Method of programmable digitization and bar code scanning apparatus employing same

摘要: A method and apparatus are provided for detecting bar-space space-bar transitions in a bar code symbol. sequence of sparsely sampled analog signals from photodetector scanner is representative the reflectance pattern Following initialization, threshold, representing value signal at transition point, derived observed samples bars spaces Sampled information accumulated as symbol scanned, program driven microprocessor calculates repeatedly updates this using maxima minima samples, also referencing binary output to determine whether or space currently being viewed. When values two successive bracket then has occurred. Linear interpolation performed on point an offset first samples. After delay corresponding offset, level changed. bit serial thus produced, relative widths spaces.