NAME
mrwtoppm - Convert Minolta DiMAGE 5/7/7Hi/7i/A1 RAW images to PPM
SYNOPSIS
mrwtoppm [-wb name | rgain:ggain:bgain] [-cmapPath pathlist]
[-darkfield mrwfile] [-darkfieldPath pathlist]
[-profilePath pathlist] [-cprofile name] [-scale scale]
[-imethod name] [-vtol val] [-Lab] [-noLab] [-vmf] [-novmf]
[-mfilter] [-nomfilter] [-blur val] [-isharp val] [-csharp val]
[-rotate angle] [-oprofile name] [-contrast val] [-gamma val]
[-tone name] [-tcPath pathlist] [-8] [-16] [-xvmini] < infile >
outfile
DESCRIPTION
mrwtoppm converts a Minolta DiMAGE 5/7/7i/7Hi/A1 RAW image read from its
standard input into a PPM image which is written to its standard output.
mrwtoppm first processes the system wide parameter file
(/usr/local/share/mrwtoppm/mrwtoppm.rc). Entries in this file (if it
exists) will override the compiled defaults.
mrwtoppm then processes the user’s parameter file
($HOME/.mrwtoppm/mrwtoppm.rc) if it exists. Entries in this file will
override both compiled defaults and entries in the system wide parameter
file.
mrwtoppm then processes command line options, which if given will
override compiled values and values set in the initialization files. The
program will then read a mrw file from its standard input, convert it as
specified, and write a PPM file to its standard output.
PROCESSING AND OPTIONS
1. The pixels input from the .mrw file are color corrected. The
algorithm is to multiply the input pixels by gain values for each
color. The default color balance is "camera", which uses the
color balance data the camera stored in the mrw file.
-wb name
Overrides the default color balance. The following color
balances are known to mrwtoppm: camera, daylight, flash,
cloudy, tungsten, flourescent, none, and preset6. None
does not balance the colors. The other color balances
are camera specific and are obtained from data stored in
the mrw file. Preset6 is a stored preset the meaning of
which is currently unknown.
-wb rgain:ggain:bgain
Manually override color balance. Red, green and blue
pixel values are multiplied by rgain/256, ggain/256 and
bgain/256 respectively.
-cmapPath pathlist
By default, color balances other than those listed above
are searched for in the following path list:
.:colormaps:$HOME/.mrwtoppm/colormaps:/usr/local/share/mrwtoppm/colormaps.
This list can be changed using this option.
2. The image is rotated by 0, 90, 180, or 270 degrees.
-rotate angle
Rotate image clockwise by angle degrees. The default is
0. The angle must be one of the above four values.
3. The image can be optionally be scaled by an even factor (N).
When the image is scaled bayer pattern interpolation is not
performed and output pixels are calculated simply by averaging
the same color pixels in N by N input blocks. If the scale does
not evenly divide the image size (that is, for scales other than
1, 2, 4, and 8) the final image size is rounded down, and the
excess input pixels are ignored. The selected pixels are centered
on the image center. The intent is to allow high-speed image
preview.
-scale scale
Divide image height and width each by scale. Legal
values are 1 (default, no scaling), 1/N for even N.
4. A dark field image, if any, is subtracted from the image data.
The dark field image must be an mrw file the same size as the
image data. It should be an image taken with the same ISO and
shutter speed as the image, but with the lens covered. The
intent is subtract the CCD "noise" caused by long exposure times.
Default is none.
-darkfield name
The dark field image is looked for in a file "name.mrw"
in the dark field path.
-darfieldpath pathlist
5. If the image is not scaled, the Bayer pattern data is
interpolated. The following algorithms are implemented:
· The vector median algorithm of Gupta and Chen (default).
· A simple bilinear interpolation scheme (faster but much lower
quality).
-imethod name
Select the interpolation method to use: bilinear,
vmedian (default), mgbrb, mgmrb.
-Lab Vector median interpolation and filtering is done in
CIELab color space (default).
-noLab Vector median interpolation and filtering is done in the
camera’s color space
-vtol value
Sets the error tolerance for the vector median algorithm
(larger is faster, but lower quality). The default is
fairly high quality.
