(iii) Segmentation: The intensity image is used to identify disjoint regions of the image with the purpose of separating the part of interest from the background. This segmented image [S] is a binary image consisting only of black and white pixels, where ‘0’ (black) and ‘1’ (white) mean background and object, respectively. Image segmentation (to separate the true image of the potato chips from the background) was performed using a threshold combined with an edge detection
technique based on the Laplacian-of-Gaussian filter (Castleman, 1996; Mery & Filbert, 2002). In our case, the region of interest within the image corresponds to the area where the potato chip is located and a robust algorithm for proper potato image segmentation was previously developed and implemented (Mery & Pedreschi, 2005).