A computer based system for matching colours during the monitoring of tea fermentation

Summary The design and development of a personal computer (PC) based system for monitoring changes in colour during the fermentation process that is used to produce tea is described. The technique is based on imaging the fermenting tea at different intervals of time and processing the colour images. A digital camera, together with a special lighting arrangement, was used to capture colour images during the fermentation process. The RGB colour model was used so that histogram dissimilarity measurements matched the colour of test images to a standard image colour. This dissimilarity measurement was represented by difference from the Manhattan norm (L1). The technique was compared with the visual methods used by expert tea tasters.