The development of a multi-piecewise-based thinning description method

Abstract

In this study, we proposed a multi-piecewise thinning description method. Thinning is a preprocessing technology often applied in the fields of binary image processing; it is used to transform thick elements in an image into lines with a single pixel width. Because lines include closed and open lines, an effective description method is required for post-processing procedures. Regarding the proposed method, branch points of thinning lines are first identified and used as a basis for segmenting the lines, which are originally connected, into multiple line segments. Subsequently, we employed the find contour function available in the OpenCV library to describe the coordinates of the contours of the line segments. The starting and endpoints of closed lines can be directly obtained using the contour results of closed lines. By contrast, the starting and endpoints of open lines are achieved by first using turning points to confirm the position of line-end points and employing the adjacent pixels of the line-end and branch points before the contour results of open lines can be used. The experimental results indicated that the proposed method effectively achieved accurate descriptions for thinned lines.