PPROBLEM TO BE SOLVED: To provide a detection method of foreign objects and impurities for precisely removing the foreign objects and impurities contained in food, such as fruits. PSOLUTION: In the detection method of foreign objects and impurities, first, the visible light of reflection light obtained by irradiating food containing fruit, or the like, and foreign objects and impurities contained in the food with light, and the absorption spectrum of near infrared rays are measured. Then, a second-order differential processing is applied to the absorption spectrum, and a wavelength band for indicating a different, second-order differential spectrum between the food and foreign object and/or impurities is selected. Then, a second-order differential spectral image of the selected wavelength band is created for the food, thus detecting the foreign objects and impurities contained in the food. PCOPYRIGHT: (C)2005,JPO&NCIPI
展开▼
