Results 271 to 280 of about 152,070 (321)

LAPLACIAN DCT COEFFICIENT MODELS

International Journal of Wavelets, Multiresolution and Information Processing, 2008
It is well known that the distribution of the discrete cosine transform (DCT) coefficients of most natural images follow a Laplace distribution. In this note, a collection of formulas is derived for the distribution of the actual DCT coefficient. The corresponding estimation procedures are derived by the method of moments and the method of maximum ...
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Randomized redundant DCT

SIGGRAPH Asia 2015 Technical Briefs, 2015
j In this paper, we propose an acceleration method for image denoising with a redundant discrete cosine transform (R-DCT). Image denoising is essential for image processing, and its efficiency is important for graphics applications. R-DCT with a hard-thresholding or shrinkage method can perform denoising while keeping detail textures.
Shu Fujita, Norishige Fukushima, Makoto Kimura, Yutaka Ishibashi   +3 more
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Optimum DCT quantization

[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.
D.M. Monro, B.G. Sherlock
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Gaussian DCT Coefficient Models

Acta Applicandae Mathematicae, 2008
It is assumed that the discrete cosine transform (DCT) coefficients of most natural images follow a Gaussian distribution. In this theoretical work, the author obtains sixteen compounded distribution models from \[ f(x)=\frac{1}{\sqrt {2\pi}}\int^\infty_0\frac{1}{\sigma}\exp\left(-\frac{y^2}{2\sigma^2}\right)g (\sigma^2)d\sigma^2 \] by taking different
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JPEG DCT Compressiom

Advanced Materials Research, 2013
With the rapid spread of image processing applications and the further development of multimedia technologies, compression standards become more and more important. This paper intends to explain JPEG (Joint Photographic Experts Group) compression, which is currently a worldwide standard for digital image compression, is based on the discrete cosine ...
Hong Li Jia, Qiang Liu
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A novel triple-image encryption and hiding algorithm based on chaos, compressive sensing and 3D DCT

Information Sciences, 2021
Xing-yuan Wang, Cheng Liu, D. Jiang
semanticscholar   +1 more source

Multi-watermarking algorithm for medical image based on KAZE-DCT

Journal of Ambient Intelligence and Humanized Computing, 2022
Cheng Zeng, Jing Liu, Jingbing Li, Jieren Cheng, Jingjun Zhou, S. Nawaz, Xiliang Xiao, U. Bhatti   +7 more
semanticscholar   +1 more source

LWT-DCT-SVD and DWT-DCT-SVD based watermarking schemes with their performance enhancement using Jaya and Particle swarm optimization and comparison of results under various attacks

Multimedia tools and applications, 2022
Divyanshu Awasthi, V. K. Srivastava
semanticscholar   +1 more source

Two Stage Color Image Steganography Using DCT (TSCIS-DCT)

2013
In frequency domain steganography, use of color images for secret data hiding may prove to be a decisive innovation. The proposed concept uses two color images for hiding a color/gray authenticating message/image. The mathematical technique of Discrete Cosine Transform (DCT) is applied on each block of size 2x2 taken in row major order from three color
Anirban Goswami, Dipankar Pal, Nabin Ghoshal   +2 more
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The discrete cosine transform DCT-4 and DCT-8

Proceedings of the 4th international conference conference on Computer systems and technologies e-Learning - CompSysTech '03, 2003
In paper two types of the discrete cosine (end sine) transforms (DCT/DST) are analyzed on the base of the linear representations of finite groups and geometrical approach. This transforms are useful for multirate systems, adaptive filtering and compression of speech signals and images.
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