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Linux / Unix Command: mogrify
Command Library


mogrify - mogrify an image


mogrify [ options ... ] file ...


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).


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 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).

drawing transform matrix
remove pixel aliasing
the background color
-blur x
blur the image with a gaussian operator
-border x
surround the image with a border of color
the border color
megabytes of memory available to the pixel cache
the type of channel
simulate a charcoal drawing
colorize the image with the pen color
preferred number of colors in the image
the type of colorspace
annotate an image with a comment
the type of image compression
enhance or reduce the image contrast
-crop x{+-}{+-}{%}
preferred size and location of the cropped image
displace image colormap by amount
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 of the image
reduce the speckles within an image
specifies the X server to contact
GIF disposal method
apply Floyd/Steinberg error diffusion to the image
annotate an image with one or more graphic primitives
detect edges within an image
emboss an image
specify the font encoding
specify endianness (MSB or LSB) of output image
apply a digital filter to enhance a noisy image
perform histogram equalization to the image
color to use when filling a graphic primitive
use this type of filter when resizing an image
create a "mirror image"
create a "mirror image"
use this font when annotating the image with text
the image format type
-frame x++
surround the image with an ornamental border
-fuzz {%}
colors within this distance are considered equal
level of gamma correction
-gaussian x
blur the image with a gaussian operator
-geometry x{+-}{+-}{%}{@} {!}{<}{>}
preferred size and location of the Image window.
direction primitive gravitates to when annotating the image.
print usage instructions
implode image pixels about the center
the type of interlacing scheme
assign a label to an image
adjust the level of image contrast
the line width for subsequent draw operations
the type of list
add Netscape loop extension to your GIF animation
choose a particular set of colors from this image
Specify a clipping mask
store matte channel if the image has one
specify the matte color
apply a median filter to the image
vary the brightness, saturation, and hue of an image
transform the image to black and white
replace every pixel with its complementary color
add or reduce noise in an image
NOOP (no option)
transform image to span the full range of color values
change this color to the pen color within the image
-page x{+-}{+-}{%}{!}{<}{>}
size and location of an image canvas
simulate an oil painting
specify the pen color for drawing operations
pointsize of the Postscript, OPTION1, or TrueType font
add ICM, IPTC, or generic profile to image
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
scale image with pixel sampling
-sampling_factor x
sampling factors used by JPEG or MPEG-2 encoder and YUV decoder/encoder.
scale the image.
set scene number
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
negate all pixels above the threshold level
displace image pixels by a random amount
color to use when stroking a graphic primitive
set the stroke width
swirl image pixels about the center
name of texture to tile onto the image background
threshold the image
tile image when filling a graphic primitive
transform the image
make this color transparent within the image
tree depth for the color reduction algorithm
trim an image
the image type
the type of image resolution
-unsharp x
sharpen the image with an unsharp mask operator
print detailed information about the image
FlashPix viewing parameters
-wave x
alter an image along a sine wave

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


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.


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.

>> Linux/Unix Command Library

>> Shell Command Library

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