dcraw

dcraw(1)                                                              dcraw(1)

NAME

       dcraw - convert raw digital photos to PPM format

SYNOPSIS

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

DESCRIPTION

       dcraw  converts  a  list  of raw digital camera files to ppm(5) format.
       Dozens of cameras are supported, and new ones are added as  they  reach
       the market.

OPTIONS

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

       -c     Write binary image data to standard output.  By  default,  dcraw
              creates files with a ".ppm" extension.

       -v     Print  verbose  messages.  Default is to print only warnings and
              errors.

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

       -q     Use  simple  bilinear  interpolation  for  quick  results.   The
              default is to use a slow, high-quality adaptive algorithm.

       -h     Half-size the output image.  Instead  of  interpolating,  reduce
              each 2x2 block of sensors to one pixel.  Much faster than -q.

       -f     Interpolate  RGB  as  four colors.  This causes a slight loss of
              detail, so use -f only if you see false  2x2  mesh  patterns  in
              blue sky.

       -a     Automatic  color  balance.   The default is to use a fixed color
              balance based on a white card photographed in sunlight.

       -w     Use the color balance specified by the camera.  If this can’t be
              found, dcraw prints a warning and reverts to the default.

       -r red_mul -l blue_mul
              Further adjust the color balance by multiplying the red and blue
              channels by these values.  Both default to 1.0.

       -b brightness
              Change the output brightness.  Default is 1.0.

       -s     For cameras based on the Fuji Super CCD SR,  use  the  secondary
              sensors,  in  effect  underexposing  the  image by four stops to
              reveal detail in the highlights.  For all other cameras,  -s  is
              silently ignored.

       -t [0-7]
              Flip  the output image.  The most common flips are 5 (90 degrees
              CCW) and 6 (90 degrees clockwise).  By default, dcraw  tries  to
              use  the  flip specified by the camera.  "-t 0" forces dcraw not
              to flip images.

       -2     Write eight bits per color value with  a  99th-percentile  white
              point  and  the standard 0.45 gamma curve.  Double the height if
              necessary to correct the aspect ratio.  This is the default.

       -4     Write sixteen bits per color value.  Output is linear with input
              -- no white point, no gamma, same aspect ratio.

       -3     Same  image  as  -4,  written  in  Adobe PhotoShop format.  File
              extension is ".psd".

SEE ALSO

       ppm(5), ppm2tiff(1), pnmtotiff(1), pnmtopng(1), gphoto2(1).

BUGS

       The -w option does not work with many cameras.

       No attempt is made to save camera settings or thumbnail images.

       Author stubbornly refuses to add more output formats.

       Don’t expect dcraw to produce the same images as software  provided  by
       the camera vendor.  Sometimes dcraw gives better results!

TIPS

       To  balance  the  color, do "dcraw -h -b 0.5" and select a rectangle of
       something that you know is white.  Compute the average R, G, and B val-
       ues for this area, then set red_mul and blue_mul to G/R and G/B.

AUTHOR

       Written by David Coffin, dcoffin a cybercom o net



                               January 19, 2005                       dcraw(1)