dcmquant(1)                       OFFIS DCMTK                      dcmquant(1)

NAME
       dcmquant - Convert DICOM color images to palette color


SYNOPSIS
       dcmquant [options] dcmfile-in dcmfile-out

DESCRIPTION
       The  dcmquant  utility  reads  a  DICOM color image, computes a palette
       color look-up table of the desired size for this image  (based  on  the
       median cut algorithm published by Paul Heckbert) and converts the color
       image into a DICOM palette color image.

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

       dcmfile-out  DICOM output filename to be written ("-" 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

   image processing and encoding options
       frame selection:

         +F   --frame  [n]umber: integer
                select specified frame

         +Fa  --all-frames
                select all frames (default)

       compatibility:

         +Mp  --accept-palettes
                accept incorrect palette attribute tags
                (0028,111x) and (0028,121x)

       median cut dimension selection:

         +Dr  --mc-dimension-rgb
                max dimension from RGB range (default)

         +Dl  --mc-dimension-lum
                max dimension from luminance

       median cut representative color selection:

         +Cb  --mc-color-avgbox
                average colors in box (default)

         +Cp  --mc-color-avgpixel
                average pixels in box

         +Cc  --mc-color-center
                select center of box

       color palette value representation:

         +pw  --write-ow
                write Palette LUT as OW (default)

         +pu  --write-us
                write Palette LUT as US (retired)

       color palette creation:

         +pe  --lut-entries-word
                write Palette LUT with 16-bit entries

         +pf  --floyd-steinberg
                use Floyd-Steinberg error diffusion

         +pc  --colors  number of colors: 2..65536 (default 256)
                number of colors to quantize to

       SOP Class UID:

         +cd  --class-default
                keep SOP Class UID (default)

         +cs  --class-sc
                convert to Secondary Capture Image
                (implies --uid-always)

       SOP Instance UID:

         +ua  --uid-always
                always assign new UID (default)

         +un  --uid-never
                never assign new UID

   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:

         +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

       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

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  dcmquant  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.

COPYRIGHT
       Copyright (C) 2001-2025 by OFFIS e.V., Escherweg  2,  26121  Oldenburg,
       Germany.

Version 3.7.0                   Mon Dec 15 2025                    dcmquant(1)
