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Paul Messier - One of the best experts on this subject based on the ideXlab platform.

  • steerable pyramid for texture classification of Photographic Paper
    Asilomar Conference on Signals Systems and Computers, 2020
    Co-Authors: Nicholas Rogers, Damon Crockett, Paul Messier
    Abstract:

    In this work, we describe the application of the ‘steerable pyramid’ (Portilla and Simoncelli, 2000), a high-dimensional texture descriptor, to the discrimination and classification of a large collection of Photographic Paper textures. This work is part of a broader effort to bring precise physical measurements to the characterization of Photographic Papers, and our intended audience includes photograph conservators, curators, and collectors. For our purposes, it is important both to enable fine-grained local comparisons of very similar textures and to identify salient groupings across the entire landscape of Photographic Papers. The steerable pyramid was developed with the explicit goal of synthesizing textures; as such, it is an overcomplete representation. Its high native dimensionality is an advantage for highly precise local comparisons of texture, as in nearest neighbor search; it is, however, a disadvantage for grouping tasks, which require a well-structured global topology. For grouping tasks, we describe a number of compression and grouping approaches designed to meet a variety of analytical needs. Finally, we validate the steerable pyramid descriptor numerically using ‘one versus all’ classification on an augmented data set that includes multiple samples per Paper type.

  • deep learning classification of Photographic Paper based on clustering by domain experts
    Asilomar Conference on Signals Systems and Computers, 2016
    Co-Authors: Andrew G Klein, Paul Messier, Andrea L Frost, David Palzer, S L Wood
    Abstract:

    Prior work on texture analysis of historic, Photographic Papers has focused primarily on measures of texture similarity. However, automated grouping or clustering of Photographic Paper textures in a way that is meaningful to art conservators remains an open problem. In this work a deep learning approach to automated classification is presented, for clusters derived from a human sorting experiment conducted by 19 art conservators and Paper experts and subsequently extended through crowd-sourcing. The proposed approach uses a deep convolutional neural network, and results are presented on the performance in automatically classifying images when compared to human experts.

  • Multiscale Anisotropic Texture Unsupervised Clustering for Photographic Paper
    2015
    Co-Authors: Stéphane G. Roux, Nicolas Tremblay, Pierre Borgnat, Patrice Abry, Herwig Wendt, Paul Messier
    Abstract:

    Texture characterization of Photographic Papers is likely to provide scholars with valuable information regarding artistic practices. Currently, texture assessment remains mostly based on visual and manual inspections, implying long repetitive tasks prone to inter- and even intra-observer variability. Automated texture characterization and classification procedures are thus important tasks in historical studies of large databases of Photographic Papers, likely to provide quantitative and reproducible assessments of texture matches. Such procedures may, for instance, produce vital information on Photographic prints of uncertain origins. The hyperbolic wavelet transform, because it relies on the use of different dilation factor along the horizontal and vertical axes, permits to construct robust and meaningful multiscale and anisotropic representation of textures. In the present contribution, we explore how unsupervised clustering strategies can be complemented both to assess the significance of extracted clusters and the strength of the contribution of each texture to its associated cluster. Graph based filterbank strategies are notably investigated with the aim to produce small size significant clusters. These tools are illustrated at work on a large database of about 2500 exposed and non exposed Photographic Papers carefully assembled and documented by the MoMA and P. Messier's foundation. Results are commented and interpreted.

  • correlation between gloss reflectance and surface texture in Photographic Paper
    Scanning, 2015
    Co-Authors: Kevin Vessot, Paul Messier, Joyce Hyde, Christopher A Brown
    Abstract:

    Summary Surface textures of a large collection of Photographic Papers dating from 1896 to the present were measured using a laser scanning confocal microscope (LSCM) with four different objective lenses. Roughness characterization parameters were calculated from the texture measurements and were compared with gloss measurements. Characterization by the area-scale fractal dimension (Das) and the area-scale fractal complexity (Asfc) provided the strongest correlations between gloss reflectance and surface texture. The measurements with the 5× and 10× objectives, which contained many large-scale, spiky measurement artifacts that distorted the measurement, resulted in the strongest correlations (R2 > 0.8) compared to the 20× and 50× (R2 < 0.5). The presence of spiky artifacts in the measurements, which increases when the magnification of the objective lens is decreased, appears to amplify surface features in such a way to improve the correlations. SCANNING 37:204–217, 2015. © 2015 Wiley Periodicals, Inc.

  • Optical Brightening Agents in Photographic Paper
    Journal of The American Institute for Conservation, 2013
    Co-Authors: Paul Messier, Valerie Baas, Diane Tafilowski, Lauren Varga
    Abstract:

    AbstractA reference collection of mostly 20th-century Photographic Paper was surveyed for the presence of optical brightening agents. Only fiber-based, gelatin silver Paper was assessed. In all, 1,804 samples were examined, dating from 1896 to 2004 and representing 40 different manufacturers. No optical brightening agents were found in samples dating from 1896 to 1949. The first occurrence of optical brightening agent was found in samples dating between 1950 and 1954. Between 1955 and 1964, the frequency of occurrence for optical brightening agents increased rapidly. Toward the latter part of this date range the occurrence of optical brighteners rose, with 70% of all samples showing brighteners. Between 1965 and 1979, occurrence of optical brightening agents declined to a low of 39% of all samples. A marked increase in occurrence was observed after 1980, when 81% of samples exhibited optical brightening agents. These results indicate that a significant proportion, and for some time periods a significant m...

Lauren Varga - One of the best experts on this subject based on the ideXlab platform.

