Cited by 337Image and Video Quality AssessmentImage Retrieval and Classification TechniquesDigital Media Forensic Detection

RRED Indices: Reduced Reference Entropic Differencing for Image Quality Assessment

Soundararajan, R., Bovik, A. C.·2012·IEEE Transactions on Image Processing

Abstract

We study the problem of automatic "reduced-reference" image quality assessment (QA) algorithms from the point of view of image information change. Such changes are measured between the reference- and natural-image approximations of the distorted image. Algorithms that measure differences between the entropies of wavelet coefficients of reference and distorted images, as perceived by humans, are designed. The algorithms differ in the data on which the entropy difference is calculated and on the amount of information from the reference that is required for quality computation, ranging from almost full information to almost no information from the reference. A special case of these is algorithms that require just a single number from the reference for QA. The algorithms are shown to correlate very well with subjective quality scores, as demonstrated on the Laboratory for Image and Video Engineering Image Quality Assessment Database and the Tampere Image Database. Performance degradation, as the amount of information is reduced, is also studied.

AI snapshot

Written from the paper’s full text.

TL;DR

The paper introduces RRED indices, reduced-reference image quality assessment algorithms that measure average absolute differences between scaled wavelet-domain entropies of a reference image and a Gaussian-scale-mixture natural-image approximation of the distorted image. Across LIVE and TID2008, the indices correlate well with subjective scores and degrade gracefully as reference information is reduced, with some variants approaching full-reference performance.

Key findings

  • On LIVE, RRED M16/16 achieved overall SROCC 0.9429 and LCC 0.9385 using L/36 scalars, compared with PSNR SROCC 0.8754 and VIF (FR) SROCC 0.9636; RRED M10/10 achieved overall SROCC 0.9343 using L/144 scalars.
  • Filtering and subsampling reduced reference information but degraded overall SROCC from 0.9429 at L/36 to 0.8543 at L/9296.
  • Single-number algorithms had overall SROCC 0.7682 for σ²W = 0, 0.7978 for σ²W = 0.1, and 0.8877 for σ²W = 1; RRED* using 4 numbers achieved overall SROCC 0.8606, outperforming WNISM (0.7651) but below Curvelet (0.9104) and HWD2 (0.9418).
  • On TID2008, RRED M16/16 achieved overall SROCC 0.824, above VIF (0.750), VSNR (0.705), PSNR (0.553), and WNISM (0.512), but below MSSIM (0.853); RRED 1/22 achieved 0.521.

Methods

  • The RRED family computes the average absolute difference between scaled entropies of wavelet coefficients after an additive Gaussian neural noise channel, modeling both reference and distorted wavelet coefficients as Gaussian scale mixtures; algorithms vary by subband and by the amount of reference information via filtering/subsampling.
  • Experiments used LIVE (779 distorted images, five distortion categories) and TID2008 (17 distortion types, 1700 distorted images), with a steerable pyramid decomposition using 6 orientations at 4 scales (25 subbands), 3×3 blocks (N = 9), and σ²W = 0.1 except in the single-number noise study; parameters were estimated by maximum likelihood without database training.
  • Performance was assessed with Spearman rank-order correlation (SROCC) and linear correlation coefficient (LCC) after logistic nonlinearity against subjective DMOS/MOS, compared with PSNR, VIF, MSSIM, VSNR, WNISM, Curvelet, and HWD2.

Limitations

  • The paper states that overall performance of single-number algorithms may be improved by better aligning scores across distortion categories, that multiscale decomposition increases complexity and needs efficient implementations, and that dependence on viewing distance requires better understanding; future work includes video.
  • The paper reports that performance degrades with subsampling and that single-number algorithms are sensitive to neural noise variance; Gaussian blur performance decreases as σ²W increases (0.9698 at 0, 0.9038 at 0.1, 0.6108 at 1).
  • Evident from reported tables, though not framed as limitations by the authors: RRED* overall SROCC 0.8606 is lower than Curvelet 0.9104 and HWD2 0.9418 on LIVE, and TID2008 RRED M16/16 is below MSSIM overall (0.824 vs 0.853) with low SROCC for mean shift (0.538) and contrast change (0.542).

