Showing papers on "Filter (video) published in 2006"
TL;DR: A comprehensive description of the primal-dual interior-point algorithm with a filter line-search method for nonlinear programming is provided, including the feasibility restoration phase for the filter method, second-order corrections, and inertia correction of the KKT matrix.
Abstract: We present a primal-dual interior-point algorithm with a filter line-search method for nonlinear programming. Local and global convergence properties of this method were analyzed in previous work. Here we provide a comprehensive description of the algorithm, including the feasibility restoration phase for the filter method, second-order corrections, and inertia correction of the KKT matrix. Heuristics are also considered that allow faster performance. This method has been implemented in the IPOPT code, which we demonstrate in a detailed numerical study based on 954 problems from the CUTEr test set. An evaluation is made of several line-search options, and a comparison is provided with two state-of-the-art interior-point codes for nonlinear programming.
7,966 citations
05 May 2006
TL;DR: In this paper, the authors derived a closed-form cardinalized probability hypothesis density (CPHD) filter, which propagates not only the PHD but also the entire probability distribution on target number.
Abstract: The multitarget recursive Bayes nonlinear filter is the theoretically optimal approach to multisensor-multitarget
detection, tracking, and identification. For applications in which this filter is appropriate, it is likely to be tractable
for only a small number of targets. In earlier papers we derived closed-form equations for an approximation of
this filter based on propagation of a first-order multitarget moment called the probability hypothesis density
(PHD). In a recent paper, Erdinc, Willett, and Bar-Shalom argued for the need for a PHD-type filter which
remains first-order in the states of individual targets, but which is higher-order in target number. In this paper
we show that this and much more is possible. We derive a closed-form cardinalized PHD (CPHD), filter, which
propagates not only the PHD but also the entire probability distribution on target number.
642 citations
01 Jul 2006
TL;DR: It is demonstrated that manually-specified point spread functions are sufficient for several challenging cases of motion-blur removal including extremely large motions, textured backgrounds and partial occluders.
Abstract: In a conventional single-exposure photograph, moving objects or moving cameras cause motion blur. The exposure time defines a temporal box filter that smears the moving object across the image by convolution. This box filter destroys important high-frequency spatial details so that deblurring via deconvolution becomes an ill-posed problem.Rather than leaving the shutter open for the entire exposure duration, we "flutter" the camera's shutter open and closed during the chosen exposure time with a binary pseudo-random sequence. The flutter changes the box filter to a broad-band filter that preserves high-frequency spatial details in the blurred image and the corresponding deconvolution becomes a well-posed problem. We demonstrate that manually-specified point spread functions are sufficient for several challenging cases of motion-blur removal including extremely large motions, textured backgrounds and partial occluders.
592 citations
TL;DR: Experimental results validate the filter design, show the feasibility of using inertial/magnetic sensor modules for real-time human body motion tracking, and validate the quaternion-based Kalman filter design.
Abstract: Real-time tracking of human body motion is an important technology in synthetic environments, robotics, and other human-computer interaction applications. This paper presents an extended Kalman filter designed for real-time estimation of the orientation of human limb segments. The filter processes data from small inertial/magnetic sensor modules containing triaxial angular rate sensors, accelerometers, and magnetometers. The filter represents rotation using quaternions rather than Euler angles or axis/angle pairs. Preprocessing of the acceleration and magnetometer measurements using the Quest algorithm produces a computed quaternion input for the filter. This preprocessing reduces the dimension of the state vector and makes the measurement equations linear. Real-time implementation and testing results of the quaternion-based Kalman filter are presented. Experimental results validate the filter design, and show the feasibility of using inertial/magnetic sensor modules for real-time human body motion tracking
556 citations
TL;DR: A method is introduced to integrate observations collected prior to the first robot encounter, using the notion of a virtual robot travelling backwards in time, which allows one to integrate all data from all robots into a single common map.
