Shoreline Detection by Digital Image Processing of Aerial Photography

Abstract

Digital image processing techniques applied to digitized (scanned) aerial photography allow significant improvements in the process of shoreline detection. Those improvements can be achieved in two areas: firstly, the area of objective and consistent shoreline recognition and secondly in the area of accurate georeferencing of the detected line. From the possible lines, the High Water Line (HWL) is most clearly represented in the photographs by a line of high brightness gradient. Three different enhancement and filtering techniques were utilized for the detection of the HWL. A combination of two of the methods provided an optimal detection methodology. The improvement in the area of georeferencing was achieved by mainly the increase in the number and accuracy of the control points relative to manual methods.