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1109/tip.2011.2166082

Cites

38 of 38 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 16 cited sources checked · 0 supported · 0 flagged

  • Findingown data
    § C. RR Quality Index · p. 9

    Filtering and subsampling scaled entropy terms over patches results in loss of performance with subsampling.

    “This procedure results in loss of performance with subsampling as illustrated in Section V.”
    Quote in the paperNot a substantial claim
    • The authors state this as an assumption: Non-overlapping blocks of wavelet coefficients are independent and identically distributed.
  • Findingown data
    § V. RESULTS AND DISCUSSION · p. 17

    The RRED indices that require only a single number from the reference are more sensitive to the choice of the neural noise variance.

    “It turns out that these algorithms are more sensitive to the choice of the neural noise variance.”
    Quote in the paperSubstantial claim
  • Findingown data
    § V. RESULTS AND DISCUSSION · p. 13

    Choosing vertical subbands yields marginally better performance than choosing horizontal subbands.

    “Further, we observe that the performance obtained by choosing the vertical subbands is marginally better than the horizontal subbands.”
    Quote in the paperNot a substantial claim
  • Findingown data
    § V. RESULTS AND DISCUSSION · p. 15

    As the RRED indices are evaluated in finer scales, they provide a better separation of quality scores.

    “As we move from (a) to (d), the RRED indices are now evaluated in finer scales, which provide a better separation of quality scores.”
    Quote in the paperSubstantial claim
  • Findingnone given
    § VI. CONCLUSION · p. 20

    Even when only a single scalar is obtained from the reference image, the algorithm achieves close to state of the art performance within each distortion category without knowing anything about the type of distortions.

    “Even when only a single scalar is obtained from the reference image, the algorithm achieves close to state of the art performance within each distortion category without knowing anything about the type of distortions that the image might have been subjected to.”
    Quote in the paperSubstantial claim
  • May combine two claims. 20
  • Classified as probably not a substantial claim. 24
  • May combine two claims.

    Findingown data
    § Abstract · p. 1

    The proposed RRED algorithms correlate very well with subjective quality scores and attain highly competitive performance on the LIVE Image Quality Assessment Database, the Tampere Image Database, and a large comprehensive database of distorted images and subjective scores.

    “The algorithms are shown to correlate very well with subjective quality scores as demonstrated on the LIVE Image Quality Assessment Database and Tampere Image Database.”
    • Also stated in: § I. INTRODUCTION · p. 4 · boosted
      “It is found that the performance attained is highly competitive on a large and comprehensive database of distorted images and subjective scores.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: The wavelet coefficients of the distorted image can be modeled as a Gaussian scale mixture distribution.
    • The authors state this as an assumption: The perceived reference and distorted images pass through an additive neural noise channel, where the noise is a zero mean Gaussian random vector for each block of coefficients.
  • May combine two claims.

    Findingown data
    § V. RESULTS AND DISCUSSION · p. 18

    RRED M_16^16 performs better than some of the best full-reference algorithms, while RRED_1^22 is competitive with PSNR and outperforms [12].

    “RRED M 16 16 performs better than some of the best full reference algorithms while RRED 1 22 is competitive with PSNR and outperforms [12].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [12] [12] Z. Wang, G. Wu, H. R. Sheikh, E. P. Simoncelli, E. H. Yang, and A. C. Bovik, 'Quality-aware images,' IEEE Trans. Image Process. , vol. 15, no. 5, pp. 1680-1689, 2006. - source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Findingnone given
    § V. RESULTS AND DISCUSSION · p. 18

    The steerable pyramid decomposition of the image has a computational complexity of O(N log N) arithmetic operations per scale, where N is the total number of pixels in the image.

    “The steerable pyramid decomposition of the image has a computational complexity of O ( N log N ) arithmetic operations per scale, where N is the total number of pixels in the image.”
    Quote in the paperNot a substantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingnone given
    § V. RESULTS AND DISCUSSION · p. 15

    The LCC results in Table II show the same trends as the SROCC results in Table I.

    “We observe the same trends in Table II as in Table I for SROCC.”
    Quote in the paperNot a substantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingown data
    § V. RESULTS AND DISCUSSION · p. 20

    Overall the algorithm requires around 2.8 seconds to transmit the desired information from each reference or distorted image.

