scholarly journals Interpolation Filter Design Based on All-Phase DST and Its Application to Image Demosaicking

Information ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 206 ◽  
Author(s):  
Xiao Zhou ◽  
Chengyou Wang ◽  
Zhi Zhang ◽  
Qiming Fu

Based on a deep understanding of all-phase digital filter (APDF) design and all-phase biorthogonal transform (APBT), this paper will further study the windowed all-phase digital filter (WAPDF) and windowed all-phase biorthogonal transform (WAPBT), discuss the principle of the WAPBT, and provide a unified construction method of the all-phase transform (APT). Based on a type of orthogonal transform, i.e., discrete sine transform (DST), an interpolation filter called an all-phase DST (APDST) filter is constructed and used for image demosaicking; it is compared with bilinear interpolation and all-phase inverse discrete cosine transform (APIDCT) interpolation filters, to test its performance in image interpolation and provide analysis and discussion. The experimental results show that APIDCT and APDST filters with a size of 7 × 7 are similar in interpolation performance, but better than the bilinear interpolation method. In addition to its use in image interpolation demosaicking, the low-pass filter designed in this paper can also be widely used in image interpolation, image denoising, image resizing, and other fields of image processing.

2021 ◽  
Author(s):  
Hongbo Sun

In this study, we presented an integrated approach to the design of digital filters using the digital filter package (DFP). We added four new features to DFP: multi-band filter design, adaptive filter design, two-dimensional filter design and TMS320 code generation. We discuss each of these new features from design consideration to realization. We present design examples and demonstrate the design results generated by DFP. We also discuss GUI design in MATLAB, the DFP GUI design structure and the data transition structure from one DFP function to another. We show that DFP can allow efficient design of the flollowing filter structures: low pass filter, high pass filter, band pass filter, band stop filter, multi band filter, differentiator, Hilbert Transformer, adaptive and 2D filters. DFP allows the use of a variety of FIR and IIR design methods as well as hardware implementation structures; it provides a useful tool to quickly examine a variety of filters and understand the trade-offs involved in varying the characteristics of the filter.


1976 ◽  
Vol 13 (4) ◽  
pp. 371-379
Author(s):  
S. M. Bozic

The object of this paper is to examine and explain in a simple manner some of the inherent properties of the bilinear z-transformation as used in the recursive low-pass filter design. It also compares it with the standard z-transformation and illustrates some finer points on a simple design example.


2021 ◽  
Author(s):  
Hongbo Sun

In this study, we presented an integrated approach to the design of digital filters using the digital filter package (DFP). We added four new features to DFP: multi-band filter design, adaptive filter design, two-dimensional filter design and TMS320 code generation. We discuss each of these new features from design consideration to realization. We present design examples and demonstrate the design results generated by DFP. We also discuss GUI design in MATLAB, the DFP GUI design structure and the data transition structure from one DFP function to another. We show that DFP can allow efficient design of the flollowing filter structures: low pass filter, high pass filter, band pass filter, band stop filter, multi band filter, differentiator, Hilbert Transformer, adaptive and 2D filters. DFP allows the use of a variety of FIR and IIR design methods as well as hardware implementation structures; it provides a useful tool to quickly examine a variety of filters and understand the trade-offs involved in varying the characteristics of the filter.


2013 ◽  
Vol 475-476 ◽  
pp. 161-166
Author(s):  
Wu Liu ◽  
Guo Qing Ding ◽  
Xin Chen

Coriolis flow meters are used in measuring flow amount of natural gas and oil due to the good performance and high precision. Orthogonal decomposition algorithm is the most efficient algorithm with the highest precision in processing the digital signals of Coriolis flow meters, and digital filter design is vital important in the algorithm. In this paper we introduce a digital filter system combining the self-adaptive lattice notch filter and low pass filter embedded with Hanning Window or Kaiser Window, we also discussed the parameters selection and adjusting method deeply and systematically. For self-adaptive lattice notch filter, we calculate the key feedback parameter ρ based on bandwidth BW, leading the relative error of frequency calculated within 0.01%. For low pass digital filter, we adjust the filter order through monitoring the sine feature of the orthogonal component that has passed the low pass filter, and the relative errors of phase difference are within 0.1%. We also demonstrate the feasibility of this system through simulation under MATALAB system and calculating experiments data of Coriolis flow meter.


2018 ◽  
Vol 11 (5-6) ◽  
pp. 509-516 ◽  
Author(s):  
Dilip Kumar Choudhary ◽  
Mahmoud A. Abdalla ◽  
Raghvendra Kumar Chaudhary

AbstractA compact low-pass filter (LPF) with wide rejection band based on T-type circuit of an enhanced dual composite right-/left-handed (D-CRLH) resonator is presented in this paper. The resonator has only one cell with series and parallel tank circuit. The parallel LC tank circuit has been realized by an interdigital capacitor and one shorted finger, whereas its series LC tank circuit is realized by an air gap capacitance and a short circuit stub. The filter has wide rejection band bandwidth with three transmission zeros (TZs). The filter bandwidth and TZs frequencies are controlled by the D-CRLH element values. The results of the proposed filter demonstrate minimum insertion loss in passband, high roll-off rate, and good figure of merit. The measured results are in good agreement with the simulated results. The detailed filter design is discussed in terms of circuit modeling, dispersion analysis, and full-wave simulation. Finally, the filter size is compact (0.10 λg × 0.15 λg) at cut-off frequency.


Author(s):  
Darine Kaddour ◽  
Jean-Daniel Arnould ◽  
Philippe Ferrari

In this paper, a miniaturized bandpass filter for ultra-wide-band applications is proposed. It is based on the embedding of high-pass structures in a low-pass filter. A semi-lumped technology combining surface-mounted capacitors and transmission lines has been used. The filter design rules have been carried out. Furthermore, two filters having a 3-dB fractional bandwidth of 142 and 150%, centered at 0.77 and 1 GHz, respectively, have been realized for a proof of concept. Measured characteristics, in good agreement with simulations, show attractive properties of return loss (|S11| <−18 dB), insertion loss (<0.3 dB), and a maximum group delay and group delay variation of 2 and 1.3 ns, respectively. A distributed filter based on the same low-pass/high-pass approach has been also realized and measured for comparison. The size reduction reaches 85% for the semi-lumped filter, and its selectivity is improved with a shape factor of 1.3:1 instead of 1.5:1. The semi-lumped filter's drawback is related to a smaller rejection bandwidth compared to the distributed one. To improve the high-frequency stopband, an original technique for spurious responses suppression based on capacitively loaded stubs has been proposed. Even if the performances do not reach that obtained for the distributed approach, with this technique spurious responses are pushed until eight times the center frequency. A sensitivity study vs. critical parameters has also been carried out, showing the robustness of the design.


Author(s):  
Hamid Radmanesh

In this paper, the application of microstrip technology is investigated in low-pass filters. A cascade microstrip low-pass filter with a sharp frequency response and a good cut-off bandwidth is presented using a modified radial resonator. The advantages of this proposed filter include minor losses in the transit band as well as the desired return. This filter design shows consistency when compared with the results of simulation and model performance. A comparison between the parameter values of this filter and previous structures indicates that it is desirable. The proposed filter can be used in modern communication systems such as aircraft distance measurement equipment (DME) antenna.


1965 ◽  
Vol AU-13 (5) ◽  
pp. 104-111 ◽  
Author(s):  
E. Foster

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