[Insight-users] affine transform

[annelaure]

In fact, when I compute the final points with the equation 8.11, all my
points seem to be projected on a plane. I do a mistake somewhere but I
really don't understand.
Thank you for your help,
Anne-Laure

annelaure wrote:
> 
> Hi,
> I apply the equation 8.11 p440 in the ITK Software Guide in order to
> obtain the final coordinates of my points. I considered that the firt
> matrix of this equation is constituted by the 9 first result parameters
> and that Cx=0,Cy=0 and Cz=0.
> I try to register a theorical rib (95 points)
> www710.univ-lyon1.fr/~adidier/cote8_thpts.txt on a segmentation rib (4280
> points)   www710.univ-lyon1.fr/~adidier/cote8_segpts.txt in using the code
> previously described. I don't obtain good results. I try to proceed to a
> classical icp registration (iterativeclosestpoint2.cxx) first but the
> results are not better. 
> Should I change some optimizer parameters? Should I proceed to a rigid
> registration before in order to bring closer the two ribs?
> Thank you so much for your answer,
> Best regards,
> Anne-Laure
> 
> 
> 
> 
> Luis Ibanez wrote:
>> 
>> 
>> 
>> Hi Annelaure,
>> 
>> 
>>                No need ot make assumptions
>> 
>> 
>> Please read the documentation of the AffineTransform class:
>> 
>> http://www.itk.org/Insight/Doxygen/html/classitk_1_1AffineTransform.html
>> 
>> In particular the GetParameters and SetParameters() methods.
>> 
>> 
>> You should also read the description of this Transform in the
>> ITK Software Guide:
>> 
>>          http://www.itk.org/ItkSoftwareGuide.pdf
>> 
>> 
>> In section 8.8.16 "Affine Transform" in pdf-pages 439-440.
>> 
>> Pay particular attention to Table 8.15 in pdf-page 439.
>> 
>> 
>> 
>> Please note that all the examples are described in detail
>> in the ITK Software Guide.
>> 
>> 
>> 
>>    Regards,
>> 
>> 
>> 
>>        Luis
>> 
>> 
>> -------------------
>> annelaure wrote:
>>> Hi,
>>> I use Iterative closest point 1 with the affine transform. I obtain 12
>>> numbers : Solution = [0.563524, -0.0204711, -0.0675956, 0.308023,
>>> 0.539417,
>>> -0.0100321, -0.0645276, -0.0436415, 0.554475, 83.8441, 81.0703,
>>> 139.525]. I
>>> suppose that the 3 last numbers are the translation parameters; but I
>>> don't
>>> know where are the rotation parameters, and the scaling parameters.
>>> Thank
>>> you so much for your help,
>>> best regards,
>>> Anne-Laure
>>> 
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>> 
>> 
> 
> 

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