NRRD (

1
NRRD (nerd) formatNearly Raw Raster Data

• ASCII header raw/ascii/gzip datafile(s)
• NrrdIO reader/writer in ITK right now
• Represents scalars, DWIs, tensors, etc.
• unu command-line swiss-army knife
• unu slice, crop, flip, permute, resample
• unu make makes header in one shot
• General orientation representation
• Conservative approach to optional info

2
NRRD in action (for scalar volume)

• NRRD0004
• content HUVA51125252
• modalitySPGR
• dimension 3
• sizes 256 256 124
• type short
• endian big
• encoding raw
• data file HUVA51125252_spgr.img
• space right-anterior-superior
• space origin (117.5,-93,119)
• space directions (-0.9375,0,0) (0,0,-0.9375)
  (0,1.5,0)
• space units "mm" "mm" "mm"
• thicknesses NaN NaN 1.5
• centerings cell cell cell
• kinds space space space

3
NRRD in action (for DWI volume)

• NRRD0004
• content HUVA33202368
• modalityDW
• dimension 4
• sizes 256 256 35 7
• type short
• endian big
• encoding raw
• data file HUVA33202368_dwi.img
• space right-anterior-superior
• space origin (117.5,-93,119)
• space directions (-0.859375,0,0) (0,0,-0.859375)
  (0,5,0) none
• space units "mm" "mm" "mm"
• thicknesses NaN NaN 4 NaN
• centerings cell cell cell none
• kinds space space space list
• DW_gradient_001 0.70710677 0.0
  0.70710677
• DW_gradient_002 0.70710677 0.70710677 0.0
• DW_gradient_003 0.0 0.70710677
  0.70710677

4
Location Orientation
space right-anterior-superior space origin
(117.5,-93,119) space directions (-0.859375,0,0)
(0,0,-0.859375) (0,5,0) none
(RAS)
superior
anterior
right