scholarly journals Gaussian Circular 2D FIR Filters Designed Using Analytical Approach

This paper proposes an analytical design procedure for a particular class of 2D filters, namelyGaussian-shaped, circularly-symmetric FIR filters. We approach both low-pass and band-pass circular filters,which are adjustable in selectivity and peak frequency. The design starts from a given 1D Gaussian prototypefilter, approximated using the Chebyshev series. A frequency transformation is applied to derive the circularfilter. Several design examples are provided for both types of filters. The filters designed through this methodare efficient, their frequency response results in a factored or nested form, convenient for implementation.

2006 ◽  
Vol 19 (2) ◽  
pp. 299-316 ◽  
Author(s):  
Radu Matei ◽  
Liviu Goraş

This paper proposes a simple and efficient method for designing a class of circularly-symmetric spatial linear filters implemented on cellular neural networks. The design method relies on a so-called 1-D prototype filter, with desired characteristics and on a 1-D to 2-D spatial frequency transformation. Several design examples are given, for 2-D low-pass and band-pass filters (both of FIR and IIR type) with imposed cut-off or peak frequency and a specified selectivity. Finally, simulation results are provided, on a real grayscale biomedical image.


2021 ◽  
Author(s):  
Ara Abdulsatar Assim Assim

This paper demonstrates the design and implementation of an inductorless analog band-pass filter (BPF). Band-pass filters are widely used in communication systems, wireless transceivers and audio systems, they only pass signals within a desired frequency range. The principles mentioned in this article can be generalized to design any analog filter regardless of its order, approximation and prototype. The design procedure can be broken down into three main parts, first of all, a passive low-pass filter (LPF) is implemented, then the passive LPF is converted into a passive BPF. Finally, the passive BPF is transformed into an active BPF by adding operational amplifiers. The active BPF is then modified into two different topologies, the first in which the inductors are replaced with simulated- inductors (gyrators), while in the second topology, less operational amplifiers are used. <br>


2015 ◽  
Vol 06 (02) ◽  
pp. 30-48 ◽  
Author(s):  
Emmanuel S. Kolawole ◽  
Warsame H. Ali ◽  
Penrose Cofie ◽  
John Fuller ◽  
C. Tolliver ◽  
...  

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Radu Matei

This paper proposes an analytical design method for two-dimensional square-shaped IIR filters. The designed 2D filters are adjustable since their bandwidth and orientation are specified by parameters appearing explicitly in the filter matrices. The design relies on a zero-phase low-pass 1D prototype filter. To this filter a frequency transformation is next applied, which yields a 2D filter with the desired square shape in the frequency plane. The proposed method combines the analytical approach with numerical approximations. Since the prototype transfer function is factorized into partial functions, the 2D filter also will be described by a factorized transfer function, which is an advantage in implementation.


2021 ◽  
Author(s):  
Ara Abdulsatar Assim Assim

This paper demonstrates the design and implementation of an inductorless analog band-pass filter (BPF). Band-pass filters are widely used in communication systems, wireless transceivers and audio systems, they only pass signals within a desired frequency range. The principles mentioned in this article can be generalized to design any analog filter regardless of its order, approximation and prototype. The design procedure can be broken down into three main parts, first of all, a passive low-pass filter (LPF) is implemented, then the passive LPF is converted into a passive BPF. Finally, the passive BPF is transformed into an active BPF by adding operational amplifiers. The active BPF is then modified into two different topologies, the first in which the inductors are replaced with simulated- inductors (gyrators), while in the second topology, less operational amplifiers are used. <br>


1968 ◽  
Vol 11 (1) ◽  
pp. 63-76
Author(s):  
Donald C. Teas ◽  
Gretchen B. Henry

The distributions of instantaneous voltage amplitudes in the cochlear microphonic response recorded from a small segment along the basilar membrane are described by computing amplitude histograms. Comparisons are made between the distributions for noise and for those after the addition to the noise of successively stronger sinusoids. The amplitudes of the cochlear microphonic response to 5000 Hz low-pass noise are normally distributed in both Turn I and Turn III of the guinea pig’s cochlea. The spectral composition of the microphonic from Turn I and from Turn III resembles the output of band-pass filters set at about 4000 Hz, and about 500 Hz, respectively. The normal distribution of cochlear microphonic amplitudes for noise is systematically altered by increasing the strength of the added sinusoid. A decrease of three percent in the number of small amplitude events (±1 standard deviation) in the cochlear microphonic from Turn III is seen when the rms voltage of a 500 Hz sinusoid is at −18 dB re the rms voltage of the noise (at the earphone). When the rms of the sinusoid and noise are equal, the decrease in small voltages is about 25%, but there is also an increase in the number of large voltage amplitudes. Histograms were also computed for the output of an electronic filter with a pass-band similar to Turn III of the cochlea. Strong 500 Hz sinusoids showed a greater proportion of large amplitudes in the filter output than in CM III . The data are interpreted in terms of an anatomical substrate.


Author(s):  
K.R. Shankarkumar ◽  
Gokul Kumar

: Filtering is an important step in the field of image processing to suppress the required parts or to remove any artifacts present in it. There are different types of filters like low pass, high pass, Band pass, IIR, FIR and adaptive filtering etc.., in these filters adaptive filters is an important filter because it is used to remove the noisy signal and images. Least Mean Square filter is a type of an adaptive filtering which is used to remove the noises present in the medical images. The working of LMS is based on the minimization of the difference between the error images using a closed loop feedback. Therefore presented technique called as Q-CSKA. Here the CSKA performs its operation in stages which is based on the nucleus stage. In the traditional CSKA the nucleus stage is depend on the parallel prefix adder in this work it is replaced by the QCA adder. The QCA adder utilizes the less area compared to PPA and it can be realized in Nanometer range also. For multiplexers, And OR Invert, OR and Invert logic is used to reduce the area and delay. Due to these advantages of the QCA, AOI-OAI logic the proposed method outperformed the LMS implementation in area, power, and accuracy and delay, this based five type image noise of medical pictures related to the best technique is out comes. It helps to medicinal practitioner to resolve the symptoms of patient with ease.


2007 ◽  
Vol 16 (04) ◽  
pp. 507-516 ◽  
Author(s):  
SHAHRAM MINAEI ◽  
ERKAN YUCE

In this paper, a universal current-mode second-order active-C filter for simultaneously realizing low-pass, band-pass and high-pass responses is proposed. The presented filter employs only three plus-type second-generation current-controlled conveyors (CCCII+s). This filter needs no critical active and passive component matching conditions and no additional active and passive elements for realizing high output impedance low-pass, band-pass and high-pass characteristics. The angular resonance frequency (ω0) and quality factor (Q) of the proposed resistorless filter can be tuned electronically. To verify the theoretical analysis and to exhibit the performance of the proposed filter, it is simulated with SPICE program.


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