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.TH mogrify 1 "1 May 1994" "ImageMagick"
.SH NAME
mogrify - transform an image or sequence of images
.SH SYNOPSIS
.B "mogrify" [ \fIoptions\fP ...] \fIfile\fP
[ [ \fIoptions\fP ...] \fIfile\fP ...]
.SH DESCRIPTION
\fBmogrify\fP transforms an image or a sequence of images.  These
transforms include image scaling, image rotation, color reduction, and
others.  The transmogrified image overwrites the original image.
.SH EXAMPLES
To scale an image of a cockatoo to exactly 640 pixels in width and 480
pixels in height, use:
.PP
.B
    mogrify -geometry 640x480! cockatoo.miff
.PP
To create a single colormap for a sequence of bird images, use:
.PP
.B
    mogrify -colors 256 scenes/birds.*
.SH OPTIONS
.TP 5
.B "-blur"
blur the image.
.TP 5
.B "-border \fI<width>x<height>fP"
surround the image with a border or color.  See \fBX(1)\fP for details
about the geometry specification.

The color of the border is obtained from the X server and is defined as
\fBbordercolor\fP (class \fBborderColor\fP).  See \fBX(1)\fP for details.
.TP 5
.B "-colors \fIvalue\fP"
preferred number of colors in the image.

The actual number of colors in the image may be less than your request,
but never more.  Note, this is a color reduction option.  Images with
less unique colors than specified with this option will remain unchanged.
Refer to \fBquantize(9)\fP for more details.

If more than one image is specified on the command line, a single
colormap is created and saved with each image.

Note, options \fB-colormap\fP, \fB-dither\fP, \fB-colorspace\fP, and
\fB-treedepth\fP affect the color reduction algorithm.
.TP 5
.B "-colorspace \fIvalue\fP"
the type of colorspace: \fBGRAY\fP, \fBOHTA\fP, \fBRGB\fP, \fBXYZ\fP,
\fBYCbCr\fP, \fBYIQ\fP, \fBYPbPr\fP, or \fBYUV\fP.

Color reduction, by default, takes place in the RGB color space.
Empirical evidence suggests that distances in color spaces such as YUV
or YIQ correspond to perceptual color differences more closely
than do distances in RGB space.  These color spaces may give better
results when color reducing an image.  Refer to \fBquantize(9)\fP for
more details.

The \fB-colors\fP or \fB-monochrome\fP option is required
for this option to take effect.
.TP 5
.B "-comment \fIstring\fP"
annotate an image with a comment.

By default, each image is commented with its file name.  Use this
option to assign a specific comment to the image.  Optionally you can
include the image filename, type, width, height, or scene number by
embedding special format characters.  Embed \fB%f\fP for filename,
\fB%m\fP for magick, \fB%w\fP for width, \fB%h\fP for height, \fB%s\fP
for scene number, or \fB\\n\fP for newline.  For example,

.nf
     -comment "%m:%f %wx%h"
.fi

produces an image comment of \fBMIFF:bird.miff 512x480\fP for an image
titled \fBbird.miff\fP and whose width is 512 and height is 480.

If the first character of \fIstring\fP is \fB@\fP, the image comment is read
from a file titled by the remaining characters in the string.
.TP 5
.B "-compress \fItype\fP"
the type of image compression: \fIQEncoded\fP or \fIRunlengthEncoded\fP.

Specify \fB\+compress\fP to store the binary image in an uncompressed format.
The default is the compression type of the specified image file.
.TP 5
.B "-contrast"
enhance or reduce the image contrast.

This option enhances the intensity differences between the
lighter and darker elements of the image.  Use \fB-contrast\fP to
enhance the image or \fB+contrast\fP to reduce the image contrast.
.TP 5
.B "-crop \fI<width>x<height>{\+-}<x offset>{\+-}<y offset>\fP"
preferred size and location of the cropped image.  See \fBX(1)\fP for details
about the geometry specification.

Use cropping to apply image processing options, or transmogrify, only a
particular area of an image.   Use \fB-crop 0x0\fP to remove edges that are
the background color.
.TP 5
.B "-density \fI<width>x<height>\fP
vertical and horizontal density of the image.

