title: Automated pollen identification using microscopic imaging and texture analysis.
abstract: Pollen identification is required in different scenarios such as prevention of allergic reactions, climate analysis or apiculture. However, it is a time-consuming task since experts are required to recognize each pollen grain through the microscope. In this study, we performed an exhaustive assessment on the utility of texture analysis for automated characterisation of pollen samples. A database composed of 1800 brightfield microscopy images of pollen grains from 15 different taxa was used for this purpose. A pattern recognition-based methodology was adopted to perform pollen classification. Four different methods were evaluated for texture feature extraction from the pollen image: Haralick's gray-level co-occurrence matrices (GLCM), log-Gabor filters (LGF), local binary patterns (LBP) and discrete Tchebichef moments (DTM). Fisher's discriminant analysis and k-nearest neighbour were subsequently applied to perform dimensionality reduction and multivariate classification, respectively. Our results reveal that LGF and DTM, which are based on the spectral properties of the image, outperformed GLCM and LBP in the proposed classification problem. Furthermore, we found that the combination of all the texture features resulted in the highest performance, yielding an accuracy of 95%. Therefore, thorough texture characterisation could be considered in further implementations of automatic pollen recognition systems based on image processing techniques.
authors.affiliation: Institute of Optics, Spanish National Research Council (CSIC), Serrano 121, Madrid, Spain. Electronic address: jvmarcos@gmail.com.
authors.forename: J Víctor
authors.initials: JV
authors.lastname: Marcos
authors.affiliation: Posgrado en Ciencia e Ingeniería de la Computación, Universidad Nacional Autónoma de México, Mexico City, Mexico. Electronic address: urielrnv@uxmcc2.iimas.unam.mx.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Nava
authors.affiliation: Institute of Optics, Spanish National Research Council (CSIC), Serrano 121, Madrid, Spain. Electronic address: gabriel@optica.csic.es.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Cristóbal
authors.affiliation: Institute of Optics, Spanish National Research Council (CSIC), Serrano 121, Madrid, Spain; VISILAB Department at the University of Castilla La Mancha, Av. Camilo José Cela s/n, Ciudad Real, Spain. Electronic address: rafa@optica.csic.es.
authors.forename: Rafael
authors.initials: R
authors.lastname: Redondo
authors.affiliation: Posgrado en Ciencia e Ingeniería de la Computación, Universidad Nacional Autónoma de México, Mexico City, Mexico. Electronic address: boris@servidor.unam.mx.
authors.forename: Boris
authors.initials: B
authors.lastname: Escalante-Ramírez
authors.affiliation: VISILAB Department at the University of Castilla La Mancha, Av. Camilo José Cela s/n, Ciudad Real, Spain. Electronic address: Gloria.Bueno@uclm.es.
authors.forename: Gloria
authors.initials: G
authors.lastname: Bueno
authors.affiliation: VISILAB Department at the University of Castilla La Mancha, Av. Camilo José Cela s/n, Ciudad Real, Spain. Electronic address: Oscar.Deniz@uclm.es.
authors.forename: Óscar
authors.initials: Ó
authors.lastname: Déniz
authors.affiliation: Centro Agrícola Marchamalo, Guadalajara, Spain. Electronic address: avgonzalez@externas.jccm.es.
authors.forename: Amelia
authors.initials: A
authors.lastname: González-Porto
authors.affiliation: Facultad de Farmacia, Universidad Complutense, Madrid, Spain. Electronic address: cpardo@farm.ucm.es.
authors.forename: Cristina
authors.initials: C
authors.lastname: Pardo
authors.affiliation: Tecnologías Avanzadas Inspiralia, Estrada 10, Madrid, Spain. Electronic address: francois.chung@inspiralia.com.
authors.forename: François
authors.initials: F
authors.lastname: Chung
authors.affiliation: Tecnologías Avanzadas Inspiralia, Estrada 10, Madrid, Spain. Electronic address: tomas.rodriguez@inspiralia.com.
authors.forename: Tomás
authors.initials: T
authors.lastname: Rodríguez
mesh_terms: D057205:Automation, Laboratory / Q000379:methods; D055598:Chemical Phenomena; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008853:Microscopy / Q000379:methods*; D011058:Pollen / Q000145:classification*; D013499:Surface Properties
keywords: Discrete Tchebichef moments; Gray-level co-occurrence matrix; Local binary patterns; Log-Gabor filters; Pollen identification; Texture analysis