Technical limitations in image capturing usually impose defective, such as contrast degradation. There are different approaches to improve the contrast of an image. Among the exiting approaches, un-sharp masking is a popular method due to its simplicity in implementation and computation. There is an important parameter in un-sharp masking, named gain factor, which affects the quality of the enh...

The frequency response masking technique is an e cient method to realize sharp 1-D lters. This technique can synthesize sharp 1-D lters with a considerably lower complexity when compared to direct-form implementations. In this paper, we extend the frequency response masking technique to the design of 2-D diamond-shaped lters. The design procedure as well as the prototype and masking lters speci...

A new method to reduce the number of multipliers in the design of sharp FIR filter by frequency-response masking technique is presented. The success of the proposed method is based on a modified frequencyresponse masking approach where one of the subfilters in frequency-response masking approach is implemented by Interpolated Finite-Impulse Response (IFIR) technique. We have shown by example th...

This paper studies the design of frequency response masking (FRM) filters with infinite duration impulse response (IIR) model and masking sub-filters. They are useful in realizing sharp cutoff digital filters with low passband delays. The designs of the model and masking filters are carried out by means of semidefinite programming (SDP) and model order reduction. Design results show that low co...

In this paper, we present an unsharp masking-based approach for noise smoothing and edge enhancing in multichannel images. The proposed structure is similar to the conventional unsharp masking structure, however, the enhancement is allowed only in the direction of maximal change and the enhancement parameter is computed as a nonlinear function of the rate of change. The proposed scheme enhances...

In this paper, we present an unsharp masking-based approach for noise smoothing and edge enhancing in multichannel images. The proposed structure is similar to the conventional unsharp masking structure, however, the enhancement is allowed only in the direction of maximal change and the enhancement parameter is computed as a nonlinear function of the rate of change. The proposed scheme enhances...

A novel computationally highly e cient realization of sharp symmetrical bandstop FIR lter is proposed. The new structure is derived using the frequency-response-masking technique, where the bandedge-shaping lter is derived from half-band lter by substituting each delay of the half-band lter by M delays. The masking lters are unconventional. They are quadrature lters derived from linear combinat...

The frequency-response masking (FRM) technique is an efficient method for realizing sharp one-dimensional (1-D) filters. Sharp 1-D filters realized using the FRM technique have considerably lower complexity than those realized in the direct form. In this paper, we present an extension of the FRM technique to the synthesis of sharp two-dimensional (2-D) diamondshaped (DS) filters. The new techni...

Sharp FIR filters have very high implementation complexities. This is even more so for sharp 2-D FIR filters. In this paper, we introduce a new efficient approach for the synthesis of sharp diamond-shaped 2-D FIR filters using the frequency response masking technique. The design procedure as well as the parameters for the minimum complexity design are presented. A design example is also include...

Contralateral masking is the phenomenon where a masker presented to one ear affects the ability to detect a signal in the opposite ear. For normal hearing listeners, contralateral masking results in masking patterns that are both sharper and dramatically smaller in magnitude than ipsilateral masking. The goal of this study was to investigate whether medial olivocochlear (MOC) efferents are need...