dcraw

dcraw(1)                                                              dcraw(1)



NAME
       dcraw - command-line decoder for raw digital photos

SYNOPSIS
       dcraw [OPTION]... [FILE]...

DESCRIPTION
       dcraw decodes raw photos, displays metadata, and extracts thumbnails.

GENERAL OPTIONS
       -v     Print verbose messages, not just warnings and errors.

       -c     Write decoded images or thumbnails to standard output.

       -e     Extract  the  camera-generated  thumbnail,  not  the  raw image.
              You'll get either a JPEG or a PPM file, depending on the camera.

       -z     Change the access and modification times of an AVI,  JPEG,  TIFF
              or  raw file to when the photo was taken, assuming that the cam‐
              era clock was set to Universal Time.

       -i     Identify files but don't decode them.  Exit status is 0 if dcraw
              can decode the last file, 1 if it can't.  -i -v shows metadata.

              dcraw cannot decode JPEG files!!

REPAIR OPTIONS
       -P deadpixels.txt
              Read the dead pixel list from this file instead of ".badpixels".
              See FILES for a description of the format.

       -K darkframe.pgm
              Subtract a dark frame from the raw data.   To  generate  a  dark
              frame,    shoot   a   raw   photo   with   no   light   and   do
              dcraw -D -4 -j -t 0.

       -k darkness
              When shadows appear foggy, you need to raise the darkness level.
              To measure this, apply pamsumm -mean to the dark frame generated
              above.

       -S saturation
              When highlights appear pink, you need to  lower  the  saturation
              level.   To  measure this, take a picture of something shiny and
              do dcraw -D -4 -j -c photo.raw | pamsumm -max

              The default darkness and saturation are usually correct.

       -n noise_threshold
              Use wavelets to erase noise while preserving real  detail.   The
              best threshold should be somewhere between 100 and 1000.

       -C red_mag blue_mag
              Enlarge  the raw red and blue layers by the given factors, typi‐
              cally 0.999 to 1.001, to correct chromatic aberration.

       -H 0   Clip all highlights to solid white (default).

       -H 1   Leave highlights unclipped in various shades of pink.

       -H 2   Blend clipped and unclipped values together for a  gradual  fade
              to white.

       -H 3+  Reconstruct  highlights.  Low numbers favor whites; high numbers
              favor colors.  Try -H 5 as a compromise.   If  that's  not  good
              enough,  do  -H 9,  cut  out the non-white highlights, and paste
              them into an image generated with -H 3.

COLOR OPTIONS
       By default, dcraw uses a fixed white balance based  on  a  color  chart
       illuminated with a standard D65 lamp.

       -w     Use  the  white balance specified by the camera.  If this is not
              found, print a warning and use another method.

       -a     Calculate the white balance by averaging the entire image.

       -A left top width height
              Calculate the white balance by  averaging  a  rectangular  area.
              First do dcraw -j -t 0 and select an area of neutral grey color.

       -r mul0 mul1 mul2 mul3
              Specify  your  own  raw white balance.  These multipliers can be
              cut and pasted from the output of dcraw -v.

       +M or -M
              Use (or don't use) any color matrix from  the  camera  metadata.
              The  default is +M if -w is set, -M otherwise.  This option only
              affects Olympus, Leaf, and Phase One cameras.

       -o [0-5]
              Select the output colorspace when the -p option is not used:

                   0   Raw color (unique to each camera)
                   1   sRGB D65 (default)
                   2   Adobe RGB (1998) D65
                   3   Wide Gamut RGB D65
                   4   Kodak ProPhoto RGB D65
                   5   XYZ

       -p camera.icm [ -o output.icm ]
              Use ICC profiles to define the camera's raw colorspace  and  the
              desired output colorspace (sRGB by default).

       -p embed
              Use the ICC profile embedded in the raw photo.

INTERPOLATION OPTIONS
       -d     Show  the  raw  data as a grayscale image with no interpolation.
              Good for photographing black-and-white documents.

       -D     Same as -d, but totally raw (no color scaling).

       -h     Output a half-size color image.  Twice as fast as -q 0.

       -q 0   Use high-speed, low-quality bilinear interpolation.

       -q 1   Use Variable Number of Gradients (VNG) interpolation.

       -q 2   Use Patterned Pixel Grouping (PPG) interpolation.

       -q 3   Use Adaptive Homogeneity-Directed (AHD) interpolation.

       -f     Interpolate RGB as four colors.  Use this if  the  output  shows
              false 2x2 meshes with VNG or mazes with AHD.

       -m number_of_passes
              After  interpolation,  clean  up  color  artifacts by repeatedly
              applying a 3x3 median filter to the R-G and B-G channels.

OUTPUT OPTIONS
       By default, dcraw writes PGM/PPM/PAM with 8-bit samples, a BT.709 gamma
       curve, a histogram-based white level, and no metadata.

       -W     Use a fixed white level, ignoring the image histogram.

       -b brightness
              Divide the white level by this number, 1.0 by default.

       -4     Write 16-bit linear samples (fixed white level, no gamma).

       -T     Write TIFF with metadata instead of PGM/PPM/PAM.

       -t [0-7,90,180,270]
              Flip the output image.  By default, dcraw applies the flip spec‐
              ified by the camera.  -t 0 disables all flipping.

       -j     For Fuji Super CCD cameras, show the image  tilted  45  degrees.
              For  cameras with non-square pixels, do not stretch the image to
              its correct aspect ratio.  In any case, this  option  guarantees
              that each output pixel corresponds to one raw pixel.

       -s [0..N-1] or -s all
              If  a file contains N raw images, choose one or "all" to decode.
              For example, Fuji Super CCD SR cameras generate a  second  image
              underexposed four stops to show detail in the highlights.

FILES
       ./.badpixels, ../.badpixels, ../../.badpixels, ...
              List of your camera's dead pixels, so that dcraw can interpolate
              around them.  Each line specifies the column, row, and UNIX time
              of death for one pixel.  For example:

               962   91 1028350000  # died between August 1 and 4, 2002
              1285 1067 0           # don't know when this pixel died

              These  coordinates  are  before any cropping or rotation, so use
              dcraw -j -t 0 to locate dead pixels.

SEE ALSO
       pgm(5), ppm(5), pam(5),  pamsumm(1),  pnmgamma(1),  pnmtotiff(1),  pnm‐
       topng(1), gphoto2(1), cjpeg(1), djpeg(1)

AUTHOR
       Written by David Coffin, dcoffin a cybercom o net



                               February 6, 2008                       dcraw(1)