Hyperspectral Imaging for Detecting Fecal and Ingesta Contaminants on Poultry Carcasses
A hyperspectral imaging system including a camera with prism-grating-prism spectrograph, fiber optic line lighting, motorized lens control, and hyperspectral image-processing software was developed for poultry safety inspection, particularly identification of fecal and ingesta contamination on poultry carcasses. Both spectral and spatial image data between 400 and 900 nm with 512 spectral bands were acquired from fecal and ingesta contaminated poultry carcasses. Four dominant wavelengths (434, 517, 565, and 628 nm) were selected by principal component analysis from visible/near-infrared spectroscopy for wavelength selection of hyperspectral images. A calibration model for the hyperspectral imaging system was developed from calibration lighting sources (HgAr, Kr, and lasers) for accurate band selection from the hyperspectral images to identify spatial and spectral characterization of fecal and ingesta contaminants. Hyperspectral image processing algorithms, specifically band ratio of dual-wavelength (565/517) images and histogram stretching, were effective in the identification of fecal and ingesta contamination of poultry carcasses. Test results indicated that the detection accuracy was 97.3% for linear and 100% for non-linear histogram stretching. This article presents the research results that hyperspectral imaging can be used effectively for detecting feces (from the duodenum, ceca, and colon) and ingesta on poultry carcasses and demonstrates the potential application for on-line safety inspection of poultry.