Results 241 to 250 of about 1,495,143 (296)

Discrete Cosine Transform

IEEE Transactions on Computers, 1974
A discrete cosine transform (DCT) is defined and an algorithm to compute it using the fast Fourier transform is developed. It is shown that the discrete cosine transform can be used in the area of digital processing for the purposes of pattern recognition and Wiener filtering.
Nasir Ahmed, K R Rao
exaly   +4 more sources

The Discrete Cosine Transform [PDF]

SIAM Review, 1999
Abstract. Each discrete cosine transform (DCT) uses [Formula: see text] real basis vectors whose components are cosines. In the DCT-4, for example, the [Formula: see text]th component of [Formula: see text] is [Formula: see text]. These basis vectors are orthogonal and the transform is extremely useful in image processing.
Gilbert Strang
exaly   +4 more sources

On the Computation of the Discrete Cosine Transform

IRE Transactions on Communications Systems, 1978
An N -point discrete Fourier transform (DFT) algorithm can be used to evaluate a discrete cosine transform by a simple rearrangement of the input data. This method is about two times faster compared to the conventional method which uses a 2N -point DFT.
M Narasimha, A Peterson
exaly   +3 more sources

Generalized Discrete Cosine Transform [PDF]

2009 Pacific-Asia Conference on Circuits, Communications and Systems, 2009
The discrete cosine transform (DCT), introduced by Ahmed, Natarajan and Rao, has been used in many applications of digital signal processing, data compression and information hiding. There are four types of the discrete cosine transform. In simulating the discrete cosine transform, we propose a generalized discrete cosine transform with three ...
Jianqin Zhou
exaly   +2 more sources

On Computing the Discrete Cosine Transform

IEEE Transactions on Computers, 1978
Haralick has shown that the discrete cosine transform of N points can be computed more rapidly by taking two N-point fast Fourier transforms (FFT's) than by taking one 2N-point FFT as Ahmed had proposed. In this correspondence, we show that if Haralick had made use of the fact that the FFT's of real sequences can be computed more rapidly than general ...
Ben-Dau Tseng, William C. Miller
openaire   +3 more sources

Discrete cosine transform filtering

Signal Processing, 1990
Circular convolution-multiplication relationships for the discrete cosine transform (DCT) that are similar to those for the discrete Fourier transform (DFT) are developed. The relations are valid if the filter frequency response is real and even. Two fairly simple relations are developed.
Bowonkoon Chitprasert, K. R. Rao 0001
openaire   +2 more sources

Convolution Using Discrete Sine and Cosine Transforms

IEEE Signal Processing Letters, 2007
In this paper, we derive a relation for the circular convolution operation in the discrete sine and cosine transform domains. The transform coefficients are either symmetric or asymmetric and hence we need to calculate only half of the total coefficients.
Soo Ngee Koh, V G Reju, Yann Soon
exaly   +2 more sources

Reversible discrete cosine transform

Proceedings of the 1998 IEEE International Conference on Acoustics, Speech and Signal Processing, ICASSP '98 (Cat. No.98CH36181), 2002
In this paper a reversible discrete cosine transform (RDCT) is presented. The N-point reversible transform is firstly presented, then the 8-point RDCT is obtained by substituting the 2 and 4-point reversible transforms for the 2 and 4-point transforms which compose the 8-point discrete cosine transform (DCT), respectively.
Kunitoshi Komatsu, Kaoru Sezaki
openaire   +1 more source

The Discrete Cosine Transform (DCT)

2009
The Fourier transform and the DFT are designed for processing complex-valued signals, and they always produce a complex-valued spectrum even in the case where the original signal was strictly realvalued. The reason is that neither the real nor the imaginary part of the Fourier spectrum alone is sufficient to represent (i.e., reconstruct) the signal ...
Wilhelm Burger, Mark J. Burge
openaire   +1 more source