Fuente: WIPO "tomato" A computer-implemented method comprising: receiving, as input, spectral image data acquired with respect to a unit of tomato; calculating, from the spectral image data, spectral reflectance values associated with the unit of tomato in at least one specified combination of spectral bands; deriving, from the spectral reflectance values, a normalized difference spectral index (NDSI) value; and determining, based on the NDSI value, a value of at least one specified quality parameter associated with the unit of tomato.