dcmdrle man page

dcmdrle — Decode RLE-compressed DICOM file


dcmdrle [options] dcmfile-in dcmfile-out


The dcmdrle utility reads a RLE-compressed DICOM image (dcmfile-in), decompresses the image data (i.e. conversion to a native DICOM transfer syntax) and writes the converted image to an output file (dcmfile-out).


dcmfile-in   DICOM input filename to be converted

dcmfile-out  DICOM output filename


general options

-h   --help
       print this help text and exit

       print version information and exit

       print expanded command line arguments

-q   --quiet
       quiet mode, print no warnings and errors

-v   --verbose
       verbose mode, print processing details

-d   --debug
       debug mode, print debug information

-ll  --log-level  [l]evel: string constant
       (fatal, error, warn, info, debug, trace)
       use level l for the logger

-lc  --log-config  [f]ilename: string
       use config file f for the logger

input options

input file format:

  +f   --read-file
         read file format or data set (default)

  +fo  --read-file-only
         read file format only

  -f   --read-dataset
         read data set without file meta information

  # This option allows one to decompress RLE compressed DICOM objects that have
  # been stored as dataset without meta-header. Such a thing should not exist
  # since the transfer syntax cannot be reliably determined without meta-header,
  # but unfortunately it does.

processing options

SOP Instance UID:

  +ud  --uid-default
         keep same SOP Instance UID (default)

  +ua  --uid-always
         always assign new UID

RLE byte segment order:

  +bd  --byte-order-default
         most significant byte first (default)

  +br  --byte-order-reverse
         least significant byte first

  # This option allows one to decompress RLE compressed DICOM files in which
  # the order of byte segments is encoded in incorrect order. This only affects
  # images with more than one byte per sample.

output options

output file format:

  +F   --write-file
         write file format (default)

  -F   --write-dataset
         write data set without file meta information

output transfer syntax:

  +te  --write-xfer-little
         write with explicit VR little endian (default)

  +tb  --write-xfer-big
         write with explicit VR big endian TS

  +ti  --write-xfer-implicit
         write with implicit VR little endian TS

post-1993 value representations:

  +u   --enable-new-vr
         enable support for new VRs (UN/UT) (default)

  -u   --disable-new-vr
         disable support for new VRs, convert to OB

group length encoding:

  +g=  --group-length-recalc
         recalculate group lengths if present (default)

  +g   --group-length-create
         always write with group length elements

  -g   --group-length-remove
         always write without group length elements

length encoding in sequences and items:

  +e   --length-explicit
         write with explicit lengths (default)

  -e   --length-undefined
         write with undefined lengths

data set trailing padding (not with --write-dataset):

  -p=  --padding-retain
         do not change padding (default if not --write-dataset)

  -p   --padding-off
         no padding (implicit if --write-dataset)

  +p   --padding-create  [f]ile-pad [i]tem-pad: integer
         align file on multiple of f bytes
         and items on multiple of i bytes

Transfer Syntaxes

dcmdrle supports the following transfer syntaxes for input (dcmfile-in):

LittleEndianImplicitTransferSyntax             1.2.840.10008.1.2
LittleEndianExplicitTransferSyntax             1.2.840.10008.1.2.1
DeflatedExplicitVRLittleEndianTransferSyntax   1.2.840.10008. (*)
BigEndianExplicitTransferSyntax                1.2.840.10008.1.2.2
RLELosslessTransferSyntax                      1.2.840.10008.1.2.5

(*) if compiled with zlib support enabled

dcmdrle supports the following transfer syntaxes for output (dcmfile-out):

LittleEndianImplicitTransferSyntax             1.2.840.10008.1.2
LittleEndianExplicitTransferSyntax             1.2.840.10008.1.2.1
BigEndianExplicitTransferSyntax                1.2.840.10008.1.2.2


The level of logging output of the various command line tools and underlying libraries can be specified by the user. By default, only errors and warnings are written to the standard error stream. Using option --verbose also informational messages like processing details are reported. Option --debug can be used to get more details on the internal activity, e.g. for debugging purposes. Other logging levels can be selected using option --log-level. In --quiet mode only fatal errors are reported. In such very severe error events, the application will usually terminate. For more details on the different logging levels, see documentation of module 'oflog'.

In case the logging output should be written to file (optionally with logfile rotation), to syslog (Unix) or the event log (Windows) option --log-config can be used. This configuration file also allows for directing only certain messages to a particular output stream and for filtering certain messages based on the module or application where they are generated. An example configuration file is provided in <etcdir>/logger.cfg.

Command Line

All command line tools use the following notation for parameters: square brackets enclose optional values (0-1), three trailing dots indicate that multiple values are allowed (1-n), a combination of both means 0 to n values.

Command line options are distinguished from parameters by a leading '+' or '-' sign, respectively. Usually, order and position of command line options are arbitrary (i.e. they can appear anywhere). However, if options are mutually exclusive the rightmost appearance is used. This behavior conforms to the standard evaluation rules of common Unix shells.

In addition, one or more command files can be specified using an '@' sign as a prefix to the filename (e.g. @command.txt). Such a command argument is replaced by the content of the corresponding text file (multiple whitespaces are treated as a single separator unless they appear between two quotation marks) prior to any further evaluation. Please note that a command file cannot contain another command file. This simple but effective approach allows one to summarize common combinations of options/parameters and avoids longish and confusing command lines (an example is provided in file <datadir>/dumppat.txt).


The dcmdrle utility will attempt to load DICOM data dictionaries specified in the DCMDICTPATH environment variable. By default, i.e. if the DCMDICTPATH environment variable is not set, the file <datadir>/dicom.dic will be loaded unless the dictionary is built into the application (default for Windows).

The default behavior should be preferred and the DCMDICTPATH environment variable only used when alternative data dictionaries are required. The DCMDICTPATH environment variable has the same format as the Unix shell PATH variable in that a colon (':') separates entries. On Windows systems, a semicolon (';') is used as a separator. The data dictionary code will attempt to load each file specified in the DCMDICTPATH environment variable. It is an error if no data dictionary can be loaded.

See Also


Referenced By


Explore man page connections for dcmdrle(1).

OFFIS DCMTK Version 3.6.1 Tue Jun 17 2014