Abstract: This paper describes an on-line algorithm for multi-robot simultaneous localization and mapping (SLAM). The starting point is the single-robot Rao-Blackwellized particle filter described by Hahnel et al., and three key generalizations are made. First, the particle filter is extended to handle multi-robot SLAM problems in which the initial pose of the robots is known (such as occurs when all robots start from the same location). Second, an approximation is introduced to solve the more general problem in which the initial pose of robots is not known a priori (such as occurs when the robots start from widely separated locations). In this latter case, it is assumed that pairs of robots will eventually encounter one another, thereby determining their relative pose. This relative attitude is used to initialize the filter, and subsequent observations from both robots are combined into a common map. Third and finally, a method is introduced to integrate observations collected prior to the first robot encounter, using the notion of a virtual robot travelling backwards in time. This novel approach allows one to integrate all data from all robots into a single common map.
409 citations
TL;DR: In this article, the authors proposed the use of a much higher number of phases in parallel together with digital control in a bidirectional dc-dc converter using three-to-five paralleled buck stages.
Abstract: Interleaving technique is used in some applications due to its advantages regarding filter reduction, dynamic response, and power management. In dual battery system vehicles, the bidirectional dc-dc converter takes advantage of this technique using three-to-five paralleled buck stages. In this paper, we propose the use of a much higher number of phases in parallel together with digital control. It will be shown that this approach opens new possibilities since changes in the technology are possible. Thus, two 1000-W prototypes have been designed using surface mount technology devices (SO-8 transistors). An additional important feature is that due to the accuracy of the digital device [field-programmable gate array (FPGA)], current loops have been eliminated, greatly simplifying the implementation of the control stage
377 citations
TL;DR: A novel technique that allows the simultaneous optimization of a spatial and a spectral filter enhancing discriminability rates of multichannel EEG single-trials is presented.
Abstract: Brain-computer interface (BCI) systems create a novel communication channel from the brain to an output device by bypassing conventional motor output pathways of nerves and muscles. Therefore they could provide a new communication and control option for paralyzed patients. Modern BCI technology is essentially based on techniques for the classification of single-trial brain signals. Here we present a novel technique that allows the simultaneous optimization of a spatial and a spectral filter enhancing discriminability rates of multichannel EEG single-trials. The evaluation of 60 experiments involving 22 different subjects demonstrates the significant superiority of the proposed algorithm over to its classical counterpart: the median classification error rate was decreased by 11%. Apart from the enhanced classification, the spatial and/or the spectral filter that are determined by the algorithm can also be used for further analysis of the data, e.g., for source localization of the respective brain rhythms
373 citations
TL;DR: A multi-point filtersim algorithm is proposed that classifies structural patterns using selected filter statistics that represent directional mean, gradient, and curvature properties in multiple-point simulation.
Abstract: Multiple-point simulation, as opposed to simulation one point at a time, operates at the pattern level using a priori structural information. To reduce the dimensionality of the space of patterns we propose a multi-point filtersim algorithm that classifies structural patterns using selected filter statistics. The pattern filter statistics are specific linear combinations of pattern pixel values that represent directional mean, gradient, and curvature properties. Simulation proceeds by sampling from pattern classes selected by conditioning data.
323 citations
TL;DR: A noise removal technique using partial differential equations (PDEs) that combines the Total Variational filter with a fourth-order PDE filter that is able to preserve edges and at the same time avoid the staircase effect in smooth regions is proposed.
Abstract: A noise removal technique using partial differential equations (PDEs) is proposed here. It combines the Total Variational (TV) filter with a fourth-order PDE filter. The combined technique is able to preserve edges and at the same time avoid the staircase effect in smooth regions. A weighting function is used in an iterative way to combine the solutions of the TV-filter and the fourth-order filter. Numerical experiments confirm that the new method is able to use less restrictive time step than the fourth-order filter. Numerical examples using images with objects consisting of edge, flat and intermediate regions illustrate advantages of the proposed model.
301 citations
TL;DR: In this paper, a novel method for designing multiband bandpass filters has been proposed, which adds some extra coupled resonator sections in a single-circuit filter to increase the degrees of freedom in extracting coupling coefficients of a multiband filter.
