Seisuke Kyochi

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The purpose of this paper is to show an another design approach of the M -band dual-tree complex wavelet transform (DTCWT). Conventionally, M -channel cosine-sine modulated filter bank has been proposed as an extension of cosine modulated filter bank. It can be easily designed by the modulation of one prototype filter. In this paper, we show that it can be(More)
In this paper, a novel design method of critically sampled contourlet transform (CSCT) is proposed. Although, several types of CSCT have been proposed, they have some problems on efficiency and flexibility of their frequency plane partition patterns. In contrast to the way in conventional design methods based on a "top-down" approach, the proposed one is(More)
This paper aims to design a new two-dimensional (2D) non-separable implementation of dyadic-valued cosine-sine modulated filter banks (2D D-CSMFBs) for low computational complexity. CSMFBs satisfy rich directional selectivity (DS) and shift-invariance (SI), and they can be easily designed by the modulation of a prototype filter. In addition, our previous(More)
In this paper, we propose a two dimensional (2D) non-separable adaptive directional lifting (ADL) structure of discrete wavelet transform (DWT) and its image coding application. Conventionally, we have proposed a polyphase representation of a 2D non-separable lifting structure of DWT. We generalize the polyphase representation in this paper and one(More)
The multiplierless fast Fourier transform (FFT) with dyadic-valued (rational) coefficients is important for many signal processing tools. The proposed lifting based FFT (L-FFT) based on fast Hartley transform (FHT) has a simpler structure than existing ones because fewer lifting steps need to be approximated. In addition, it has a structure of real-valued(More)
This paper proposes a directional and shift-invariant transform based on M-channel rational-valued cosine-sine modulated filter banks (R-CSMFBs) for the practical implementation on hardware devices. M-channel CSMFBs can be easily designed by the modulation of a prototype filter and achieve a good stopband attenuation. In addition, in our previous work, the(More)
Complex-valued conjugate-symmetric Hadamard transforms (C-CSHT) are variants of complex Hadamard transforms and found applications in signal processing. In addition, their real-valued transform counterparts (R-CSHTs) perform comparably with Hadamard transforms (HTs) despite their lower computational complexity. Closed-form factorizations of C-CSHTs and(More)
In recent years, two-channel complex-valued filterbanks have been studied and found theirs several important applications by many researchers, such as complex signal and image processing. One of those important results is that there is no two-channel complex-valued linear-phase paraunitary filterbank (CLPPUFB), except for its filter lengths of 2. In this(More)