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PCbanter Windows
XP Help Forum
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[
#adjoin
-adjoin
|
#affine
-affine
|
#annotate
-annotate
|
#antialias
-antialias
|
#append
-append
|
#authenticate
-authenticate
|
#average
-average
|
#backdrop
-backdrop
|
#background
-background
|
#blue-primary
-blue-primary
|
#blur
-blur
|
#border
-border
|
#bordercolor
-bordercolor
|
#borderwidth
-borderwidth
|
#box
-box
|
#cache
-cache
|
#channel
-channel
|
#charcoal
-charcoal
|
#chop
-chop
|
#clip
-clip
#clone
-clone
|
#coalesce
-coalesce
|
#colorize
-colorize
|
#colormap
-colormap
|
#colors
-colors
|
#colorspace
-colorspace
|
#combine
-combine
|
#comment
-comment
|
#compose
-compose
|
#compress
-compress
|
#contrast
-contrast
|
#convolve
-convolve
|
#crop
-crop
|
#cycle
-cycle
|
#debug
-debug
|
#deconstruct
-deconstruct
|
#define
-define
|
#delay
-delay
|
#delete
-delete
|
#density
-density
|
#depth
-depth
|
#descend
-descend
|
#despeckle
despeckle
|
#displace
-displace
|
#display
-display
|
#dispose
-dispose
|
#dissolve
-dissolve
|
#dither
-dither
|
#draw
-draw
|
#edge
-edge
|
#emboss
-emboss
|
#encoding
-encoding
|
#endian
-endian
|
#enhance
-enhance
|
#equalize
-equalize
|
#evaluate
-evaluate
|
#extract
-extract
|
#fill
-fill
|
#filter
-filter
|
#flatten
-flatten
|
#flip
-flip
|
#flop
-flop
|
#font
-font
|
#foreground
-foreground
|
#format
-format
|
#format
-format
|
#frame
-frame
|
#frame
-frame
|
#fuzz
-fuzz
|
#fx
-fx
|
#gamma
-gamma
|
#gaussian
-gaussian
|
#geometry
-geometry
|
#gravity
-gravity
|
#green-primary
-green-primary
|
#frame
-help
|
#iconGeometry
-iconGeometry
|
#iconic
-iconic
|
#identify
-identify
|
#immutable
-immutable
|
#implode
-implode
|
#insert
-insert
|
#intent
-intent
|
#interlace
-interlace
|
#label
-label
|
#lat
-lat
|
#level
-level
|
#limit
-limit
|
#linewidth
-linewidth
|
#list
-list
|
#log
-log
|
#loop
-loop
|
#magnify
-magnify
|
#map
-map
|
#map
-map
|
#mask
-mask
|
#matte
-matte
|
#mattecolor
-mattecolor
|
#median
-median
|
#metric
-metric
|
#mode
-mode
|
#modulate
-modulate
|
#monitor
-monitor
|
#monochrome
-monochrome
|
#morph
-morph
|
#mosaic
-mosaic
|
#name
-name
|
#negate
-negate
|
#noise
-noise
|
#normalize
-normalize
|
#opaque
-opaque
|
#page
-page
|
#paint
-paint
|
#pause
-pause
|
#pause
-pause
|
#pen
-pen
|
#ping
-ping
|
#pointsize
-pointsize
|
#posterize
-posterize
|
#preview
-preview
|
#process
-process
|
#profile
-profile
|
#quality
-quality
|
#quiet
-quiet
|
#radial-blur
-radial-blur
|
#raise
-raise
|
#red-primary
-red-primary
|
#region
-region
|
#remote
-remote
|
#render
-render
|
#repage
-repage
|
#resample
-resample
|
#resize
-resize
|
#roll
-roll {
|
#rotate
-rotate
|
#sample
-sample
|
#sampling-factor
-sampling-factor
|
#scale
-scale
|
#scene
-scene
|
#scenes
-scenes
|
#screen
-screen
|
#segment
-segment
|
#separate
-separate
|
#sepia-tone
-sepia-tone
|
#set
-set
|
#shade
-shade
|
#shadow
-shadow
|
#shared-memory
-shared-memory
|
#sharpen
-sharpen
|
#shave
-shave
|
#shear
-shear
|
#sigmoidal-contrast
-sigmoidal-contrast
|
#silent
-silent
|
#size
-size
|
#snaps
-snaps
|
#solarize
-solarize
|
#splice
-splice
|
#spread
-spread
|
#stegano
-stegano
|
#stereo
-stereo
|
#strip
-strip
|
#stroke
-stroke
|
#strokewidth
-strokewidth
|
#swap
-swap
|
#swirl
-swirl
|
#text-font
-text-font
|
#texture
-texture
|
#threshold
-threshold
|
#thumbnail
-thumbnail
|
#tile
-tile
|
#tint
-tint
|
#title
-title
|
#transform
-transform
|
#transparent
-transparent
|
#treedepth
-treedepth
|
#trim
-trim
|
#type
-type
|
#update
-update
|
#units
-units
|
#unsharp
-unsharp
|
#use-pixmap
