dcmconv(1) OFFIS DCMTK dcmconv(1) # [NAME](#NAME) dcmconv - Convert DICOM file encoding # [SYNOPSIS](#SYNOPSIS) ``` dcmconv [options] dcmfile-in dcmfile-out ``` # [DESCRIPTION](#DESCRIPTION) The **dcmconv** utility reads a DICOM file (*dcmfile-in*), performs an encoding conversion and writes the converted data to an output file (*dcmfile-out*). # [PARAMETERS](#PARAMETERS) ``` dcmfile-in DICOM input filename to be converted ("-" for stdin) dcmfile-out DICOM output filename to write to ("-" for stdout) ``` # [OPTIONS](#OPTIONS) ## [general 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 -l --log-level [l]evel: string constant (fatal, error, warn, info, debug, trace) use level l for the logger -l --log-config [f]ilename: string use config file f for the logger ``` ## [input options](#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 file meta information: +ml --use-meta-length use file meta information group length (default) -ml --ignore-meta-length ignore file meta information group length 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 explicit VR: +ev --use-explicit-vr use explicit VR from dataset (default) -ev --ignore-explicit-vr ignore explicit VR (prefer data dictionary) handling of non-standard VR: +vr --treat-as-unknown treat non-standard VR as unknown (default) -vr --assume-implicit try to read with implicit VR little endian TS 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 handling of private max-length elements (implicit VR): -sq --maxlength-dict read as defined in dictionary (default) +sq --maxlength-seq read as sequence with undefined length handling of wrong delimitation items: -rd --use-delim-items use delimitation items from dataset (default) +rd --replace-wrong-delim replace wrong sequence/item delimitation items handling of illegal undefined length OB/OW elements: -oi --illegal-obow-rej reject dataset with illegal element (default) +oi --illegal-obow-conv convert undefined length OB/OW element to SQ handling of VOI LUT Sequence with OW VR and explicit length: -vi --illegal-voi-rej reject dataset with illegal VOI LUT (default) +vi --illegal-voi-conv convert illegal VOI LUT to SQ handling of explicit length pixel data for encaps. transfer syntaxes: -pe --abort-expl-pixdata abort on explicit length pixel data (default) +pe --use-expl-pixdata use explicit length pixel data general handling of parser errors: +Ep --ignore-parse-errors try to recover from parse errors -Ep --handle-parse-errors handle parse errors and stop parsing (default) other parsing options: +st --stop-after-elem [t]ag: "gggg,eeee" or dictionary name stop parsing after element specified by t 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](#processing_options) ``` specific character set: # the following options require support from an underlying character # encoding library (see output of --version on which one is available) +U8 --convert-to-utf8 convert all element values that are affected by Specific Character Set (0008,0005) to UTF-8 +L1 --convert-to-latin1 convert affected element values to ISO 8859-1 +A7 --convert-to-ascii convert affected element values to 7-bit ASCII +C --convert-to-charset [c]harset: string convert affected element values to the character set specified by the DICOM defined term c -Ct --transliterate try to approximate characters that cannot be represented through similar looking characters -Cd --discard-illegal discard characters that cannot be represented in destination character set other processing options: -ig --no-invalid-groups remove elements with invalid group number ``` ## [output options](#output_options) ``` output file format: +Fm --write-new-meta-info write file format with new meta information (default) +F --write-file write file format -F --write-dataset write data set without file meta information output transfer syntax: +t= --write-xfer-same write with same TS as input (default) +te --write-xfer-little write with explicit VR little endian TS +tb --write-xfer-big write with explicit VR big endian TS +ti --write-xfer-implicit write with implicit VR little endian TS +td --write-xfer-deflated write with deflated explicit VR little endian TS +tg --write-xfer-ge write private GE implicit VR little endian with big endian pixel data TS (non-standard) 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 +eo --write-oversized write oversized explicit length sequences and items with undefined length (default) -eo --abort-oversized abort on oversized explicit sequences/items 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 deflate compression level (only with --write-xfer-deflated): +cl --compression-level [l]evel: integer (default: 6) 0=uncompressed, 1=fastest, 9=best compression ``` # [LOGGING](#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*. # [COMMAND LINE](#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](#ENVIRONMENT) The **dcmconv** 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. Depending on the command line options specified, the **dcmconv** utility will attempt to load character set mapping tables. This happens when DCMTK was compiled with the oficonv library (which is the default) and the mapping tables are not built into the library (default when DCMTK uses shared libraries). The mapping table files are expected in DCMTK's *<datadir>*. The *DCMICONVPATH* environment variable can be used to specify a different location. If a different location is specified, those mapping tables also replace any built-in tables. # [SEE ALSO](#SEE_ALSO) [**dcmdump**(1)](/man/os/dcmtk/dcmdump.1) # [COPYRIGHT](#COPYRIGHT) Copyright (C) 1994-2025 by OFFIS e.V., Escherweg 2, 26121 Oldenburg, Germany. Mon Dec 15 2025 Version 3.7.0 --- Document: dcmconv(1) from dcmtk 3.7.0-r8 (Chainguard OS) Source: https://github.com/DCMTK/dcmtk