact. The proposed algorithm is fast as it is a one-shot solution without iterative computation and post-processing or even manual operation. Experimental results demonstrate that the proposed method outperforms the existing commercial products.

Single best exposure tone-mapped Standard HDR Our result . An exposure stack taken at a sculpture garden. In the first row from left to right: single best exposure tone-mapped, standard HDR, and our result. Our result captures all the... more

- by Marius Tico
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- High Dynamic Range Imaging, High Dynamic Range, Noise, Camera Calibration

A switched-capacitor logarithmic pipeline ADC scheme that does not require squaring or any other complex analog functions is described. This approach is ideal where a high dynamic range, but not a high peak SNDR, is required. A signed, 8-bit 1.5 bit-per-stage logarithmic pipeline ADC is implemented in 0.18 mum CMOS. The 22 MS/s ADC achieves a measured DR of 80 dB and a measured SNDR of 36 dB, occupies 0.56 mm2, and consumes 2.54 mW from a 1.62 V supply. The measured dynamic range figure of merit is 174 dB.

- by sunghyun Park
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- High Dynamic Range, Cmos, Pipelines, Prototypes

A new numerical method of image processing suitable for visual-ization of corona images taken during total solar eclipses is presented. This method allows us to study both small-and large-scale coronal structures that remain invisible on original images because of their very high dynamic range of the coronal brightness. The method is based on the use of adaptive filters inspired by human vision and the sensitivity of resulting images is thus very close to that of the human eye during an eclipse. A high precision alignment method for white-light corona images is also discussed. The proposed method highly improves a widely used unsharp masking method employing a radially blurred mask. The results of these numerical image processing techniques are illustrated by a series of images taken during eclipses of the last decade. The method minimizes the risk of processing artifacts.

- by V. Rušin
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- Image Processing, Numerical Method, High Dynamic Range, Adaptive Filter

In recent years, High Dynamic Range Textures (HDRTs) have been frequently used in real-time applications and video-games to enhance realism. Unfortunately, HDRTs consume a considerable amount of memory, and efficient compression methods are not straightforward to implement on modern GPUs. We propose a framework for efficient HDRT compression using tone mapping and its dual, inverse tone mapping. In our method, encoding is performed by compressing the dynamic range using a tone mapping operator ...

- by A. Chalmers
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- High Dynamic Range, Tone mapping

We present a novel approach to HDR (high-dynamic-range) image fusion that copes with image blur degradation often present in longexposed images. The proposed approach can deal with both camera and object motion blur in a computationally efficient manner suitable for implementation on a mobile device. The main idea is to exploit the differences between the image degradations that affect images captured for HDR fusion. Short-exposed images are mainly affected by sensor noise and less affected by motion blur, whereas longer exposed images are less noisy but potentially blurry due to motion during their exposure. Our approach consists of two steps. First we calculate an HDR representation of the scene by applying a typical HDR fusion approach. This representation could be blurry if some of the input images with long exposure time are blurry. We then fuse the HDR result with a photometrically modified version of the image with the shortest exposure time, which allows us to retain the sharpness of the short-exposed image and the noise-free characteristics of the HDR-fused image. The method does not assume an invariant blur PSF over any of the input images, and hence it can solve both for local and global blur, due to object or camera motion, respectively. We demonstrate the algorithm through a series of experiments and comparisons on natural images.

- by Natasha Malik
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- High Dynamic Range Imaging, High Dynamic Range, Mobile Device, Motion Blur

The signal handling capability of the filters is called dynamic range. In this paper, a topological form for the synthesis of filters with high dynamic range is proposed. A biquad notch/all-pass filter is shown in conformity with the given topological form. It is shown that there is a trade-off between dynamic range and high input impedance property. The presented circuit is compared with other notch filters in the literature. It has less number of components, better high-frequency response and dynamic range compared to others. Since the circuit includes a minimum number of resistors, it can easily provide electronically tunable circuits through resistor/controlled current conveyor replacement. Simulations are performed to verify the theoretical results. Routh-Hurwitz stability analyses are also given.