-use-pixmap
|
#verbose
-verbose
|
#version
-version
|
#view
-view
|
#virtual-pixel
-virtual-pixel
|
#visual
-visual
|
#watermark
-watermark
|
#wave
-wave
|
#white-point
-white-point
|
#window
-window
|
#window-group
-window-group
|
#write
-write
]
Below is list of command-line options recognized by the ImageMagick
../www/command-line-tools.html
command-line tools
. If you want a description of a particular option, click on the option name in the navigation bar above and you will go right to it.
-adjoin
join images into a single multi-image file.
By default, all images of an image sequence are stored in the same file. However, some formats (e.g. JPEG) do not support more than one image and are saved to separate files. Use
#adjoin
+adjoin
to force this behavior for all image format.
-affine
matrix
drawing transformation matrix.
This option provides a transformation matrix {
sx
,
rx
,
ry
,
sy
,
tx
,
ty
} for use by subsequent
#draw
-draw
or
#transform
-transform
options.
The transformation matrix has 3x3 elements, but three of them are omitted from the input because they are constant. The new coordinate {
x-new y-new
} of a pixel {
x y
} in the transformed image is calculated using the following matrix equation:
|  sx  rx  0 |
{ x-new  y-new  1 } = { x  y  1 } * |  ry  sy  0 |
|  tx  ty  1 |
The size of the resulting image is set so that the rotated and scaled source image is exactly contained within the new image area.  The
tx
and
ty
parameters subsequently shift the image pixels so that those that are moved out of the image area are cut off.
Since the transformation usually changes the image size, the origin of the transformation is the image center, not the upper left edge.  Consequently, the coordinate values
x
and
y
differ from the pixel coordinates by
image-width/2
, or
image-height/2
, respectively.
As do the pixel coordinates, the transform matrix uses a left-handed coordinate system (positive direction is rightward resp. downward; positive rotation is clockwise).
Scaling by the factor
s
is accomplished with the matrix:
{s, 0, 0, s, 0, 0}
Translation by a displacement {
dx
,
dy
} is accomplished with the matrix:
{1, 0, 0, 1, dx, dy}
Rotation clockwise about the origin by an angle
a
is accomplished with the matrix:
{cos(a), sin(a), -sin(a), cos(a), 0, 0}
A series of operations can be accomplished by using a matrix that is the multiple of the matrices for each operation.
-annotate
x-rotate
text
-annotate
x-rotate
x
y-rotate
{+-}
x
{+-}
y text
annotate an image with text.
This is a convenience option for annotating your image with text. For more precise control over your text annotations, use
#draw
-draw
.
X-rotate
and
y-rotate
give the angle of the text and
x
and
y
are offsets that give the location of the text relative to the upper left corner of the image.
-antialias
remove pixel aliasing.
By default, objects are antialiased when drawn (e.g. lines, polygon, etc.).  Use
#antialias
+antialias
to disable antialiasing.  Without antialiasing, you can avoid increasing the unique colors in an image, draw fixed width lines, or improve the rendering speed.
-append
append a set of images.
This option creates a single image where the images in the original set are stacked top-to-bottom. If they are not of the same width, any narrow images will be expanded to fit using the background color. Use
#append
+append
to stack images left-to-right. The set of images is terminated by the appearance of any option. If the
#append
-append
option appears after all of the input images, all images are appended.
-authenticate
string
decrypt image with this password.
