ImageMagick - Mogrify an Image

NAME

mogrify - mogrify an image

Contents

Synopsis
Description
Examples
Options
Image Segmentation
Environment
Authors
Copyright

Synopsis

mogrify [ options ... ] file ...

Description

Mogrify transforms an image or a sequence of images. These transforms include image scaling, image rotation, color reduction, and others. Each transmogrified image overwrites the corresponding original image, unless an option such as -format causes the output filename to be different from the input filename.

The graphics formats supported by mogrify are listed in ImageMagick(1).

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Examples

To convert all the TIFF files in a particular directory to JPEG, use:

    mogrify -format jpeg *.tiff

To convert a directory full of JPEG images to thumbnails, use:

    mogrify -size 120x120 *.jpg -resize 120x120 +profile "*"

In this example, '-size 120x120' gives a hint to the JPEG decoder that the images are going to be downscaled to 120x120, allowing it to run faster by avoiding returning full-resolution images to ImageMagick for the subsequent resizing operation. The '-resize 120x120' specifies the desired dimensions of the output images. It will be scaled so its largest dimension is 120 pixels. The '+profile "*"' removes any ICM, EXIF, IPTC, or other profiles that might be present in the input and aren't needed in the thumbnails.

To scale an image of a cockatoo to exactly 640 pixels in width and 480 pixels in height, use:

    mogrify -resize 640x480! cockatoo.miff

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Options

Options are processed in command line order. Any option you specify on the command line remains in effect for the set of images that follows, until the set is terminated by the appearance of any option or -noop.

For a more detailed description of each option, see ImageMagick(1).

-affine <matrix>

drawing transformation matrix

-antialias

remove pixel aliasing

-authenticate <string>

decrypt image with this password

-background <color>

the background color

-blue-primary <x>,<y>

blue chromaticity primary point

-blur <radius>{x<sigma>}

blur the image with a Gaussian operator

-border <width>x<height>

surround the image with a border of color

-bordercolor <color>

the border color

-cache <threshold>

(This option has been replaced by the -limit option)

-channel <type>

the type of channel

-charcoal <factor>

simulate a charcoal drawing

-colorize <value>

colorize the image with the pen color

-colors <value>

preferred number of colors in the image

-colorspace <value>

the type of colorspace

-comment <string>

annotate an image with a comment

-compose <operator>

the type of image composition

-compress <type>

the type of image compression

-contrast

enhance or reduce the image contrast

-convolve <kernel>

convolve image with the specified convolution kernel

-crop <width>x<height>{+-}<x>{+-}<y>{%}

preferred size and location of the cropped image

-cycle <amount>

displace image colormap by amount

-debug <events>

enable debug printout

-delay <1/100ths of a second>

display the next image after pausing

-density <width>x<height>

vertical and horizontal resolution in pixels of the image

-depth <value>

depth of the image

-despeckle

reduce the speckles within an image

-display <host:display[.screen]>

specifies the X server to contact

-dispose <method>

GIF disposal method

-dither

apply Floyd/Steinberg error diffusion to the image

-draw <string>

annotate an image with one or more graphic primitives

-edge <radius>

detect edges within an image

-emboss <radius>

emboss an image

-encoding <type>

specify the text encoding

-endian <type>

specify endianness (MSB or LSB) of output image

-enhance

apply a digital filter to enhance a noisy image

-equalize

perform histogram equalization to the image

-extract <width>x<height>{+-}<x>{+-}<y>{%}{@} {!}{<}{>}

extract an area from the image while decoding

-fill <color>

color to use when filling a graphic primitive

-filter <type>

use this type of filter when resizing an image

-flip

create a "mirror image"

-flop

create a "mirror image"

-font <name>

use this font when annotating the image with text

-format <type>

the image format type

-frame <width>x<height>+<outer bevel width>+<inner bevel width>

surround the image with an ornamental border

-fuzz <distance>{%}

colors within this distance are considered equal

-gamma <value>

level of gamma correction

-Gaussian <radius>{x<sigma>}

blur the image with a Gaussian operator

-geometry <width>x<height>{+-}<x>{+-}<y>{%}{@} {!}{<}{>}

preferred size and location of the Image window.

-gravity <type>

direction primitive gravitates to when annotating the image.

-green-primary <x>,<y>

green chromaticity primary point

-help

print usage instructions

-implode <factor>

implode image pixels about the center

-interlace <type>

the type of interlacing scheme

-label <name>

assign a label to an image

-lat <width>x<height>{+-}<offset>{%}

perform local adaptive thresholding

-level <black_point>{,<white_point>}{%}{,<gamma>}

adjust the level of image contrast

-limit <type> <value>

Disk, File, Map, or Memory resource limit

-linewidth

the line width for subsequent draw operations

-list <type>

the type of list

-log <string>

-loop <iterations>

add Netscape loop extension to your GIF animation

-map <filename>

choose a particular set of colors from this image

-mask <filename>

Specify a clipping mask

-matte

store matte channel if the image has one

-mattecolor <color>

specify the color to be used with the -frame option

-median <radius>

apply a median filter to the image

-modulate <value>

vary the brightness, saturation, and hue of an image

-monochrome

transform the image to black and white

-negate

replace every pixel with its complementary color

-noise <radius|type>

add or reduce noise in an image

-noop

NOOP (no option)

