1. Computing
Linux / Unix Command: mogrify
Command Library

NAME

mogrify - mogrify an image

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. The transmogrified image overwrites the 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).

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:


convert -size 120x120 *.jpg -resize 120x120 +profile '*'

In this example, "-i 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. 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

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
drawing transform matrix
-antialias
remove pixel aliasing
-background
the background color
-blur x
blur the image with a gaussian operator
-border x
surround the image with a border of color
-bordercolor
the border color
-cache
megabytes of memory available to the pixel cache
-channel
the type of channel
-charcoal
simulate a charcoal drawing
-colorize
colorize the image with the pen color
-colors
preferred number of colors in the image
-colorspace
the type of colorspace
-comment
annotate an image with a comment
-compress
the type of image compression
-contrast
enhance or reduce the image contrast
-crop x{+-}{+-}{%}
preferred size and location of the cropped image
-cycle
displace image colormap by amount
-debug
enable debug printout
-delay <1/100ths of a second>
display the next image after pausing
-density x
vertical and horizontal resolution in pixels of the image
-depth
depth of the image
-despeckle
reduce the speckles within an image
-display
specifies the X server to contact
-dispose
GIF disposal method
-dither
apply Floyd/Steinberg error diffusion to the image
-draw
annotate an image with one or more graphic primitives
-edge
detect edges within an image
-emboss
emboss an image
-encoding
specify the font encoding
-endian
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
-fill
color to use when filling a graphic primitive
-filter
use this type of filter when resizing an image
-flip
create a "mirror image"
-flop
create a "mirror image"
-font
use this font when annotating the image with text
-format
the image format type
-frame x++
surround the image with an ornamental border
-fuzz {%}
colors within this distance are considered equal
-gamma
level of gamma correction
-gaussian x
blur the image with a gaussian operator
-geometry x{+-}{+-}{%}{@} {!}{<}{>}
preferred size and location of the Image window.
-gravity
direction primitive gravitates to when annotating the image.
-help
print usage instructions
-implode
implode image pixels about the center
-interlace
the type of interlacing scheme
-label
assign a label to an image
-level
adjust the level of image contrast
-linewidth
the line width for subsequent draw operations
-list
the type of list
-loop
add Netscape loop extension to your GIF animation
-map
choose a particular set of colors from this image
-mask
Specify a clipping mask
-matte
store matte channel if the image has one
-mattecolor
specify the matte color
-median
apply a median filter to the image
-modulate
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
add or reduce noise in an image
-noop
NOOP (no option)
-normalize
transform image to span the full range of color values
-opaque
change this color to the pen color within the image
-page x{+-}{+-}{%}{!}{<}{>}
size and location of an image canvas
-paint
simulate an oil painting
-pen
specify the pen color for drawing operations
-pointsize
pointsize of the Postscript, OPTION1, or TrueType font
-profile
add ICM, IPTC, or generic profile to image
-quality
JPEG/MIFF/PNG compression level
-raise x
lighten or darken image edges
-region x{+-}{+-}
apply options to a portion of the image
-resize x{%}{@}{!}{<}{>}
resize an image
-roll {+-}{+-}
roll an image vertically or horizontally
-rotate {<}{>}
apply Paeth image rotation to the image
-sample
scale image with pixel sampling
-sampling_factor x
sampling factors used by JPEG or MPEG-2 encoder and YUV decoder/encoder.
-scale
scale the image.
-scene
set scene number
-seed
pseudo-random number generator seed value
-segment x
segment an image
-shade x
shade the image using a distant light source
-sharpen x
sharpen the image
-shave x
shave pixels from the image edges
-shear x
shear the image along the X or Y axis
-size x{+offset}
width and height of the image
-solarize
negate all pixels above the threshold level
-spread
displace image pixels by a random amount
-stroke
color to use when stroking a graphic primitive
-strokewidth
set the stroke width
-swirl
swirl image pixels about the center
-texture
name of texture to tile onto the image background
-threshold
threshold the image
-tile
tile image when filling a graphic primitive
-transform
transform the image
-transparent
make this color transparent within the image
-treedepth
tree depth for the color reduction algorithm
-trim
trim an image
-type
the image type
-units
the type of image resolution
-unsharp x
sharpen the image with an unsharp mask operator
-verbose
print detailed information about the image
-view
FlashPix viewing parameters
-wave x
alter an image along a sine wave

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

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.

SEE ALSO

display(1), animate(1), identify(1), montage(1), convert(1), ImageMagick(1), composite(1)


Important: Use the man command (% man) to see how a command is used on your particular computer.

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