Abstract: Spectral images of red jujubes with different types of surface damage were collected by hyperspectral imaging technology over the wavelength range of 650–950 nm. Principal component analysis (PCA) was applied for dimension reduction of the spectra. The characteristic wavelengths of 715 nm and 668 nm, where samples were recognized, were proposed based on eigenvalues obtained from PCA. As a result, classification of surface damage in red jujubes achieved with an accuracy of 98.7%.

Key words: red jujube, damage form, feature extraction, PCA