6. (Experimental) A median of medians filter may be applied.
-mfilter
Apply median of medians filter.
-nomfilter
Do not apply median of medians filter (default).
7. The image’s tone curve is adjusted.
-tone name
Apply the named tone curve. Default is "minolta". The
tone curve "none" is just that.
-tcpath pathlist
Set the tone curve search path. The default tone curve
search path is
.:tonecurves:$HOME/.mrwtoppm/tonecurves:/usr/local/share/mrwtoppm/tonecurves.
8. An additional vector median filtering step may be performed.
-vmf Apply additional vector median filter.
-novmf Do not apply additional vector median filter (default)
9. The image may be sharpened or blurred. In Lab mode, the
luminance and chrominance channels can be sharpened/blurred
independently. Sharpening is done by unsharp masking.
-blur val
Determine convolution matrix used for blurring This is a
3x3 matrix having the following values:
1 1/val 1
1/val 1/val^2 1/val
1 1/val 1
The matrix is scaled so that the matrix elements sum to
1. Larger values cause more blurring. Default is 0.5.
-isharpen val
Sharpen pixels by val times the difference between the
original and blurred values. Negative values blur the
image. An amt of -1 replaces the pixel with the blurred
pixel generated above. In Lab mode, only the L channel
is affected. In RGB mode, all channels are affected.
Default is 2.
-csharpen val
In Lab mode only, sharpen/blur the two chrominance
channels by val. Default is -1.
10. The image is converted from the camera’s color space into the
output color space. The former defaults to the camera’s color
space, the latter to sRGB.
-cprofile name
Overrides the default camera profile.
-oprofile name
Overrides the default output profile.
-profilePath pathlist
Set the profile search path. The default tone curve
search path is
.:profiles:$HOME/.mrwtoppm/profiles:/usr/share/liblcms/profiles:/usr/share/mrwtoppm/profiles.
11. The image is further gamma corrected and contrast stretched.
-gamma val
Overrides the default gamma factor to correct for. The
default gamma to correct for is 1 (meaning no change).
-contrast val
Override the default contrast setting. The image is
contrast stretched so that the val/2000 largest color
values and the val/2000 smallest color values are output
as the maximum or minimum value respectively. The
default is 1. If the contrast value is 0, the color
values are only scaled such that the largest value is
output as the maximum value. If the contrast value is
negative, no contrast stretching is done.
12. The image is output as a raw PPM file or as an xv thumbnail. The
output file can contain either 8 or 16 bits per color per pixel.
-8 Output an 8 bit/color/pixel PPM file (default).
-16 Output a 16 bit/color/pixel PPM file.
-xvmini
Output an xv thumbnail file (8 bits total per pixel: 3
red, 3 green, 2 blue). Legal thumbnail files must be no
larger than 80x80. The user is responsible for selecting
a suitable scale factor for achieving this.
FILES
$HOME/.mwrtoppm/mrwtoppm.rc
The initialization file consist of a sequence of lines. Each
line sets one option. Option names are the same as the command
line options, except that the leading dash ("-") is omitted.
Options that take a parameter have the form option=value.
Options that do not have a parameter have the form option= (the
need for the = is a bug that will get squished later).
/usr/share/mrwtoppm/colormaps/
Location of colormaps used for color balance correction.
/usr/share/mrwtoppm/profiles
Location of camera profiles used for color space conversion.
/usr/share/mrwtoppm/tonecurves/
Location of tone curves used for tone curve adjustment.
SEE ALSO
mrwinfo(1), mrwguesswb(1), fixtc(1)
BUGS
Neither this program nor any others in the package take image files as
parameters. They all read the image from the standard input and write
their results (a PPM file in this case) to standard output.
Unfortunately, this causes new users lots of grief.
AUTHOR
mrwtoppm was written by Bradley Broom 〈dobroom@swbell.net〉.
This manual page was converted from mrwtoppm’s manual by Guus Sliepen
〈guus@sliepen.warande.net〉 for the Debian GNU/Linux system.