This paper presents an interpolation/extrapolation technique for sequence partitions. It consists of four steps: region parametrization, region interpolation, region ordering and partition creation. The evolution of each region is divided into two types: regular motion and random deformations. Both types of evolution are parametrized by means of the Fourier descriptors of the regions and they a...

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 this section we discuss the theory of Fourier Series for functions of a real variable. In the next sections we will study an analogue which is the “discrete” Fourier Transform. Early in the Nineteenth century, Fourier studied sound and oscillatory motion and conceived of the idea of representing periodic functions by their coefficients in an expansion as a sum of sines and cosines rather tha...

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.

at the target knots yj ∈ [−14 , 1 4 ], j = 1, . . . ,M , where σ = a + ib, a > 0, b ∈ R denotes a complex parameter. Fast Gauss transforms for real parameters σ were developed, e.g., in [15, 8, 9]. In [12], we have specified a more general fast summation algorithm for the Gaussian kernel. Recently, a fast Gauss transform for complex parameters σ with arithmetic complexity O(N log N + M) was int...

We then show how to derive simple operations (image shift, rotation and stretch) directly in the curvelet domain. The basic transforms are needed for subsequent seismic migration. We demonstrate how to interpolate in the curvelet domain, using the Shannon interpolation formula. It appears that the interpolation scheme imposes some specific conditions on the shapes of the filters used for the cu...

The emergence of multimedia technology and the rapid growth in the number and type of multimedia assets controlled by several entities, yet because the increasing range of image and video documents showing on the Internet, have attracted vital analysis efforts in providing tools for effective retrieval and management of visual data. So the need for image retrieval system arose. Out of many exis...

White Blood Cancer is one of the deadliest diseases for human being and its presence can be early diagnosed by detecting the existence of nucleolus in White Blood Cells (WBC) of peripheral blood smear images. In this paper, the author would like to compare the performance of nucleolus candidate zone extraction algorithm by utilizing Wavelet transforms and Curvelet transform. The result confirms...

Discrete transforms such as the discrete Fourier transform (DFT) or the discrete Hartley transform (DHT) furnish an indispensable tool in signal processing. The successful application of transform techniques relies on the existence of the so-called fast transforms. In this paper some fast algorithms are derived which meet the lower bound on the multiplicative complexity of the DFT/DHT. The appr...