[Insight-users] Registration question - optimizer

[Mary Chou]

We are trying to register images using the TranslationTransform,
GradientDescentStepOptimizer, and the Mean Square Image to Image metric, but
are having a problem with the convergence of the method, in that the metric
values do
not seem to converge to a minimum at all.  The original images are 0 - ~6500
in intensity value range.

We have tried registration using the ITK Examples file
ImageRegistration1.cxx and have tried adjusting the values for the
Optimizer, maximum step length and minimum step length.  Any suggestions for
optimizer parameter selection?

//  optimizer->SetMaximumStepLength( 4.00 );
//  optimizer->SetMinimumStepLength( 0.01 );
  optimizer->SetMaximumStepLength( 0.01 );
  optimizer->SetMinimumStepLength( 0.0001 );

0 = 2.72438e+006 : [-2.08739, -3.41216]
1 = 1.73376e+006 : [-1.98374, -1.41484]
2 = 2.01186e+006 : [-2.5951, -2.2062]
3 = 1.70106e+006 : [-3.36987, -2.83844]
4 = 1.6264e+006 : [-3.03848, -2.46403]
5 = 1.64197e+006 : [-2.67566, -2.11999]
6 = 1.70971e+006 : [-2.86588, -2.28223]
7 = 1.66576e+006 : [-3.04977, -2.45159]
8 = 1.64041e+006 : [-2.95655, -2.36831]
9 = 1.65473e+006 : [-2.99801, -2.41508]
10 = 1.65153e+006 : [-3.01273, -2.47582]
11 = 1.64687e+006 : [-2.99193, -2.4525]
12 = 1.6475e+006 : [-2.96613, -2.47014]
13 = 1.64447e+006 : [-2.96402, -2.50132]
14 = 1.64206e+006 : [-2.98953, -2.51937]
15 = 1.64255e+006 : [-3.01521, -2.53718]
16 = 1.64318e+006 : [-3.04244, -2.55252]
17 = 1.6372e+006 : [-3.07013, -2.567]
18 = 1.63179e+006 : [-3.09843, -2.58026]
19 = 1.62691e+006 : [-3.12752, -2.59168]
20 = 1.62251e+006 : [-3.15762, -2.60005]
21 = 1.61852e+006 : [-3.18874, -2.6029]
22 = 1.61484e+006 : [-3.2191, -2.5955]
23 = 1.61146e+006 : [-3.24348, -2.57595]
24 = 1.60868e+006 : [-3.26375, -2.55217]
25 = 1.60643e+006 : [-3.28371, -2.52812]
26 = 1.60444e+006 : [-3.30364, -2.50405]
27 = 1.60269e+006 : [-3.32351, -2.47993]
28 = 1.60117e+006 : [-3.31086, -2.47077]
29 = 1.60208e+006 : [-3.29818, -2.46164]
30 = 1.60315e+006 : [-3.28548, -2.45253]
31 = 1.60439e+006 : [-3.27277, -2.44345]
32 = 1.60579e+006 : [-3.26002, -2.43441]
33 = 1.60736e+006 : [-3.24725, -2.42541]
34 = 1.6091e+006 : [-3.23444, -2.41646]
35 = 1.61101e+006 : [-3.22159, -2.40757]
36 = 1.61309e+006 : [-3.20869, -2.39876]
37 = 1.61534e+006 : [-3.19573, -2.39003]
38 = 1.61777e+006 : [-3.18269, -2.38143]
39 = 1.62038e+006 : [-3.16955, -2.37297]
40 = 1.62317e+006 : [-3.15627, -2.36474]
41 = 1.62614e+006 : [-3.1428, -2.35682]
42 = 1.6293e+006 : [-3.12903, -2.34942]
43 = 1.63265e+006 : [-3.11478, -2.34303]
44 = 1.63618e+006 : [-3.09962, -2.33923]
45 = 1.63979e+006 : [-3.08574, -2.34639]
46 = 1.64205e+006 : [-3.08088, -2.36125]
47 = 1.64154e+006 : [-3.0654, -2.36335]
Result =
 Translation X = -3.0654
 Translation Y = -2.36335
 Iterations    = 49
 Metric value  = 1.64479e+006
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