Abstract: A novel method for designing multiband bandpass filters has been proposed in this paper. Coupling structures with both Chebyshev and quasi-elliptic frequency responses are presented to achieve dual- and triple-band characteristics without a significant increase in circuit size. The design concept is to add some extra coupled resonator sections in a single-circuit filter to increase the degrees of freedom in extracting coupling coefficients of a multiband filter and, therefore, the filter is capable of realizing the specifications of coupling coefficients at all passbands. To verify the presented concept, four experimental examples of filters with a dual-band Chebyshev, triple-band Chebyshev, dual-band quasi-elliptic, and triple-band quasi-elliptic response have been designed and fabricated with microstrip technology. The measured results are in good agreement with the full-wave simulation results
298 citations
01 Jan 2006
TL;DR: In this article, the authors present a basic understanding of A/D conversion in continuous-time modulators, including DAC nonidealities in Continuous-Time Modulators (CIMMs).
Abstract: Basic Understanding of ?? A/D Conversion.- Continuous-Time ?? Modulators.- DAC Nonidealities in Continuous-Time ?? Modulators.- Filter Nonidealities in Continuous-Time ?? Modulators.- Quantizer Nonidealities in Continuous-Time ?? Modulators.- CT ?? Modulator Design Examples.
TL;DR: In this article, a single-band-pass tunable microwave filter was proposed based on a broadband optical source and a fiber Mach-Zehnder interferometer and showed a high Q factor over a tuning range of 5-17 GHz.
Abstract: The authors present the theoretical analysis and experimental demonstration of a novel single-bandpass tunable microwave filter. The filter is based on a broadband optical source and a fiber Mach-Zehnder interferometer and shows a high Q factor over a tuning range of 5-17 GHz. A generalized analysis considering that the optical signal propagates along optical delay lines with a dispersion slope different from zero is presented.
TL;DR: In this paper, a low-loss interference filter was used to reduce the sensitivity of the external cavity feedback against misalignment, leading to an increased tunability of the laser.
01 Jul 2006
TL;DR: A compact reconstruction function is introduced that is used to decompose an HDR video stream into a residual stream and a standard LDR stream, which can be played on existing MPEG decoders, such as DVD players.
Abstract: To embrace the imminent transition from traditional low-contrast video (LDR) content to superior high dynamic range (HDR) content, we propose a novel backward compatible HDR video compression (HDR MPEG) method. We introduce a compact reconstruction function that is used to decompose an HDR video stream into a residual stream and a standard LDR stream, which can be played on existing MPEG decoders, such as DVD players. The reconstruction function is finely tuned to the content of each HDR frame to achieve strong decorrelation between the LDR and residual streams, which minimizes the amount of redundant information. The size of the residual stream is further reduced by removing invisible details prior to compression using our HDR-enabled filter, which models luminance adaptation, contrast sensitivity, and visual masking based on the HDR content. Designed especially for DVD movie distribution, our HDR MPEG compression method features low storage requirements for HDR content resulting in a 30% size increase to an LDR video sequence. The proposed compression method does not impose restrictions or modify the appearance of the LDR or HDR video. This is important for backward compatibility of the LDR stream with current DVD appearance, and also enables independent fine tuning, tone mapping, and color grading of both streams.
Patent•
20 Jan 2006TL;DR: In this article, a frequency varying wave generator with a gain element adapted to amplify a wave having a wavelength, a time varying tunable wavelength selective filter element in communication with the gain element, the tunable filter element, and the feedback element define a circuit such that the roundtrip time for the wave to propagate through the circuit is substantially equal to a nonzero integer multiple of the period T.
Abstract: In one aspect the invention relates to a frequency varying wave generator. The generator includes a gain element adapted to amplify a wave having a wavelength; a time varying tunable wavelength selective filter element in communication with the gain element, the tunable Filter element adapted to selectively filter waves during a period T; and a feedback element in communication with the tunable filter element and the gain element, wherein the tunable wavelength selective filter element, the gain element and the feedback element define a circuit such that the roundtrip time for the wave to propagate through the circuit is substantially equal to a non-zero integer multiple of the period T.
