Assessing the Spectral Characteristics of Dye- and Pigment-Based Inkjet Prints by VNIR Hyperspectral Imaging

Fine art photography, paper documents, and other parts of printing that aim to keep value are searching for credible techniques and mediums suitable for long-term archiving purposes. In general, long-lasting pigment-based inks are used for archival print creation. However, they are very often replaced or forged by dye-based inks, with lower fade resistance and, therefore, lower archiving potential. Frequently, the difference between the dye- and pigment-based prints is hard to uncover. Finding a simple tool for countrified identification is, therefore, necessary. This paper assesses the spectral characteristics of dye- and pigment-based ink prints using visible near-infrared (VNIR) hyperspectral imaging. The main aim is to show the spectral differences between these ink prints using a hyperspectral camera and subsequent hyperspectral image processing. Two diverse printers were exploited for comparison, a hobby dye-based EPSON L1800 and a professional pigment-based EPSON SC-P9500. The identical prints created via these printers on three different types of photo paper were recaptured by the hyperspectral camera. The acquired pixel values were studied in terms of spectral characteristics and principal component analysis (PCA). In addition, the obtained spectral differences were quantified by the selected spectral metrics. The possible usage for print forgery detection via VNIR hyperspectral imaging is discussed in the results.

Identification of Corrosion Minerals Using Shortwave Infrared Hyperspectral Imaging

In this study, we propose a new method to identify corrosion minerals in carbon steel using hyperspectral imaging (HSI) in the shortwave infrared range (900–1700 nm). Seven samples were artificially corroded using a neutral salt spray test and examined using a hyperspectral camera. A normalized cross-correlation algorithm is used to identify four different corrosion minerals (goethite, magnetite, lepidocrocite and hematite), using reference spectra. A Fourier Transform Infrared spectrometer (FTIR) analysis of the scraped corrosion powders was used as a ground truth to validate the results obtained by the hyperspectral camera. This comparison shows that the HSI technique effectively detects the dominant mineral present in the samples. In addition, HSI can also accurately predict the changes in mineral composition that occur over time.

Detection of spring wheat plants affected by powdery mildew using hyperspectral survey data

In laboratory experiments, spectral characteristics of three varieties of Siberian selection spring wheat affected under field conditions by powdery mildew (Blumeria graminis (DC.) Speer) were obtained using hyperspectral camera. The variety specificity of the reflectivity of wheat leaves affected by powdery mildew with the same severity has been established. A change in the leaves reflectivity depending on the severity was revealed. The most informative spectral indicator (index) for the powdery mildew detection has been determined.

Custom Fluorescence Imaging System Exploiting Hyperspectral Camera to Characterize and Diagnose RNA Breast Cancer

Early diagnosis of breast malignancy is a challenging task to permit this cancer. RNA offers incredible potential as a biomarker for malignant growth because of its noteworthy blood dependability and characteristic articulation in various diseases. We explored the total RNA to select the optimum spectral signature concerning entire blood that could segregate between liver cancer (HCC), early breast cancer growth, and normal persons. A custom Hyperspectral Imaging (HSI) system comprises a hyperspectral camera that works in wavelength (380~1050 nm) with ultraviolet (UV) source light (20 mW, 395 nm). It is associated with the custom software system to measure the total RNA signature of (n=50) subjects (n= 10 HCC patients, n= 15 breast cancer, and n=25 normal persons as a control). The experimental result shows that the scattering absorption of all the investigated samples is high at 395 nm based on (size, shape, medical state). Breast cancer RNA demonstrates fluorescence emission at 431 nm and 493 nm and Phosphorescence at 768 nm compared to the normal and HCC patients. Verifying the experimental results with the RNA cuvette spectral images shows that we could discriminate the HCC from the normal total RNA at 431 nm and the breast cancer from both normal and HCC at 768 nm. This prospective investigation shows that the mutation of the total RNA regarding certain diseases affecting its spectral signature exhibits potential detection of breast tumor and HCC in tissues using extracted RNA from Blood in advance and subsequently surgery in subjects with initial-stage breast cancer. A wavelength of 431 nm was optimum for discrimination between the HCC and the normal total RNA, and a wavelength of 768 nm was ideal for breast cancer discrimination.