Quantitative Assessment of Impact and Sensitivity of Imaging Spectroscopy for Monitoring of Ageing of Archival Documents

Abstract

Ageing of historical documents often results in changes in the optical properties of the constituent materials. Imaging spectroscopy (IS) can be a valuable tool for monitoring of such changes, if the method fulfils two important conditions. Firstly, compared to natural ageing, the accumulated light dose from repeated measurements of the monitored document must not induce any significant degradation. Secondly, the monitoring instrumentation and procedures should be sensitive enough to detect changes in the materials before they become visible. We present experimental methods to evaluate the suitability of IS instrumentation for monitoring purposes. In the first set of experiments, the impact of repeated monitoring measurements was determined using a set of Blue Wool Standard materials. In the second set of experiments, the capability of the instrument to detect spectral changes was tested using ISO standard materials and several documents representative of European archive collections. It is concluded that the tested hyperspectral instrument is suitable for monitoring of the colour change of documents during display. The described experimental approach can be recommended to test the suitability of other imaging spectroscopy instruments for monitoring applications.

Hyperspectral Image Compression Using Implicit Neural Representation

“…The costs associated with capturing high-resolution temporal, spatial, and spectral data continue to decrease, and it is no surprise that hyperspectral images have found widespread use in areas such as, remote sensing, biotechnology, crop analysis, environmental monitoring, food production, medical diagnosis, pharmaceutical industry, mining, and oil & gas exploration, etc. [20,24,2,19,33,9,3,30,48,41,17,25,18,12]. Unlike color images that record red, green, and blue channels per pixel, hyperspectral images record 100s of channels per pixel, representing pixels' spectra.…”

Preliminary measurements of oil paint on paper using a mid-infrared hyperspectral imaging system with a bolometer camera and image interferometer.

“…Statistical analysis of the spectral groups can visualize differences in materials in the sample invisible to the naked eye. HSI is used in various elds [1][2][3][4][5][6][7][8][9][10][11] ; for example, Sugawara et al have studied applications such as inspecting document materials in forensic science and measuring paintings in cultural heritage science [12][13][14][15][16][17][18][19][20][21] . HSI techniques include visible (0.4-0.7 µm), near-infrared, mid-infrared, and far-infrared HSI, depending on the wavelength of light used.…”

Ink Mismatch Detection From Hyperspectral Image Document

“…This HSI system was quite strong, but its considerable acquisition time limited its application. Morales et al [15] Proposed employing Least Square SVM classification for ink analysis in pen verification and handwritten documents. Silva et al [16] created a non-destructive method for detecting fraud in documents using various chemometric techniques.…”