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</o:shapelayout></xml><![endif]--></head><body lang=ZH-TW link=blue vlink=purple style='text-justify-trim:punctuation'><div class=WordSection1><p class=MsoNormal><span lang=EN-US>Hi all,<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>I tried to load two vector images, one using itk::Image< itk::SymmetricSecondRankTensor< double, 3> > and the other using itk::VectorImage< double, 3 >. I got the voxel values using itk::ImageRegionIterator::Get() function. However, very strange thing occurred to me. The order of the vector elements the iterators read behaves not in a way I create the phamton vector images. The vector I created is [0 1 2 3 4 5] for the symmetric tensor and [0 1 2 3 4 5 6 7 8] for the VectorImage. The voxel I got from the iterators are [0 1 3 2 4 5] and [0 1 3 6 2 4 7 5 8]. Why is that? Is there anything to do with the image headers? I’m using nifti .nii. <o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>The header file for the symmetric tensor image is as below. The header of VectorImage differs only in the dimension, which is dim: [5 20 20 20 1 9 1 1].<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US> sizeof_hdr: 348<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> data_type: ''<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> db_name: ''<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> extents: 0<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> session_error: 0<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> regular: 'r'<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> dim_info: 0<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US> dim: [5 20 20 20 1 6 1 1]<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> intent_p1: 0<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> intent_p2: 0<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> intent_p3: 0<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> intent_code: 1005<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> datatype: 16<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> bitpix: 32<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> slice_start: 0<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> pixdim: [-1 0.8984 0.8984 3 1 1 1 1]<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> vox_offset: 352<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> scl_slope: 1<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> scl_inter: 0<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> slice_end: 0<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> slice_code: 0<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> xyzt_units: 2<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> cal_max: 0.0017<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> cal_min: 0<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> slice_duration: 0<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> toffset: 0<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> glmax: 0.0017<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> glmin: 0<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US> descrip: 'FSL4.0'<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> aux_file: ''<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> qform_code: 1<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> sform_code: 1<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> quatern_b: 0.0066<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> quatern_c: 0.9946<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> quatern_d: -0.0764<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> qoffset_x: 110.0322<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> qoffset_y: -113.4360<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> qoffset_z: 28.6710<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> srow_x: [-0.8895 0.0214 -0.4165 110.0322]<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> srow_y: [0.0021 0.8879 0.4586 -113.4360]<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> srow_z: [-0.1265 -0.1357 2.9353 28.6710]<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> intent_name: ''<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> magic: 'n+1'<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>Best regards,<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>Meng-Kang Hsieh (Michael)<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>OpSciTech, Erasmus Mundus<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>Delft University of Technology<o:p></o:p></span></p></div></body></html>