Use this option to supply a password for decrypting an image or an image sequence, if it is being read from a format such as PDF that supports encryption. Encrypting images being written is not supported.
-average
average a set of images.
The set of images is terminated by the appearance of any option. If the
#average
-average
option appears after all of the input images, all images are averaged.
-backdrop
color
display the image centered on a backdrop.
This backdrop covers the entire workstation screen and is useful for hiding other X window activity while viewing the image. The color of the backdrop is specified as the background color. The color is specified using the format described under the
#fill
-fill
option.
-background
color
the background color.
The color is specified using the format described under the
#fill
-fill
option.
-blue-primary
x
,
y
blue chromaticity primary point.
-blur
radius
-blur
radius
x
sigma
blur the image with a Gaussian operator.
Blur with the given radius and standard deviation (sigma).
-border
width
-border
width
x
height
surround the image with a border of color.
See
#geometry
-resize
for details about the geometry specification.
-bordercolor
color
the border color.
The color is specified using the format described under the
#fill
-fill
option.
-borderwidth
geometry
the border width.
-box
color
set the color of the annotation bounding box.
The color is specified using the format described under the
#fill
-fill
option.
See
#draw
-draw
for further details.
-cache
threshold
(This option has been replaced by the
#limit
-limit
option).
-channel
type
the type of channel.
Choose from:
Red
,
Green
,
Blue
,
Alpha
,
Cyan
,
Magenta
,
Yellow
,
Black
,
Opacity
,
Index
,
RGB
,
RGBA
,
CMYK
, or
CMYKA
.
By default, ImageMagick applies operations all channels, except the opacity channel, in an image. Use this option to apply an operation to only select channels of an image. For example to only negate the alpha channel of an image, use
-channel Alpha -negate
-charcoal
factor
simulate a charcoal drawing.
-chop
width
{%}
-chop
width
x
height
{
+-
}
x
{
+-
}
y
{
%
}
remove pixels from the interior of an image.
Width
and
height
give the number of columns and rows to remove, and
x
and
y
are offsets that give the location of the leftmost column and topmost row to remove.
The
x
offset normally specifies the leftmost column to remove. If the
#gravity
-gravity
option is present with
NorthEast
,
East
, or
SouthEast
gravity, it gives the distance leftward from the right edge of the image to the rightmost column to remove. Similarly, the
y
offset normally specifies the topmost row to remove, but if the
#gravity
-gravity
option is present with
SouthWest
,
South
, or
SouthEast
gravity, it specifies the distance upward from the bottom edge of the image to the bottom row to remove.
The
#chop
-chop
option removes entire rows and columns, and moves the remaining corner blocks leftward and upward to close the gaps.
-clip
apply the clipping path, if one is present.
If a clipping path is present, it will be applied to subsequent operations.
For example, if you type the following command:.
convert -clip -negate cockatoo.tif negated.tif
only the pixels within the clipping path are negated.
The
#clip
-clip
feature requires the XML library. If the XML library is not present, the option is ignored.
-clone
index(s)
make a copy of an image (or images).
Specify the image by its index in the sequence.  The first image is index 0.
Negative indexes are relative to the end of the sequence, for example, -1 represents the last image of the sequence.  Specify a range of images with a dash (e.g. 0-4).  Separate indexes with a comma (e.g. 0,2).  Use
#clone
+clone
make a copy of the last image in the image sequence.
-coalesce
merge a sequence of images.
Each image N in the sequence after Image 0 is replaced with the image created by flattening images 0 through N.
The set of images is terminated by the appearance of any option. If the
#coalesce
-coalesce
option appears after all of the input images, all images are coalesced.
-colorize
value
colorize the image with the fill 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 delimited with commas (e.g.
0,0,50
).
-colormap
type
define the colormap type.
Choose between
shared
or
private
.
This option only applies when the default X server visual is
PseudoColor
or
GrayScale
. Refer to
#visual
-visual
for more details. By default, a shared colormap is allocated. The image shares colors with other X clients. Some image colors could be approximated, therefore your image may look very different than intended. Choose
Private
and the image colors appear exactly as they are defined. However, other clients may go
technicolor
when the image colormap is installed.
