Advantages And Disadvantages Of Wavelets

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Wavelets, based on time-scale representations, provide an alternative to time-frequency representation based signal processing. Wavelets are then represented by dilation equations, as opposed to difference or differential equations. Wavelets maintain orthogonality with respect to their dilations and translations. Orthogonality of wavelets with respect to dilations leads to multigrid representation. Wavelets decompose the signal at one level of approximation into approximation and detail signals at the next level. Thus subsequent levels can add more detail to the information content. The perfect reconstruction property of the analysis and synthesis wavelets and the absence of perceptual degradation at the block boundaries favor use of wavelets…show more content…
The same procedure is adapted to obtain one level 2-D DWT by using two vertical filters as shown in Fig. 1. Implementation results are discussed in section 4. The advantage of flipping method is it requires only four multipliers and eight adders instead of eight multipliers and four adders to implement 9/7 filter compare to lifting scheme. Main disadvantage of flipping is serial operation. In 1-D DWT of FA, odd and even input samples are processed by five blocks namely , , , , (1 &2)in the cascade manner.1 &2are scaling blocks. Since the output from one block is fed as the input to the next block, the maximum rate at which the input can be fed to the system depends on the sum of the delays in all four stages. The speed may be increased by introducing pipelining at the points indicated by dotted lines Fig.3. In this case, the input rate is determined by the largest delay among all four blocks.The delay in the individual stages may be reduced further by using constant coefficient multiplier (KCM) which uses a look up table (LUT) for finding the product of a constant and a variable. 2.2 Modified Flipping Architecture Modified flipping architecture (MFA) is implemented using MBW-PKCM technique.
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