This option specifies an image density for a Postscript page.
The default is 72 dots per inch in the horizontal and vertical direction.
Use this option to alter the default density.
.TP 5
.B "-despeckle"
reduce the speckles within an image.
.TP 5
.B "-display \fIhost:display[.screen]\fP"
specifies the X server to contact; see \fBX(1)\fP.
.TP 5
.B "-dither"
apply Floyd/Steinberg error diffusion to the image.

The basic strategy of dithering is to trade intensity resolution for
spatial resolution by averaging the intensities of several neighboring
pixels.  Images which suffer from severe contouring when reducing colors
can be improved with this option.

The \fB-colors\fP or \fB-monochrome\fP option is required for this option
to take effect.
.TP 5
.B "-edge"
detect edges within an image.
.TP 5
.B "-enhance"
apply a digital filter to enhance a noisy image.
.TP 5
.B "-equalize"
perform histogram equalization to the image.
.TP 5
.B "-flip"
create a "mirror image" by reflecting the image scanlines in the vertical
direction.
.TP 5
.B "-flop"
create a "mirror image" by reflecting the image scanlines in the horizontal
direction.
.TP 5
.B "-gamma \fIvalue\fP"
level of gamma correction.

The same color image displayed on two different workstations may look
different due to differences in the display monitor.  Use gamma
correction to adjust for this color difference.  Reasonable values
extend from 0.8 to 2.3.

You can apply separate gamma values to the red, green, and blue
channels of the image with a gamma value list delineated with commas
(i.e. 1.7,2.3,1.2).
.TP 5
.B "-font \fIname\fP"
This option specifies the font to be used  for displaying normal text.
The default is \fBfixed\fP.
.TP 5
.B "-geometry \fI<width>{%}x<height>{%}{!}"
preferred width and height of the image.  See \fBX(1)\fP for details
about the geometry specification.

By default, the width and height are maximum values.  That is, the
image is expanded or contracted to fit the width and height value while
maintaining the aspect ratio of the image.  Append an exclamation point
to the geometry to force the image size to exactly the size you
specify.  For example, if you specify \fB640x480!\fP the image width is
set to 640 pixels and height to 480.  If only one factor is
specified, both the width and height assume the value. 

To specify a percentage width or height instead, append \fB%\fP.  The
image size is multiplied by the width and height percentages to obtain
the final image dimensions.  To increase the size of an image, use a
value greater than 100 (e.g. 125%).  To decrease an image's size, use a
percentage less than 100.
.TP 5
.B "-interlace \fItype\fP"
the type of interlacing scheme: \fBNONE\fP, \fBLINE\fP, or \fBPLANE\fP.

This option is used to specify the type of interlacing scheme for raw
image formats such as \fBRGB\fP or \fBYUV\fP.  \fBNONE\fP means do not
interlace (RGBRGBRGBRGBRGBRGB...), \fBLINE\fP uses scanline
interlacing (RRR...GGG...BBB...RRR...GGG...BBB...), and \fBPLANE\fP uses
plane interlacing (RRRRRR...GGGGGG...BBBBBB...).
.B "-label \fIname\fP"
assign a label to an image.

Use this option to assign a specific label to the image.  Optionally
you can include the image filename, type, width, height, or scene
number in the label by embedding special format characters.   Embed
\fB%f\fP for filename, \fB%m\fP for magick, \fB%w\fP for width,
\fB%h\fP for height, or \fB%s\fP for scene number.  For example,
.nf
     -label "%m:%f %wx%h"
.fi
produces an image label of \fBMIFF:bird.miff 512x480\fP for an image
titled \fBbird.miff\fP and whose width is 512 and height is 480.

If the first character of \fIstring\fP is \fB@\fP, the image label is read
from a file titled by the remaining characters in the string.
 
When converting to Postscript, use this option to specify a header string
to print above the image.
.TP 5
.B "-map \fIfilename\fP"
choose a particular set of colors from this image.

By default, color reduction chooses an optimal set of colors that
best represent the original image.  Alternatively, you can choose a
particular set of colors with this option.  This is useful when
you want to create a sequence of images with one particular set of
colors for each image.
.TP 5
.B "-modulate \fIvalue\fP"
vary the brightness, saturation, and hue of an image.

