The Component Development of Digital Close Range Photogrammetry for the Construction Structure Displacement Analysis

In this study, this researcher designed the routine of image analysis with object concept, so as to increase the efficiency of displacement interpretation of structure by digital image analysis. For the hierarchical connection performance of analysis routine, this researcher formed the constant attribute of objectification of photogrammetry process by constituting the classes such as target location, transformation of coordinates of scan image, bundle adjustment, and direct linear transformation (DLT). And, this researcher performed the efficient location of sub-pixel coordinates by manufacturing the routine of coordinates location of image including target recognition, grouping, image segmentation and location etc. and the module of additional functions such as the establishment of pixel size and the indication function of recognized target. For the development of component of digital photogrammetry that the location of subpixel of high accuracy is possible, this researcher extracted the image segmentation (T3) method which uses the average and standard error of greylevel values in search area, and ellipse fitting(ELI) method by edge detection and thinning by executing error analysis by the methods of coordinates location of sub-pixel, and could know that the accuracy of location is improved in accordance with the increase of threshold value. And, by developing the component to be based on the establishment of hierarchical diagram of classes through designing each subject of process of image analysis with the class of objectification concept, more efficient displacement interpretation of structure was possible.