Draft Line Detection Based on Image Processing for Ship Draft Survey

Draft line detection is the first and significant step for ship draft survey, usually determined by visual observation manually. In order to overcome the man-made error, an automated draft line detection method based on image process is proposed in this paper. Firstly, the image containing draft line is obtained and preprocessed, then the contours including draft line are extracted from the image by Canny edge detection algorithm, finally the draft line is detected by Hough transform. The experimental results show that the proposed method is effective to detect the draft line and helpful to improve the accuracy of ship survey.