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Your search keyword '"Karwal V"' showing total 2 results
Start Over Author "Karwal V" Topic computer algorithms
2 results on '"Karwal V"'

1. Improved Algorithm for ODCT Computation of a Running Data Sequence.

Author

Akhter, S., Karwal, V., and Jain, R. C.

Subjects
*COMPUTER algorithms, *DISCRETE cosine transforms, *DATA analysis, *REAL-time computing, *COEFFICIENTS (Statistics), *COMPUTATIONAL complexity, *COMPUTER simulation
Abstract

Fast windowed update algorithms capable of independently updating the odd discrete cosine transform (ODCT) and odd discrete sine transform(ODST) of a running data sequence are analytically developed. In this algorithm, to compute the ODCT coefficients of a real-time sequence, we do not require the ODST coefficients. Similarly, the ODST coefficients of the shifted sequence can be calculated without using ODCT coefficients. The running input data sequence is sampled using a rectangular window. However, this idea can be easily extended for other windows. The update algorithm derived herein can be used to compute the transform coefficients of the shifted sequence as new data points are available. The complexity of developed algorithm is O(N). The validity of algorithm is tested by MATLAB simulations. [ABSTRACT FROM AUTHOR]

Published
2012
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2. Independently updating the DCT and DST for shifting windowed data.

Author

Karwal, V., Sherlock, B.G., and Kakad, Y.P.

Subjects
*DISCRETE cosine transforms, *DISCRETE sine transforms, *DATA analysis, *SIGNAL processing, *COMPUTER algorithms, *HARTLEY transform algorithms
Abstract

Abstract: When processing a signal or an image using the Discrete Cosine Transform (DCT) or Discrete Sine Transform (DST), a typical approach is to extract a portion of the signal by windowing and then form the DCT or DST of the window contents. By shifting the window point by point over the signal, the entire signal may be processed. In this paper we develop algorithms to “update” the DCT and DST to reflect the modified window contents using less computation than by directly evaluating the modified transform via standard Fast Transform algorithms. Our algorithms constitute an improvement over previous DCT/ DST update algorithms because our approach establishes independence between the DCT and the DST: the algorithm for DCT makes use only of DCT terms, and similarly for DST. Algorithms are derived for use without windowing and with split-triangular, Hanning, Hamming and Blackman windows. [Copyright &y& Elsevier]

Published
2013
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