Active Visual Inference of Surface Shape - Roberto Cipolla Part 3 docx

... its sign is given by: sign(t~ n) = -sign(w.L(w)) = -( a)Usign(g t) - 2aj31rslsign(p.L(rs) ) - ( /31 rsl)2sign(n s) = -( a)2sign(n t) - ( /3] rs D2sign(n s) (2 .32 ) since by the conjugacy relationship ... the shape of the rim, a convexity of the contour corresponds to a convex patch of surface, a concavity to a saddle-shaped patch. Inflections of the con...

Ngày tải lên: 10/08/2014, 01:22

... for a: N.n p (1 - (p.m)~) a p a -~ -( 1- (p.m)2). (4 .37 ) Differentiating (4.20) and rearranging we can recover the other component, /3: at p -2 n ~ ( 1-( p.m)2)'/2] - -( p.m) 2) p U.p] ... xB.U 3rip [(P'T)(U'tP)] (4.40) ntP= ( 1-( p.T)2 )3/ 2 - A( 1-( p.T)2)I/2' In the special ease of viewing a section of curve which projects t...

Ngày tải lên: 10/08/2014, 01:22

... parameterisation 30 2.6 Dynamic properties of apparent contours 33 2.6.1 Recovery of depth from image velocities 33 2.6.2 Surface curvature from deformation of the apparent contour 33 2.6 .3 Sidedness of ... Cataloging-in-Publication data applied for Die Deutsche Bibliothek - CIP-Einheitsaufnahme Cipolla, Roberto: Active visual inference of surface shape...

Ngày tải lên: 10/08/2014, 01:22

... 3D shape of surfaces in the vicinity of their apparent contours. We describe the real-time implementations of these algorithms for use in tasks involving the active exploration of visible surface ... relate these first to the descriptions of local 3D shape developed from the differ- ential geometry of surfaces and then to the analysis of visual motion of apparent...

Ngày tải lên: 10/08/2014, 01:22

... the 3D geometry of the surface in the vicinity of ext~vmal boundary. The surface is recovered as a family of s-parameter curves - the contour generators - and t-parameter curves - portions of ... 3. 5. Detecting extremal boundaries and recovering surface shape 73 Figure 3. 14: Recovery of surface strip in vicinity of extremM boundary. From a minimum...

Ngày tải lên: 10/08/2014, 01:22

... CO2q .~P(4.70) qtt. ap = O-ts ~'~t'~v-t-2 ~ -~ -~ t .1. -~ Apart from (~ [~) which we have seen determines the magnitude of the tan- gential component of image curve velocity (and ... Ay/A). From (5.2) to (5. 13) we have: U1 U0 ~-~ 2 A U2 v0 - + f~1 A curl~ = -2 ~3 + (-VlAy + U2A~) (5.16) A2 U3 U1A~ + U~Ay diw7 = 2-~ - + A2 (5.17) (UtA~...

Ngày tải lên: 10/08/2014, 01:22

... [ 133 ] and in the recovery of 3D shape up to a relief transformation [ 130 , 131 ]. 5 .3. Differential invariants of the image velocity field 135 are cancelled out. By taking the difference of ... the ray, eurl~7 deh7 a.q _ + {- (5 .33 ) 4. With no additional information - the constraints on 3D shape Koenderink and Van Doorn [ 130 ] showed that surface shape inf...

Ngày tải lên: 10/08/2014, 01:22

... interpretation of random-dot stereograms have shown that even with sparse data the human visual system arrives at unique interpretations of surface shape - the perception of dense and coherent surfaces ... whereas the interpretation of the surface consistency theory is that the surface has at most one surface inflection in the absence of zero-crossings [32 ]. The i...

Ngày tải lên: 10/08/2014, 01:22

... velocities from the output of a set of spatio-temporal filters. A bank of 24 spatio-temporal Gabor filters runs continuously in each neighbour- hood of a time-varying image. Each of the filters is tuned ... contour of objects made of gen- eralised cylinders can be used to determine the sign of curvature of the surface. The disadvantages of these methods is that they ar...

Ngày tải lên: 10/08/2014, 01:22

... [129] [13o] [ 131 ] [ 132 ] [ 133 ] [ 134 ] [ 135 ] [ 136 ] [ 137 ] [ 138 ] [ 139 ] J.J. Koenderink and A.J. Van Doorn. The singularities of the visual map- ping. Biological Cybernetics, 24:5 1-5 9, 1976. ... q (C3g ~ 2 02q O~t s 0 (cOq)t.n+ C32q ~ (C.5) qtt.n = \ (-~ -Is] -~ t "n+2 ~ -~ - e -~ - .n. 0g From (C .3) we see that (NI8) determines th...

Ngày tải lên: 10/08/2014, 01:22