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Discrete cosine transform of encrypted images
2008 15th IEEE International Conference on Image Processing, 2008Processing a signal directly in the encrypted domain provides an elegant solution in application scenarios where valuable signals must be protected from a malicious processing device. In a previous paper we considered the implementation of the ID discrete fourier transform (DFT) in the encrypted domain, by using the homomorphic properties of the ...
Tiziano Bianchi +2 more
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Comments on "Discrete Cosine Transform"
IEEE Transactions on Computers, 1975In the above correspondence,1 Ahmed et al. proposed a discrete cosine transform (DCT) and compared its performance with the Karhunen-Loeve transform (KLT). They offered empirical evidence showing that the DCT and the KLT compare closely for a number of digital signal processing applications.
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Running discrete cosine transform
Journal of Biomedical Engineering, 1992The discrete cosine transform (DCT) has become an important tool in digital signal processing because its performance is close to the optimal Karhunen-Loeve transform. In this work the running discrete cosine transform (RDCT) is introduced. Using the properties of the discrete Fourier transform kernel W = exp (-2 pi j/N), a fast recursive algorithm was
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Canonical transformations of the discrete cosine transform
Signal Processing, 2007We provide different transformation formulae between the different discrete cosine transform (DCT) types of the same size. The transformations use only diagonal and special lower/upper triangular matrices that minimize the overhead of transformation. These transformations provide a tool for using any of the DCT types as a core module for computing all ...
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On asymmetrical performance of discrete cosine transform
IEEE Transactions on Acoustics, Speech, and Signal Processing, 1990The discrete cosine transform (DCT) is considered as a suboptimum transform for many practical source-coding applications. Autoregressive order 1 (AR(1)) source models are good first approximations to several natural signals. It is known that the performance of the DCT depends on the sign of the autocorrelation coefficient of the AR(1) source.
Ali N. Akansu, Richard A. Haddad
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On the multiplicative complexity of discrete cosine transforms
IEEE Transactions on Information Theory, 1992Computing the discrete cosine transform (DCT) involves multiplying an arbitrary real vector of length \(N\) by the matrix \(K_ N:=(\cos(2\pi j(2k+1)/(4N)))^{N-1}_{j,k=0}\). The minimum number of nonrational multiplications required to compute the product of an arbitrary real vector of length \(N\) by a real \((N,N)\)-matrix \(M\) is denoted by \(\mu(M)\
Ephraim Feig, Shmuel Winograd
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Mixed-radix discrete cosine transform
IEEE Transactions on Signal Processing, 1993Presents two new fast discrete cosine transform computation algorithms: a radix-3 and a radix-6 algorithm. These two new algorithms are superior to the conventional radix-3 algorithm as they (i) require less computational complexity in terms of the number of multiplications per point, (ii) provide a wider choice of the sequence length for which the DCT
Yuk-Hee Chan, Wan-Chi Siu
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On the embedding limits of the discrete cosine transform
Multimedia Tools and Applications, 2015This paper investigates the embedding capacity limits of high-capacity data hiding in color images based on a locally Adaptive-Region Discrete Cosine Transform (AR-DCT) frequency domain data hiding scheme, and explores the relationship between hiding capacity and image quality.
Tamer Rabie, Ibrahim Kamel
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On computing the discrete Fourier and cosine transforms
IEEE Transactions on Acoustics, Speech, and Signal Processing, 1985An efficient algorithm based on real matrix decomposition is developed for computing a class of sinusoidal transforms, that include the discrete Fourier and cosine transform.
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Image encryption scheme based on discrete cosine Stockwell transform and DNA-level modulus diffusion
Optics and Laser Technology, 2022Nanrun Zhou
exaly