dcmdecap(1)

NAME
dcmdecap - Extract encapsulated file from DICOM encapsulated storage object

SYNOPSIS

dcmdecap [options] dcmfile-in encfile-out

DESCRIPTION

The dcmdecap utility reads a DICOM file of one of the Encapsulated Storage SOP Classes (dcmfile-in), extracts the embedded document and writes it to an output file (encfile-out). Optionally a command can be executed after the creation of the output file.

PARAMETERS

dcmfile-in   DICOM input filename ("-" for stdin)
encfile-out  Encapsulated document output filename ("-" for stdout)

OPTIONS

  general options

  -h   --help
         print this help text and exit
       --version
         print version information and exit
       --arguments
         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
input transfer syntax:
  -t=  --read-xfer-auto
         use TS recognition (default)
  -td  --read-xfer-detect
         ignore TS specified in the file meta header
  -te  --read-xfer-little
         read with explicit VR little endian TS
  -tb  --read-xfer-big
         read with explicit VR big endian TS
  -ti  --read-xfer-implicit
         read with implicit VR little endian TS
parsing of odd-length attributes:
  +ao  --accept-odd-length
         accept odd length attributes (default)
  +ae  --assume-even-length
         assume real length is one byte larger
handling of undefined length UN elements:
  +ui  --enable-cp246
         read undefined len UN as implicit VR (default)
  -ui  --disable-cp246
         read undefined len UN as explicit VR
handling of defined length UN elements:
  -uc  --retain-un
         retain elements as UN (default)
  +uc  --convert-un
         convert to real VR if known
automatic data correction:
  +dc  --enable-correction
         enable automatic data correction (default)
  -dc  --disable-correction
         disable automatic data correction
bitstream format of deflated input:
  +bd  --bitstream-deflated
         expect deflated bitstream (default)
  +bz  --bitstream-zlib
         expect deflated zlib bitstream

  processing options
execution options:

  -x   --exec  [c]ommand: string
         execute command c after document extraction

NOTES

Option --exec allows for the execution of a certain command line after the creation of the PDF document. The command line to be executed is passed to this option as a parameter. The specified command line may contain the placeholder '#f', which will be replaced by the output filename at run time. The specified command line is executed in the foreground, i.e. dcmdecap will be blocked until the command terminates.

LOGGING

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.

EXIT CODES

The dcmdecap utility uses the following exit codes when terminating. This enables the user to check for the reason why the application terminated.

  general

EXITCODE_NO_ERROR                         0
EXITCODE_COMMANDLINE_SYNTAX_ERROR         1

  input file errors

EXITCODE_CANNOT_READ_INPUT_FILE          20
EXITCODE_NO_INPUT_FILES                  21
EXITCODE_INVALID_INPUT_FILE              22

  output file errors

EXITCODE_CANNOT_WRITE_OUTPUT_FILE        40

  processing errors

EXITCODE_EXEC_FAILED                     91

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).

ENVIRONMENT

The dcmdecap 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

dcmencap(1)

COPYRIGHT

Copyright (C) 2007-2025 by OFFIS e.V., Escherweg 2, 26121 Oldenburg, Germany.