Fourier descriptors are powerful features for the recognition of two-dimensional connected shapes. In this article, we propose a method to define Fourier descriptors even for broken shapes, i.e. shapes that can have more than one contour. The method is based on the convex hull of the shape and the distance to the closest actual contour point along the convex hull. We define different invariant ...

In some signal processing applications, the input data are real. In this case, the Bruun algorithm for computation of the Discrete Fourier Transform (DFT) is attractive. This correspondence offers a pipeline and a recirculated shuffle network implementation of the Bruun algorithm. The parallel pipeline and recirculated FFT structures are implemented based on the modified perfect shuffle network.

In this paper the complexity of the local solution of Fredholm integral equations is studied. For certain Sobolev classes of multivariate periodic functions with dominating mixed derivative we prove matching lower and upper bounds. The lower bound is shown using relations to s-numbers. The upper bound is proved in a constructive way providing an implementable algorithm of optimal order based on...

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This paper proposes an efficient memory-based radix-2 FFT architecture, which greatly improves the memorybased FFT [5], [6] by reducing 50% memory size requirement, while maintaining a simple address generator. Specifically the memory size is reduced to 1.25N words. In addition, the multiplier utilization rate is 100%.