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Volume 2, Algorithms - mipav - National Institutes of Health

Volume 2, Algorithms - mipav - National Institutes of Health

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M I P A V<br />

M e d i c a l I m a g e P r o c e s s i n g, A n a l y s i s, & V i s u a l i z a t i o n<br />

Chapter 2, Using MIPAV <strong>Algorithms</strong>: B-Spline Automatic Registration<br />

for coordinate k. If the problem is to register images <strong>of</strong> three dimensions,<br />

and the B-spline bases for all three dimensions are selected to have degree 1,<br />

then<br />

EQUATION 11<br />

B i0 , i 1<br />

, i 2<br />

=<br />

⎛i ----- 0<br />

----- i 1<br />

i 2⎞<br />

⎜ , , ----- ⎟<br />

⎝n 0<br />

n 1<br />

n 2 ⎠<br />

For a B-spline basis <strong>of</strong> degree 2 or larger, the initial placement <strong>of</strong> the control<br />

point coordinates is computed by the method <strong>of</strong> least squares. Again<br />

referring to Equation 1 for the definition <strong>of</strong> the B-spline mapping function,<br />

the identity map for coordinate k is<br />

n k<br />

j k<br />

⎛ j k ⎞<br />

-------------- = N<br />

p ∑ ik , d<br />

⎜--------------<br />

⎟ Bik<br />

k – 1<br />

k ⎝p k – 1 ⎠<br />

i k<br />

= 0<br />

for any target image coordinate j k satisfying 0

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