- -blur factor
- blurs an image. Specify factor as the percent
enhancement (0.0 - 99.9%).
- -border <width>x<height>
- surround the image with a border of color. See X(1)
for details about the geometry specification.
- The color of the border is obtained from the X server
and is defined as bordercolor (class borderColor). See
X(1) for details.
- -box color
- set the color of the annotation bounding box. See -draw
for further details.
- -charcoal factor
- simulate a charcoal drawing.
- See \fBX(1)\fP for details about the color specification.
- -colorize value
- colorize the image with the pen color.
- Specify the amount of colorization as a percentage. You can apply
separate colorization values to the red, green, and blue channels of the
image with a colorization value list delineated with slashes (e.g. 0/0/50).
- -colors value
- 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 have any duplicate
or unused colors removed.
Refer to quantize(9) 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 -colormap, -dither, -colorspace, and
-treedepth affect the color reduction algorithm.
- -colorspace value
- the type of colorspace: GRAY, OHTA, RGB,
Transparent, XYZ, YCbCr, YIQ, YPbPr,
YUV, or CMYK.
- 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
quantize for more details.
The Transparent color space behaves uniquely in that it preserves
the matte channel of the image if it exists.
- The -colors or -monochrome option is required for this
option to take effect.
- -comment string
- 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 %f for filename,
%d for directory, %e for filename extention, %t for
top of filename, %m for magick, %w for width, %h for
height, %s for scene number, or \n for newline. For example,
-comment "%m:%f %wx%h"
- produces an image comment of MIFF:bird.miff 512x480 for
an image titled bird.miff and whose width is 512 and
height is 480.
- If the first character of string is @, the image
comment is read from a file titled by the remaining
characters in the string.
- -compress type
- the type of image compression: None, JPEG, LZW,
RunlengthEncoded or Zip.
- Specify +compress to store the binary image in an
uncompressed format. The default is the compression
type of the specified image file.
- -contrast
- enhance or reduce the image contrast.
- This option enhances the intensity differences between
the lighter and darker elements of the image. Use
-contrast to enhance the image or +contrast to reduce
the image contrast.
- -crop <width>{%}x<height>{%}{+-}<x offset>{+-}<y offset>
- preferred size and location of the cropped image. See
X(1) for details about the geometry specification.
- To specify a percentage width or height instead, append
%. For example to crop the image by ten percent on all
sides of the image, use -crop 10%.
- Use cropping to apply image processing options, or
transmogrify, only a particular area of an image. Use
-crop 0x0 to remove edges that are the background
color. Omit the x and y offset
to generate one or more subimages of a uniform size.
- -cycle amount
- displace image colormap by amount.
- Amount defines the number of positions each colormap entry is
shifted.
- -delay <1/100ths of a second>
- display the next image after pausing.
This option is useful for regulating the animation of
GIF images within Netscape.. 1/100ths of a second must
expire before the display of the next image. The
default is no delay between each showing of the image sequence.
The maximum delay is 65535.
- -density <width>x<height>
- vertical and horizontal resolution in pixels of the image.
- This option specifies an image density when decoding a
Postscript or Portable Document page. The default is
72 pixels per inch in the horizontal and vertical
direction. This option is used in concert with -page.
- -despeckle
- reduce the speckles within an image.
- -display host:display[.screen]
specifies the X server to contact; see X(1).
- -dispose method
- GIF disposal method.
- Here are the valid methods:
0 No disposal specified.
1 Do not dispose.
2 Restore to background color.
3 Restore to previous.
- -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 -colors or -monochrome option is required for this
option to take effect.
- -draw string
- annotate an image with one or more graphic primitives.
- Use this option to annotate an image with one or more graphic primitives.
The primitives include
point
line
rectangle
fillRectangle
circle
fillCircle
polygon
fillPolygon
color
matte
text
image
- Point, line, color, matte, text, and
image each require a single coordinate. Line requires a
start and end coordinate, while rectangle expects an upper left
and lower right coordinate. Circle has a center coordinate and a
coordinate on the outer edge. Finally, polygon requires three or
more coordinates defining its boundaries. Coordinates are integers
separated by an optional comma. For example, to define a circle
centered at 100,100 that extends to 150,150 use:
-draw 'circle 100,100 150,150'
- Use color to change the color of a pixel. Follow the
pixel coordinate with a method:
point
replace
floodfill
reset
- Consider the target pixel as that specified by your coordinate. The
point method recolors the target pixel. The replace method
recolors any pixel that matches the color of the target pixel.
