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dcraw - convert raw digital photos to PPM format
dcraw
[OPTION]... [FILE]...
dcraw converts raw digital photos to ppm(5)
format.
- -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 blurs the image a little, but it eliminates false 2x2
mesh patterns.
- -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.
- -n
- By default, dcraw clips all colors to prevent pink hues in the
highlights. Combine this option with -b 0.25 to leave the image data completely
unclipped.
- -m
- Write raw camera colors to the output file. By default, dcraw
converts to sRGB colorspace.
- -j
- For Fuji Super CCD cameras, show the image
tilted 45 degrees so that each output pixel corresponds to one raw pixel.
- -s
- For Fuji Super CCD SR cameras, use the secondary sensors, in effect underexposing
the image by four stops to reveal detail in the highlights.
- For all other
cameras,
- -j and -s are 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".
ppm(5)
, ppm2tiff(1)
, pnmtotiff(1)
, pnmtopng(1)
,
gphoto2(1)
.
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!
Written by David Coffin, dcoffin a cybercom o net
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