-normalize

transform image to span the full range of color values

-opaque <color>

change this color to the pen color within the image

-page <width>x<height>{+-}<x>{+-}<y>{%}{!}{<}{>}

size and location of an image canvas

-paint <radius>

simulate an oil painting

-pen <color>

(This option has been replaced by the -fill option)

-pointsize <value>

pointsize of the PostScript, OPTION1, or TrueType font

-profile <filename>

add ICM, IPTC, or generic profile to image

-quality <value>

JPEG/MIFF/PNG compression level

-raise <width>x<height>

lighten or darken image edges

-red-primary <x>,<y>

red chromaticity primary point

-region <width>x<height>{+-}<x>{+-}<y>

apply options to a portion of the image

-render

render vector operations

-resize <width>x<height>{%}{@}{!}{<}{>}

resize an image

-roll {+-}<x>{+-}<y>

roll an image vertically or horizontally

-rotate <degrees>{<}{>}

apply Paeth image rotation to the image

-sample <geometry>

scale image with pixel sampling

-sampling-factor <horizontal_factor>x<vertical_factor>

sampling factors used by JPEG or MPEG-2 encoder and YUV decoder/encoder.

-scale <geometry>

scale the image.

-scene <value>

set scene number

-seed <value>

pseudo-random number generator seed value

-segment <cluster threshold>x<smoothing threshold>

segment an image

-shade <azimuth>x<elevation>

shade the image using a distant light source

-sharpen <radius>{x<sigma>}

sharpen the image

-shave <width>x<height>{%}

shave pixels from the image edges

-shear <x degrees>x<y degrees>

shear the image along the X or Y axis

-size <width>x<height>{+offset}

width and height of the image

-solarize <factor>

negate all pixels above the threshold level

-spread <amount>

displace image pixels by a random amount

-stroke <color>

color to use when stroking a graphic primitive

-strokewidth <value>

set the stroke width

-swirl <degrees>

swirl image pixels about the center

-texture <filename>

name of texture to tile onto the image background

-threshold <value>{<green>,<blue>,<opacity>}{%}

threshold the image

-tile <filename>

tile image when filling a graphic primitive

-transform

transform the image

-transparent <color>

make this color transparent within the image

-treedepth <value>

tree depth for the color reduction algorithm

-trim

trim an image

-type <type>

the image type

-units <type>

the type of image resolution

-unsharp <radius>{x<sigma>}{+<amount>}{+<threshold>}

sharpen the image with an unsharp mask operator

-verbose

print detailed information about the image

-version

print ImageMagick version string

-view <string>

FlashPix viewing parameters

-virtual-pixel <method>

specify contents of "virtual pixels"

-wave <amplitude>x<wavelength>

alter an image along a sine wave

-white-point <x>,<y>

chromaticity white point

For a more detailed description of each option, see ImageMagick(1).

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Image Segmentation

Use -segment to segment an image by analyzing the histograms of the color components and identifying units that are homogeneous with the fuzzy c-means technique. The scale-space filter analyzes the histograms of the three color components of the image and identifies a set of classes. The extents of each class is used to coarsely segment the image with thresholding. The color associated with each class is determined by the mean color of all pixels within the extents of a particular class. Finally, any unclassified pixels are assigned to the closest class with the fuzzy c-means technique.

The fuzzy c-Means algorithm can be summarized as follows:

Build a histogram, one for each color component of the image.
For each histogram, successively apply the scale-space filter and build an interval tree of zero crossings in the second derivative at each scale. Analyze this scale-space "fingerprint" to determine which peaks or valleys in the histogram are most predominant.
The fingerprint defines intervals on the axis of the histogram. Each interval contains either a minima or a maxima in the original signal. If each color component lies within the maxima interval, that pixel is considered "classified" and is assigned an unique class number.
Any pixel that fails to be classified in the above thresholding pass is classified using the fuzzy c-Means technique. It is assigned to one of the classes discovered in the histogram analysis phase.

The fuzzy c-Means technique attempts to cluster a pixel by finding the local minima of the generalized within group sum of squared error objective function. A pixel is assigned to the closest class of which the fuzzy membership has a maximum value.

For additional information see:

Young Won Lim, Sang Uk Lee, ``On The Color Image Segmentation Algorithm Based on the Thresholding and the Fuzzy c-Means Techniques'', Pattern Recognition, Volume 23, Number 9, pages 935-952, 1990.

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Environment

DISPLAY

To get the default host, display number, and screen.

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Authors

John Cristy, magick-users@imagemagick.org, ImageMagick Studio LLC,
Glenn Randers-Pehrson, randeg@alum.rpi.edu, ImageMagick Studio LLC.

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Copyright

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files ("ImageMagick"), to deal in ImageMagick without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of ImageMagick, and to permit persons to whom the ImageMagick is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of ImageMagick.

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