[Insight-users] MutualInformationImageToImageMetric: Lack of
Transform Initialization
MALEMPATI
deepa_malempati at rediff.com
Thu May 24 01:08:19 EDT 2007
Hi Luis,
i Read the software guide,i understood the initialisation of transform.Luis
how to initialise the setoffset() and setparameters() methods for a
translation transform.
Thanking U in Advance,
Malempati
Luis Ibanez wrote:
>
>
> Hi Malempati,
>
>
> Please do your Homework...
>
>
> Sooner of later you will have to read the documentation...
>
>
>
> ----
>
> If you have taken the time of reading the section of the
> ITK Software Guide that we suggested you to read, you would
> have found by now that the initialization of the transform
> is done with the following code:
>
>
> typedef RegistrationType::ParametersType ParametersType;
> ParametersType initialParameters(
> transform->GetNumberOfParameters() );
>
> initialParameters[0] = 0.0; // Initial offset in mm along X
> initialParameters[1] = 0.0; // Initial offset in mm along Y
>
> registration->SetInitialTransformParameters( initialParameters );
>
>
> ----
>
>
> Regards,
>
>
>
> Luis
>
>
>
>
>
> ==================
>
> MALEMPATI wrote:
>> Hi Luis,
>> I could not follow the ITK Documentation about the attributes that should
>> be
>> passed to these 2 methods,could u let me know them including syntax.
>> And where could i get the different DataSets for Registration.I need them
>> very urgently,as i have only 2 datasets.
>> Thank u in advance,
>> Malempati
>>
>> Luis Ibanez wrote:
>>
>>>
>>>Hi Malempati,
>>>
>>>When you report the "size" of an image, you
>>>should indicated in terms of the number of
>>>pixels along every dimension.
>>>
>>>For example: 1024 x 768 pixels.
>>>
>>>
>>>The report:
>>>
>>> Size: 42496
>>>
>>>is not very useful.
>>>
>>>
>>>---
>>>
>>>If you are *not initializing* the Transform,
>>>then that's the source of your registration
>>>problem.
>>>
>>>
>>>At a minimum, you should initialize the Transform
>>>in such a way that the centers of both images will
>>>overlap.
>>>
>>>For a description on how to do this
>>>please read the ITK Software Guide
>>>
>>> http://www.itk.org/ItkSoftwareGuide.pdf
>>>
>>>in particular the "Image Registration" chapter.
>>>
>>>For instruction on how to initialize transforms
>>>see, Section 8.6.1., pdf-pages 382-382,
>>>
>>>As you will see, the computation involves the number
>>>of pixels of the image along every dimension, the
>>>pixel spacing and the origin.
>>>
>>>
>>>
>>> Regards,
>>>
>>>
>>> Luis
>>>
>>>
>>>
>>>---------------------------------------
>>>deepa_malempati at rediff.com wrote:
>>>
>>>>Hi,
>>>>Luis.
>>>>The details of images are given below:
>>>>1:Fixedimage 2:MovingImage
>>>> a.Size: 42496 Size: 39277
>>>> b.Spacing: [1.2, 1.01562] Spacing: [1, 1]
>>>> c. Origin: [0, 0] Origin: [0, 0]
>>>>And i'm using the Translation Transform.It is not Initialized with any
>>>>values in the code.
>>>>
>>>>Luis Ibanez wrote:
>>>>
>>>>
>>>>>Hi Malempati,
>>>>>
>>>>>It is very unlikely that the source of the problem
>>>>>is the size in Kilobytes of your images.
>>>>>
>>>>>
>>>>>If you have an observer and the error message
>>>>>appears before the observer reports on the first
>>>>>iteration, then you can remove the Optimizer
>>>>>as a suspect, and instead focus on the most
>>>>>likely reasons;
>>>>>
>>>>>
>>>>> 1) A poor initialization of the Transform.
>>>>>
>>>>>or
>>>>>
>>>>> 2) Invalid values of origin & spacing in the
>>>>> fixed and moving images.
