Christopher J Brooke | University of Nottingham (original) (raw)

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Papers by Christopher J Brooke

Heritage Science, 2023

Visual analysis and authentication of artworks are challenging tasks central to art history and c... more Visual analysis and authentication of artworks are challenging tasks central to art history and criticism. This preliminary study presents a computational tool for scholars examining and authenticating a restricted class of paintings, with a specific focus on the paintings of Raffaello Sanzio da Urbino, more popularly known as Raphael. We applied transfer learning to the ResNet50 deep neural network for feature extraction and used a support vector machine (SVM) binary classifier in support of authentication. Edge detection and analysis algorithms, considered to be crucial for capturing the essence of Raphael's artistic style, including the brushwork signatures, were also integrated and are used as an authentication tool. The machine learning approach we have developed demonstrates an accuracy of 98% in image-based classification tasks during validation using a test set of well known and authentic paintings by Raphael. Of course, a full authentication protocol relies on provenance, history, material studies, iconography, studies of a work's condition, and more. Our work, then, contributes to just a portion of a full authentication protocol. Our findings suggest that machine learning methods, properly employed by experts aware of context, may enhance and expand traditional visual analysis for problems in art authentication.

Heritage, 2023

A painted stone reredos in the Priory Church of St Cuthbert, Worksop, Nottinghamshire, UK, was an... more A painted stone reredos in the Priory Church of St Cuthbert, Worksop, Nottinghamshire, UK, was analysed before recent conservation to determine the pigment scheme employed. The screen was created by the eminent British architect Sir George Gilbert Scott in the middle decade of the 19th Century. The results help inform the wider range of palettes employed by British architects and craftspeople working in the 19th and early 20th centuries which have previously been little studied. The pigments generally were high-quality vermilion (red), chrome yellow (yellow), and ultramarine (blue), and several alternatives were also evident such as red lead and haematite for red, bone black, and carbon black for black. Lightening and darkening agents were incorporated as lead white, barytes, and carbon, and pigment mixtures were used to achieve the colours dark blue-red, and green.

This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY 4.0)

Archaeometry, 2022

Coade stone has played a significant role in architectural and ornamental design since its incept... more Coade stone has played a significant role in architectural and ornamental design since its inception in the early 18th century. It is well known that earlier, experimental, architectural stoneware products existed, but few of these have been studied in detail scientifically, and only one major analytical study of Coade stone has appeared in the literature. This paper presents a new spectroscopic analysis of Coade stone along with that of a newly discovered sample from Oxnead Hall in Norfolk where it known that Sir Clement Paston experimented with artificial stone in the late 16th century. The results demonstrate that it is possible to differentiate between the two variants on the basis of both the raw materials used and the different phases formed in their production processes.

Heritage, 2020

An organ case from Lincoln, England, designed by the architect Temple Moore in 1907 was examined ... more An organ case from Lincoln, England, designed by the architect Temple Moore in 1907 was examined during conservation work using Raman spectroscopy in order to analyze the decorative paint composition. Samples from the six principal colours were extracted and examined using a Bruker Senterra R200-L spectrometer. The results are the first known formal analysis of a painted scheme by this architect, and they reveal a mixture of commonly used pigments for the period and the unexpected use of simpler, earth pigments, along with an unusual admixture in the red, along with an organic additive. The findings are of importance to both the conservation of Temple Moore's artwork, in understanding the experimentation used in early twentieth-century England, and in furthering our knowledge of ecclesiastical decorative artwork of the late nineteenth and early twentieth centuries.

Remote Sensing, 2019

There is a long history of the use of aerial imagery for archaeological research, but the applica... more There is a long history of the use of aerial imagery for archaeological research, but the application of multisensor image data has only recently been facilitated by the development of unmanned aerial vehicles (UAVs). Two archaeological sites in the East Midlands U.K. that differ in age and topography were selected for survey using multisensor imaging from a fixed-wing UAV. The aim of this study was to determine optimum methodology for the use of UAVs in examining archaeological sites that have no obvious surface features and examine issues of ground control target design, thermal effects, image processing and advanced filtration. The information derived from the range of sensors used in this study enabled interpretation of buried archaeology at both sites. For any archaeological survey using UAVs, the acquisition of visible colour (RGB), multispectral, and thermal imagery as a minimum are advised, as no single technique is sufficient to attempt to reveal the maximum amount of potential information.

