Efficient implementation of all-digital interpolation

B-splines are commonly used for continuous representation of discrete time signals. This kind of representation proves to be very useful in applicatio ns such as image interpolation, rotation and edge detection. In all these a pplications, the first step is to compute the B-spline coefficients of the signal, and this involves the use of an IIR noncausal filter called the dir ect B-spline filter. The signal reconstruction is achieved using the indire ct B-spline filter, which in many applications operates at a higher rate. In this paper, we introduce a simplified implementation of the signal recon struction part that will significantly reduce the overall complexity. We al so show that the direct B-spline filter can safely be replaced with a short FIR filter, without compromising the performance of the traditional method . Numerous examples will show both visually and numerically that the differ ences between this method and the traditional one are indeed very small. Fi nally, we report the performance of these newly proposed methods in other i mage processing applications such as edge detection and least squares appro ximation.