Characteristics of Hough Transform: a Global View

An image line segment is transformed by the Hough transform into a set of sinusoidal curves in the （ρ,θ） parameter space.By carefully investigating the positions of π/2phase deviation from peak points in the parameter space,the π/2-line concept is introduced,by which segment lengths and continuity information in the image space are derived.In addition,an algorithm is proposed to recover the image line segments directly from the （ρ,θ） space. By studying the properties of sinusoids going through two peak points,the information,such as whether segments intersect and their intersecting coordinates,is obtained. Finally,an algorithm of reconstructing object contours by means of peak points and intersecting points is also proposed.