dcmdjpeg(1)                       OFFIS DCMTK                      dcmdjpeg(1)

NAME
       dcmdjpeg - Decode JPEG-compressed DICOM file


SYNOPSIS
       dcmdjpeg [options] dcmfile-in dcmfile-out

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

PARAMETERS
       dcmfile-in   DICOM input filename to be converted ("-" for stdin)

       dcmfile-out  DICOM 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

         # This option allows one to decompress JPEG 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
       color space conversion:

         +cp   --conv-photometric
                 convert if YCbCr photometric interpretation (default)

         # If the compressed image uses YBR_FULL or YBR_FULL_422 photometric
         # interpretation, convert to RGB during decompression.

         +cl   --conv-lossy
                 convert YCbCr to RGB if lossy JPEG

         # If the compressed image is encoded in lossy JPEG, assume YCbCr
         # color model and convert to RGB.

         +cg   --conv-guess
                 convert to RGB if YCbCr is guessed by library

         # If the underlying JPEG library "guesses" the color space of the
         # compressed image to be YCbCr, convert to RGB.

         +cgl  --conv-guess-lossy
                 convert to RGB if lossy JPEG and YCbCr is
                 guessed by the underlying JPEG library

         # If the compressed image is encoded in lossy JPEG and the underlying
         # JPEG library "guesses" the color space to be YCbCr, convert to RGB.

         +ca   --conv-always
                 always convert YCbCr to RGB

         # If the compressed image is a color image, assume YCbCr color model
         # and convert to RGB. Warning: This will lead to an incorrectly decoded
         # image if the color space is in fact RGB. Images compressed with lossless
         # JPEG are almost never encoded in YCbCr, this option should thus be used
         # with care on such images.

         +cn   --conv-never
                 never convert YCbCr to RGB

         # Never convert color space from YCbCr to RGB during decompression.
         # Note that a conversion from YBR_FULL_422 to YBR_FULL will still take
         # place if the source images has been compressed with subsampling.

       planar configuration:

         +pa   --planar-auto
                 automatically determine planar configuration
                 from SOP class and color space (default)

         # If the compressed image is a color image, store in color-by-plane
         # planar configuration if required by the SOP class and photometric
         # interpretation. Hardcopy Color images are always stored color-by-
         # plane, and the revised Ultrasound image objects are stored color-by-
         # plane if the color model is YBR_FULL.  Everything else is stored
         # color-by-pixel.

         +px   --color-by-pixel
                 always store color-by-pixel

         # If the compressed image is a color image, store in color-by-pixel
         # planar configuration.

         +pl   --color-by-plane
                 always store color-by-plane

         # If the compressed image is a color image, store in color-by-plane
         # planar configuration.

       SOP Instance UID:

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

         #  Never assigns a new SOP instance UID.

         +ua   --uid-always
                 always assign new UID

         # Always assigns a new SOP instance UID.

       workaround options for incorrect JPEG encodings:

         +w6   --workaround-pred6
                 enable workaround for JPEG lossless images
                 with overflow in predictor 6

         # DICOM images with 16 bits/pixel have been observed "in the wild"
         # that are compressed with lossless JPEG and need special handling
         # because the encoder produced an 16-bit integer overflow in predictor
         # 6, which needs to be compensated (reproduced) during decompression.
         # This flag enables a correct decompression of such faulty images, but
         # at the same time will cause an incorrect decompression of correctly
         # compressed images. Use with care.

         +wi   --workaround-incpl
                 enable workaround for incomplete JPEG data

         # This option causes dcmjpeg to ignore incomplete JPEG data
         # at the end of a compressed fragment and to start decompressing
         # the next frame from the next fragment (if any). This permits
         # images with incomplete JPEG data to be decoded.

         +wc   --workaround-cornell
                 enable workaround for 16-bit JPEG lossless
                 Cornell images with Huffman table overflow

         # One of the first open-source implementations of lossless JPEG
         # compression, the "Cornell" library, has a well-known bug that leads
         # to invalid values in the Huffmann table when images with 16 bit/sample
         # are compressed. This flag enables a workaround that permits such
         # images to be decoded correctly..fi

   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
       dcmdjpeg 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   1.2.840.10008.1.2.1.99 (*)
       BigEndianExplicitTransferSyntax                1.2.840.10008.1.2.2
       JPEGProcess1TransferSyntax                     1.2.840.10008.1.2.4.50
       JPEGProcess2_4TransferSyntax                   1.2.840.10008.1.2.4.51
       JPEGProcess6_8TransferSyntax                   1.2.840.10008.1.2.4.53
       JPEGProcess10_12TransferSyntax                 1.2.840.10008.1.2.4.55
       JPEGProcess14TransferSyntax                    1.2.840.10008.1.2.4.57
       JPEGProcess14SV1TransferSyntax                 1.2.840.10008.1.2.4.70

       (*) if compiled with zlib support enabled

       dcmdjpeg  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

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
       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 dcmdjpeg 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
       dcmcjpeg(1)

COPYRIGHT
       Copyright  (C)  2001-2024  by OFFIS e.V., Escherweg 2, 26121 Oldenburg,
       Germany.

Version 3.6.9                   Wed Dec 11 2024                    dcmdjpeg(1)
