SUBPIXEL EDGE DETECTION WITH QUALITY INDICATOR AIDED TO PRESERVING THE DEPTH DISCONTINUITIES

摘要

The integrity of geometric edge is vital to the high-quality 3-D scene representation. Thus, under the task of automated as well as successful 3-D scene or object reconstruction by photogrammetric approaches, edge detection and matching become an indispensable essential. Various edge detection techniques can only provide the locations of edge up to one pixel level, which may still incur significant intersection error when dealing with acute depth discontinuities. It was aimed in this study to obtain the subpixel accuracy of edge position to support dense image matching by image moment through appropriate function and weighting. In addition, an indicator giving the reliability of detected edges was also proposed. It was demonstrated that the proposed work scheme can support subpixel edge location on one hand and identify those weak edges to be denied or cautiously employed for the follow-up tasks, on the other hand.