This document discusses image segmentation techniques, specifically linking edge points through local and global processing. Local processing involves linking edge-detected pixels that are similar in gradient strength and direction within a neighborhood. Global processing uses the Hough transform to link edge points into lines by mapping points in the image space to the parameter space of slope-intercept or polar coordinates. Thresholding in parameter space identifies coherent lines composed of edge points. The Hough transform allows finding lines even if there are gaps or other defects in detected edge points.