In this paper, we present implementations of a pattern recognition algorithm which uses a RBF (Radial Basis Function) neural network. Our aim is to elaborate a quite efficient system which realizes real time faces tra...
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ISBN:
(纸本)0819445584
In this paper, we present implementations of a pattern recognition algorithm which uses a RBF (Radial Basis Function) neural network. Our aim is to elaborate a quite efficient system which realizes real time faces tracking and identity verification in natural video sequences. Hardware implementations have been realized on an embedded system developed by our laboratory. This system is based on a DSP (Digital signal Processor) TMS320C6x. The optimization of implementations allow us to obtain a processing speed of 4.8 images (240 x 320 pixels) per second with a correct rate of 95% of faces tracking and identity verification.
The proceedings contains 58 papers from the conference of SPIE: advancedsignalprocessingalgorithms, architectures, and implementations VIII. The topics discussed include: blind channel identification and extraction...
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The proceedings contains 58 papers from the conference of SPIE: advancedsignalprocessingalgorithms, architectures, and implementations VIII. The topics discussed include: blind channel identification and extraction of more sources than sensors;blind channel estimation for CDMA systems with orthogonal modulation;blind equalization and source separation with MSK inputs and adaptive blind channel estimation by least-squares smoothing for CDMA.
The Sensor-Angle Distribution (SAD) is a recently introduced tool representing the power arriving at each sensor as a function of angle (or spatial frequency). It can be used to characterize near-field scatter environ...
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ISBN:
(纸本)0819445584
The Sensor-Angle Distribution (SAD) is a recently introduced tool representing the power arriving at each sensor as a function of angle (or spatial frequency). It can be used to characterize near-field scatter environments. The SAD, as originally introduced, under-sampled the spatial correlation of the received signal (measured at each sensor) causing the SAD to be aliased for common source location cases. In this paper we indicate how this may be overcome. Additional results are provided showing that the SAD may be implemented as a multiple weighted subarray beamformer.
The Volume contains 44 conference papers. The topic covered include Toeplitz matrices, time-frequency distribution and nonstationary signals, bit-level systolic arrays and computer arithmetic, radar signalprocessing,...
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ISBN:
(纸本)0819406945
The Volume contains 44 conference papers. The topic covered include Toeplitz matrices, time-frequency distribution and nonstationary signals, bit-level systolic arrays and computer arithmetic, radar signalprocessing, signal estimation, array processing and beamforming.
Analytical approximations of translational subpixel shifts in both signal and image registrations are derived by setting the derivatives of a normalized cross correlation function to zero and solving them. Without the...
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ISBN:
(纸本)9780819472946
Analytical approximations of translational subpixel shifts in both signal and image registrations are derived by setting the derivatives of a normalized cross correlation function to zero and solving them. Without the need of iterative searching, this methods achieves a complexity of only O(mn), given an image size of m x n. Without the need to upsample, computation memory is also saved. Tests using simulated signals and images show good results.
作者:
Hughes, DHUSAF
Res Lab Ctr Integrated Transmiss & Exploitat Rome NY 13441 USA
A femtosecond electromagnetic pulse propagating in a linear dispersive medium is analyzed in phase spaces of (space, wave number) and (time, frequency). First moment densities are computed as eigenvalues of differenti...
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ISBN:
(纸本)0819450782
A femtosecond electromagnetic pulse propagating in a linear dispersive medium is analyzed in phase spaces of (space, wave number) and (time, frequency). First moment densities are computed as eigenvalues of differential operators acting on Hilbert ray representations of the pulse in relevant domains. These moment densities are used as metrics in the relevant phase spaces to measure the local mean values and their deviations in position and wavenumber, and in time and frequency. For example, arrival times of the pulse over its spectral content are computed as the mean arrival time at a particular frequency to within one half the local deviation at that frequency. These metrics on the pulse are compared to the relevant phase space Wigner distribution.
This paper shows the design and the evaluation of on-line arithmetic modules for the most common operators used in DSP applications, using FPGAs as the target technology. The designs are highly optimized for the targe...
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ISBN:
(纸本)0819441880
This paper shows the design and the evaluation of on-line arithmetic modules for the most common operators used in DSP applications, using FPGAs as the target technology. The designs are highly optimized for the target technology and the common range of precision in DSP. The results are based on experimental data collected using CAD tools. All designs are synthesized for the same type of devices (Xilinx XC4000) for comparison, avoiding rough estimates of the system performance, and generating a more reliable and detailed comparison of on-line signalprocessing solutions with other 'state of the art' approaches, such as distributed arithmetic. We show that on-line designs have a hard stand for basic DSP applications that use only addition and multiplication. However, we also show that on-line designs are able to overtake other approaches as the applications become more sophisticated, e.g. when data dependencies exist, or when non constant multiplicands restrict the use of other approaches.
This study has been realized to improve industrial machines that allow to analyze planks by detecting their width and too important defects thanks to a computer vision system. These machines are currently piloted by s...
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ISBN:
(纸本)0819437611
This study has been realized to improve industrial machines that allow to analyze planks by detecting their width and too important defects thanks to a computer vision system. These machines are currently piloted by software with the help of PCs. The aim of our work is to realize a hardware card to increase the processing speed.
Multiple input multiple output (MIMO) communications have been a hot research area in recent years. Most literature makes the assumption that the channel information is not known at the transmitter but known perfectly...
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ISBN:
(纸本)0819445584
Multiple input multiple output (MIMO) communications have been a hot research area in recent years. Most literature makes the assumption that the channel information is not known at the transmitter but known perfectly at the receiver. We focus on the situation where both the transmitter and the receiver know the channel information. We consider a transmit diversity scheme that maximizes the signal to noise ratio at the receiver. We analyze its performance in terms of capacity, duality and asymptotic behavior. By simulation, we compare this scheme with Alamouti's transmit diversity to show the advantage of utilizing the channel side information to improve the performance of the wireless systems.
Some image processing applications require an image meet a quality metric before processing it. If an image is so degraded that it is difficult or impossible to reconstruct, the input image may be discarded. In this p...
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ISBN:
(纸本)9780819472946
Some image processing applications require an image meet a quality metric before processing it. If an image is so degraded that it is difficult or impossible to reconstruct, the input image may be discarded. In this paper, we present a metric that measures the relative sharpness with respect to a reference image frame. The reference frame may be a previous input image or an output frame from the system. The sharpness metric is based on analyzing edges. The assumption of this problem is that input images are similar to each other in terms of observation angle and time.
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