Hyperspectral imaging and chemometrics

Zhang, X. et al (2012) Application of hyperspectral imaging and chemometric calibrations for variety... 

Hyperspectral Imaging and Chemometrics A Perfect Combination for the Analysis of Food Structure, Composition and Quality... 

Classical chemometric methods, that is, the classification and regression presented in Section 4.3.1, are also applied to hyperspectral images.However,XxYx X matrices have to be unfolded into (1 ) 1 matrices before processing. In other words, the three-way OOV array is unfolded into a classical two-way OV matrix. 

One final piece of advice the product in data processing is only as good as the informational content of the input data. The field of study we now call chemometrics began in earnest about three decades ago with application of statistical principles to chemical data. Hyperspectral images provide lots and lots of data, and chemometrics can be used to extract important information from these data however, it is still limited by the quality of the input data. 

Manley et al. (2011) used near infrared hyperspectral imaging combined with chemometrics techniques for tracking diffusion of conditioning water in single wheat kernels of different hardnesses. NIR analysers is a commonly, non-destructive, non-contact and fast solution for quality control, and a used tool to detect the moisture-content of carrot samples during storage but Firtha (2009) used hyperspectral system that is able to detect the spatied... 

Siripatrawan et al. (2011) have developed a rapid method for the detection of Escherichia coli contamination in packaged fresh spinach using hyperspectral imaging (400-1000 nm) and chemometrics techniques. The PCA was implemented to remove redundant information of the hyperspectral data and artificial neural network (ANN) to correlate spectra with number of E. coli and to construct a prediction map of all pixel spectra of an image to display the number of E. coli in the sample. 

Nicolai et al. (2007) wrote a review about the applications of non-destructive measurement of fruit and vegetable quality. Measurement principles are compwed, and novel techniques (hyperspectral imaging) are reviewed. Special attention is p>aid to recent developments in portable systems. The problem of calibration transfer from one spectrophotometer to another is introduced, as well as techniques for calibration transfer. Chemometrics is an essential part of spectroscopy and the choice, of corrected techniques, is primary (linear or nonlinear regression, such as kernel-based methods are discussed). The principal objective of spectroscopy system applications in fruit and vegetables sector have focused on the nondestructive measurement of soluble solids content, texture, dry matter, acidity or disorders of fruit and vegetables, (root mean square error of prediction want to be achieved). 

PARAFAC modeling of three-way hyperspectral images Endogenous fluorophores as health biomarkers in aquatic species, Chemometrics and Intelligent Laboratory Systems, Vol. 106, No. 1, pp. 115-124... 

Fernandez Pierna, J.A. et al. (2012) NIR hyperspectral imaging spectroscopy and chemometrics for the detection... 

The second part of the book—Chapters 9-12— presents some selected applications of chemometrics to different topics of interest in the field of food authentication and control. Chapter 9 deals with the application of chemometric methods to the analysis of hyperspectral images, that is, of those images where a complete spectrum is recorded at each of the pixels. After a description of the peculiar characteristics of images as data, a detailed discussion on the use of exploratory data analytical tools, calibration and classification methods is presented. The aim of Chapter 10 is to present an overview of the role of chemometrics in food traceability, starting from the characterisation of soils up to the classification and authentication of the final product. The discussion is accompanied by examples taken from the different ambits where chemometrics can be used for tracing and authenticating foodstuffs. Chapter 11 introduces NMR-based metabolomics as a potentially useful tool for food quality control. After a description of the bases of the metabolomics approach, examples of its application for authentication, identification of adulterations, control of the safety of use, and processing are presented and discussed. Finally, Chapter 12 introduces the concept of interval methods in chemometrics, both for data pretreatment and data analysis. The topics... 

Multivariate Image Analysis Strong and Weak Multiway Methods Strong and weak -way methods analyze 3D and 2D matrices, respectively. Hyperspectral data cube structure is described using chemometric vocabulary [17]. A two-way matrix, such as a classical NIR spectroscopy data set, has two modes object (matrix lines) and V variables (matrix columns). Hyperspectral data cubes possess two object modes and one variable mode and can be written as an OOV data array because of their two spatial directions. 

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