Virtual raster pattern identification method for images associated with raster lines, involves converting image into unit pulse sets and calculating spatial frequency spectrum based on two dimensional Fourier transform

摘要

The method involves identifying all marks on the image by one or more picture elements (pixels) where marks are identified with a value that exceeds a predetermined or calculated threshold value. The center of gravity is calculated for all such picture elements belonging to a mark and is used in subsequent processing. Image is then converted into set of dots by the marks being replaced by unit pulses which are placed at the centers of gravity of the marks. A number of partial steps are then implemented that are based on Fourier analysis of the image or set of dots. Independent claims are made for a computer-readable program and a device for position determination comprising of a sensor for the method of virtual raster identification.