gdcmimg - Man Page

gdcmimg — Manipulate DICOM image file.

gdcmimg is a low level tool to allow de-/encapsulation from/to DICOM image. This tool does not understand Transfer Syntax conversion. It will encapsulate the raw data as-is. This has some impact in some cases, see special warnings below.

It is important to note that gdcmimg can only encapsulate proper input file, for instance JPG and or JP2 are accepted since an associated DICOM Transfer Syntax can be found. However input such as TIFF and/or PNG are not, since DICOM does not support those. See instead a tool such as gdcm2vtk.

gdcmimg [options] file-in file-out

The gdcmimg command line tool can be used in two fashions:

• 1. Converting a recognized file format into its encapsulated DICOM counterpart,
• 2. Anonymizing a rectangular portion of a DICOM file.

file-in   input filename (non-DICOM)

file-out  DICOM output filename

  -i --input     Input filename
  -o --output    Output filename

     --endian %s       Endianness (LSB/MSB).
  -d --depth %d        Depth (Either 8/16/32 or BitsAllocated eg. 12 when known).
     --sign %s         Pixel sign (0/1).
     --spp  %d         Sample Per Pixel (1/3).
     --pc [01]         Change planar configuration.
     --pi [str]        Change photometric interpretation.
     --pf %d,%d,%d     Change pixel format: (BA,BS,HB).
  -s --size %d,%d      Size.
     --offset %ull     Start Offset.
  -C --sop-class-uid   SOP Class UID (name or value).
  -T --study-uid       Study UID.
  -S --series-uid      Series UID.
     --template        Template DICOM file.
     --keep-meta       Keep meta info from template file (advanced users only).
     --root-uid        Root UID.

  -R --region %d,%d    Region.
  -F --fill %d         Fill with pixel value specified.

  -h   --help
         print this help text and exit

  -v   --version
         print version information and exit

  -V   --verbose
         verbose mode (warning+error).

  -W   --warning
         warning mode, print warning information

  -E   --error
         error mode, print error information

  -D   --debug
         debug mode, print debug information

  GDCM_ROOT_UID Root UID

gdcmimg will base it's conversion process based on the file extension. Follows the list of recognized file extension. When no extension is found, DICOM file is assumed.

input format

  * RAW       (raw, rawl, gray, rgb)
  * RLE       (rle)
  * PNM       (pgm, pnm, ppm)
  * JPEG-LS   (jls)
  * JPEG 2000 (jp2, j2k, j2c, jpx, jpc)
  * JPEG      (jpg, jpeg, ljpg, ljpeg)
  * DICOM     ()

output format:

  * PGM       (pgm, pnm, ppm)
  * DICOM     ()

For RAW file format, you should take special care of the –endian option. For the (old) JPEG file format, both the lossy and lossless format are supported, user should pay attention to the –sign option. For file format such as RLE or RAW, user is expected to fill in information required to find the dimension and type of input data as there is no other way to find this information. For all other file format, the properties are derived from the file format itself.

PNM file are supposed to be big endian (important for depth > 8)

gdcmimg handle nicely a set of files (for instance jpeg):

$ gdcmimg -C 1.2.840.10008.5.1.4.1.1.12.1 1.jpg 2.jpg 3.jpg 4.jpg output.dcm

It is important to specify an SOP Class that supports multi-frames images otherwise gdcmimg will fail.

In some case, one may want to create a 2D slice from an arbitrary volume (e.g 3D). In which case –offset becomes handy:

$ gdcmimg --offset 4954104330 --size 1673,1673 Input3D_1673_1673_1775.raw slice_1770.dcm

There are a couple of issues with gdcmimg implementation:

For RAW file, one should pay attention that when using –endian MSB the Pixel Data will be encapsulated as is (not touched by gdcmimg). Therefore the only possible transfer syntax available is Implicit VR Big Endian DLX (G.E Private). GDCM does handle this private Transfer Syntax. So if you need to convert this Transfer Syntax to another one (and allow Pixel Data manipulation), you can use:

$ gdcmconv --raw --force input_big_endian_dlx.raw -o output_implicit_vr_little_endian.dcm

For JFIF file and JP2 file (with header) the header is copied into the Pixel Data element which is illegal for JP2. Use gdcmconv to properly re-encode a JP2/JFIF file into J2K/JPG.

$ gdcmimg input.jp2 output_jp2.dcm
$ gdcmconv --j2k --force output_jp2.dcm output_j2k.dcm

For RLE file, no check is done for crossing the row boundary. It is recommended to use gdcmconv –rle to re-encode into a proper RLE file in case of doubt.

Of course if the compression is not ok with your setup, you can always de-encapsulated the DICOM file (typically JPEG) to a non-encapsulated form, using gdcmconv:

$ gdcmconv --raw input_jpeg.dcm output_raw.dcm

gdcmdump(1), gdcm2vtk(1), gdcmraw(1), convert(1), dd(1)

Mathieu Malaterre

Copyright © 2006, 2011 Mathieu Malaterre

gdcm2pnm(1), gdcm2vtk(1).