[Insight-users] MutualInformationEuler2DRegistration

[Luis Ibanez]

Hi Ying,

You have not done your homework !,

The file that we sent you was intended only to make easier
for you to start your training. It was not intended to solve
your entire problem.

When you feed the program with different images, you still
need to fine tune the parameters of the registration according
to the characteristics of the new images.

What is the content of the TIFF images that you are feeding
now to the program  ?

Just the fact of being stored in TIFF shouldn't affect at all
the registration. You don't need to convert your images to JPEG
in order to succeed with the registration. You should rather look
at the particular characteristics of the image content.


For example:

   - The dynamic range of the pixel values
   - The level of noise
   - The distribution of homogeneous regions


and,... go through the learning process of registration as we
suggest you in the previous email. Read the Tutorials on
registration and the Registration chapter on the SoftwareGuide.



You will not find the Example

              ImageRegistration13.cxx

in the ITK 1.6 release, because the release was cut in
February 2004, and the example was to CVS added yesterday   :-)


If you want to get this example you must use the CVS version.

Instructions for downloading ITK through CVS are available
in the Download page

   http://www.itk.org/HTML/Download.php

in the tutorials

   http://www.itk.org/HTML/Tutorials.htm

and in the SoftwareGuide

   http://www.itk.org/ItkSoftwareGuide.pdf


There is no way out...
you will have to do your homework.


Please let us know if you have further questions,


    Thanks


      Luis



----------------
Ying Du wrote:

> Hi Luis,
> 
> Thank you so much for the help. I tried the program, it works beautifully on
> those jpeg images.
> 
> One question is that when I tried it on the same images but with the "TIF"
> format, the result is quite different and not good. Does TIF has some
> problem here? The real medical images I will be working on are all in "TIF"
> format now, do I need to convert them to jpg?
> 
> I am using InsightToolkit-1.6.0, and I did not find
> "ImageRegistration13.cxx" under Examples/Registration, are the new examples
> like this one appear in the CVS version?
> 
> Thanks again!
> 
> Ying
> 
> 
> ----- Original Message ----- 
> From: "Luis Ibanez" <luis.ibanez at kitware.com>
> To: "Ying Du" <duying at hotmail.com>
> Cc: <insight-users at itk.org>
> Sent: Thursday, July 01, 2004 3:22 PM
> Subject: Re: [Insight-users] MutualInformationEuler2DRegistration
> 
> 
> 
>>Hi Ying,
>>
>>The best remedy agains "parameter sensitivity" is "user-training"  :-)
>>
>>What we use to call 'sensitivity' simply reflects the uncertainty
>>on the ranges and values that should be used for configuring the
>>registration. The solution is simply for you to follow the examples
>>in the SoftwareGuide, that introduce you progressively to the
>>trade-offs involved in Image Registration. This training will help
>>you understand how to fine tune the parameters of registration
>>algorithms in order to get reasonable results.
>>
>>
>>Please look at the CenteredRidig2D example in the Software Guide
>>
>>            http://www.itk.org/ItkSoftwareGuide.pdf
>>
>>Section 8.5, pdf-page 263.  The source code associated with this
>>example is in
>>
>>              Insight/Examples/Registration/
>>                            ImageRegistration5.cxx
>>
>>You will find there a discussion on the importance of selecting
>>the center of rotation for the image.
>>
>>Note that your images have the interesting characteristic of
>>having a center of rotation that is far from the corner of the
>>image *and* far from the center for the image.
>>
>>It is very important that you initialize the center of rotation
>>of the transform. That will reduce a lot the sensibility to
>>the initial parameters of the registration.
>>
>>Attached you will find a source code file that registers your
>>images in 200 iterations (about 7 seconds in a Pentium 4 at 2.4Ghz)
>>
>>Note that it is using MattesMutualInformation and the Centered
>>transform initializer class.
>>
>>The same file has been commited as a new example in
>>
>>
>>   Insight/Examples/Registration/
>>                ImageRegistration13.cxx
>>
>>
>>
>>
>>Please let us know if you have further questions.
>>
>>
>>  Regards,
>>
>>
>>     Luis
> 
>