title: Nonlinear Fusion of Multispectral Citrus Fruit Image Data with Information Contents.
abstract: The main issue of vison-based automatic harvesting manipulators is the difficulty in the correct fruit identification in the images under natural lighting conditions. Mostly, the solution has been based on a linear combination of color components in the multispectral images. However, the results have not reached a satisfactory level. To overcome this issue, this paper proposes a robust nonlinear fusion method to augment the original color image with the synchronized near infrared image. The two images are fused with Daubechies wavelet transform (DWT) in a multiscale decomposition approach. With DWT, the background noises are reduced and the necessary image features are enhanced by fusing the color contrast of the color components and the homogeneity of the near infrared (NIR) component. The resulting fused color image is classified with a C-means algorithm for reconstruction. The performance of the proposed approach is evaluated with the statisticalFmeasure in comparison to some existing methods using linear combinations of color components. The results show that the fusion of information in different spectral components has the advantage of enhancing the image quality, therefore improving the classification accuracy in citrus fruit identification in natural lighting conditions.
authors.affiliation: School of Engineering, University of South Australia, Mawson Lakes 5095, Australia. liypl001@mymail.unisa.edu.au.
authors.forename: Peilin
authors.initials: P
authors.lastname: Li
authors.affiliation: School of Engineering, University of South Australia, Mawson Lakes 5095, Australia. Sang-Heon.Lee@unisa.edu.au.
authors.forename: Sang-Heon
authors.initials: SH
authors.lastname: Lee
authors.affiliation: School of Engineering, University of South Australia, Mawson Lakes 5095, Australia. Hung-Yao.Hsu@unisa.edu.au.
authors.forename: Hung-Yao
authors.initials: HY
authors.lastname: Hsu
authors.affiliation: Department of Electronics Engineering, Incheon National University, 119 Academy Road, Yeon Su Gu, Incheon 22012, Korea. jaepark@inu.ac.kr.
authors.forename: Jae-Sam
authors.initials: JS
authors.lastname: Park
keywords: clustering; entropy filter; image fusion; multiscale decomposition; wavelet transform