Floodfill recolors any pixel that matches the color of the target
pixel and is a neighbor. Finally, reset recolors all pixels.
- Use matte to the change the pixel matte value to transparent.
Follow the pixel coordinate with a method (see the color
primitive for a description of methods). The point method
changes the matte value of the target pixel. The replace method
changes the matte value of any pixel that matches the color of the
target pixel. Floodfill changes the matte value of any pixel
that matches the color of the target pixel and is a neighbor. Finally
reset changes the matte value of all pixels.
- Use text to annotate an image with text. Follow the
text coordinates with a string. If the string has embedded spaces,
enclose it in double quotes. Optionally you can
include the image filename, type, width, height, or scene number by
embedding special format characters. Embed %f for filename,
%d for directory, %e for filename extention, %t for
top of filename, %m for magick, %w for width, %h for
height, %s for scene number, or \n for newline. For example,
-draw 'text 100,100 "%m:%f %wx%h"'
Use image to composite an image with another image. Follow the
image coordinates with the filename of an image.
annotates the image with MIFF:bird.miff 512x480 for an image
titled bird.miff and whose width is 512 and height is 480.
You can set the primitive color, font color, and font bounding box color with
-pen, -font, and -box respectively. Options are
processed in command line order so be sure to use -pen
before the -draw option.
- If the first character of string is @, the text is read
from a file titled by the remaining characters in the string.
- -edge factor
- detect edges within an image. Specify factor as the percent
enhancement (0.0 - 99.9%).
- -emboss
- emboss the image.
- -enhance
- apply a digital filter to enhance a noisy image.
- -equalize
- perform histogram equalization to the image.
- -flip
- create a "mirror image" by reflecting the image
scanlines in the vertical direction.
- -flop
- create a "mirror image" by reflecting the image
scanlines in the horizontal direction.
- -format type
- the image format type.
- This option will convert any image to the image format
you specify. See convert(1) for a list of image format
types supported by ImageMagick.
- By default the file is written to its original name.
However, if the filename extension matches a supported
format, the extension is replaced with the image format
type specified with -format. For example, if you specify tiff as
the format type and the input image filename is image.gif,
the output image filename becomes image.tiff.
- -font name
- use this font when annotating the image with text.
- If the font is a fully qualified X server font name, the font is obtained
from an X server (e.g.
-*-helvetica-medium-r-*-*-12-*-*-*-*-*-iso8859-*). To
use a TrueType font, precede the TrueType filename with a @ (e.g.
@times.ttf). Otherwise, specify a Postscript font (e.g.
helvetica).
- -frame <width>x<height>+<outer bevel width>+<inner bevel width>
- surround the image with an ornamental border. See
X(1) for details about the geometry specification.
- The color of the border is specified with the
-mattecolor command line option.
- -gamma value
- 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 slashes (i.e. 1.7/2.3/1.2).
- Use +gamma to set the image gamma level without actually adjusting
the image pixels. This option is useful if the image is of a known
gamma but not set as an image attribute (e.g. PNG images).
- -geometry <width>{%}x<height>{%}{!}{<}{>}
- preferred width and height of the image. See X(1) 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 640x480! 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
%. 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.
- Use > to change the dimensions of the image
only if its size exceeds the geometry
specification. < resizes the image only
if its dimensions is less than the geometry specification.
For example, if you specify 640x480> and the image
size is 512x512, the image size does not change. However, if
the image is 1024x1024, it is resized to 640x480.
- -implode amount
- implode image pixels about the center. Specify factor as the
percent implosion (0 - 99.9%) or explosion (-99.9 - 0%).
- -interlace type
- the type of interlacing scheme: None, Line, Plane,
or Partition. The default is None.
- This option is used to specify the type of interlacing scheme for raw
image formats such as RGB or YUV. None means do not
interlace (RGBRGBRGBRGBRGBRGB...), Line uses scanline interlacing
(RRR...GGG...BBB...RRR...GGG...BBB...), and Plane uses plane
interlacing (RRRRRR...GGGGGG...BBBBBB...). Partition is like plane
except the different planes are saved to individual files (e.g. image.R,
image.G, and image.B).
