Manju Manuel

Design of frequency response masking FIR filter in the Canonic Signed Digit space using modified Artificial Bee Colony algorithm

Frequency response masking (FRM) technique along with the Canonic Signed Digit (CSD) representation is a good alternative for the design of a computationally efficient, sharp transition width, high speed finite impulse response (FIR) filter. This paper proposes two novel approaches for the joint optimization of an FRM FIR digital filter in the CSD space. The first approach uses the recently emerged Artificial Bee Colony (ABC) algorithm and the second approach uses the Differential Evolution (DE) algorithm. In this paper, both the algorithms are modified in such a way that, they are suitable for the solution of the optimization problem posed, in which the search space consists of integers and the objective function is nonlinear. The optimization variables are encoded such that they permit the reduction in computational cost. The salient feature of the above approaches is the reduced computational complexity while obtaining good performance. Simulation results show that the ABC based design technique performs better than that using DE, which in turn outperforms the one using integer coded genetic algorithm (GA). The proposed optimization approaches can be extended to the solution of integer programming problems in other engineering disciplines also.

Design of multiplier-less FRM FIR filter using Artificial Bee Colony Algorithm

Ever since the pioneering work of Y.C. Lim[1] on frequency response masking for the design of sharp FIR filters, lot of significant research have been carried out in this area. Among the various Signed Power of Two(SPT) forms, the Canonic Signed Digit(CSD) is a minimal representation, since it represents a given multiplier coefficient using minimum number of nonzero terms. This paper proposes the design of a CSD based FRM filter with reduced computational complexity using the Artificial Bee Colony Algorithm. Optimization is done in the discrete space, where the coefficient encoding is done with the help of the look up table created. The reduction in computational complexity is achieved by the appropriate selection of the initial food sources in ABC algorithm. Besides, the ABC algorithm is tailor made so that, in every exploitation and exploration phase, the candidate solutions turn out to be integers.

Detection of copy-move forgery based on Gabor filter

In recent years, digital images are widely used in many applications and for multiple purposes. The number of tools and software of digital image editing is also increasing day-by-day which makes it easy to manipulate the actual information of an image. Therefore it is important to ascertain the authenticity of the image under use. There are many ways in which a forger can tamper an image, out of which the most popular way is copy-move forgery. This type of forgery is used to either hide an object or replicate it by copying and pasting it on another area of the same image. This paper proposes a method for detecting such type of forgery. The algorithm uses feature vectors extracted from the Gabor response of each overlapping block of the image. Experimental results show the ability of the method to precisely locate the duplicated regions.

An embedded musculo-skeletal injury detection system

Continuous field monitoring of load carriage has proven difficult. An algorithm is proposed for estimating load from a single body-worn accelerometer. The accelerometer used is ADXL335. Accelerometer is interfaced with an Arduino Uno. Platform for the algorithm is Arduino Script and MATLAB. The algorithm has three different steps that characterizes torso movement dynamics. The three different steps are feature extraction, walking detection and multivariate regression. The system maps the extracted dynamics features to load estimates using a machine learning multivariate regression technique. The algorithm is applied, using leave-one-subject-out cross validation, to two field collections of soldiers and civilians walking with varying loads.

Delay efficient error detection and correction of parallel IIR filters using VLSI algorithms

Almost all electronic systems suffer from errors caused by various internal and external factors. In many designs automatic detection and correction of errors is of prime importance. In the meantime the techniques that add to detect and correct errors will make the system more sluggish. This paper proposes a method for error detection and correction in parallel IIR filters based on error correction codes. Even though a lot of studies have been done with FIR filters, the area of IIR filters have received very less attention. The reason for this is design of an IIR filter is much complicated than an FIR filter due to its recursive nature. Scaling and roundoff error plays a major role and special care must be taken to overcome this. To improve the speed of the system, the conventional adders and multipliers are replaced with carry select adder and Booth multiplier. The effectiveness of the scheme is shown in terms of error protection, hardware utilization and delay. A remarkable reduction in delay is obtained through the application of these algorithms.

An efficient transformation for two dimensional circularly symmetric wideband FIR filters

This paper proposes a novel transformation for the design of two-dimensional (2D) finite impulse response (FIR) wideband filters with perfect circular symmetry. The proposed transformation is based on the kth order McClellan transformation and is found to be successful in generating precise circular contours even for wideband filters. The proposed method outperforms the state of the art transformations in terms of contour approximation accuracy. Design examples illustrate the effectiveness of the proposed transformation.