Remote Sensing, 2018

A significant problem in understanding the archaeology of standing buildings relates to the prosc... more A significant problem in understanding the archaeology of standing buildings relates to the proscription to uncover features and structures within plastered and rendered walls due to the susceptibility and historic importance of such structures. Infrared thermography offers a method of visualization that is nondestructive and capable of revealing various types of archaeological anomaly that has been demonstrated on a small scale in the past. A passive infrared thermal camera is used to examine several historic buildings that are known or suspected to contain hidden archaeological information; the technique is also presented on complex, exposed historic building fabric. The results confirm that it is possible to detect various types of man-made anomaly and to differentiate building materials. In consequence, the use of passive thermal infrared imaging is shown to be a valuable tool in the examination and recording of historic buildings and structures.

Analytical and Bioanalytical Chemistry, 2007

Accurate, detailed descriptions of parish churches outside of academic publications are rare. Sin... more Accurate, detailed descriptions of parish churches outside of academic publications are rare. Since 2000, a small team
from the diocese of Southwell and Nottingham and the University of Nottingham, backed by volunteers and students,
has been researching and web-publishing detailed descriptions of the history, archaeology, and fittings of churches in
the diocese. Aided by a grant from the Heritage Lottery Fund, the project now has details of 384 churches and church
sites in varying stages of completeness. The project has demonstrated the value of a flexible, internet-based approach
for publishing church histories, and the techniques by which volunteers may be trained and managed to achieve a
high quality product. It has also produced a great deal of new research, and some unexpected findings. Finally, it has
provided the basis for comparative studies.

Thermal prospection techniques have applications for detecting shallow ground dis- turbance that ... more Thermal prospection techniques have applications for detecting shallow ground dis- turbance that results from differential heat flux in soil and vegetation canopies. The paper reviews the potential of airborne thermal prospection and then presents an in- vestigation of measured thermal response over several geological and archaeological targets in the UK. The results show that potential of thermal imaging for detecting buried structures is limited to the top 50cm in most of the areas studied. We inves- tigate thermal models including day-night inertia and report on the optimum image processing techniques for geophysical interpretation. Finally, we compare the results with magnetic and soil resistance surveys.

Heritage Science, 2023

Visual analysis and authentication of artworks are challenging tasks central to art history and c... more Visual analysis and authentication of artworks are challenging tasks central to art history and criticism. This preliminary study presents a computational tool for scholars examining and authenticating a restricted class of paintings, with a specific focus on the paintings of Raffaello Sanzio da Urbino, more popularly known as Raphael. We applied transfer learning to the ResNet50 deep neural network for feature extraction and used a support vector machine (SVM) binary classifier in support of authentication. Edge detection and analysis algorithms, considered to be crucial for capturing the essence of Raphael's artistic style, including the brushwork signatures, were also integrated and are used as an authentication tool. The machine learning approach we have developed demonstrates an accuracy of 98% in image-based classification tasks during validation using a test set of well known and authentic paintings by Raphael. Of course, a full authentication protocol relies on provenance, history, material studies, iconography, studies of a work's condition, and more. Our work, then, contributes to just a portion of a full authentication protocol. Our findings suggest that machine learning methods, properly employed by experts aware of context, may enhance and expand traditional visual analysis for problems in art authentication.

Heritage, 2023

A painted stone reredos in the Priory Church of St Cuthbert, Worksop, Nottinghamshire, UK, was an... more A painted stone reredos in the Priory Church of St Cuthbert, Worksop, Nottinghamshire, UK, was analysed before recent conservation to determine the pigment scheme employed. The screen was created by the eminent British architect Sir George Gilbert Scott in the middle decade of the 19th Century. The results help inform the wider range of palettes employed by British architects and craftspeople working in the 19th and early 20th centuries which have previously been little studied. The pigments generally were high-quality vermilion (red), chrome yellow (yellow), and ultramarine (blue), and several alternatives were also evident such as red lead and haematite for red, bone black, and carbon black for black. Lightening and darkening agents were incorporated as lead white, barytes, and carbon, and pigment mixtures were used to achieve the colours dark blue-red, and green.

This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY 4.0)

Archaeometry, 2022

Coade stone has played a significant role in architectural and ornamental design since its incept... more Coade stone has played a significant role in architectural and ornamental design since its inception in the early 18th century. It is well known that earlier, experimental, architectural stoneware products existed, but few of these have been studied in detail scientifically, and only one major analytical study of Coade stone has appeared in the literature. This paper presents a new spectroscopic analysis of Coade stone along with that of a newly discovered sample from Oxnead Hall in Norfolk where it known that Sir Clement Paston experimented with artificial stone in the late 16th century. The results demonstrate that it is possible to differentiate between the two variants on the basis of both the raw materials used and the different phases formed in their production processes.

