A new computationally efficient framework for vehicle tracking on a mobile platform is proposed. The principal component of the framework is the log-polar transformation applied to video frames captured from a standard uniformly sampled format camera. The log-polar transformation provides two major benefits to real-time vehicle tracking from a mobile vehicle platform moving along a single or mu...

In this paper, an iterative time-frequency (TF) synthesis/time-varying ltering algorithm in the discrete Gabor transform domain is proposed. A su cient condition is obtained for the Gabor synthesis and analysis window functions so that the iterative algorithm converges. It is proved that under the condition the algorithm converges to a signal that has its Gabor transform located exactly in a de...

In the companion paper, we addressed the low-power DCT/IDCT VLSI architectures of linear complexity increase based on the multirate approach. In this paper, we will discuss other aspects of the low-power design. Firstly, we consider the design of low-power architectures that can lower the power consumption at only O(log M) increase in hardware complexity. Next, we will extend the low-power DCT ...

Obtaining a non-trivial (super-linear) lower bound for computation of the Fourier transform in the linear circuit model has been a long standing open problem for over 40 years. An early result by Morgenstern from 1973, provides an Ω(n log n) lower bound for the un-normalized Fourier transform when the constants used in the computation are bounded. The proof uses a potential function related to ...

We consider the problem of computing a k-sparse approximation to the discrete Fourier transform of an n-dimensional signal. Our main result is a randomized algorithm that computes such an approximation using O(k log n(log log n)) signal samples in time O(k log n(log log n)), assuming that the entries of the signal are polynomially bounded. The sampling complexity improves over the recent bound ...

We prove the boundedness of a general class of Fourier multipliers, in particular of the Hilbert transform, on modulation spaces. In general, however, the Fourier multipliers in this class fail to be bounded on L spaces. The main tools are Gabor frames and methods from time-frequency analysis.

The derivation of the noise covariance of the ith projection view in Equation (5) is similar to the Appendix of Tilley et al. [22]; the difference is that our application is for DBT geometry in which the imaged volume is very close to the detector. As a result, we neglect the focal spot blur so the blurring operation in our study only includes the detector blur. For the directly measured projec...

A group of algorithms is presented generalizing the fast Fourier transform to the case of nonin-teger frequencies and nonequispaced nodes on the interval [-r, r]. The schemes of this paper are based on a combination of certain analytical considerations with the classical fast Fourier transform and generalize both the forward and backward FFTs. Each of the algorithms requires O(N log N + N-log(I...

In order to solve the problem of rotation invariant texture image retrieval, an image retrieval algorithm based on Log-Polar and nonsubsampled contourlet transform (NSCT) is proposed. Log-Polar transform was first applied to texture image to convert the rotation to translation. Then, translation invariant NSCT was employed to decompose the transformed images. Standard deviations, energies and e...

A new method of parameter identification based on linear time-frequency representation and Hilbert transform is proposed in this paper to identify modal parameters of linear time-varying systems from measured vibration responses. With Gabor expansion and synthesis theory, measured responses are represented in time-frequency domain and modal components are reconstructed by time-frequency filteri...