-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.  The ordering of an existing color palette may be altered. When converting an image from color to grayscale, convert the image to the gray colorspace before reducing the number of colors since doing so is most efficient. Refer to the
../www/quantize.html
color reduction algorithm
for more details.
Note, options
#dither
-dither
,
#colorspace
-colorspace
, and
#treedepth
-treedepth
affect the color reduction algorithm.
-colorspace
value
the type of colorspace.
Choices are:
CMYK
,
GRAY
,
HSL
,
HWB
,
OHTA
,
Rec601Luma
,
Rec709Luma
,
RGB
,
Transparent
,
XYZ
,
YCbCr
,
YIQ
,
YPbPr
, or
YUV
.
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 the
/www/quantize.html
color reduction algorithm
for more details..
The
Transparent
color space behaves uniquely in that it preserves the matte channel of the image if it exists.
The
#colors
-colors
or
#monochrome
-monochrome
option, or saving to a file format which requires color reduction, is required for this option to take effect.
-combine
combine one or more images into a single image.
The grayscale value of the pixels of each image in the sequence is assigned in order to the specified channels of the combined image. The typical ordering would be image 1 = Red, 2 = Green, 3 = Blue, etc.
-comment
string
annotate an image with a comment.
Use this option to assign a specific comment to the image, when writing to an image format that supports comments.  You can include the image filename, type, width, height, or other image attribute by embedding special format characters listed under the
#format
-format
option. The comment is not drawn on the image, but is embedded in the image datastream via a "Comment" tag or similar mechanism. If you want the comment to be visible on the image itself, use the
#draw
-draw
option.
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.
-compose
operator
the type of image composition.
The description of composition uses abstract terminology in order to allow the the description to be more clear, while avoiding constant values which are specific to a particular build configuration. Each image pixel is represented by red, green, and blue levels (which are equal for a gray pixel). QuantumRange is the maximum integral value which may be stored in the red, green, or blue channels of the image. Each image pixel may also optionally (if the image matte channel is enabled) have an associated level of opacity (ranging from opaque to transparent), which may be used to determine the influence of the pixel color when compositing the pixel with another image pixel. If the image matte channel is disabled, then all pixels in the image are treated as opaque. The color of an
opaque
pixel is fully visible while the color of a
transparent
pixel color is entirely absent (pixel color is ignored).
By definition, raster images have a rectangular shape. All image rows are of equal length, and all image columns have the same number of rows. By treating the alpha channel as a visual "mask" the rectangular image may be given a "shape" by treating the alpha channel as a cookie-cutter for the image. Pixels within the shape are opaque, while pixels outside the shape are transparent. Pixels on the boundary of the shape may be between opaque and transparent in order to provide antialiasing (visually smooth edges). The description of the composition operators use this concept of image "shape" in order to make the description of the operators easier to understand. While it is convenient to describe the operators in terms of "shapes" they are by no means limited to mask-style operations since they are based on continuous floating-point mathematics rather than simple boolean operations.
The following composite operators are available:
Operator
Description
clear
Both the color and the alpha of the destination are cleared. Neither the source nor the destination are used as input.
src
The source is copied to the destination. The destination is not used as input.
dst
The destination is left untouched.
src-over
The source is composited over the destination.
dst-over
The destination is composited over the source and the result replaces the destination.
src-in
The part of the source lying inside of the destination replaces the destination.
dst-in
The part of the destination lying inside of the source replaces the destination.
src-out
The part of the source lying outside of the destination replaces the destination.
dst-out
The part of the destination lying outside of the source         replaces the destination.
src-atop
The part of the source lying inside of the destination is  composited onto the destination.
dst-atop
The part of the destination lying inside of the source is composited over the source and replaces the destination.
xor
The part of the source that lies outside of the destination is combined with the part of the destination that lies outside of the source.
plus
The source is added to the destination and replaces the destination. This operator is useful for animating a dissolve between two images.
multiply
The source is multiplied by the destination and replaces the destination. The resultant color is always at least as dark as either of the two constituent colors. Multiplying any color with black produces black. Multiplying any color with white leaves the original color unchanged.
screen
The source and destination are complemented and then multiplied and then replace the destination. The resultant color is always at least as light as either of the two constituent colors. Screening any color with white produces white. Screening any color with black leaves the original color unchanged.