01 Jul 2006
TL;DR: A simple filter that takes an arbitrary input motion signal and modulates it in such a way that the output motion is more "alive" or "animated", and shows that the filtered motion exhibits anticipation, follow-through, exaggeration and squash-and-stretch effects which are not present in the original input motion data.
Abstract: We present the "Cartoon Animation Filter", a simple filter that takes an arbitrary input motion signal and modulates it in such a way that the output motion is more "alive" or "animated". The filter adds a smoothed, inverted, and (sometimes) time shifted version of the second derivative (the acceleration) of the signal back into the original signal. Almost all parameters of the filter are automated. The user only needs to set the desired strength of the filter. The beauty of the animation filter lies in its simplicity and generality. We apply the filter to motions ranging from hand drawn trajectories, to simple animations within PowerPoint presentations, to motion captured DOF curves, to video segmentation results. Experimental results show that the filtered motion exhibits anticipation, follow-through, exaggeration and squash-and-stretch effects which are not present in the original input motion data.
TL;DR: This work derives a simple and advanced algorithm for the optimum joint statistical adaptation of both filter coefficients in time-varying and noisy acoustic environments based on the Kalman filter theory.
TL;DR: In this article, the authors presented the characteristics of a miniaturized microstrip filter, which has two separate coupling paths: electric coupling path and magnetic coupling path between two resonators.
Abstract: This paper presents the characteristics of a miniaturized microstrip filter, which has two separate coupling paths: electric coupling path and magnetic coupling path between two resonators. Either magnetic coupling or electric coupling in two paths can be dominant in the total coupling coefficient of the inter-stage resonators with the similar configuration, but different positions of transmission zero points (ZPs). Based on the proposed filter topology, second- and fourth-order filters have been designed and fabricated for the first time. Advantages of using this type of filter are not only its low insertion loss and much more compact size, but also its controllable transmission ZPs.
Patent•
26 Jul 2006
TL;DR: In this paper, a position measurement apparatus includes a movable stage structure, a measurement unit using a laser to measure a moved position of the stage and to output a corresponding measured value.
Abstract: A position measurement apparatus includes a movable stage structure, a measurement unit using a laser to measure a moved position of the stage and to output a corresponding measured value, a first filter configured to attenuate a first component of a certain frequency region of the measured value outputted by the measurement unit, a second filter connected in parallel with the first filter configured to attenuate a second component other than the certain frequency region of the measured value outputted by the measurement unit, a third filter connected in series to the second filter with the series connection of the second and third filters connected in parallel with the first filter, configured to attenuate the first component of the certain frequency region of the measured value outputted by the measurement unit, and a processing unit configured to combine an output of the first filter and an output of the series connection of the second and third filters and to thereby output a first combined value.
TL;DR: In this article, a two-element Lyot filter operating in the terahertz (THz) frequency range is demonstrated, which can be continuously tuned from 0.388to 0.564THz using magnetically controlled birefringence in nematic liquid crystals.
Abstract: A two-element tunable Lyot filter operating in the terahertz (THz) frequency range is demonstrated. The central bandpass frequency of the filter can be continuously tuned from 0.388to0.564THz (a fractional tuning range of 40%) using magnetically controlled birefringence in nematic liquid crystals. The transmission bandwidth is 0.1THz and the insertion loss of the present device is 8dB due to the scattering of LC molecules in the thick LC cells. This filter can be operated at room temperature.
01 Jan 2006
TL;DR: This chapter proposed a three dimensional set partitioned embedded block coder for hyperspectral image compression that automatically exploits inter-band dependence and provides better performance for lossy representation.
Abstract: This chapter proposed a three dimensional set partitioned embedded block coder for hyperspectral image compression The three dimensional wavelet transform automatically exploits inter-band dependence Two versions of the algorithm were implemented The integer filter implementation enables lossy-to-lossless compression, and the floating point filter implementation provides better performance for lossy representation Wavelet packet structure and bit shifting were applied on the integer filter implementation to make the transform approximately unitary
TL;DR: In this paper, a compact ultra-wideband bandpass filter based on the composite microstrip-coplanar-waveguide (CPW) structure is proposed, which has the merits of compact size, flat group delay, good insertion/return loss and good selectivity.
