# Extract Data Element Value Field.

## SYNOPSIS

    gdcmraw [options] file-in file-out

## DESCRIPTION

The gdcmraw tool is mostly used for development purpose. It is used to extract a specific binary field from a DICOM DataSet.

## PARAMETERS

    file-in   DICOM input filename

    file-out  output filename

## OPTIONS

### PARAMETERS

      -i --input     Input filename
      -o --output    Output filename
      -t --tag       Specify tag to extract value from.

### OPTIONS

      -S --split-frags  Split fragments into multiple files.
      -p --pattern      Specify trailing file pattern (see split-frags).
      -P --pixel-data   Pixel Data trailing 0.

### general options

      -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

## Typical usage

### Copy Attribute Value to file

This will extract the value at Tag (0025,101b):

    $ gdcmraw -i GE_MR_0025xx1bProtocolDataBlock.dcm -t 25,101b -o pdb.raw

### Extract Pixel Data

If you do not specify any tag, the Pixel Data element is the default one. So for instance to grab the Pixel Data from an image:

    $ gdcmraw -i test.acr -o test.raw

You can then for example compute the md5sum of this pixel data (very useful):

    $ md5sum test.raw
    f845c8f283d39a0204c325654493ba53  test.raw

### Encapsulated Syntax

When the Pixel Data is encapsulated, multiple fragments can be used to store a single slice image:

    $ gdcmdump D_CLUNIE_CT1_J2KR.dcm

    \&...
    (7fe0,0010) OB                                                    # u/l,1 Pixel Data
      (fffe,e000) ?? []                           # 0,1 Item
      (fffe,e000) ?? ff\\4f\\ff\\51\\00\\29\\00\\00\\00\\00\\02\\00\\00\\00\\02\\00\\00\\00\\00\\00\\00\\00\\00\\00\\00\\00\\02\\00\\00\\00\\02\\00         # 65536,1 Item
      (fffe,e000) ?? 2c\\b7\\ee\\68\\de\\e3\\93\\2d\\b3\\b8\\ba\\90\\7b\\42\\3e\\f8\\42\\16\\64\\88\\46\\30\\37\\d4\\50\\95\\9b\\b6\\a5\\c7\\38\\9b         # 65536,1 Item
      (fffe,e000) ?? 48\\3c\\03\\e8\\c4\\3f\\44\\e1\\8a\\5c\\73\\3b\\02\\0a\\ad\\a5\\8f\\e4\\0c\\81\\76\\a2\\d7\\1b\\7f\\b7\\cd\\bc\\30\\c6\\6a\\6a         # 43308,1 Item
    (fffe,e0dd) 0

In order to create a J2K image out of it, we need to extract each fragments and concatenate them:

    $ gdcmraw -i D_CLUNIE_CT1_J2KR.dcm -o D_CLUNIE_CT1_J2KR.j2k

This is a valid J2K file, using the Kakadu software package:

    $ kdu_expand -i D_CLUNIE_CT1_J2KR.j2k -o D_CLUNIE_CT1_J2KR.tiff -record D_CLUNIE_CT1_J2KR.txt

    $ cat D_CLUNIE_CT1_J2KR.txt

    Sprofile=PROFILE2
    Scap=no
    Sextensions=0
    Ssize={512,512}
    Sorigin={0,0}
    Stiles={512,512}
    Stile_origin={0,0}
    Scomponents=1
    Ssigned=yes
    Sprecision=16
    Ssampling={1,1}
    Sdims={512,512}
    Cycc=no
    Cmct=0
    Clayers=1
    Cuse_sop=no
    Cuse_eph=no
    Corder=LRCP
    Calign_blk_last={no,no}
    Clevels=5
    Cads=0
    Cdfs=0
    Cdecomp=B(-:-:-)
    Creversible=yes
    Ckernels=W5X3
    Catk=0
    Cuse_precincts=no
    Cblk={64,64}
    Cmodes=0
    Qguard=1
    Qabs_ranges=18,19,19,20,19,19,20,19,19,20,19,19,20,19,19,20

    >> New attributes for tile 0:

### Extract fragments as single file

Sometimes each fragments is in fact a single slice, so we would not need to concatenate them:

    $ gdcmdump 00191113.dcm

    \&...
    (7fe0,0010) OB                                                    # u/l,1 Pixel Data
      (fffe,e000) ?? 00\\00\\00\\00\\6b\\38\\01\\00\\10\\77\\02\\00\\37\\b6\\03\\00\\a7\\f4\\04\\00         # 20,1 Item
      (fffe,e000) ?? ff\\d8\\ff\\c3\\00\\0b\\08\\02\\00\\02\\00\\01\\00\\11\\00\\ff\\c4\\00\\1b\\00\\01\\01\\01\\01\\01\\01\\01\\01\\00\\00\\00\\00         # 79970,1 Item
      (fffe,e000) ?? ff\\d8\\ff\\c3\\00\\0b\\08\\02\\00\\02\\00\\01\\00\\11\\00\\ff\\c4\\00\\1b\\00\\01\\01\\01\\01\\01\\01\\01\\01\\00\\00\\00\\00         # 81564,1 Item
      (fffe,e000) ?? ff\\d8\\ff\\c3\\00\\0b\\08\\02\\00\\02\\00\\01\\00\\11\\00\\ff\\c4\\00\\1b\\00\\01\\01\\01\\01\\01\\01\\01\\01\\00\\00\\00\\00         # 81694,1 Item
      (fffe,e000) ?? ff\\d8\\ff\\c3\\00\\0b\\08\\02\\00\\02\\00\\01\\00\\11\\00\\ff\\c4\\00\\1b\\00\\01\\01\\01\\01\\01\\01\\01\\01\\00\\00\\00\\00         # 81511 (81512),1 Item
    (fffe,e0dd) 0

Let's try to extract those 4 individual Lossless jpeg individually:

    $ gdcmraw --split-frags -i 00191113.dcm -o jpeg --pattern %02d.ljpeg

This will output 4 files:

    -rw-r--r--  1 mathieu mathieu   81512 2008-08-08 22:10 jpeg03.ljpeg
    -rw-r--r--  1 mathieu mathieu   81694 2008-08-08 22:10 jpeg02.ljpeg
    -rw-r--r--  1 mathieu mathieu   81564 2008-08-08 22:10 jpeg01.ljpeg
    -rw-r--r--  1 mathieu mathieu   79970 2008-08-08 22:10 jpeg00.ljpeg

## Footnote about JPEG files

It is a common misunderstanding to interchange 'JPEG 8bits lossy' with simply JPEG file. The JPEG specification is much broader than simply the common lossy 8bits file (as found on internet).

You can have

- JPEG Lossy 8bits
- JPEG Lossy 12bits
- JPEG Lossless 2-16bits

Those are what is defined in ITU-T T.81, ISO/IEC IS 10918-1.

## SEE ALSO

gdcmdump(1), gdcmraw(1)

## COPYRIGHT

Copyright (c) 2006-2009 Mathieu Malaterre