    “Overall the algorithm requires around 2.8 seconds to transmit the desired information from each (reference or distorted) image.”
    Quote in the paperNot a substantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingown data
    § V. RESULTS AND DISCUSSION · p. 20

    Computation of the index from the numbers transmitted from the reference and distorted requires time of the order of milliseconds.

    “Finally, computation of the index from the numbers transmitted from the reference and distorted requires time of the order of milliseconds.”
    Quote in the paperNot a substantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingnone given
    § V. RESULTS AND DISCUSSION · p. 18

    The estimation of K_U requires O(N) operations, while the singular value decomposition of K_U requires O(M^3) operations, where K_U is of size M × M.

    “The estimation of K U requires O ( N ) operations, while the singular value decomposition of K U requires O ( M 3 ) operations, where K U is of size M × M .”
    Quote in the paperNot a substantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Findingnone given
    § V. RESULTS AND DISCUSSION · p. 15

    Similar trends are observed for the other subbands as well.

    “Similar trends are observed for the other subbands as well.”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Findingown data
    § V. RESULTS AND DISCUSSION · p. 13

    Most RRED indices considerably outperform PSNR for all distortion types except Gaussian noise, as well as on the entire LIVE database.

    “Further, most of the RRED indices considerably outperform PSNR for all distortion types (except images distorted by Gaussian noise) as well as on the entire database.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingnone given
    § V. RESULTS AND DISCUSSION · p. 15

    The overall performance decays in the subband at the finest scale while the performance in the individual categories is still very good.

    “The overall performance decays in the subband at the finest scale while the performance in the individual categories is still very good.”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Findingreasoning
    § V. RESULTS AND DISCUSSION · p. 14

    The performance of fast fading errors goes down with the fineness of the scale even though the overall performance on the database is still very good.

    “The performance of fast fading errors goes down with the fineness of the scale even though the overall performance on the database is still very good.”
    Quote in the paperNot a substantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Findingnone given
    § V. RESULTS AND DISCUSSION · p. 13

    The algorithms are robust to the exact choice of the size of neighborhoods, yielding approximately the same performance for different sizes.

    “However, the algorithms are robust to the exact choice of the size of neighborhoods and we get approximately the same performance for different sizes.”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Findingnone given
    § V. RESULTS AND DISCUSSION · p. 17

    While the overall performance increases as σ_W^2 increases, the performance within the category of images distorted by Gaussian blur decreases.

    “While the overall performance increases as σ 2 W increases, the performance within the category of images distorted by Gaussian blur decreases.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data
    § V. RESULTS AND DISCUSSION · p. 16

    Even though overall correlations are reduced by increases in the degree of subsampling, the correlation score for each individual distortion category remains very competitive with state of the art full-reference algorithms.

    “Observe that even though the overall correlations are reduced by increases in the degree of subsampling, the correlation score for each individual distortion category remains very competitive with state of the art FR algorithms.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data
    § V. RESULTS AND DISCUSSION · p. 15

    The algorithm evaluated in subband 10 yields excellent overall performance in terms of both SROCC and LCC, as well as for compression, noise and blur distortions.

    “The algorithm evaluated in subband 10 yields excellent overall performance (in terms of both SROCC and LCC) as well as for compression, noise and blur distortions.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingnone given
    § V. RESULTS AND DISCUSSION · p. 18

    The estimation of local variance parameters (premultipliers) requires O(NM^2) operations, while sending the desired information from the reference or distorted image can be upper bounded by a cost of O(N).

    “Further, the estimation of local variance parameters (premultipliers) requires O ( NM 2 ) operations, while sending the desired information from the reference or distorted image can be upper bounded by a cost of O ( N ) .”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Findingreasoning
    § V. RESULTS AND DISCUSSION · p. 14

    Blur and fast fading errors are better captured by subbands at finer scales, while coarser scales perform better for compressed and noisy images.

    “While blur and fast fading errors are better captured by subbands at finer scales, the coarser scales perform better for compressed and noisy images.”
    Quote in the paperSubstantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingown data
    § V. RESULTS AND DISCUSSION · p. 20

    Computing the scaled entropies for a subband, which is also the information required to be transmitted, takes 0.9-1 seconds for the largest subband.

    “Computing the scaled entropies for a subband, which is also the information required to be transmitted takes 0.9-1 seconds for the largest subband.”
    Quote in the paperNot a substantial claim
  • Classified as probably not a substantial claim.

