Mohammad Hasan Savoji

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In this paper we present a modification of the usual decimation-interpolation steps for resampling of speech signals which is especially adapted to arbitrary modification of fundamental frequency and duration of speech segments. The modification is intended to overcome the time and frequency domain limitation that such a resampling scheme imposes so it can(More)
The final quality of a concatenation synthesis system is directly related to the continuity of the spectrum at the concatenation point. Due to the subjective auditory masking, if we minimize the spectral distortion in the formant frequencies, the quality will increase significantly. In this paper we present, along with results concerning pitch marking, an(More)
Walsh-Hadamard transform (WHT) has many applications in digital signal processing including bioinformatics. While there are efficient algorithms for implementing this transform such as fast WHT (FWHT), performing WHT continuously on a sliding window over a long sequence is time consuming. As it is not reasonable to compute a separate WHT upon arrival of(More)
Hash functions play the most important role in various cryptologic applications, ranging from data integrity checking to digital signatures. Our goal is to introduce a new hash function using Walsh-Hadamard transform for achieving dimensionality reduction (compression) with a regular and one-way distribution. Merkle-Damgard (MD) transform is applied to this(More)
We introduce a new concept coined "knowledge based blind deconvolution" as the problem of estimating the input of an unknown non-minimum phase FIR system using only noisy observed output and an initial model of the original input. Here, unlike conventional blind deconvolution where some assumptions on the statistical properties of the white source signal(More)
A novel wide-band speech coding scheme based on bandwidth extension and sparse linear prediction is proposed in this paper. Bandwidth extension utilizes the correlation that exists between the low and high frequency parts of the wide-band speech signal to regenerate, at the decoder, the high frequency components using the decoded low band signal. This leads(More)
This paper evaluates the problems of implementing two well-known zero-tree-based re-encoding schemes of Embedded Zero-tree Wavelet (EZW) and the set partitioning in hierarchical trees (SPIHT) for perceptually audio and high quality speech coding. Since the original EZW and SPIHT algorithms are designed for image compression, some new modifications have been(More)
This paper reports on the results of four re-encoding schemes on perceptually quantized wavelet packet transform (WPT) coefficients of audio and high quality speech. These schemes comprises: 1- Embedded Zero-tree Wavelet (EZW) 2- The set partitioning in hierarchical trees (SPIHT) 3-JPEG-based entropy/run length Huffman and 4- JPEG-type Audio Huffman coding(More)