Specify the percent change in brightness, the color saturation, and the color
hue separated by commas.  For example, to increase the color brightness
by 20% and decrease the color saturation by 10% and leave the hue unchanged,
use: \fB-modulate 20,-10\fP.
.TP 5
.B "-monochrome"
transform the image to black and white.
.TP 5
.B "-negate"
apply color inversion to image.

The red, green, and blue intensities of an image are negated.
.TP 5
.B "-noise"
reduce the noise in an image with a noise peak elimination filter.

The principal function of noise peak elimination filter is to smooth
the objects within an image without losing edge information and without
creating undesired structures.  The central idea of the algorithm is to
replace a pixel with its next neighbor in value within a 3 x 3 window,
if this pixel has been found to be noise.  A pixel is defined as noise
if and only if this pixel is a maximum or minimum within the 3 x 3 window.
.TP 5
.B "-normalize"
transform image to span the full range of color values.

This is a contrast enhancement technique.
.TP 5
.B "-page \fI<width>x<height>{\+-}<x offset>{\+-}<y offset>\fP"
preferred size and location of the Postscript page.

Use this option to specify the dimensions of the Postscript page in
picas or a TEXT page in pixels.  The default for a Postscript page is
to center the image on a letter page 612 by 792 dots per inch.  The
left and right margins are 18 picas and the top and bottom 94 picas
(i.e.  612x792+36+36).  Other common sizes are:

    540x720   Note
    612x1008  Legal
    842x1190  A3
    595x842   A4
    421x595   A5
    297x421   A6
    709x1002  B4
    612x936   U.S. Foolscap
    612x936   European Foolscap
    396x612   Half Letter
    792x1224  11x17
    1224x792  Ledger

The page geometry is relative to the vertical and horizontal density of the
Postscript page.  See \fB-density\fP for details.

The default page dimensions for a TEXT image is 612x792+36+36.
.TP 5
.B "-quality \fIvalue\fP"
JPEG quality setting.

Quality is 0 (worst) to 100 (best). The default is 85.
.TP 5
.B "-roll \fI{\+-}<x offset>{\+-}<y offset>\fP"
roll an image vertically or horizontally.  See \fBX(1)\fP for details
about the geometry specification.
 
A negative \fIx offset\fP rolls the image left-to-right.  A negative
\fIy offset\fP rolls the image top-to-bottom.
.TP 5
.B "-rotate \fIdegrees\fP"
apply Paeth image rotation to the image.

Empty triangles left over from rotating the image are filled with
the color defined as \fBbordercolor\fP (class \fBborderColor\fP).
See \fBX(1)\fP for details.
.TP 5
.B "-scene \fIvalue\fP"
image scene number.
.TP 5
.B "-sharpen"
sharpen the image.
.TP 5
.B "-shear \fI<x degrees>x<y degrees>\fP"
shear the image along the X or Y axis by a positive or negative shear angle.

Shearing slides one edge of an image along the X or Y axis, creating a
parallelogram.  An X direction shear slides an edge along the X axis,
while a Y direction shear slides an edge along the Y axis.  The amount
of the shear is controlled by a shear angle.  For X direction shears,
\fIx degrees>\fP is measured relative to the Y axis, and similarly, for
Y direction shears \fIy degrees\fP is measured relative to the X axis.

Empty triangles left over from shearing the image are filled with
the color defined as \fBbordercolor\fP (class \fBborderColor\fP).
See \fBX(1)\fP for details.
.TP 5
.B "-size \fI<width>{%}x<height>{%}{+colors}{!}"
width and height of the image.

Use this option to specify the width and height of raw images whose
dimensions are unknown such as \fBGRAY\fP, \fBRGB\fP, or \fBCMYK\fP.
In addition to width and height, use \fB-size\fP to tell the number
of colors in a \fBMAP\fP image file, (e.g. -size 640x512+256).
.TP 5
.B "-treedepth \fIvalue\fP"
Normally, this integer value is zero or one.  A zero or one tells
\fBmogrify\fP to choose a optimal tree depth for the color reduction
algorithm.

An optimal depth generally allows the best representation of the source
image with the fastest computational speed and the least amount of
memory.  However, the default depth is inappropriate for some images.
To assure the best representation, try values between 2 and 8 for this
parameter.  Refer to \fBquantize(9)\fP for more details.