- Use Line, or Plane to create an interlaced GIF
or progressive JPEG image.
- -label name 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 %f for filename,
%d for directory, %e for filename extention, %t for
top of filename, %m for magick, %w for width, %h for
height, %s for scene number, or \n for newline. For example,
-label "%m:%f %wx%h"
- produces an image label of MIFF:bird.miff 512x480 for
an image titled bird.miff and whose width is 512 and
height is 480.
- If the first character of string is @, 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. Specify the label font with
-font.
- -layer type
- the type of layer: Red, Green, Blue,
or Matte.
- Use this option to extract a particular layer from the image.
Matte, for example, is useful for extracting the opacity values
from an image.
- -linewidth value
- set the width of a line. See -draw for further
details.
- -loop iterations
- add Netscape loop extension to your GIF animation.
- A value other than zero forces the animation to repeat itself up to
iterations times.
- -map filename
- 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 from an image file with this option. Use
+map to reduce all images in an image sequence to a single
optimal set of colors that best represent all the images.
- -matte
- store matte channel if the image has one.
- -modulate value
- vary the brightness, saturation, and hue of an image.
- Specify the percent change in brightness, the color
saturation, and the 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: -modulate 20/-10.
- -monochrome
- transform the image to black and white.
- -negate
- apply color inversion to image.
- The red, green, and blue intensities of an image are negated.
Use +negate to only negate the grayscale pixels of the
image.
- -noise
- add or reduce noise in an image.
- 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.
- Use +noise followed by a noise type to add noise to an image.
Choose from these noise types:
uniform
gaussian
multiplicative
impulse
laplacian
poisson
- -normalize
- transform image to span the full range of color values.
This is a contrast enhancement technique.
- -opaque color
change this color to the pen color within the image. See \fB-pen\fP for
more details.
- -page <width>{%}x<height>{%}{+-}<x
offset>{+-}<y offset>{!}{<}{>}
- size and location of an image canvas.
- Use this option to specify the dimensions of the
PostScript page in dots per inch or a TEXT page in
pixels. The choices for a Postscript page are:
Letter 612x 792
Tabloid 792x1224
Ledger 1224x 792
Legal 612x1008
Statement 396x 612
Executive 540x 720
A3 842x1190
A4 595x 842
A5 420x 595
B4 729x1032
B5 516x 729
Folio 612x 936
Quarto 610x 780
10x14 720x1008
- For convenience you can specify the page size by media
(e.g. A4, Ledger, etc.). Otherwise, -page behaves much like
-geometry (e.g. -page letter+43+43>).
- To position a GIF image, use -page
{+-}<x offset>{+-}<y offset>
(e.g. -page +100+200). For a Postscript page, the image is sized
as in -geometry and positioned relative to the lower left hand corner
of the page by {+-}<x offset>{+-}<y offset>. The default
is to center the image within the page. If the image size exceeds the
Postscript page, it is reduced to fit the page.
- The default page dimensions for a TEXT image is 612x792.
- This option is used in concert with -density.
- -paint radius
- simulate an oil painting.
- Each pixel is replaced by the most frequent color in a circular
neighborhood whose width is specified with radius.
- -pen color
- set the color of the font or opaque color. See -draw for further
details.
- See X(1) for details about the color specification.
- -pointsize value
- pointsize of the Postscript font.
- -quality value
- JPEG/MIFF/PNG compression level.
- For the JPEG image format, quality is 0 (worst) to 100 (best).
The default quality is 75.
- Quality for the MIFF and PNG image format sets the amount of image compression
(quality / 10) and filter-type (quality % 10). Compression quality
values range from 0 (worst) to 100 (best). If filter-type is 4
or less, the specified filter-type is used for all scanlines:
0: none
1: sub
2: up
3: average
4: Paeth
- If filter-type is 5, adaptive filtering is used when quality
is greater than 50 and the image does not have a color map,
otherwise no filtering is used.
- If filter-type is 6 or more, adaptive filtering with
minimum-sum-of-absolute-values is used.
- The default is quality is 75. Which means nearly the best compression
with adaptive filtering.
- For further information, see the PNG specification
(RFC 2083).
- -raise <width>x<height>
- lighten or darken image edges to create a 3-D effect. See X(1)
for details about the geometry specification.
