[Insight-users] exception when writing row or column images

[Luis Ibanez]

Hi Zach,

This is a safeguard that was introduced on purpose
in order to prevent the missuse of the writers.

If you are sure that you want to save 1-row images,
you can simply override this control.


For this, just go to:

           Insight/Code/IO/
                    itkJPEGImageIO.cxx


move to line 457 and comment out the three lines:


   // Make sure the region to be written is 2D
   if ( ioRegion.GetRegionDimension() != 2 )
     {
     itkExceptionMacro(<<"JPEG Writer can only
             write 2-dimensional images");
     }



What happens is that the method: GetRegionDimension()
considers that an image should have more than one pixel
along every dimension. Therefore, dimensions that are
just one pixel wide, are assumed to be flattened.


We could probably set a flag on the file

                itkImageIORegion.h

in order to change the limit from "1" to "0".

In this way, images of one pixel along a dimension
will not considered to be of inferior dimension.


Please let us know if this works for you,
and whether you will find useful to have such
a flag available or not.


    Thanks,


      Luis


----------------------
Zachary Pincus wrote:

> Hello,
> 
> A tool that I'm building sometimes segments out an object that is it  
> the far edge of an image, leading me to try to save to disk an image  
> that, while 2D by type, consists of a single row or column. (i.e. that  
> has a degenerate second dimension.)
> 
> Unfortunately, this does not appear to be possible, and instead  
> generates the exception:
> 
>> itk::ERROR: JPEGImageIO(0x2101070): JPEG Writer can only write  
>> 2-dimensional images
> 
> (the same general error appears regardless of which ImageIO you choose.)
> 
> I'm sure that 1 x n or n x 1 images are valid in most if not all image  
> format specifications.
> 
> Is this a bug? And if it's been brought up before, I apologize -- I  
> didn't find anything on the mailing list archive.
> 
> Thanks,
> Zach Pincus
> 
> Department of Biochemistry and Program in Biomedical Informatics
> Stanford University School of Medicine
> 
> 
> Here is code to reproduce this error:
> 
> #include "itkImageFileWriter.h"
> #include "itkImage.h"
> #include <iostream>
> 
> const unsigned int Dimension = 2;
> typedef unsigned short PixelType;
> typedef itk::Image<PixelType, Dimension>  ImageType;
> typedef itk::ImageFileWriter<ImageType> WriterType;
> 
> int main(int argc, char *argv[]) {
>     ImageType::Pointer image = ImageType::New();
>     
>     ImageType::IndexType start;
>     start[0] =   0;
>     start[1] =   0;
>     
>     ImageType::SizeType  size;
>     size[0]  = 2;
>     size[1]  = 1;
> 
>     ImageType::RegionType region;
>     region.SetSize( size );
>     region.SetIndex( start );
> 
>     image->SetRegions( region );
>     image->Allocate();
>     std::cout << image << std::endl;
>     
>     WriterType::Pointer writer = WriterType::New();
>     writer->SetFileName("foo.jpg");
>     writer->SetInput(image);
>     
>     try {
>     writer->Update();
>     } catch( itk::ExceptionObject & err ) {
>         std::cout << "ExceptionObject caught !" << std::endl;
>         std::cout << err << std::endl;
>         return -1;
>     }
>     return 0;
> }
> 
> 
> Running this code results in this:
> 
> Image (0x2100420)
>   RTTI typeinfo:   N3itk5ImageItLj2EEE
>   Reference Count: 2
>   Modified Time: 4
>   Debug: Off
>   Observers:
>     none
>   Source: (none)
>   Source output index:  0
>   Release Data: Off
>   Data Released: False
>   Global Release Data: Off
>   PipelineMTime: 0
>   UpdateMTime: 0
>   LargestPossibleRegion:
>     Dimension: 2
>     Index: [0, 0]
>     Size: [2, 1]
>   BufferedRegion:
>     Dimension: 2
>     Index: [0, 0]
>     Size: [2, 1]
>   RequestedRegion:
>     Dimension: 2
>     Index: [0, 0]
>     Size: [2, 1]
>   Spacing: [1, 1]
>   Origin: [0, 0]
>   PixelContainer: ImportImageContainer (0x21004f0)
>   RTTI typeinfo:   N3itk20ImportImageContainerImtEE
>   Reference Count: 2
>   Modified Time: 5
>   Debug: Off
>   Observers:
>     none
>   Pointer: 0x2100534
>   Container manages memory: true
>   Size: 2
>   Capacity: 2
> 
> ExceptionObject caught !
> 
> itk::ExceptionObject (0x2101020)
> Location: "Unknown"
> File:  /Volumes/Atlotl/Developer/ITK/ITK-CVS-src/Insight/Code/IO/ 
> itkJPEGImageIO.cxx
> Line: 459
> Description: itk::ERROR: JPEGImageIO(0x2101070): JPEG Writer can only  
> write 2-dimensional images
> 
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