Ioannis Konstantinidis

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It is becoming increasingly important to be able to credential and identify authorized personnel at key points of entry. Such identity management systems commonly employ biometric identifiers. In this paper, we present a novel multimodal facial recognition approach that employs data from both visible spectrum and thermal infrared sensors. Data from multiple(More)
We present a general mathematical theory for lifting frames that allows us to modify existing filters to construct new ones that form Parseval frames. We apply our theory to design nonseparable Parseval frames from separable (tensor) products of a piecewise linear spline tight frame. These new frame systems incorporate the weighted average operator, the(More)
In this paper, we propose a new method to denoise a surface. This method is motivated by the Laplacian flow and the theory of tight frames. Mesh denoising is achieved by building local Wiener filtering into the detail representation of the surface. We have performed a number of experiments to assess the accuracy, advantages and limitations of our approach(More)
In this paper, we present a novel frames-based denoising algorithm. Using a general result on lifting frames, we construct a non-separable 3D frame capable of robust edge detection. This frame detects edge information by ensemble thresholding of the filtered data. The denoising uses a hysteresis thresholding step and an affine thresholding function, which(More)
CAZAC (Constant Amplitude Zero Auto-Correlation) sequences are important in waveform design because of their optimal transmission efficiency and tight time localization properties. Certain classes of CAZAC sequences have been used in radar processing for many years, while recently discovered sequences invite further study. This paper compares different(More)
Constant amplitude zero autocorrelation (off the dc component) waveforms are constructed. These are called CAZAC waveforms. In the d-dimensional case they consist of N vectors, where N is given, and N is generally greater than d. The constructions are algebraic and have been implemented in user friendly software. They have the added feature that they are a(More)
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