Machine Vision System for Tea Quality Determination -Tea Quality Index (TQI)

Abstract: -Fermentation process plays an important role in tea manufacturing which is responsible for deciding the final quality of tea. But, during fermentation, it is always not possible to check the tea grains quality in uniform manner because of heavy lot of material. Also human access to the process is not advisable as the whole lot of material can not be tested with uniformity. Color and size appearance of tea grains may give substantial information regarding the tea quality and this has been harnessed in the proposed work. A machine vision system offers a fair solution in order to solve this problem. It is proposed to explore the possibility of testing the color of tea during the fermentation process imaging by a digital camera and then by using the red, green and blue (RGB) color model. An application such as color matching in fermented tea can be accomplished accurately in spite of the variation in illumination, color and internal reflection in the camera, by using a specific imaging setup of constant illumination and camera direction and distance. An algorithm is proposed to be designed that evaluate the color of the fermented tea during the process and produce the histogram (RGB as well as gray) so that the color based inference could be resulted out. A Tea Quality Index (TQI) is proposed also by applying Image Processing techniques on acquired Images of tea grains. For determination of TQI, very firstly, the average size of grains in image is computed by applying size estimation algorithm and then the diameter, area and perimeter of each grain are determined. Then after, a TQI is computed with appropriate weights to the grain dia, perimeter, area and average color. Further, TQI may be fine tuned by inserting more tea grain parameters when extracted in future