Abstract: Compact ultra-wideband bandpass filters are proposed based on the composite microstrip-coplanar-waveguide (CPW) structure. In this study, the microstrip-CPW transitions and the CPW shorted stubs are adopted as quasi-lumped-circuit elements for realizing a three-pole high-pass filter prototype. By introducing a cross-coupled capacitance between input and output ports of this high-pass filter and suitably designing the transition stretch stubs, a compact three-pole ultra-wideband bandpass filter is implemented with two transmission zeros located close to the passband edges. To further improve the selectivity, two microstrip shorted stubs are added to implement a five-pole ultra-wideband bandpass filter with good out-of-band response. Being developed from the quasi-lumped elements, and not from the transmission lines, the proposed ultra-wideband filters have sizes more compact than those of the published wideband filters. The proposed ultra-wideband filters have the merits of compact size, flat group delay, good insertion/return loss, and good selectivity. Agreement between simulated and measured responses of these filters is demonstrated
TL;DR: In this paper, a tri-band microstrip bandpass filter (BPF) is proposed to produce three passbands at the commercially practical frequencies through a single piece of filter circuitry.
Abstract: A new tri-band microstrip bandpass filter (BPF) is designed to produce three passbands at the commercially practical frequencies through a single piece of filter circuitry. The basic component used to build the proposed filter consists of two quarter-wavelength (lambda/4) stepped-impedance resonators (SIRs). One of the lambda/4 SIRs is designed to operate at 1.57 GHz and 5.25 GHz, and the other at 2.45 GHz. The feed positions for the two lambda/4 SIRs are carefully located to have the same distance from the via-hole ground and meanwhile to give the required external quality factors (Qe's). In such a way, the microstripline sections between the via-hole and each of the feed positions can be combined into one to simplify the filter structure, and to reduce the BPF circuit size. Performance of the newly designed tri-band BPF is verified by measured results
TL;DR: In experiments with planar arrangements for curves up to degree four, the modular filter accelerated the computation for arrangements of cubic curves by a factor of about 6.
Abstract: We report on the effects of a filter based on modular arithmetic that has been introduced recently into the EXACUS library. Our experiments with planar arrangements for curves up to degree four show that the exact construction and comparison of real algebraic numbers are some of the most time consuming operations when solving intersection problems for curved objects. In our experiments the modular filter accelerated the computation for arrangements of cubic curves by a factor of about 6.
TL;DR: A digit-reconfigurable finite-impulse response (FIR) filter architecture with a very fine granularity that provides a flexible yet compact and low-power solution to FIR filters with a wide range of precision and tap length is presented.
Abstract: In this brief, we present a digit-reconfigurable finite-impulse response (FIR) filter architecture with a very fine granularity. It provides a flexible yet compact and low-power solution to FIR filters with a wide range of precision and tap length. Based on the proposed architecture, an 8-digit reconfigurable FIR filter chip is implemented in a single-poly quadruple-metal 0.35-mum CMOS technology. Measurement results show that the fabricated chip operates up to 86 MHz when the filter draws 16.5 mW of power from a 2.5-V power supply
TL;DR: In this article, the effect of the long-period filter cut-off on elastic spectral displacements was investigated using a strong ground-motion database from Europe and the Middle East, and the relation between the filter and oscillator responses was considered to observe the influence of Tc for both analogue and digital records.
Abstract: The effect of the long-period filter cut-off, Tc, on elastic spectral displacements is investigated using a strong ground-motion database from Europe and the Middle East. The relation between the filter and oscillator responses is considered to observe the influence of Tc for both analogue and digital records, and the variations with site classification, magnitude, filter order and viscous damping. Robust statistics are derived using the re-processed European data to generalize the effects of the long-period filter cut-off on maximum oscillator deformation demands as a function of these seismological and structural features. Statistics with a 95% confidence interval are derived to suggest usable period ranges for spectral displacement computations as a function of Tc. The results indicate that the maximum period at which spectral displacements can be confidently calculated depend strongly on the site class, magnitude and filter order. The period range where reliable long-period information can be extracted from digital accelerograms is twice that of analogue records. Copyright © 2006 John Wiley & Sons, Ltd.