- Use -raise to create a raised effect, otherwise use +raise.
- -region <width>x<height>{+-}<x
offset>{+-}<y offset>
- apply options to a portion of the image.
- By default, any command line options are applied to the entire image. Use
-region to restrict operations to a particular area of the image.
- -roll {+-}<x offset>{+-}<y offset>
- roll an image vertically or horizontally. See X(1) for
details about the geometry specification.
- A negative x offset rolls the image left-to-right. A
negative y offset rolls the image top-to-bottom.
- -rotate degrees{<}{>}
- apply Paeth image rotation to the image.
- Use > to rotate the image only if its width exceeds the
height. < rotates the image only if its width is less than
the height. For example, if you specify -90> and the image size
is 480x640, the image is not rotated by the specified angle. However,
if the image is 640x480, it is rotated by -90 degrees.
- Empty triangles left over from rotating the image are
filled with the color defined as bordercolor (class
borderColor). See X(1) for details.
- -sample geometry
- scale image with pixel sampling. See -geometry for
details about the geometry specification.
- -scene value
- image scene number.
- -seed value
- pseudo-random number generator seed value.
- -segment <cluster threshold>x<smoothing threshold>
- segment an image by analyzing the histograms of the color components and
identifying units that are homogeneous with the fuzzy c-means technique.
- Specify cluster threshold as the number of pixels in each cluster
must exceed the the cluster threshold to be considered valid. Smoothing
threshold eliminates noise in the second derivative of the
histogram. As the value is increased, you can expect a smoother second
derivative. The default is 1.5. See Image Segmentation
for details.
- -shade <azimuth>x<elevation>
- shade the image using a distant light source.
- Specify azimuth and elevation as the position of the light
source. Use +shade to return the shading results as a grayscale image.
- -sharpen weight
- sharpen an image. Specify factor as the percent
enhancement (0.0 - 99.9%).
- -shear <x degrees>x<y degrees>
- 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, x degrees> is measured relative to
the Y axis, and similarly, for Y direction shears y
degrees is measured relative to the X axis.
- Empty triangles left over from shearing the image are
filled with the color defined as bordercolor (class
borderColor). See X(1) for details.
- -size <width>{%}x<height>{%}{+offset}{!}
- width and height of the image.
- Use this option to specify the width and height of
raw images whose dimensions are unknown such as GRAY,
RGB, or CMYK. In addition to width and height, use
-size to skip any header information in the image or tell
the number of colors in a MAP image file, (e.g. -size 640x512+256).
- For Photo CD images, choose from these sizes:
192x128
384x256
768x512
1536x1024
3072x2048
- Finally, use this option to choose a particular resolution layer of a JBIG
or JPEG image (e.g. -size 1024x768).
- -solarize factor
- negate all pixels above the threshold level. Specify factor
as the percent threshold of the intensity (0 - 99.9%).
- This option produces a solarization effect seen when exposing
a photographic film to light during the development process.
- -spread amount
- displace image pixels by a random amount.
- Amount defines the size of the neighborhood around each pixel to
choose a candidate pixel to swap.
- -swirl degrees
- swirl image pixels about the center.
- Degrees defines the tightness of the swirl.
- -transparency color
- make this color transparent within the image.
- -texture filename
- name of texture to tile onto the image background.
- -threshold value
- threshold the image.
- Create a bi-level image such that any pixel intensity that
is equal or exceeds the threshold is reassigned the maximum intensity otherwise
the minimum intensity.
- -treedepth value
- Normally, this integer value is zero or one. A zero or
one tells mogrify 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
quantize for more details.
- The -colors or -monochrome option is required for this
option to take effect.
- -undercolor <undercolor factor>x<black-generation factor>
- 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 1.0x1.0. 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 0.5x0.7.
- -verbose
- print detailed information about the image.
- This information is printed: image scene number; image
name; image size; the image class (DirectClass or
PseudoClass); the total number of unique colors (if
known); and the number of seconds to read and
transform the image. Refer to miff(5) for a
description of the image class.
If -colors is also specified, the total unique colors
in the image and color reduction error values are
printed. Refer to quantize(9) for a description of
these values.
- -wave <amplitude>x<wavelength>
- alter an image along a sine wave.
- Specify amplitude and wavelength to effect the
characteristics of the wave.
Image manipulation software that works like magic.