[Insight-users] Failed to allocate memory

[Luis Ibanez]

Hi Sajendra,

Yes,
2.5 Gb sounds about right for the amount of RAM memory that
you would need for running this filter.

Note however that a process in Windows 32bits system cannot
allocate more than 2Gb of RAM.


    Regards,


        Luis


-------------------------------
Nithiananthan, Sajendra wrote:
> Luis,
> 
> The pixel type is "float", 4 bytes/pixel. So the image size is approximately
> 100 million pixels, or 400MB.
> I chose to represent the deformation field with a vector of floats, so they
> are three times as big, or about 1.2GB.
> Specifically:
>     const unsigned int DIMENSION = 3;
>     typedef itk::Image<float, DIMENSION>	ImageType;
>     //representation of the deformation field:
>     typedef itk::Vector<float, DIMENSION>   VectorPixelType;
>     typedef itk::Image<VectorPixelType, DIMENSION>  DeformationFieldType;
> 
> So to represent the fixed image, moving image, deformation field, and output
> image, I would expect usage about 2.5GB?
> 
> -Sajendra
> 
> 
> 
> 
>>-----Original Message-----
>>From: Luis Ibanez [mailto:luis.ibanez at kitware.com]
>>Subject: Re: [Insight-users] Failed to allocate memory
>>
>>Hi Sajendra,
>>
>>What was the image size (in pixels) ?
>>
>> From a 400Mb image, if we assume that you are using "signed short"
>>as pixel type, then we are probably talking about:
>>
>>                       200 Million pixels
>>
>>Demons will internally construct a deformation field with a 3D vector
>>of doubles per pixel. That will be:
>>
>>               2e8 x 3 x 8 bytes = 4.9 Gigabytes.
>>
>>To this you will have to add the 400Mb of the output image.
>>
>>
>>Therefore your observed memory actually looks small for this problem.
>>
>>
>>    Regards,
>>
>>
>>
>>       Luis
>>
>>
>>
>>-------------------------------
>>Nithiananthan, Sajendra wrote:
>>
>>>I was in a situation similar to the OP, Zhihong, trying to 
>>
>>use ITK based
>>
>>>Demons registration on larger images (~400MB). It failed 
>>
>>spectacularly  on
>>
>>>32 bit Windows. Compiling and running on a 64 bit machine solved the
>>>problem.
>>>The peak memory was about 4.5 GB, which seems high (no 
>>
>>histogram matching or
>>
>>>casting used). I had imported the images into ITK from VTK 
>>
>>so perhaps that
>>
>>>explains some of the increased memory usage. Either way, it 
>>
>>did run well and
>>
>>>gave me the results I would have expected (compared the 
>>
>>output for a smaller
>>
>>>image to that from a 32bit machine). I will hopefully 
>>
>>confirm later that
>>
>>>nothing strange is happening with memory usage.
>>>
>>>Thank you for your input
>>>-Sajendra
>>>
>>>
>>>
> 
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