Submitted to: Transactions of the ASABE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 19, 2011
Publication Date: April 20, 2011
Repository URL: http://hdl.handle.net/10113/50220
Citation: Kim, M.S., Chao, K., Chan, D.E., Jun, W., Lefcourt, A.M., Delwiche, S.R., Lee, K. 2011. Line-scan hyperspectral imaging platform for agro-food safety and quality evaluation: System enhancement and characterization. Transactions of the ASABE. 54(2):703-711. Interpretive Summary: There is a pressing need for techniques to rapidly detect diseased and/or contaminated commodities during processing. We have developed a series of hyperspectral imaging systems along with image analysis techniques to address food safety and quality concerns during food processing. In this methodology paper, the spectral and spatial system performance of the latest generation of hyperspectral imaging system in the visible and near-infrared (NIR) spectral regions was evaluated and determined to provide high quality imaging capabilities. The results of this investigation can be used as a reference in future system design as well as a baseline for evaluating image quality in food safety and quality inspection applications. The presented methodologies are useful to food processing scientists, engineers, and food processing industries.
Technical Abstract: Line-scan-based hyperspectral imaging techniques have often served as a research tool to develop rapid multispectral methods based on only a few spectral bands for rapid online applications. With continuing technological advances and greater accessibility to and availability of optoelectronic imaging sensors and spectral imaging spectrographs, the range of implementation for hyperspectral imaging has been broadening across quality and safety inspection needs in the food and agricultural industries. We have developed a series of food inspection imaging systems based on hyperspectral line-scan imaging with the use of a low-light sensitive, electron-multiplying charge-coupled device (EMCCD). In this methodology paper, the spectral and spatial system performance of the latest generation of the ARS hyperspectral imaging system capable of reflectance and fluorescence measurements in the visible and near-infrared (NIR) spectral regions from 400 to 1000 nm were evaluated. Results showed that the spectral resolution of the system is 4.4 nm at full-width at half maximum (FWHM) and 6 nm FWHM at our typical operation mode (6 spectral pixel binning). We enhanced the system throughput-responses using spectral weighing filters to better utilize the dynamic range of the analogue to digital converter. With this system throughput adjustment, noise equivalent reflectance measurements were significantly reduced by approximately 50 percent in the NIR region for a range of standard diffused reflectance targets. The responsivity of the system from 450 nm to 950 nm regions was determined to be linear.