The \fB-colors\fP or \fB-monochrome\fP option is required for this option
to take effect.
.TP 5
.B "-undercolor \fI<undercolor factor>x<black-generation factor>\fP"
control undercolor removal and black generation on CMYK images.

This option enables you to perform undercolor removal and black
generation on CMYK images-- images to be printed on a four-color
printing system. You can control how much cyan, magenta, and yellow
to remove from your image and how much black to add to it.
The standard undercolor removal is \fB1.0x1.0\fP.  You'll
frequently get better results, though, if the percentage of black you
add to your image is slightly higher than the percentage of C, M, and Y
you remove from it.  For example you might try \fB0.5x0.7\fP.
.TP 5
.B -verbose
print detailed information about the image.

This information is printed: image scene number;  image name;  image
size; the image class (\fIDirectClass\fP or \fIPseudoClass\fP); the total
number of unique colors (if known);  and the number of seconds to read and
transform the image.  Refer to \fBmiff(5)\fP for a description of
the image class.

If \fB-colors\fP is also specified, the total unique colors in the image
and color reduction error values are printed.  Refer to \fBquantize(9)\fP
for a description of these values.
.PP
Options are processed in command line order.
Any option you specify on the command line remains in effect until it is
explicitly changed by specifying the option again with a different effect.
For example, to mogrify two images, the first with 32 colors and the
second with only 16 colors, use:
.PP
     mogrify -colors 32 cockatoo.miff -colors 16 macaw.miff
.PP
Change \fI-\fP to \fI\+\fP in any option above to reverse its effect.
For example, specify \fB\+compress\fP to store the binary image in an
uncompressed format.
.PP
By default, the image format is determined by its magic number. To
specify a particular image format, precede the filename with an image
format name and a colon (i.e. ps:image) or specify the image type as
the filename suffix (i.e. image.ps).  See \fBconvert(1)\fP for a list
of valid image formats.
.PP
Specify \fIfile\fP as \fI-\fP for standard input and output.  If
\fIfile\fP has the extension \fB.Z\fP or \fB.gz\fP, the file is
uncompressed with \fBuncompress\fP or \fBgunzip\fP respectively and
subsequently compressed using with \fBcompress\fP or \fBgzip\fP.
Finally, precede the image file name with \fI|\fP to pipe to or from a
system command.
.PP
Use an optional index enclosed in brackets after a file name to specify
a desired subimage of a multi-resolution image format like Photo CD
(e.g. img0001.pcd[4]).
.SH SEE ALSO
.B
display(1), animate(1), import(1), montage(1), convert(1),
segment(1), combine(1), xtp(1)
.SH COPYRIGHT
Copyright 1994 E. I. du Pont de Nemours and Company
.PP
Permission to use, copy, modify, distribute, and sell this software and
its documentation for any purpose is hereby granted without fee,
provided that the above copyright notice appear in all copies and that
both that copyright notice and this permission notice appear in
supporting documentation, and that the name of E. I. du Pont de Nemours
and Company not be used in advertising or publicity pertaining to
distribution of the software without specific, written prior
permission.  E. I. du Pont de Nemours and Company makes no representations
about the suitability of this software for any purpose.  It is provided
"as is" without express or implied warranty.
.PP
E. I. du Pont de Nemours and Company disclaims all warranties with regard
to this software, including all implied warranties of merchantability
and fitness, in no event shall E. I. du Pont de Nemours and Company be
liable for any special, indirect or consequential damages or any
damages whatsoever resulting from loss of use, data or profits, whether
in an action of contract, negligence or other tortuous action, arising
out of or in connection with the use or performance of this software.
.SH ACKNOWLEDGEMENTS
Michael Halle, Spatial Imaging Group at MIT, for the initial
implementation of Alan Paeth's image rotation algorithm.
.PP
David Pensak, E. I. du Pont de Nemours and Company, for providing a
computing environment that made this program possible.
.PP
Paul Raveling, USC Information Sciences Institute, for the original
idea of using space subdivision for the color reduction algorithm.
.SH AUTHORS
John Cristy, E.I. du Pont de Nemours and Company Incorporated