Heritage, 2020

An organ case from Lincoln, England, designed by the architect Temple Moore in 1907 was examined ... more An organ case from Lincoln, England, designed by the architect Temple Moore in 1907 was examined during conservation work using Raman spectroscopy in order to analyze the decorative paint composition. Samples from the six principal colours were extracted and examined using a Bruker Senterra R200-L spectrometer. The results are the first known formal analysis of a painted scheme by this architect, and they reveal a mixture of commonly used pigments for the period and the unexpected use of simpler, earth pigments, along with an unusual admixture in the red, along with an organic additive. The findings are of importance to both the conservation of Temple Moore's artwork, in understanding the experimentation used in early twentieth-century England, and in furthering our knowledge of ecclesiastical decorative artwork of the late nineteenth and early twentieth centuries.

Remote Sensing, 2019

There is a long history of the use of aerial imagery for archaeological research, but the applica... more There is a long history of the use of aerial imagery for archaeological research, but the application of multisensor image data has only recently been facilitated by the development of unmanned aerial vehicles (UAVs). Two archaeological sites in the East Midlands U.K. that differ in age and topography were selected for survey using multisensor imaging from a fixed-wing UAV. The aim of this study was to determine optimum methodology for the use of UAVs in examining archaeological sites that have no obvious surface features and examine issues of ground control target design, thermal effects, image processing and advanced filtration. The information derived from the range of sensors used in this study enabled interpretation of buried archaeology at both sites. For any archaeological survey using UAVs, the acquisition of visible colour (RGB), multispectral, and thermal imagery as a minimum are advised, as no single technique is sufficient to attempt to reveal the maximum amount of potential information.

Remote Sensing, 2018

A significant problem in understanding the archaeology of standing buildings relates to the prosc... more A significant problem in understanding the archaeology of standing buildings relates to the proscription to uncover features and structures within plastered and rendered walls due to the susceptibility and historic importance of such structures. Infrared thermography offers a method of visualization that is nondestructive and capable of revealing various types of archaeological anomaly that has been demonstrated on a small scale in the past. A passive infrared thermal camera is used to examine several historic buildings that are known or suspected to contain hidden archaeological information; the technique is also presented on complex, exposed historic building fabric. The results confirm that it is possible to detect various types of man-made anomaly and to differentiate building materials. In consequence, the use of passive thermal infrared imaging is shown to be a valuable tool in the examination and recording of historic buildings and structures.

Analytical and Bioanalytical Chemistry, 2007

Accurate, detailed descriptions of parish churches outside of academic publications are rare. Sin... more Accurate, detailed descriptions of parish churches outside of academic publications are rare. Since 2000, a small team
from the diocese of Southwell and Nottingham and the University of Nottingham, backed by volunteers and students,
has been researching and web-publishing detailed descriptions of the history, archaeology, and fittings of churches in
the diocese. Aided by a grant from the Heritage Lottery Fund, the project now has details of 384 churches and church
sites in varying stages of completeness. The project has demonstrated the value of a flexible, internet-based approach
for publishing church histories, and the techniques by which volunteers may be trained and managed to achieve a
high quality product. It has also produced a great deal of new research, and some unexpected findings. Finally, it has
provided the basis for comparative studies.

Thermal prospection techniques have applications for detecting shallow ground dis- turbance that ... more Thermal prospection techniques have applications for detecting shallow ground dis- turbance that results from differential heat flux in soil and vegetation canopies. The paper reviews the potential of airborne thermal prospection and then presents an in- vestigation of measured thermal response over several geological and archaeological targets in the UK. The results show that potential of thermal imaging for detecting buried structures is limited to the top 50cm in most of the areas studied. We inves- tigate thermal models including day-night inertia and report on the optimum image processing techniques for geophysical interpretation. Finally, we compare the results with magnetic and soil resistance surveys.

14th International Conference on Software, Knowledge, Information Management and Applications (SKIMA), 2022

Convolutional neural network (CNN) based deep learning has recently become the standard de facto ... more Convolutional neural network (CNN)
based deep learning has recently become the standard de
facto for computer assisted image analysis and
classification. In this work, we use an in-house trained
deep face recognition model to extract facial features
from images of old portraits to compare their degree of
similarity. Taking the well-known Visual Geometry
Group (VGG) deep learning model as the basis, our inhouse
trained model is fine-tuned for enhanced facial
similarity analysis, providing particular attention to the
effects from prominent parts of the face, such as the eyes,
nose and mouth features. We show how this model can be
efficiently utilised to evaluate faces present in age-old
master portraits. More specifically, we undertake facial
similarity analysis of the faces in the oil paintings of
Madonna and Child of de Brécy Tondo and Sistine
Madonna by Raphael, of which the former has been the
subject of national and international research for nearly
40 years.