Optical characterization method

Abstract

This invention includes an optical characterization method capable of determining various characteristics of samples that preferably include naturally-occurring color deviations. In the preferred embodiment, this method is used in connection with food products and, particularly, potato products such as french fried potatoes. The method of this invention overcomes such disadvantages by generating from the RGB pixel values a sample-based color space that corresponds to the naturally-occurring color deviations of the samples. Preferably, the method includes generating HSI pixel values that correspond to the RGB pixel values and are defined with respect to an HSI color space having hue, saturation, and intensity coordinates. The sample-based representation of the color characteristics of the samples is determined on a pixel-by-pixel basis. As a result, color grades for the samples can be assigned according to the distribution of pixels within the sample-based representation. Moreover, defects or color variation, as well as the length distribution of the samples, may also be determined.