Results 211 to 220 of about 20,648 (268)
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A fast 4*4 DCT algorithm for the recursive 2-D DCT
IEEE Transactions on Signal Processing, 1992The authors present an efficient algorithm for the computation of the 4*4 discrete cosine transform (DCT). The algorithm is based on the decomposition of the 4*4 DCT into four 4-point 1-D DCTs. Thus, only 1-D transformations and some additions are required.
S U Lee, N I Cho
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Gradient-DCT (G-DCT) descriptors
2014 4th International Conference on Image Processing Theory, Tools and Applications (IPTA), 2014Many feature-based object detectors have shown that the use of gradient image information can be a very efficient way to describe the appearance of objects. Especially, the gradient sizes, directions and histograms are commonly used. In this area, the histogram of oriented gradients (HOG) is considered as the state-of-the-art method. The histograms and
Radovan Fusek, Eduard Sojka
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International Journal of Wavelets, Multiresolution and Information Processing, 2007
It is well known that the distribution of the discrete cosine transform (DCT) coefficients of most natural images follows a Laplace distribution. In this note, using a Bayesian approach, we derive two popular models for the distribution of the actual DCT coefficient.
Saralees Nadarajah, Samuel Kotz
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It is well known that the distribution of the discrete cosine transform (DCT) coefficients of most natural images follows a Laplace distribution. In this note, using a Bayesian approach, we derive two popular models for the distribution of the actual DCT coefficient.
Saralees Nadarajah, Samuel Kotz
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Fast DCT domain filtering using the DCT and the DST
IEEE Transactions on Image Processing, 1999A method for efficient spatial domain filtering, directly in the discrete cosine transform (DCT) domain, is developed and proposed. It consists of using the discrete sine transform (DST) and the DCT for transform-domain processing on the in JPEG basis of the previously derived convolution-multiplication properties of discrete trigonometric transforms ...
Renato Kresch, Neri Merhav
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Theoretical Complex Cepstrum of DCT and Warped DCT Filters
IEEE Signal Processing Letters, 2007In this letter, we derive the theoretical complex cepstrum (TCC) of the discrete cosine transform (DCT) and warped DCT (WDCT) filters. Using these derivations, we intend to develop an analytic model of the warped discrete cosine transform cepstrum (WDCTC), which was recently introduced as a speech processing feature.
Rangarao Muralishankar +2 more
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2014
The paper shows performance comparison of DST-DCT, Haar-DCT, Walsh-DCT, Hartley-DCT, Slant-DCT and Kekre-DCT Hybrid Wavelet Transforms using Normalization for ‘Color to Gray and Back’. The color information of the image is embedded into its gray scale version using hybrid wavelet transform [HWT] and normalization method.
H. B. Kekre +2 more
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The paper shows performance comparison of DST-DCT, Haar-DCT, Walsh-DCT, Hartley-DCT, Slant-DCT and Kekre-DCT Hybrid Wavelet Transforms using Normalization for ‘Color to Gray and Back’. The color information of the image is embedded into its gray scale version using hybrid wavelet transform [HWT] and normalization method.
H. B. Kekre +2 more
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On the DCT Coefficient Distributions
IEEE Signal Processing Letters, 2006Explicit expressions are derived for the actual discrete cosine transform (DCT) coefficient distribution.
Saralees Nadarajah, Samuel Kotz
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On the distribution of the DCT coefficients
Proceedings of ICASSP '94. IEEE International Conference on Acoustics, Speech and Signal Processing, 2002The paper presents a statistical study in order to improve the image compression rate in discrete cosine transform (DCT) based methods and especially for compression methods which are defined in JPEG norm. It is realised extensively, using a battery of parametric and non-parametric fit-tests and laws such as those of Cauchy, Laplace, Gauss, and a ...
Thierry Eude +3 more
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[Proceedings] DCC `93: Data Compression Conference, 2002
The paper offers a solution to the problem of determining good quantization tables for use with the discrete cosine transform. Using the methods proposed, the designer of a system can choose a selection of test images and a coefficient weighting scenario, from which a quantization table can be produced, optimized for the choices made.
Donald M. Monro, Barry G. Sherlock
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The paper offers a solution to the problem of determining good quantization tables for use with the discrete cosine transform. Using the methods proposed, the designer of a system can choose a selection of test images and a coefficient weighting scenario, from which a quantization table can be produced, optimized for the choices made.
Donald M. Monro, Barry G. Sherlock
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