Laser-light backscattering imaging for early decay detection in citrus fruit using both a statistical and a physical model

The early detection of decay caused by fungi in citrus fruit is a primary concern in the post-harvest phase, the automation of this task still being a challenge. This work reports new progress in the automatic detection of early symptoms of decay in citrus fruit after infection with the pathogen Pen...

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Main Authors: Lorente, Delia, Zude, Manuela, Idler, C., Gómez-Sanchís, Juan, Blasco, José
Format: Artículo
Language:Inglés
Published: 2017
Online Access:http://hdl.handle.net/20.500.11939/5540
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author Lorente, Delia
Zude, Manuela
Idler, C.
Gómez-Sanchís, Juan
Blasco, José
author_browse Blasco, José
Gómez-Sanchís, Juan
Idler, C.
Lorente, Delia
Zude, Manuela
author_facet Lorente, Delia
Zude, Manuela
Idler, C.
Gómez-Sanchís, Juan
Blasco, José
author_sort Lorente, Delia
collection ReDivia
description The early detection of decay caused by fungi in citrus fruit is a primary concern in the post-harvest phase, the automation of this task still being a challenge. This work reports new progress in the automatic detection of early symptoms of decay in citrus fruit after infection with the pathogen Penicillium digitatum using laser-light backscattering imaging. Backscattering images of sound and decaying parts of the surface of oranges cv. ‘Valencia late’ were obtained using laser diode modules emitting at five wavelengths in the visible and near-infrared regions. The images of backscattered light captured by a camera had radial symmetry with respect to the incident point of the laser beam, these being reduced to a one-dimensional profile through radial averaging. Two models were used to characterise backscattering profiles: a statistical model using the Gaussian–Lorentzian cross product (GL) distribution function with five parameters and a physical approach calculating the absorption, , and reduced scattering, , coefficients from Farrell’s diffusion theory. Models described radial profiles accurately, with slightly better curve-fitting results (R2 ⩾ 0.996) for the GL model compared to Farrell’s model (R2 ⩾ 0.982), both indicating significant differences in the parameters between sound and decaying orange skin at the five wavelengths. For dimensionality reduction purposes, feature selection methods were employed to select the most relevant backscattering profile parameters for the detection of early decay lesions. The feature vectors obtained were used to discriminate between sound and decaying skin using a supervised classifier based on linear discriminant analysis. The best classification results were achieved using a reduced set of GL parameters, yielding a maximum overall classification accuracy of 93.4%, with a percentage of well-classified sound and decaying samples of 92.5% and 94.3%, respectively. Results also pointed out application limits of Farrell’s diffusion theory at 532 nm laser wavelength, for which high absorption of pigments occurred.
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institution Instituto Valenciano de Investigaciones Agrarias (IVIA)
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spelling ReDivia55402025-04-25T14:43:14Z Laser-light backscattering imaging for early decay detection in citrus fruit using both a statistical and a physical model Lorente, Delia Zude, Manuela Idler, C. Gómez-Sanchís, Juan Blasco, José The early detection of decay caused by fungi in citrus fruit is a primary concern in the post-harvest phase, the automation of this task still being a challenge. This work reports new progress in the automatic detection of early symptoms of decay in citrus fruit after infection with the pathogen Penicillium digitatum using laser-light backscattering imaging. Backscattering images of sound and decaying parts of the surface of oranges cv. ‘Valencia late’ were obtained using laser diode modules emitting at five wavelengths in the visible and near-infrared regions. The images of backscattered light captured by a camera had radial symmetry with respect to the incident point of the laser beam, these being reduced to a one-dimensional profile through radial averaging. Two models were used to characterise backscattering profiles: a statistical model using the Gaussian–Lorentzian cross product (GL) distribution function with five parameters and a physical approach calculating the absorption, , and reduced scattering, , coefficients from Farrell’s diffusion theory. Models described radial profiles accurately, with slightly better curve-fitting results (R2 ⩾ 0.996) for the GL model compared to Farrell’s model (R2 ⩾ 0.982), both indicating significant differences in the parameters between sound and decaying orange skin at the five wavelengths. For dimensionality reduction purposes, feature selection methods were employed to select the most relevant backscattering profile parameters for the detection of early decay lesions. The feature vectors obtained were used to discriminate between sound and decaying skin using a supervised classifier based on linear discriminant analysis. The best classification results were achieved using a reduced set of GL parameters, yielding a maximum overall classification accuracy of 93.4%, with a percentage of well-classified sound and decaying samples of 92.5% and 94.3%, respectively. Results also pointed out application limits of Farrell’s diffusion theory at 532 nm laser wavelength, for which high absorption of pigments occurred. 2017-06-01T10:12:32Z 2017-06-01T10:12:32Z 2015 JUN 2015 article Lorente, D., Zude, M., Idler, C., Gomez-Sanchis, J., Blasco, J. (2015). Laser-light backscattering imaging for early decay detection in citrus fruit using both a statistical and a physical model. Journal of Food Engineering, 154, 76-85. 0260-8774 http://hdl.handle.net/20.500.11939/5540 10.1016/j.jfoodeng.2015.01.004 en openAccess Impreso
spellingShingle Lorente, Delia
Zude, Manuela
Idler, C.
Gómez-Sanchís, Juan
Blasco, José
Laser-light backscattering imaging for early decay detection in citrus fruit using both a statistical and a physical model
title Laser-light backscattering imaging for early decay detection in citrus fruit using both a statistical and a physical model
title_full Laser-light backscattering imaging for early decay detection in citrus fruit using both a statistical and a physical model
title_fullStr Laser-light backscattering imaging for early decay detection in citrus fruit using both a statistical and a physical model
title_full_unstemmed Laser-light backscattering imaging for early decay detection in citrus fruit using both a statistical and a physical model
title_short Laser-light backscattering imaging for early decay detection in citrus fruit using both a statistical and a physical model
title_sort laser light backscattering imaging for early decay detection in citrus fruit using both a statistical and a physical model
url http://hdl.handle.net/20.500.11939/5540
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AT gomezsanchisjuan laserlightbackscatteringimagingforearlydecaydetectionincitrusfruitusingbothastatisticalandaphysicalmodel
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