Distribution shape of two-dimensional DCT coefficients of natural images

Müller, Frank

doi:10.1049/el:19931288

Cited by 179 publications

(86 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Other DCT coefficient distribution models have been suggest in the literature, such as generalized gaussian [34], gaussian mixtures [35], or generalized gamma [36]. The support for those distribution models consisted of theoretical (i.e., the Central Limit theorem) and quantitative results (i.e., the χ-square and Kolmogorov-Smirnov goodness-of-fit tests).…”

Section: Modeling Dct Coefficient Datamentioning

confidence: 99%

No-Reference Quality Assessment of H.264/AVC Encoded Video

Brandão

Queluz

2010

IEEE Trans. Circuits Syst. Video Technol.

View full text Add to dashboard Cite

Abstract-This paper proposes a no-reference quality assessment metric for digital video subject to H.264/AVC encoding. The proposed metric comprises two main steps: coding error estimation and perceptual weighting of this error. Error estimates are computed in the transform domain, assuming that DCT coefficients are corrupted by quantization noise. The DCT coefficient distributions are modeled using Cauchy or Laplace probability density functions, whose parameterization is performed using the quantized coefficient data and quantization steps. Parameter estimation is based on a maximum-likelihood estimation method combined with linear prediction. The linear prediction scheme takes advantage of the correlation between parameter values at neighbor DCT spatial frequencies. As for the perceptual weighting module, it is based on a spatio-temporal contrast sensitivity function applied to the DCT domain that compensates image plane movement by considering the movements of the human eye, namely smooth pursuit, natural drift and saccadic movements. The video related inputs for the perceptual model are the motion vectors and the frame rate, which are also extracted from the encoded video. Subjective video quality assessment tests have been carried out in order to validate the results of the metric. A set of eleven video sequences, spanning a wide range of content, have been encoded at different bitrates and the outcome was subject to quality evaluation. Results show that the quality scores computed by the proposed algorithm are well correlated with the mean opinion scores associated to the subjective assessment.

show abstract

Section: Modeling Dct Coefficient Datamentioning

confidence: 99%

No-Reference Quality Assessment of H.264/AVC Encoded Video

Brandão

Queluz

2010

IEEE Trans. Circuits Syst. Video Technol.

View full text Add to dashboard Cite

show abstract

“…To get a theoretically justified weighting form of the quantized transform coefficients, we start with modeling a single transform coefficient C uv with zero-mean GGD [23] described as follows:…”

Section: B Generalized Gaussian Modeling For Integer Transform Coeffmentioning

confidence: 99%

Novel Statistical Modeling, Analysis and Implementation of Rate-Distortion Estimation for H.264/AVC Coders

Zhao

Sun

et al. 2010

IEEE Trans. Circuits Syst. Video Technol.

View full text Add to dashboard Cite

Abstract-In H.264/advanced video coding, the encoder employs the rate-distortion optimization (RDO) to select the optimal coding mode of each block. Although it is effective to employ the RDO technique for mode decision, the computation load increases drastically. To reduce the computation complexity of the RDO technique, in this paper, we propose efficient algorithms for the estimation of block-level rate and distortion. For rate estimation, we model the transform coefficients with accurate generalized Gaussian distributions, and the weighted sum of absolute quantized transform coefficients is proposed as an efficient rate estimator, where the weights provide an implicit mechanism for evaluating different contributions of different frequency components to the coding bits. For distortion estimation, we first analyze the origins of distortion thoroughly. Then a direct relationship between the discarded bits in quantization and the distortion is explored. According to this investigation, a simple and efficient algorithm is proposed for the distortion estimation. With above proposed algorithms, the RDO technique can be efficiently implemented in a low-complexity way. Extensive experimental results demonstrate that, compared with the original RDO implementation, the proposed algorithms achieve about 32% reduced total encoding time with ignorable coding performance degradation.

show abstract

“…To this end, we first need a probability model for the DCT coefficients . Following literature at this point, we use the generalized Gaussian distribution [16], [27] with shape parameter (17a) where This PDF has zero-mean and variance . Typically, the shape parameter takes on values between 0.10 and 0.50.…”

Section: B Model For the Dct-based Energiesmentioning

confidence: 99%

Optimal differential energy watermarking of DCT encoded images and video

Langelaar

Lagendijk

2001

IEEE Trans. on Image Process.

274

111

View full text Add to dashboard Cite

Abstract-This paper proposes the differential energy watermarking (DEW) algorithm for JPEG/MPEG streams. The DEW algorithm embeds label bits by selectively discarding high frequency discrete cosine transform (DCT) coefficients in certain image regions. The performance of the proposed watermarking algorithm is evaluated by the robustness of the watermark, the size of the watermark, and the visual degradation the watermark introduces. These performance factors are controlled by three parameters, namely the maximal coarseness of the quantizer used in pre-encoding, the number of DCT blocks used to embed a single watermark bit, and the lowest DCT coefficient that we permit to be discarded. In this paper, we follow a rigorous approach to optimizing the performance and choosing the correct parameter settings by developing a statistical model for the watermarking algorithm. Using this model, we can derive the probability that a label bit cannot be embedded. The resulting model can be used, for instance, for maximizing the robustness against re-encoding and for selecting adequate error correcting codes for the label bit string.

show abstract

Distribution shape of two-dimensional DCT coefficients of natural images

Cited by 179 publications

References 3 publications

No-Reference Quality Assessment of H.264/AVC Encoded Video

No-Reference Quality Assessment of H.264/AVC Encoded Video

Novel Statistical Modeling, Analysis and Implementation of Rate-Distortion Estimation for H.264/AVC Coders

Optimal differential energy watermarking of DCT encoded images and video

Contact Info

Product

Resources

About