[Insight-users] Continuous Index

[Xiang Hao]

Hi Luis,

Got it, I have discretize the continuous index and output the continuous
index to an txt file.

Thanks,
Xiang

On Wed, Jul 1, 2009 at 2:29 PM, Luis Ibanez <luis.ibanez at kitware.com> wrote:

>
>
> Hi Xiangn,
>
>
> In order to write the track out into a binary image,
> you will have to discretize the continous index.
>
>
> As described in my previous email,
> you can do this with the following code:
>
>     ImageType::IndexType index;
>
>     index.CopyWithRound( continousIndex );
>
>     image->SetPixel( index, tractValue );
>
>
> Note that,
> by doing this, you are losing information
> on the actual position of the tract.
>
>
>
>    Regards,
>
>
>          Luis
>
>
> ---------------------------------------------
>
> On Wed, Jul 1, 2009 at 3:53 PM, Xiang Hao <haoxiang at yahoo.cn> wrote:
>
>> Hi Luis,
>>
>> I can compute the features at the continuous index by following your
>> suggestion. Thank you again. Now I want to save the tract(path) in an binary
>> image, but I have a problem about how to write an value in a continuous
>> index.
>>
>> Cheers,
>> Xiang
>>
>>
>> On Tue, Jun 30, 2009 at 12:41 PM, Xiang Hao <haoxiang at yahoo.cn> wrote:
>>
>>> Great, Luis. Thank you again. I appreciate it very much.
>>>
>>> Cheers,
>>> Xiang
>>>
>>>
>>> On Tue, Jun 30, 2009 at 11:30 AM, Luis Ibanez <luis.ibanez at kitware.com>wrote:
>>>
>>>>
>>>> Hi Xiang,
>>>>
>>>> If you need to evaluat the image at ContinousIndex positions,
>>>> or at Point positions you will need to use an Interpolator.
>>>>
>>>> Something like
>>>>
>>>>    interpolator->SetImage( image );
>>>>    interpolator->Evaluate( point );
>>>>    interpolator->Evaluate( continuousIndex );
>>>>
>>>> For a list of ITK Interpolators, please look at:
>>>>
>>>> http://public.kitware.com/Insight/Doxygen/html/group__ImageInterpolators.html
>>>>
>>>>
>>>> Note however, that, depending on how you track
>>>> fibers, what you may actually need is to compute
>>>> features at those points (or continuous indices)
>>>> and therefore you may have to use ImageFunctions
>>>> there.
>>>>
>>>> For example:
>>>>
>>>> itkGaussianBlurImageFunction.h
>>>> itkGaussianDerivativeImageFunction.h
>>>>
>>>>
>>>>
>>>>        Regards,
>>>>
>>>>
>>>>                 Luis
>>>>
>>>>
>>>>
>>>> ----------------------------------------------------------------------
>>>>
>>>> On Tue, Jun 30, 2009 at 1:22 PM, Xiang Hao <haoxiang at yahoo.cn> wrote:
>>>>
>>>>> Hi Luis,
>>>>>
>>>>> Thank you so much, Luis. I will try it, and BTW, as I remember, there
>>>>> is a problem about setPixel() and getPixel() method while I am using the
>>>>> ContinuousIndex. It said it cannot find the corresponding method. Anyway, I
>>>>> will try your method and try to make it work.
>>>>>
>>>>> Thank you again,
>>>>> Xiang
>>>>>
>>>>>
>>>>> On Tue, Jun 30, 2009 at 10:29 AM, Luis Ibanez <luis.ibanez at kitware.com
>>>>> > wrote:
>>>>>
>>>>>>
>>>>>>
>>>>>> Hi Xian,
>>>>>>
>>>>>> If you need sub-pixel locations for the points of the fibers,
>>>>>> yes, it makes sense to use ContinuousIndex instead of
>>>>>> Indexes for representing the location of fibers centers.
>>>>>>
>>>>>> That said, it may be preferable to use itk::Point<> since
>>>>>> that will take into account also the pixel spacing, image
>>>>>> origin, and image orientation, and you will be able to
>>>>>> do things like overlapping a visualization of the fibers
>>>>>> with the original image.
>>>>>>
>>>>>> A) If you need to convert Index to ContinousIndex you
>>>>>>      can use the method:
>>>>>>
>>>>>>     Constructor
>>>>>>
>>>>>>      IndexType  index;
>>>>>>      ContinuousIndexType  cindex( index );
>>>>>>
>>>>>> B) In order to convert Continuous index to Index you
>>>>>>      can use the method CopyWithRound()
>>>>>>
>>>>>>     index.CopyWithRound( continousIndex )
>>>>>>
>>>>>> C) In order to convert an index into a physical point
>>>>>>      and back you can use the image methods
>>>>>>
>>>>>>       TransformIndexToPhysicalPoint( index, point );
>>>>>>       TransformPhysicalPointToIndex(point, index );
>>>>>>
>>>>>>
>>>>>>
>>>>>>   Regards,
>>>>>>
>>>>>>
>>>>>>
>>>>>>         Luis
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> ----------------------------------------------------------------------------------------------
>>>>>> On Sun, Jun 28, 2009 at 2:42 PM, Xiang Hao <haoxiang at yahoo.cn> wrote:
>>>>>>
>>>>>>> Hi,
>>>>>>>
>>>>>>> I am trying to write a tractography program.
>>>>>>> Now I use discrete index:
>>>>>>>
>>>>>>> Dimension =3;
>>>>>>> typedef int OutputPixelType;
>>>>>>> typedef itk::Image< OutputPixelType, Dimension > OutputImageType;
>>>>>>> OutputImageType::IndexType pixelIndex;
>>>>>>>
>>>>>>> So now the pixelIndex is discrete index and I want to change it to
>>>>>>> continuous index. I know there is an ContinuousIndex class in ITK. I wonder
>>>>>>> whether I should use this class and how to use it in order to change the
>>>>>>> index to continuous index.
>>>>>>>
>>>>>>>
>>>>>>> --
>>>>>>> Cheers,
>>>>>>> Xiang
>>>>>>>
>>>>>>>
>>>>>>> --
>>>>>>> Cheers,
>>>>>>> Xiang
>>>>>>>
>>>>>>> _____________________________________
>>>>>>> Powered by www.kitware.com
>>>>>>>
>>>>>>> Visit other Kitware open-source projects at
>>>>>>> http://www.kitware.com/opensource/opensource.html
>>>>>>>
>>>>>>> Please keep messages on-topic and check the ITK FAQ at:
>>>>>>> http://www.itk.org/Wiki/ITK_FAQ
>>>>>>>
>>>>>>> Follow this link to subscribe/unsubscribe:
>>>>>>> http://www.itk.org/mailman/listinfo/insight-users
>>>>>>>
>>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> Cheers,
>>>>> Xiang
>>>>>
>>>>
>>>>
>>>
>>>
>>> --
>>> Cheers,
>>> Xiang
>>>
>>
>>
>>
>> --
>> Cheers,
>> Xiang
>>
>
>


-- 
Cheers,
Xiang
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.itk.org/pipermail/insight-users/attachments/20090701/dee0eb50/attachment.htm>