    Interpretationreasoning
    § C. RR Quality Index · p. 9

    The almost reference free algorithm still requires the single number without which quality cannot be computed.

    “The algorithm still requires the single number without which quality cannot be computed.”
    Quote in the paperSubstantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationnone given
    § C. RR Quality Index · p. 9

    The two methods reduce the amount of information gradually from an almost full reference scenario to an almost reference free scenario.

    “The two methods described above illustrate how the amount of information can be reduced gradually from an almost full reference scenario to an almost reference free scenario.”
    Quote in the paperNot a substantial claim
  • Classified as probably not a substantial claim.

    Interpretationreasoning
    § C. RR Quality Index · p. 9

    RRED 1_k requires only a single scalar from the reference for quality computation.

    “RRED 1 k denotes the algorithm in which all the scaled entropy terms in the subband are added and only the sum, which is a single scalar, is required for quality computation.”
    Quote in the paperSubstantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationreasoning
    § C. RR Quality Index · p. 8

    The reduced reference QA index corresponding to subband k is a reduced reference index because M_k is less than the size of the image.

    “The above index is a reduced reference index since M k is less than the size of the image.”
    Quote in the paperNot a substantial claim
    • The authors state this as an assumption: The covariance matrices K_U_k and K_V_k are full rank.
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation
    § I. INTRODUCTION · p. 3

    The algorithm based on Weibull statistics of wavelet coefficients achieves good performance at a given data rate.

    “The algorithm by [20] based on Weibull statistics of wavelet coefficients achieves good performance at a given data rate.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [20] [20] W. Xue and X. Mou, 'Reduced reference image quality assessment based on Weibull statistics,' in Second International Workshop on Quality of Multimedia Experience , Trondheim, 2010. - source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation
    § I. INTRODUCTION · p. 2

    SSIM, VIF, VSNR and JND are successful full reference algorithms that have been shown to perform well in predicting the quality scores of human subjects.

    “The structural similarity index (SSIM) [2], visual information fidelity (VIF) [3], visual signal to noise ratio (VSNR) [4] and just noticeable difference (JND) metrix [5], are examples of successful full reference algorithms which have been shown to perform well in predicting the quality scores of human subjects.”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites [2] [2] Z. Wang, A. C. Bovik, H. R. Sheikh, and E. P. Simoncelli, 'Image quality assessment: From error measurement to structural similarity,' IEEE Trans. Image Process. , vol. 13, no. 4, pp. 600-612, Apr. 2004. -

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [3] [3] H. R. Sheikh and A. C. Bovik, 'Image information and visual quality,' IEEE Trans. Image Process. , vol. 15, no. 2, pp. 430-444, Feb. 2006. - source

      Not checked in the free run.

    • cites [4] [4] D. M. Chandler and S. S. Hemami, 'VSNR: A wavelet-based visual signal-to-noise ratio for natural images,' IEEE Trans. Image Process. , vol. 16, no. 9, pp. 2284-2298, Sep. 2007. - source

      Not checked in the free run.

  • May combine two claims.

    Interpretationown data
    § II. INFORMATION THEORETIC APPROACHES TO QA · p. 5

    The proposed RRED algorithms possess desirable psychovisual properties leading to excellent performance.

    “However, we show later on that this procedure still possesses desirable psychovisual properties leading to excellent performance of the algorithms.”
    Quote in the paperSubstantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Interpretationnone given
    § A. Scale-Space-Orientation Decomposition · p. 10

    The first step in the RR algorithm is a wavelet decomposition of the image at multiple scales and orientations, which imitates the signal processing in the primary visual cortex (area V1).

    “The first step in the RR algorithm, similar to IFC/VIF, is a wavelet decomposition of the image at multiple scales and orientations. This step imitates the signal processing that happens in the primary visual cortex (area V1) of the human visual system.”
    Quote in the paperNot a substantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationreasoning
    § I. INTRODUCTION · p. 3

    The proposed framework allows users to choose an algorithm from this class for general purpose or distortion specific quality assessment.

    “The framework also allows users to choose an algorithm from this class for general purpose or distortion specific quality assessment.”
    Quote in the paperNot a substantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation
    § I. INTRODUCTION · p. 2

    Training-based no reference QA techniques perform at least as well as mean squared error.

