RT info:eu-repo/semantics/article T1 Examination of lemon bruising using different CNN-based classifiers and local spectral-spatial hyperspectral imaging A1 Pourdarbani, Razieh A1 Sabzi, Sajad A1 Dehghankar, Mohsen A1 Rohban, Mohammad H. A1 Arribas Sánchez, Juan Ignacio K1 Frutas K1 Cítricos K1 Cítricos - Cultivo K1 Citrus K1 Citrus cultivation K1 Citrus fruits K1 Classification K1 Neural networks (Computer science) K1 Redes neuronales (Informática) K1 Hyperspectral imaging K1 Fruit K1 Fruit - Quality K1 Food science K1 Machine learning K1 Aprendizaje automático K1 Artificial intelligence K1 Image processing - Digital techniques K1 Procesamiento de imágenes - Técnicas digitales. K1 Computer mathematics K1 Ordenadores - Matemáticas K1 Numerical analysis K1 Análisis numérico K1 Bruise K1 1203.17 Informática K1 1203.04 Inteligencia Artificial K1 3102 Ingeniería Agrícola AB The presence of bruises on fruits often indicates cell damage, which can lead to a decrease in the ability of the peel to keep oxygen away from the fruits, and as a result, oxygen breaks down cell walls and membranes damaging fruit content. When chemicals in the fruit are oxidized by enzymes such as polyphenol oxidase, the chemical reaction produces an undesirable and apparent brown color effect, among others. Early detection of bruising prevents low-quality fruit from entering the consumer market. Hereupon, the present paper aims at early identification of bruised lemon fruits using 3D-convolutional neural networks (3D-CNN) via a local spectral-spatial hyperspectral imaging technique, which takes into account adjacent image pixel information in both the frequency (wavelength) and spatial domains of a 3D-tensor hyperspectral image of input lemon fruits. A total of 70 sound lemons were picked up from orchards. First, all fruits were labeled and the hyperspectral images (wavelength range 400–1100 nm) were captured as belonging to the healthy (unbruised) class (class label 0). Next, bruising was applied to each lemon by freefall. Then, the hyperspectral images of all bruised samples were captured in a time gap of 8 (class label 1) and 16 h (class label 2) after bruising was induced, thus resulting in a 3-class ternary classification problem. Four well-known 3D-CNN model namely ResNet, ShuffleNet, DenseNet, and MobileNet were used to classify bruised lemons in Python. Results revealed that the highest classification accuracy (90.47%) was obtained by the ResNet model, followed by DenseNet (85.71%), ShuffleNet (80.95%) and MobileNet (73.80%); all over the test set. ResNet model had larger parameter sizes, but it was proven to be trained faster than other models with fewer number of free parameters. ShuffleNet and MobileNet were easier to train and they needed less storage, but they could not achieve a classification error as low as the other two counterparts. PB MDPI SN 1999-4893 YR 2023 FD 2023 LK https://uvadoc.uva.es/handle/10324/63627 UL https://uvadoc.uva.es/handle/10324/63627 LA eng NO Algorithms, 2023, Vol. 16, Nº. 2, 113 NO Producción Científica DS UVaDOC RD 27-dic-2024