Search results
Results From The WOW.Com Content Network
A discrete cosine transform (DCT) expresses a finite sequence of data points in terms of a sum of cosine functions oscillating at different frequencies.The DCT, first proposed by Nasir Ahmed in 1972, is a widely used transformation technique in signal processing and data compression.
The modified discrete cosine transform (MDCT) is a transform based on the type-IV discrete cosine transform (DCT-IV), with the additional property of being lapped: it is designed to be performed on consecutive blocks of a larger dataset, where subsequent blocks are overlapped so that the last half of one block coincides with the first half of the next block.
The most widely used transform coding technique in this regard is the discrete cosine transform (DCT), [1] [2] proposed by Nasir Ahmed in 1972, [3] [4] and presented by Ahmed with T. Natarajan and K. R. Rao in 1974. [5] This DCT, in the context of the family of discrete cosine transforms, is the DCT-II.
Discrete cosine transform. Modified discrete cosine transform; Discrete Hartley transform; Discrete sine transform; Discrete wavelet transform; Hadamard transform (or, Walsh–Hadamard transform) Fast wavelet transform; Hankel transform, the determinant of the Hankel matrix; Discrete Chebyshev transform. Equivalent, up to a diagonal scaling, to ...
Take the discrete cosine transform of the list of mel log powers, as if it were a signal. The MFCCs are the amplitudes of the resulting spectrum. There can be variations on this process, for example: differences in the shape or spacing of the windows used to map the scale, [ 4 ] or addition of dynamics features such as "delta" and "delta-delta ...
He is best known for inventing the discrete cosine transform (DCT) in the early 1970s. The DCT is the most widely used data compression transformation, the basis for most digital media standards (image, video and audio) and commonly used in digital signal processing. He also described the discrete sine transform (DST), which is related to the ...
JPEG uses 8×8 blocks, on which the discrete cosine transform (DCT) is performed. The DCT is a Fourier-related transform, and ringing occurs because of loss of high frequency components or loss of precision in high frequency components.
In this case, if we make a very large matrix with complex exponentials in the rows (i.e., cosine real parts and sine imaginary parts), and increase the resolution without bound, we approach the kernel of the Fredholm integral equation of the 2nd kind, namely the Fourier operator that defines the continuous Fourier transform. A rectangular ...