  • Optical Brightening Agents in Photographic Paper
    Journal of The American Institute for Conservation, 2013
    Co-Authors: Paul Messier, Valerie Baas, Diane Tafilowski, Lauren Varga
    Abstract:

    AbstractA reference collection of mostly 20th-century Photographic Paper was surveyed for the presence of optical brightening agents. Only fiber-based, gelatin silver Paper was assessed. In all, 1,804 samples were examined, dating from 1896 to 2004 and representing 40 different manufacturers. No optical brightening agents were found in samples dating from 1896 to 1949. The first occurrence of optical brightening agent was found in samples dating between 1950 and 1954. Between 1955 and 1964, the frequency of occurrence for optical brightening agents increased rapidly. Toward the latter part of this date range the occurrence of optical brighteners rose, with 70% of all samples showing brighteners. Between 1965 and 1979, occurrence of optical brightening agents declined to a low of 39% of all samples. A marked increase in occurrence was observed after 1980, when 81% of samples exhibited optical brightening agents. These results indicate that a significant proportion, and for some time periods a significant m...

Hannah R. Morris - One of the best experts on this subject based on the ideXlab platform.

  • OPTICAL BRIGHTENERS IN BLACK-AND-WHITE Photographic Paper: APPEARANCE AND DEGRADATION
    Journal of The American Institute for Conservation, 2013
    Co-Authors: Sandra A. Connors-rowe, Paul M. Whitmore, Hannah R. Morris
    Abstract:

    Abstract Forty-five optically brightened blackand- white Photographic Papers from 12 manufacturers spanning 1956-2006 were studied to evaluate the brightener's impact on appearance and its light sensitivity under simulated daylight conditions. The appearance tests showed both small and large changes in appearance when the optical brightener was activated by inclusion of UV in the illuminating light source. All Papers showed a decrease in the Yellowness Index value upon brightener activation, indicating a change in appearance to a color that is whiter than its unbrightened version. Three Papers that were originally warm white in appearance, however, remained somewhat yellow in color even with activation of their optical brighteners. All of the 45 Papers experienced some optical brightener loss as a result of prolonged exposure to simulated daylight with UV wavelengths included; many also experienced other color changes such as bleaching or yellowing of the Paper substrate and loss of a chromophore at 570 n...

Sandra A. Connors-rowe - One of the best experts on this subject based on the ideXlab platform.

  • OPTICAL BRIGHTENERS IN BLACK-AND-WHITE Photographic Paper: APPEARANCE AND DEGRADATION
    Journal of The American Institute for Conservation, 2013
    Co-Authors: Sandra A. Connors-rowe, Paul M. Whitmore, Hannah R. Morris
    Abstract:

    Abstract Forty-five optically brightened blackand- white Photographic Papers from 12 manufacturers spanning 1956-2006 were studied to evaluate the brightener's impact on appearance and its light sensitivity under simulated daylight conditions. The appearance tests showed both small and large changes in appearance when the optical brightener was activated by inclusion of UV in the illuminating light source. All Papers showed a decrease in the Yellowness Index value upon brightener activation, indicating a change in appearance to a color that is whiter than its unbrightened version. Three Papers that were originally warm white in appearance, however, remained somewhat yellow in color even with activation of their optical brighteners. All of the 45 Papers experienced some optical brightener loss as a result of prolonged exposure to simulated daylight with UV wavelengths included; many also experienced other color changes such as bleaching or yellowing of the Paper substrate and loss of a chromophore at 570 n...

Vedel Béatrice - One of the best experts on this subject based on the ideXlab platform.

  • Hyperbolic Wavelet Transform for Historic Photographic Paper Classification Challenge
    'Institute of Electrical and Electronics Engineers (IEEE)', 2015
    Co-Authors: Roux Stéphane, Abry Patrice, Wendt Herwig, Jaffard Stéphane, Vedel Béatrice
    Abstract:

    Photographic Paper texture characterization constitutes a challenging image processing task and an important stake both for manufacturers and art museums. The present contribution shows how the Hyperbolic Wavelet Transform, thanks to its joint multiscale and anisotropie nature, permits to achieve an accurate Photographic Paper texture analysis and characterization. A cepstral-type distance, constructed on the coefficients of the Hyperbolic Wavelet Transform, is then used to measure similarity between pairs of Paper textures. Spectral clustering followed by Ascendant Hierarchical Clustering applied to the similarity matrix enables an unsupervised classification of Photographic Paper sheets. This methodology is applied to a test dataset made available in the framework of the Historic Photographic Paper Classification Challenge. The relevance of the proposed texture characterization and classification procedure is assessed by comparisons against the database documentation provided by experts

  • Hyperbolic Wavelet Transform for Historic Photographic Paper Classification Challenge
    HAL CCSD, 2014
    Co-Authors: Roux Stéphane, Abry Patrice, Wendt Herwig, Jaffard Stéphane, Vedel Béatrice
    Abstract:

    International audiencePhotographic Paper texture characterization constitutes a challenging image processing task and an important stake both for manufacturers and art museums. The present contribution shows how the Hyperbolic Wavelet Transform, thanks to its joint multiscale and anisotropie nature, permits to achieve an accurate Photographic Paper texture analysis and characterization. A cepstral-type distance, constructed on the coefficients of the Hyperbolic Wavelet Transform, is then used to measure similarity between pairs of Paper textures. Spectral clustering followed by Ascendant Hierarchical Clustering applied to the similarity matrix enables an unsupervised classification of Photographic Paper sheets. This methodology is applied to a test dataset made available in the framework of the Historic Photographic Paper Classification Challenge. The relevance of the proposed texture characterization and classification procedure is assessed by comparisons against the database documentation provided by experts