A New Effective Method on Critical Point Detection of Planar Curves
Ren Jin · Dianzi xuebao · 2002
Critical point detection (CPD) of planar curves can be well applied in approaching of curves using poly lines,which has very important applications in image recognition,measurement and analysis.As digital lines are commonly composed by several continuous short lines,which are horizontal (k is 0),vertical (k is 1) and ±45°(k is ±1) lines.We call these four lines basic lines and define the maximum length of every basic line as corresponded directional pixel length (DPL),which are further denoted as Lx,Ly,L+ and L .Furthermore,four theorems on DPL are proposed,based on which,an automatic algorithm for CPD is also presented.The comparisons of algorithms from Ansari Huang,Zhu Chirlian and ours was showed.The satisfactory experimental results have demonstrated that our algorithm has apparent advantages in reducing critical point number and spatial temporal spending.