>>>>>
>>>>>
>>>>>Questions:
>>>>>
>>>>>1) What is the size of your images in pixels ?
>>>>>2) What is the pixel spacing of each image ?
>>>>>3) What is the origin of the images ?
>>>>>
>>>>>
>>>>>You can get all this information by calling
>>>>>
>>>>> reader->GetOutput()->Print( std::cout )
>>>>>
>>>>>
>>>>>
>>>>>Also:
>>>>>
>>>>>
>>>>>4) What transform are you using ?
>>>>>5) How are you initializing the Transform ?
>>>>>
>>>>>
>>>>>
>>>>> Regards,
>>>>>
>>>>>
>>>>>
>>>>> Luis
>>>>>
>>>>>
>>>>>
>>>>>-------------------------------------------
>>>>>deepa_malempati at rediff.com wrote:
>>>>>
>>>>>
>>>>>>Hi,
>>>>>>Luis,thanks for u'r reply.
>>>>>>i have used the observer,but not even single iteration is getting
>>>>>>performed.Would it be due to the size variation of the images.The
sizes
>>>>>>of the fixed image is 21KB and that of moving image is 6 KB.
>>>>>>waiting for u'r reply,
>>>>>>Thanking u,
>>>>>>MALEMPATI.
>>>>>>Luis Ibanez wrote:
>>>>>>
>>>>>>
>>>>>>
>>>>>>>Hi Malempati:
>>>>>>>
>>>>>>>
>>>>>>>1) Read the ITK Software Guide
>>>>>>>
>>>>>>> http://www.itk.org/ItkSoftwareGuide.pdf
>>>>>>>
>>>>>>> in particular the Image Registration chapter.
>>>>>>>
>>>>>>>
>>>>>>>2) Make sure that your images have valid values
>>>>>>> of image origin and image spacing
>>>>>>>
>>>>>>>3) Make sure that you initialize the Transform
>>>>>>> parameters
>>>>>>>
>>>>>>>4) Add an observer to the Optimizer, and print
>>>>>>> out the values of the metric and transform
>>>>>>> parameters at every iteration.
>>>>>>>
>>>>>>>5) Identify how many iterations you manage to
>>>>>>> run before you get the error message.
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>The error means that the Fixed and Moving images
>>>>>>>have such small overlap that the registration
>>>>>>>process can't continue.
>>>>>>>
>>>>>>>The problem may be caused by:
>>>>>>>
>>>>>>>a) incorrect image information
>>>>>>>b) bad initialization
>>>>>>>c) poor choices in the optimizer parameters
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> Regards
>>>>>>>
>>>>>>>
>>>>>>> Luis
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>-------------------
>>>>>>>MALEMPATI wrote:
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>>Hi,
>>>>>>>>all.how to get rid of this error given below.
>>>>>>>>
>>>>>>>>itk::ERROR: MutualInformationImageToImageMetric(012C9D90): All the
>>>>>>>>sampled point mapped to outside of the moving image
>>>>>>>
>>>>>>>_______________________________________________
>>>>>>>Insight-users mailing list
>>>>>>>Insight-users at itk.org
>>>>>>>http://www.itk.org/mailman/listinfo/insight-users
>>>>>>>
>>>>>>>
>>>>>>
>>>>>>Quoted from:
>>>>>>http://www.nabble.com/MutualInformationImageToImageMetric-tf3762435.html#a10652461
>>>>>>
>>>>>>
>>>>>
>>>>>_______________________________________________
>>>>>Insight-users mailing list
>>>>>Insight-users at itk.org
>>>>>http://www.itk.org/mailman/listinfo/insight-users
>>>>>
>>>>>
>>>>
>>>>Quoted from:
>>>>http://www.nabble.com/MutualInformationImageToImageMetric-tf3762435.html#a10664017
>>>>
>>>>
>>>
>>>_______________________________________________
>>>Insight-users mailing list
>>>Insight-users at itk.org
>>>http://www.itk.org/mailman/listinfo/insight-users
>>>
>>>
>>
>>
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