tic signal. The discrete-time ratio spectrum of X ( k ) is Recently, Lam and Harris have developed a novel specN-I tral representation called the ratio spectrum [l]. The I K r " ( k ) 1 2 (1) Output Power k=O N-1 ratio spectrum is formed by taking the ratio of the power of a low-pass filtered signal to the power of the original unfiltered signal for all filter cutoff frequencies. FeaX(m) = Inpu...

In this paper, we propose a blind method using hybrid signal extrapolation at the decoder to regenerate lost high-frequency components which are removed by encoders. At first, a decoded signal spectral resolution is enhanced by time domain linear predictive extrapolation and then the cut off frequency of each frame is estimated to avoid the spectrum gap between the end of original low frequency...

Due to the independence of azimuth-invariant assumption an echo signal, time-domain algorithms have significant performance advantages for missile-borne synthetic aperture radar (SAR) focusing with curve moving trajectory. The Cartesian factorized back projection (CFBP) algorithm is a newly proposed fast implementation which can avoid massive interpolations improve computational efficiency. How...

Line Spectrum Pair (LSP) was first introduced by Itakura [1,21 as an alternative LPC spectral representations. It was found that this new representation has such interesting properties as (I) all zeros of LSP polynomials are on the unit circle, (2) the corresponding zeros of the symmetric and anti-symmetric LSP polynomials are interlaced, and (3) the reconstructed LPC all-pole filter preserves ...

We propose a new, simple approach to enhance the spectral compression process arising from nonlinear pulse propagation in an optical fibre. We numerically show that an additional sinusoidal temporal phase modulation of the pulse enables efficient reduction of the intensity level of the side lobes in the spectrum that are produced by the mismatch between the initial linear negative chirp of the ...

We propose a generic framework to describe classical Ising-like models defined on arbitrary graphs. The energy spectrum is shown to be the Hadamard transform of a suitably defined sparse "coding" vector associated with the graph. We expect that the existence of a fast Hadamard transform algorithm (used, for instance, in image compression processes), together with the sparseness of the coding ve...

The major cue to shape from texture is the compression of texture as a function of surface curvature [J. Exp. Psychol. 13, 242 (1987); Vision Res. 33, 827 (1993)]. A number of computational models have been proposed in which compression is measured by detection of changes in the spatial-frequency spectrum [Comput. Graphics Image Process. 5, (1976)]. We propose that the visual system uses a stra...

Subject terms: electro-holography, holographic computation, holographic bandwidth compression, diffractionspecific, fringelet, hogel vector Abstract. A novel electro-holographic bandwidth compression technique, fringelet bandwidth compression, is described and implemented. This technique uses spatial subsampling to reduce the bandwidth and complexity of holographic fringe computation for real-t...

In this paper, a practical quasi-lossless compression concept and corresponding compression ratio and quality requirements are proposed for the multiple band images database construction and web release application. The physical therapy of 3D wavelet analysis to the multiple band images data compression is discussed and the fast 3D wavelet transformation model and algorithm to the multiple band...

This work proposes a direct sequence spread spectrum transmitter with high transmission range and efficiency for audio signals. It is shown that by choosing high process gain for spread spectrum signal the data could reach a range of 55km in the 2.4GHz ISM band. By employing a light modulation scheme, we have a relaxed SNR requirement for having a low bit error rate (BER) which translates to re...