Non-uniform bandwidth frequency-planar (NUB-FP) filter banks

Abstract

A 3D non-uniform bandwidth frequencyplanar (NUB-FP) filter bank structure is described, having a steady-state frequency response with a 3D stop band that approximates that of a wide band 3D cone.Equivalently, the 3D pass band ideally surrounds a 3D plane and has a 3D bandwidth that is approximately proportional to distance from the origin in the 3D frequency space. It is shown that the proposed NUB-FP filter bank is useful for the selective filtering of 3D spatio-temporal constant velocity signals (Le. linear trajectory signals) and yields improved results over that of conventional 3D frequency-planar (FP) velocity fdters. An example is given that yields improved moving high-frequency object details in a de-noised video sequence.

3-D IIR filtering using decimated DFT-polyphase filter bank structures

“…Previous studies [ 1] [2] [3] [4] [5] [6] [7] [8] [9] showed that 3D linear digital filtering is often preferred to selectively enhance 3D IT signals based on their trajectories and 3D plane-waves based on their DOAs, due to their superior performance in noisy environments. Several useful 3D passband shapes are known and the simplest way to obtain filters having passbands that closely approximate these shapes is often to design 3D finite impulse response (FIR) filters.…”

“…Attempts to realize 3D hR filters using closed form expressions have been reported [9] in order to selectively enhance 3D plane-waves with one particular range of DOAs. Earlier work of our multidimensional signal processing (MDSP) group [4] [5] [6] [7] aimed at demonstrating the use of a closed form design method for designing general 3D hR filters that may be used to selectively enhance 3D IT signals based on their trajectories and for designing general 3D hR filters that may be used to selectively enhance 3D plane-waves based on their DOA. So far promising results have been reported [4][5][6] [7].…”

“…Earlier work of our multidimensional signal processing (MDSP) group [4] [5] [6] [7] aimed at demonstrating the use of a closed form design method for designing general 3D hR filters that may be used to selectively enhance 3D IT signals based on their trajectories and for designing general 3D hR filters that may be used to selectively enhance 3D plane-waves based on their DOA. So far promising results have been reported [4][5][6] [7]. But it has been concluded that in order to utilize these filters efficiently, the computational complexity needs to be reduced [5] [6].…”

Improving the Attenuation of Moving Interfering Objects in Videos Using Shifted-Velocity Filtering

“…Such VFs find numerous applications in advanced driver assistance systems, traffic analysis, motion detection and analysis, radar tracking and the attenuation of sunlight flicker patterns [1]- [10]. Previously reported designs of VFs include both finite-extent impulse response (FIR) and infiniteextent impulse response (IIR) digital filters having planarshaped [5], [11], [12] or wedge-shaped (i.e., exterior of a wide-angle cone) [3], [7], [8], [13], [14] passbands in the associated spatio-temporal 3-D frequency domain. We refer to these filters as conventional VFs.…”

Highly directional and selective three dimensional adaptive IIR filter

“…[3]. One of the challenges in designing such adaptive 3D filter bank is to alleviate the distortion caused [1], [2], [4] by the 3D bilinear transformation, which is applied to the continuous domain pseudo-passive 3D IIR transfer function of each subband filter of the filter bank. These distortions are especially significant in the 3D region away from the origin in the 3D Nyquist box.…”