SLIDE 14 M F
FIXED IMAGE INTENSITY MOVING IMAGE INTENSITY
Σ Σ
i=1 BM j=1 BF
hj (i, j) ln N ⨉ hj (i, j) hF ( i ) ⨉ hM ( j ) C = 1 N
Traditional Serial CPU
is very fast
(time required is negligible)
Generate Histograms
compute vector for each voxel get corresponding voxels in moving image
A B C D
1 2 3 4
Nearest Neighbors Partial Volumes
compute partial volumes use partial volumes for moving & joint
Compute Score
simply cycle thru histograms
Compute Gradient
∂C ∂P = ∂C ∂v ∂v ∂P ⨉
M F
get vector for each voxel
A B C D
1 2 3 4
Nearest Neighbors Partial Volumes
compute partial volume derivatives
get corresponding voxels in moving image
ln N ⨉ hj (in, jn ) hF ( in ) ⨉ hM ( jn ) = ∂C ∂h
xn
Σ
n=1 4
∂C ∂v = ∂C ∂h xn
(
⨉ ∂wn ∂v)
change in cost as vector changes
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SLIDE 14 OF 33