Adaptive Background Estimation
نویسندگان
چکیده
Adaptive background techniques are useful for a wide spectrum of applications, ranging from security surveillance, traffic monitoring to medical and space imaging. With a properly estimated background, moving or new objects can be easily detected and tracked. Existing techniques are not suitable for real-world implementation, either because they are slow or because they do not perform well in the presence of frequent outliers or camera motion. We address the issue by computing a learning rate for each pixel, a function of a local confidence value that estimates whether a pixel is (or not) an outlier, and a global correlation value that detects camera motion. After discussing the role of each parameter, we report our experimental results, showing that our technique is fast but efficient, even in a real-world situation. mean value and standard deviation of Gaussian distributions see [6, 7, 81 for a few examples. In all those techniques, a fixed adaptation rate is considered. Namely, for a pixel (or a disparity) value xi, the value pi(t) of the i-th pixel of the estimated background will be given by pi(t) = axi ( t ) + (1 a )p i ( t 1). In this paper, we suggest that the learning rate cr should vary according to a confidence value a t each pixel, in such a way that temporally present outliers be ignored, persistent outlier gradually become part of the background and significant background motion be rapidly learned. Such approach would yield increased flexibility in real-world applications. In traffic surveillance for example, a camera could be switched between different perspectives and rapidly adapt to the new background. Similarly, increased performance would be obtained in segmenting video streams or videoconferencing data with rapidly changing contexts.
منابع مشابه
A Robust Distributed Estimation Algorithm under Alpha-Stable Noise Condition
Robust adaptive estimation of unknown parameter has been an important issue in recent years for reliable operation in the distributed networks. The conventional adaptive estimation algorithms that rely on mean square error (MSE) criterion exhibit good performance in the presence of Gaussian noise, but their performance drastically decreases under impulsive noise. In this paper, we propose a rob...
متن کاملA Robust Adaptive Observer-Based Time Varying Fault Estimation
This paper presents a new observer design methodology for a time varying actuator fault estimation. A new linear matrix inequality (LMI) design algorithm is developed to tackle the limitations (e.g. equality constraint and robustness problems) of the well known so called fast adaptive fault estimation observer (FAFE). The FAFE is capable of estimating a wide range of time-varying actuator fault...
متن کاملDesing And Implementation of Adaptive Active Filters for Exact Estimation And Elimination of AC Network Distortions
In recent years, active filters have been considered and developed for elimation of harmonics in power networks. Comparing with passive, they are smaller and have better compensating characteristics and resistance to line distortions. In this paper, a novel idea based on adaptive filter theory in presented to develop an active filter to eliminate the distortions of an arbitrary signal. Using th...
متن کاملHarmonics Estimation in Power Systems using a Fast Hybrid Algorithm
In this paper a novel hybrid algorithm for harmonics estimation in power systems is proposed. The estimation of the harmonic components is a nonlinear problem due to the nonlinearity of phase of sinusoids in distorted waveforms. Most researchers implemented nonlinear methods to extract the harmonic parameters. However, nonlinear methods for amplitude estimation increase time of convergence. Hen...
متن کاملDesing And Implementation of Adaptive Active Filters for Exact Estimation And Elimination of AC Network Distortions
In recent years, active filters have been considered and developed for elimation of harmonics in power networks. Comparing with passive, they are smaller and have better compensating characteristics and resistance to line distortions. In this paper, a novel idea based on adaptive filter theory in presented to develop an active filter to eliminate the distortions of an arbitrary signal. Using th...
متن کامل