Digital Instrumentation Numeric Characters Quickly Identify Systematic Study

Numerical instruments are widely used in industrial and detection system field for its high precision, convenient reading and easily setup. data displayed by instrument need to be automatically collected. As for some instruments that have no interface to communicate with computer, in order to achieve automatic detection, image processing technique is used to collect and recognize the numerical characters displayed by instruments. So instrument recognition is very valuable.Numerical characters recognition using image processing technique and image recognition technique is studied in this dissertation. The current condition and development trend of numerical characters recognition are firstly analyzed, and then a new high speed recognition approach of numerical characters is presented according to its inherent features. Image smooth filtering, gray stretching and global threshold binarization method based on LoG algorithms edge detecting are taken to preprocess original image. And then image is thinned by improved Zhang thining method and the inclination angle of image is fixed through hough transformation. After image skew adjusting using coordinate rotating transition method, each numerical character regions are segmented by projecting method and the center coordinates of 7s LED segments of each characters are fixed. After fixation of center coordinates of 7s LED segments, following images are only needed to be monochromized, enhance and binarization, and then extract the pixel values of center of 7 LEDs segments of each character, judge whether it is lighted, finally gets its display value through a decoding program. Compared with BP neural network method and template matching method, this method has simple algorithm and high speed recognition. Several numerical instruments character images are processed in this dissertation and the results show that the algorithm can satisfy our demand well.In the end of this dissertation, concluding the total contents, pointing out the current problems to be resolved.