    “Training based NR QA techniques have resulted in algorithms that perform at least as well as mean squared error, which has the benefit of a reference image [9], [10].”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [9] [9] A. K. Moorthy and A. C. Bovik, 'A two-step framework for constructing blind image quality indices,' IEEE Signal Processing Letters , vol. 17, no. 5, pp. 587-599, May 2010. - source

      Not checked in the free run.

    • cites [10] [10] M. A. Saad, A. C. Bovik, and C. Charrier, 'A DCT statistics based blind image quality index,' IEEE Signal Processing Letters , vol. 17, no. 6, pp. 583-586, Jun. 2010. - source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation
    § I. INTRODUCTION · p. 2

    The DNT-extended KL divergence algorithm depends on a number of parameters that need to be trained on databases.

    “However, this algorithm depends on a number of parameters that need to be trained on databases.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [13] [13] Q. Li and Z. Wang, 'Reduced-reference image quality assessment using divisive normalization-based image representation,' IEEE Journal of Selected Topics in Signal Processing: Special issue on Visual Media Quality Assessment , vol. 3, pp. 202211, 2009. - source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation
    § I. INTRODUCTION · p. 2

    The quality aware images algorithm performs well only for certain individual distortion categories.

    “The performance of this algorithm is good only for certain individual distortion categories.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [12] [12] Z. Wang, G. Wu, H. R. Sheikh, E. P. Simoncelli, E. H. Yang, and A. C. Bovik, 'Quality-aware images,' IEEE Trans. Image Process. , vol. 15, no. 5, pp. 1680-1689, 2006. - source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

    Interpretationnone given
    § C. RR Quality Index · p. 8

    Any enhanced image would show a difference in entropies and the difference should be interpreted as an improvement in quality.

    “Also, any enhanced image would show a difference in entropies and the difference should be interpreted as an improvement in quality.”
    Quote in the paperNot a substantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductcitation
    § V. RESULTS AND DISCUSSION · p. 13

    The neural noise variance value σ_W^2 = 0.1 is the same as used in prior algorithms and does not involve training on the database.

    “Note that this is the same value of neural noise variance that has been used in prior algorithms [3] and we do not imply any training on the database.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [3] [3] H. R. Sheikh and A. C. Bovik, 'Image information and visual quality,' IEEE Trans. Image Process. , vol. 15, no. 2, pp. 430-444, Feb. 2006. - source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Premisecitation
    § V. RESULTS AND DISCUSSION · p. 13

    Human subjects are more sensitive to horizontal and vertical orientations than to other orientations.

    “The analysis in [22] suggests that human subjects are more sensitive to horizontal and vertical orientations than others.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [22] [22] H. R. Sheikh, A. C. Bovik, and G. de Veciana, 'An information fidelity criterion for image quality assessment using natural scene statistics,' IEEE Trans. Image Process. , vol. 14, no. 12, pp. 2117-2128, Dec. 2005. - source

      Not checked in the free run.

  • May combine two claims.

    Interpretationreasoning
    § B. Contrast Masking · p. 11

    Divisive normalization approximates conditioning and vice versa.

    “Therefore, divisive normalization approximates conditioning and vice versa.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: The perceived reference and distorted images pass through an additive neural noise channel, where the noise is a zero mean Gaussian random vector for each block of coefficients.
  • Probably not a substantial claim: may not pass S4 (based).

    Study design and conductnone given
    § V. RESULTS AND DISCUSSION · p. 13

    The reduced reference algorithm operates without knowledge of the distortion type.

    “Note that the reduced reference algorithm operates without knowledge of the distortion type.”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Interpretationnone given
    § V. RESULTS AND DISCUSSION · p. 16

    In JPEG, increases in entropy occur due to the introduction of discontinuous blocking artifacts, while decreases in entropy occur in smoother regions that are heavily quantized.

    “For example, in JPEG, increases in entropy occur due to the introduction of discontinuous blocking artifacts, while decreases in entropy occur in smoother regions that are heavily quantized.”
    Quote in the paperSubstantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Interpretationnone given
    § VI. CONCLUSION · p. 20

    The use of a multiscale multiorientation decomposition before computing the index increases the complexity of the algorithm.

