The resultant binary image was then processed using morphological closing and opening operations. It was closed using a disk-shaped structuring element with a radius of 2, and opened using a diamond-shaped structuring element with a distance of 19. The resultant connected components were then filled, and the contours of the objects were smoothed with morphological erosion and hole-filling operations. Furthermore, the unwanted cells around the colony regions, which are smaller than the user-specified threshold, were removed using a size filtering method. We noticed that a size of 9000 pixels was suitable for removing the other regions that surround the colony area. Finally, the resultant segmented colony region was evaluated for further quantitative feature measurements by connected component labeling with eight-neighbor connectivity. This method is generally used to estimate adjacent pixels that share the same set of intensity values . The segmentation results of the healthy and unhealthy colony image are shown in Figs 2 and 3, respectively.