To the Graduate Council: I am submitting herewith a dissertation ...
To the Graduate Council: I am submitting herewith a dissertation ...
To the Graduate Council: I am submitting herewith a dissertation ...
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an orthonormal fr<strong>am</strong>e formed by a normal vector n 1 , a reference vector n 2 and <strong>the</strong>ircross product. n 1 is defined as <strong>the</strong> unit normal vector of a plane P fitted through <strong>the</strong>space curve C. The distance between C and P can be plotted as a function, whichserves as <strong>the</strong> feature of <strong>the</strong> center point and is called <strong>the</strong> Point Signature. Due to <strong>the</strong>simple representation, matching Point Signatures is efficient.Johnson and Hebert [45] proposed <strong>the</strong> Spin Image for surface registration. <strong>To</strong> createa Spin Image, a local 2D basis is computed at an oriented point that is a 3D pointwith surface normal. The coordinates of <strong>the</strong> o<strong>the</strong>r points on <strong>the</strong> surface with respectto <strong>the</strong> basis are <strong>the</strong>n used in a voting procedure to create <strong>the</strong> descriptive Spin Imagefor <strong>the</strong> point. With <strong>the</strong> surface point p and its normal n, two coordinates α and β of agiven point x are computed. α represents <strong>the</strong> distance from x to <strong>the</strong> tangent plane atp and β is <strong>the</strong> distance from x to n. Next, a bin is determined by discretizing (α, β)and <strong>the</strong>n used to match <strong>the</strong> corresponding points.The concept of Spin Images wasdeveloped from Geometric Hashing [50], but Spin Images use <strong>the</strong> image to describe <strong>the</strong>feature instead of performing lookup in a hash table. The term Spin Image c<strong>am</strong>e from<strong>the</strong> cylindrical symmetry of <strong>the</strong> representation. The Spin Image was also applied to 3Dobject recognition by Carmichael et al. [18].Y<strong>am</strong>any and Farag [105] proposed a modified version of Spin Image, which is called<strong>the</strong> Surface Point Signature (SPS), where α and β are differently defined from <strong>the</strong> SpinImage. α represents <strong>the</strong> distance between <strong>the</strong> center point and every surface point, andβ is <strong>the</strong> angle between <strong>the</strong> normal of <strong>the</strong> center point and <strong>the</strong> segment created by <strong>the</strong>18