Multi-scale Bar Code Image Restoration Techniques And Their Applications In The Digital Level

The purpose of this study is to solve the practical problems that we met in the development of digital level. Multi-scale bar code signal model has been proposed in view of the convolution model of the optical system in this thesis. The technology of bar code signal restoration has been studied from the two aspects of low and high spacial frequency. At the condition of low spacial frequency, we studied the two methods of edge detection and bar-space barycenter detection, proposed variational threshold method to ascertain the bars or spaces region, it has a broader applicable scope. The experimental result indicated that, the method of barycenter detection has greater ability of anti-noise and anti-fuzzy. At the condition of high spacial frequency, the principle and methods of image blind deconvolution has been studied, and the method of regularization image blind deconvolution based total variation has been used in the restoration problem of the 1-D bar code signals. The problem of blurring and interaction of bar signals under convolution with the SPF was solved with the method.After using the restructured bar code signals in the measure algorithm, the effectual work scope of our digital level was increased to 65m from original 30m, and the accuracy is 0.55mm/km, which achieved the DS level of the state standard.