Bar code identification of digital levels

This paper introduced the algorithm of bar code identification of digital level. In the digital level system, the original gauge rod is substituted by bar code rod. The CCD-sensor is used to substitute the eyes of people. The automatic measuring is realized by identifying the bar code on the rod using image process, code principle and the geometry optics technology. The data processing algorithm is achieved purposively after analyzing the data and waveform of CCD output signal. At first, the noise is attenuated with the filter algorithm and signal noise ratio is increased. Then the bar code information from bar image of the gauge is gotten with the speedy edge detection algorithm based on exponent, and the load of calculation is decreased. According to the principle of photoelectric transform of CCD, identify the corresponding bar code and the altitude of the point was calculated. The experiment results indicate that the algorithm of bar code identification is feasible.