dcraw

dcraw(1)                    General Commands Manual                   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
              camera 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
       -I     Read the raw pixels from standard input in CPU byte order with
              no header.  Use dcraw -E -4 to get the raw pixel values.

       -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,
              typically 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 with the original unscaled pixel values.

       -E     Same as -D, but masked pixels are not cropped.

       -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.

       -g power toe_slope
              Set the gamma curve, by default BT.709 (-g 2.222 4.5).  If you
              prefer sRGB gamma, use -g 2.4 12.92.  For a simple power curve,
              set the toe slope to zero.

       -6     Write sixteen bits per sample instead of eight.

       -4     Linear 16-bit, same as -6 -W -g 1 1.

       -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
              specified 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),
       pnmtopng(1), gphoto2(1), cjpeg(1), djpeg(1)

AUTHOR
       Written by David Coffin, dcoffin a cybercom o net



                                 May 14, 2009                         dcraw(1)