    “The use of a multiscale multiorientation decomposition before computing the index increases the complexity of the algorithm.”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Interpretationreasoning
    § V. RESULTS AND DISCUSSION · p. 16

    When the entropies are summed up after the absolute value of the difference is calculated for every block, the changes in the entropies are still preserved, leading to an algorithm that possesses better overall performance.

    “When the entropies are summed up after the absolute value of the difference is calculated for every block, the changes in the entropies are still preserved leading to an algorithm that possesses better overall performance.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Interpretationown data
    § V. RESULTS AND DISCUSSION · p. 17

    The neural noise variance of the model impacts the perception of blur apart from being able to better align scores belonging to different distortion categories.

    “This suggests that the neural noise variance of our model does impact the perception of blur apart from being able to better align scores belonging to different distortion categories.”
    Quote in the paperSubstantial claim
39 of 39
  • The authors state this as an assumption.

    Modifications of natural image statistics are perceptually noticeable.

    “It is also based on the assumption that such modifications of natural image statistics are perceptually noticeable.”
  • The authors state this as an assumption.

    Non-overlapping blocks of wavelet coefficients are independent and identically distributed.

    “Non-overlapping blocks are assumed independent and identically distributed (i.i.d.).”
  • The authors state this as an assumption.

    The wavelet coefficients of the distorted image can be modeled as a Gaussian scale mixture distribution.

    “This means that we model the wavelet coefficients of the distorted image as well as a Gaussian scale mixture distribution.”
  • The authors state this as an assumption.

    The perceived reference and distorted images pass through an additive neural noise channel, where the noise is a zero mean Gaussian random vector for each block of coefficients.

    “We additionally model the perceived reference and distorted images as passing through an additive neural noise channel, where the noise is assumed to be a zero mean Gaussian random vector for each block of coefficients.”
  • The authors state this as an assumption.

    The covariance matrices K_U_k and K_V_k are full rank.

    “In the following, assume that K U k and K V k are full rank matrices.”
  • The authors state this as an assumption.

    The scalar premultiplier S_mk and the Gaussian vector U_mk are independent.

    “Also, S mk and ¯ U mk are independent.”
  • The authors state this as an assumption.

    The neural noise vectors W_mk and W'_mk are independent of each other, independent of C_mk and D_mk, and independent across indices m and k.

    “where W mk ∼ N (0 , σ 2 W I N ) and W ′ mk ∼ N (0 , σ 2 W I N ) , W mk and W ′ mk are independent of each other, independent of ¯ C mk and ¯ D mk and independent across the indices m and k .”
7 of 7

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Gaussian-blur SROCC differs for the same algorithm

    Minor

    Tables I and III report different Gaussian-blur SROCC values for the unsubsampled RRED M16 algorithm.

  • Opposite claims about fast-fading performance across scales

    Minor

    The paper says finer-scale subbands capture fast-fading errors better, then says fast-fading performance goes down as the scale becomes finer.

2 of 2

Cites

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Research works printed but not linked: 1

  1. 0, JNDmetrix Technology

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Authors
Soundararajan, R., & Bovik, A. C.
Affiliations
The University of Texas at Austin (US)
Venue
IEEE Transactions on Image Processing
Published
2012-02
Volume
21
Issue
2
Pages
517-526
ISSN
  • 1057-7149 (ISSN-L)
  • 1941-0042
OpenAlex
W2037243393
Cited by
337
References
38
Citations by year
2026: 5 · 2025: 17 · 2024: 9 · 2023: 14 · 2022: 22 · 2021: 23 · 2020: 21 · 2019: 22 · 2018: 41 · 2017: 36 · 2016: 36 · 2015: 27 · 2014: 33 · 2013: 21 · 2012: 9
FWCI
21.69
Type
journal article
Language
en
Open access
closed
Locations
  • IEEE Transactions on Image Processing (publishedVersion)
  • PubMed (publishedVersion)
Topics
  • Physical Sciences › Computer Science › Computer Vision and Pattern Recognition › Image and Video Quality Assessment
  • Physical Sciences › Computer Science › Computer Vision and Pattern Recognition › Image Retrieval and Classification Techniques
  • Physical Sciences › Computer Science › Computer Vision and Pattern Recognition › Digital Media Forensic Detection
Keywords
reduced-reference image quality assessment, entropy difference, wavelet coefficients, image distortion, visual perception, subjective quality correlation

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-09.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-09.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

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