A Novel Current-Mode Multifunction Inverse Filter using Single CFA

A novel current-mode multifunction inverse filter configuration using single current feedback amplifier (CFA) is presented. The proposed filter employs only one CFA and few passive components. The proposed circuit realizes inverse lowpass, inverse bandpass and inverse highpass filter functions with proper admittances. The characteristics of proposed multifunction inverse filter configuration are- current-mode realization; use of only one CFA; use of grounded passive components except one virtually grounded and realizing all three basic inverse filters. The proposed current-mode inverse filter circuit has been tested by TINA PRO simulation program and results justified the theoretical analysis.

Restoration for blurred noisy images based on guided filtering and inverse filter

The development of complex life leads into a need using images in several fields, because these images degraded during capturing the image from mobiles, cameras and persons who do not have sufficient experience in capturing images. It was important using techniques differently to improve images and human perception as image enhancement and image restoration etc. In this paper, restoration noisy blurred images by guided filter and inverse filtering can be used for enhancing images from different types of degradation was proposed. In the color images denoising process, it was very significant for improving the edge and texture information. Eliminating noise can be enhanced by the image quality. In this article, at first, The color images were taken. Then, random noise and blur were added to the images. Then, the noisy blurred image passed to the guided filtering to get on denoised image. Finally, an inverse filter applied to the blurred image by convolution an image with a mask and getting on the enhanced image. The results of this research illustrated good outcomes compared with other methods for removing noise and blur based on PSNR measure. Also, it enhanced the image and retained the edge details in the denoising process. PSNR and SSIM measures were more sensitive to Gaussian noise than blur.

Realization of Filter/Inverse Filter Topologies using single FTFNTA

In this manuscript, two different topologies are presented for the realization of a conventional filter/inverse filter using the Four Terminal Floating Nullor Transconductance Amplifier (FTFNTA). The first topology can synthesize the inverse low-pass (ILP), inverse high-pass (IHP), and inverse band-pass (IBP) filter with applicable impedance choices. Subsequently, another topology that can synthesize conventional low-pass (LP), and band-pass (BP) active filter, as well as inverse high-pass (IHP), and inverse band-pass (IBP) filter from the same circuit topology with a viable solution of impedances as resistor/capacitor. To verify the workability of both topologies, SPICE simulation is performed using 180nm CMOS TSMC technology.

Assessment of the lateral petals parameters of the compressed signal at the inverse filter output under the conditions of uncertainty

The paper presents the results of the parameters assessment of the lateral petals of the compressed signal at the inversion filter output under the conditions of uncertainty, caused by the presence of zero values in the signal spectrum when using the methods of correction and limiting the signal spectrum or frequency spectrum. Assessment of the lateral petals parameters was made according to the radio of the main peak energy to the energy of the lateral petals and the level of maximum lateral petal.

Measurement of reflection coefficient for a double-layered scaled model using the inverse filter

A method of measuring the reflection coefficient for a double-layered scaled model using the inverse filter is presented. First, the response of the circuit and underwater acoustical channel is measured, and the retransmitted inverse signal isestimated with the least square method for solving the cost function, which is constructed by the inverse filtering theory. Then, by retransmitting the inverse signal, the incident signal at the position of the double-layered scaled model is focused with high-main-lobe resolution, low side-lobelevel and a narrow pulse signal in temporal domain. The focus improves the measurement accuracy of the reflection coefficient for the double-layered scaled model in low frequencies. The feasibility of replacing the whole cylindrical with the double-layered scaled model is verified by simulation. The validity of the proposed method is verified by experiments carried out in a cylindrical tank for a double-layered scaled model at the frequency 0.5 kHz~10 kHz. The experimental results show that the proposed method is effective to the measurement of the reflection coefficient for the double-layered scaled model.The experimental results for the double-layered scaled model with acoustical coating on different shells have strongly directive significance for the process design and improvement of the acoustical coating.

Realization of Inverse Active Filters Using Single Current Differencing Buffered Amplifier

The authors introduce a new single current differencing buffered amplifier (CDBA) based inverse filter configuration. By appropriate selection of admittances, different inverse filter circuits like inverse high-pass (IHP) circuit, inverse low-pass (ILP) circuit, inverse band-reject (IBR) circuit and inverse band-pass (IBP) circuit can be realized from the same configuration. The capacitors used here are grounded/virtually grounded for all the realizations. The performances of the proposed filters have been judged by using CMOS structure of CDBA with TSMC 0.35 µm technology as well as by using the available IC of current feedback operational amplifier (CFOA) i.e. AD844 based CDBA. The simulation results agreed well with the theoretical results. Monte-Carlo simulation has also been performed to check the robustness of the proposed configuration.

Multi-rate Sampling Wavelet Lifting Scheme Based Video Compression with Enhanced Adaptive Rood Search Integral Projections

This paper presents the research on video compression for videos by developing a multi rate wavelet lifting scheme method which works better for both colour and grayscale videos along with Enhanced Adaptive Rood Search with Integral Projections for motion Estimation. In wavelet lifting scheme sampling is performed at different rates at the upper and lower branches. It is a powerful alternative to traditional convolution involving forward and inverse filter banks with the total amount of arithmetic computations required is substantially lesser. The ratio used is 3:2 for the upper branch and 3:1 for lower branch of lifting scheme, more low frequency coefficients are preserved as compared to high frequency coefficients to have a better picture quality with a small compromise in compression ratio. The Listless speck has been used as the Encoder and an Enhanced Adaptive Rood Search technique has been developed for motion Estimation as it improved over the problem with Adaptive Rood Search which does not consider the diagonal direction. The proposed method has produced better compression results with quality and reduced latency than the existing ones as validated in the experimentation.