TL;DR: For a three-phase buck-type pulsewidth modulation rectifier input stage of a high-power telecommunications power supply module, a differential-mode (DM) electromagnetic compatibility (EMC) filter is designed for compliance to CISPR 22 Class B.
Abstract: For a three-phase buck-type pulsewidth modulation rectifier input stage of a high-power telecommunications power supply module, a differential-mode (DM) electromagnetic compatibility (EMC) filter is designed for compliance to CISPR 22 Class B in the frequency range of 150 kHz-30 MHz. The design is based on a harmonic analysis of the rectifier input current and a mathematical model of the measurement procedure including the line impedance stabilization network (LISN) and the test receiver. Guidelines for a successful filter design are given, and components for a 5-kW rectifier prototype are selected. Furthermore, formulas for the estimation of the quasi-peak detector output based on the LISN output voltage spectrum are provided. The damping of filter resonances is optimized for a given attenuation in order to facilitate a higher stability margin for system control. Furthermore, the dependence of the filter input and output impedances and the attenuation characteristic on the inner mains impedance are discussed. As experimentally verified by using a three-phase common-/Differential-Mode separator, this procedure allows accurate prediction of the converter DM conducted emission levels and therefore could be employed in the design process of the rectifier system to ensure compliance to relevant EMC standards
TL;DR: In this paper, a single phase inductance-capacitance inductance (LCL) output stage for grid coupled inverters is designed and built, and an accurate model and observer of the output filter and the distorted grid voltage are implemented.
Abstract: In this paper, a single phase inductance–capacitance– inductance (LCL) output stage for grid coupled inverters is designed and built. An accurate model and observer of the output filter and the distorted grid voltage are implemented. The paper deals with the construction of a 14-state model, and the feedback control loop to obtain adequate closed loop response. Simulations indicate a good performance of the controller, with a total harmonic current distortion (THD) below 1%. Experimental results confirm simulations, and illustrate the correct operation of the Kalman observer to estimate the distorted grid voltage (THD 3%). The observer only uses the inverter current measurement as input. The output filter effectively reduces the pulsewidth modulation harmonics in the grid current.
Patent•
17 Feb 2006
TL;DR: In this article, a mirror-based resonant tunable filter is selected in which the spectral response in reflection has an angular dependence, and a tilt scheme is used whereby by selecting an appropriate angle between the filter's nominal optical axis and the cavity optical axis, a narrowband peak spectral reflection is provided to the laser cavity.
Abstract: An external cavity laser has a mirror-based resonant tunable filter, such as a Fabry Perot tunable filter or Gires-Tournois interferometer tuning element, with the tunable filter being preferably used as a laser cavity mirror. A mirror-based resonant tunable filter is selected in which the spectral response in reflection has an angular dependence. A tilt scheme is used whereby by selecting an appropriate angle between the filter's nominal optical axis and the cavity optical axis, a narrowband peak spectral reflection is provided to the laser cavity. This tunable narrowband spectral reflection from the filter is used to lock and tune the laser output wavelength.
TL;DR: A fourth-order low-pass continuous-time filter for a UMTS/WLAN receiver of a reconfigurable terminal is presented and the full chip has been designed using an automatic design tool, which is validated by the agreement between the experimental results and the expected performance.
Abstract: A fourth-order low-pass continuous-time filter for a UMTS/WLAN receiver of a reconfigurable terminal is presented. The filter uses the cascade of two Active-Gm-RC biquad cells. A single opamp is used for each biquad and its unity-gain-bandwidth is comparable to the filter cut-off frequency. Thus, the opamp power consumption is strongly reduced w.r.t. other closed-loop filter configurations. The cut-off frequency deviation due to the technological spread, aging and temperature variation is adjusted by an on-chip tuning circuit. The device in a 0.13 mum CMOS technology occupies a 0.9 mm2 area and it consumes 3.4 mW and 11 4.2 mW for the UMTS and WLAN, respectively. The full chip has been designed using an automatic design tool, which is validated by the agreement between the experimental results and the expected performance