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Show 75 $ilhou.ett:e. Figure 16 - Implicit Creation of Silhouette Tracker depends on which of the threp types of local maximum is where du=u-uo dv=v-vo passed. A true local maximum, where Yu=Yv=O, is a bulge in the middle of the patch. When it is passed, two silhouette edge tracking points must be created on either side of the bulge. The obvious initial guess at the location of these points is at the u,v of the local maximum itself. This will not work, however, because the Newton iteration which refines this guess to the correct location depends on the first derivatives of Y, and these are zero at the local maximum. The initial guesses at the location of these two silhouette trackers must, then, be m?de from the second derivatives at the local maximum. There, the Y function cn be approximated by ::= 1 Y(u,v) Y(uo,vo) + 2 1 2 2 du Yuu + du dv Yuv + 2 dv Yvv At the position of the scan plane, just below' the local maximum, the level curve can be approximated by an ellipse whose equation is: |
