A system for inspecting a product that includes a scanner to scan across the product and generate an image of the product, the image including a matrix of pixels each having a grayscale value, and an analyzing device electrically coupled with the scanner to receive and analyze the image of the product, the analyzing device including a microprocessor to calculate a reference grayscale value associated with each of the pixels in the image, wherein the reference grayscale value includes an average of the grayscale values of pixels located adjacent to the each pixel, a memory to store the reference grayscale value associated with each of the pixels and at least one threshold associated with the reference grayscale value, and a comparing module to compare the grayscale value of each of the pixels in the image with the at least one threshold associated with the each pixel.