A simple algorithm for pitch distance determination

摘要

The paper describes algorithms used for the determination of pitch distances in the calibration of optical scales. The algorithm used to calculate the edges in the digital image captured by the camera is based on a fuzzy inference engine. It has a simple rule set which provides a robust solution to the problem. The gray level values of the pixels are converted to fuzzy membership values, upon which the inference engine works. As a result pixels are categorized as black, whiter or edge pixels. The algorithm used to calculate the centreline of the graduation or measuring line is derived from the centre of gravity formed by the gray values of the individual pixels. The resistance of the algorithm to various distortions on the scale was investigated using real objects.