Technology Of Automatic Search And Measurement Of Crack On Engineering Structure Component

During resent years, there occur great numbers of cracks on architecture construction component. It can be called vast numbers and wide range. The so-called wide range means that occurring radio is relatively high. There are considerable numbers of architecture construction having such crack problems. We develop a set of recognizable and analyzable software according to the problems, which need be solved urgently in the architecture realm and provide full-scale and accurate data for research of engineering safety controlling. The main work of this thesis is carried out about the detection of the crack skeleton and boundary, diameter information. The works can be included as follows:1.Analysis of the intensity characters of the crack imageThe crack image is deeply analyzed on the base of vascular shape. Three intensity characteristics are acquired, which are the rules for the detection of the 2-D information in the image.2.Detection of the crack skeletonImage pre-processing technologies are firstly used to eliminate noise and enhance the image, such as Top-Hat transform.Then extract the crack area on the self-adaptive threshold.At last, the un-direct method that thins the crack as the skeleton is adopted on the research of the direct and un-direct methods.The connectivity-number thinning method is presented to skeletonize the crack area.3.Detection of the continuous crack boundaryThe continuous crack boundary is the base for getting the parameters in latter work.The Max-Cost (MC) is presented on the base of the study of the traditional edge detecting methods and ISEF.It is consisted of two steps: the fist step is that the cost field is built up by the traditional edge detecting method –differential method; The second step is that the boundary, the curve with maximal cost I the segmented area, is detected serially bye the dynamic programming (DP).The MC inherits the merits of the traditional method, and its boundary is continuous and one-pixel wide.4.The width measurement of the main crack The width measurement is based on the skeleton and continuous boundary of crack.The crack is re-sampled by the skeleton and calculate via vertical direction of the tangent direction of the point on skeleton.