We have implemented a four-tap adaptive lter in a continuous-time analog VLSI circuit. Since an ideal delay is impossible to implement in continuous-time hardware, we implemented the delay line as a cascade of low-pass lters (called the Gamma lter). Since many years of research in our lab has shown that the Gamma lter outperforms the delay line for a wide range of applications, the Gamma lter s...

This paper presents a generalization of the Canny–Deriche $lter for ramp edge detection with optimization criteria used by Canny (signal-to-noise ratio, localization, and suppression of false responses). Using techniques similar to those developed by Deriche, we derive a $lter which maximizes the product of the $rst two criteria under the constraint of the last one. The result is an in$nite len...

Scientists within the Long-Term Ecological Research (LTER) Network have provided leadership in ecological informatics since the inception of LTER in 1980. The success of LTER, where research projects span wide temporal and spatial scales, depends on the quality and longevity of the data collected. Scientists have devised data collection, data entry, data access, QA/QC and archiving strategies f...

A multi lter is a lter with matrix-valued coe cients, and is used in the processing of vector-valued signals, e.g. color images. Convolution becomes a vector sum of matrix-vector multiplication. In this paper, we e ciently implement a multi lter as a parallel combination of scalar lters. Each scalar lter works on one component of the input vector signal, which increases processing speed by the ...

A matlab toolbox has been developed that analyzes digital lter structures. After describing the digital lter structure in a SPICE-like format, the programs of this toolbox can map a digital lter structure into a state-space description, convert a state-space description to a z-domain transfer function, compute the maximum signal magnitude when input is bounded by unity, compute noise power at t...

|The magnitude of the lters associated with Daubechies' wavelets is shown to converge to an ideal high-pass lter when the length of the support of the wavelets increases to 1. The convergence of the lters is monotonic. That is, the larger support of a Daubechies' wavelet, the better quality of the lter associated with. The rate of the convergence is also given. The magnitude of the lter associa...

This article addresses the problem of designing twochannel near-perfect-reconstruction lter banks over multidimensional lattices. First, a cosine-modulated lter structure having arbitrary spatial shift and phase parameters is considered. The use of this structure leads to many possible two-channel multirate systems. The perfect reconstruction conditions are studied and appropriate choices for t...

Recently connections between the wavelet transform and lter banks have been established. We show that similar relations exist between the Gabor expansion and DFT lter banks. We introduce the \z-Zak transform" by suitably extending the discrete-time Zak transform and show its equivalence to the polyphase representation. A systematic discussion of parallels between DFT lter banks and Weyl-Heisenb...

In this paper we have two interesting results. One is of theoretical interest and the other practical. The theoretical result is that the optimum FIR orthonormal lter bank of a xed nite degree that maximizes the coding gain does not always contain an optimum compaction lter. In other words, in general, there does not exist a principal component lter bank (PCFB) of a given nonzero degree. This i...

| This paper studies approximations for a class of nonlinear lters known as Volterra lters. Although the Volterra lter provides a relatively simple and general representation for nonlinear ltering, often it is highly over-parameterized. Due to the large number of parameters, the utility of the Volterra lter is limited. The over-parameterization problem is addressed in this paper using a tensor ...