TY  - JOUR
JF  - IEEE Transactions on Signal Processing
PB  - IEEE
EP  - 1637
ID  - upm9450
SN  - 1053-587X
UR  - http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=5339141&tag=1
A1  - Perez Villalon, Gerardo
IS  - 3
AV  - public
TI  - Quasi-interpolation by means of filter-banks
SP  - 1628
N2  - We consider the problem of approximating a regular function f(t) from its samples, f(nT), taken in a uniform grid. Quasi-interpolation schemes approximate f(t) with a dilated version of a linear combination of shifted versions of a kernel ??(t), specifically fapprox T(t) = ??af[n]??(t/T - n), in a way that the polynomials of degree at most L-1 are recovered exactly. These approximation schemes give order L, i.e., the error is O(TL) where T is the sampling period. Recently, quasi-interpolation schemes using a discrete prefiltering of the samples f(nT) to obtain the coefficients af[n], have been proposed. They provide tight approximation with a low computational cost. In this work, we generalize considering rational filter banks to prefilter the samples, instead of a simple filter. This generalization provides a greater flexibility in the design of the approximation scheme. The upsampling and downsampling ratio r of the rational filter bank plays a significant role. When r = 1, the scheme has similar characteristics to those related to a simple filter. Approximation schemes corresponding to smaller ratios give less approximation quality, but, in return, they have less computational cost and involve less storage load in the system
VL  - 58
Y1  - 2010/02//
ER  -