Determining digitizing distances on sculptured surfaces using short time Fourier transform

S i i r face d ig i t i za t ion is a m e t h o d for ob ta in ing threed i m e ii s i o ii. a1 11% eas tire in e nt of a i i 11 iikii o zuii surf (1 ce . Tlie p e r f o r m a n c e a n d qua l i t y of d ig i t i za t ion are depeiirleirt iipoii t h e choice o f d ig i t i z ing dev ices aiid approaches . An efJicieizt d ig i t i z ing m e t h o d i i o t oiily reduces t h e elapsed t i m e of t h e d ig i t i z ing process , bu t also i m p r o v e s the p r e c i s i o n of m e a s u r e m e n t . This paper p r e s e n t s a n e w n o n u n i f o r m t e c h n i q u e for digi t iz ing of s cu lp tured s u r f a c e s based o n t h e s h o r t t i m e F o u r i e r I r m i s f o r m (STFT). The d ig i t i z ing d i s tances air t h e a: u n d y d i rec t ions fo r each pre -d iv ided block o f t h e surf u c c are ad jus t ed according t o t h e h ighes t spa t ia l f r e quei ic ies con ta ined in t h e block w h i c h i s in coi i trast t o t h e ui i i fornr t eck i i i que in w h i c h t h e d ig i t i z ing d i s tance is d e t e r m i n e d according t o t h e h ighes t spa t ia l f r equenc ies of tlre e n t i r e sur face . The speed of t h e d ig i t i z ing yrocess i s thus in iproved a n d m e a n w h i l e tlre accuracy of t h e s u r f a c e represen ta t io i s i s m a i n t a i n e d . S i m n l a tioirs a n d ex1xrinaental r e su l t s are prov ided t o v e r i f y t h e proposed m e t h o d .