Results 261 to 270 of about 38,586 (315)
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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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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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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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The quantized DCT and its application to DCT-based video coding
IEEE Transactions on Image Processing, 2002The two-dimensional (2-D) discrete cosine transform (DCT) and the subsequent quantization of the transform coefficients are two computationally demanding steps of any DCT-based video encoder. In this paper, we propose an efficient joint implementation of these two steps, where the precision in computing the DCT can be exchanged for a reduction in the ...
Alen Docef +3 more
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DCT-domain spatial transcoding using generalized DCT decimation
IEEE International Conference on Image Processing 2005, 2005In this paper, we propose a generalized DCT-domain spatial downscaling scheme to improve the visual quality. We analyze the filtering performances and computational complexities of the proposed scheme and the pixel-domain downscaling schemes. The analyses show that the proposed scheme can reduce the aliasing artifact compared to the existing schemes ...
Yuh-Ruey Lee, Chia-Wen Lin
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Systolic CORDIC DCT: an effective method for computing 2d-DCT
Seventh International Symposium on Signal Processing and Its Applications, 2003. Proceedings., 2003The 2D-DCT is used in image and speech processing for real-time application. In this paper a new hardware method is proposed for computing 2D-DCT. The hardware employs systolic array for doing recursive equation and use a CORDIC algorithm for determining some part of computation. So the method is called systolic CORDlC DCT or SCDCT.
Ali Khayatzadeh +2 more
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