overlay
Multiplies or screens the colors, dependent on the destination color. Source colors overlay the destination whilst preserving its highlights and shadows. The destination color is not replaced, but is mixed with the source color to reflect the lightness or darkness of the destination.
darken
Selects the darker of the destination and source colors.  The destination is replaced with the source when the source is darker, otherwise it is left unchanged.
lighten
Selects the lighter of the destination and source colors.  The destination is replaced with the source when the source is lighter, otherwise it is left unchanged.
color-dodge
Brightens the destination color to reflect the source color. Painting with black produces no change.
color-burn
Darkens the destination color to reflect the source color.  Painting with white produces no change.
hard-light
Multiplies or screens the colors, dependent on the source color value. If the source color is lighter than 0.5, the destination is lightened as if it were screened. If the source color is darker than 0.5, the destination is darkened, as if it were multiplied. The degree of lightening or darkening is proportional to the difference between the source color and 0.5. If it is equal to 0.5 the destination is unchanged. Painting with pure black or white produces black or white.
soft-light
Darkens or lightens the colors, dependent on the source color value. If the source color is lighter than 0.5, the destination is lightened. If the source color is darker than 0.5, the destination is darkened, as if it were burned in. The degree of darkening or lightening is proportional to the difference between the source color and 0.5. If it is equal to 0.5, the destination is unchanged. Painting with pure black or white produces a distinctly darker or lighter area, but does not result in pure black or white.
difference
Subtracts the darker of the two constituent colors from the lighter. Painting with white inverts the destination color. Painting with black produces no change.
exclusion
Produces an effect similar to that of 'difference', but appears as lower contrast. Painting with white inverts the destination color. Painting with black produces no change.
-compress
type
the type of image compression.
Choices are:
None
,
BZip
,
Fax
,
Group4
,
JPEG
,
JPEG2000
,
Lossless
,
LZW
,
RLE
or
Zip
.
Specify
#compress
+compress
to store the binary image in an uncompressed format. The default is the compression type of the specified image file.
If
LZW
compression is specified but LZW compression has not been enabled, the image data will be written in an uncompressed LZW format that can be read by LZW decoders. This may result in larger-than-expected GIF files.
Lossless
refers to lossless JPEG, which is only available if the JPEG library has been patched to support it. Use of lossless JPEG is generally not recommended.
Use the
#quality
-quality
option to set the compression level to be used by JPEG, PNG, MIFF, and MPEG encoders. Use the
#sampling-facto
-sampling-factor
option to set the sampling factor to be used by JPEG, MPEG, and YUV encoders for downsampling the chroma channels.
-contrast
enhance or reduce the image contrast.
This option enhances the intensity differences between the lighter and darker elements of the image. Use
#contrast
-contrast
to enhance the image or
#contrast
+contrast
to reduce the image contrast.
For a more pronounced effect you can repeat the option:.
convert rose: -contrast -contrast rose_c2.png
-convolve
kernel
convolve image with the specified convolution kernel.
The kernel is specified as a comma-separated list of integers, ordered left-to right, starting with the top row.  The order of the kernel is determined by the square root of the number of entries. Presently only square kernels are supported.
-crop
width
{%}
-crop
width
x
height
{
+-
}
x
{
+-
}
y
{
%
}
preferred size and location of the cropped image.
See
#geometry
-geometry
for details about the geometry specification.
The width and height give the size of the image that remains after cropping, and
x
and
y
are offsets that give the location of the top left corner of the cropped image with respect to the original image. To specify the amount to be removed, use
#shave
-shave
instead.
If the
x
and
y
offsets are present, a single image is generated, consisting of the pixels from the cropping region. The offsets specify the location of the upper left corner of the cropping region measured downward and rightward with respect to the upper left corner of the image. If the
#gravity
-gravity
option is present with
>NorthEast
,
East
, or
SouthEast
gravity, it gives the distance leftward from the right edge of the image to the right edge of the cropping region. Similarly, if the
#gravity
-gravity
option is present with
SouthWest
,
South
,
or
SouthEast
gravity, the distance is measured upward between the bottom edges.
If the
x
and
y
offsets are omitted, a set of tiles of the specified geometry, covering the entire input image, is generated. The rightmost tiles and the bottom tiles are smaller if the specified geometry extends beyond the dimensions of the input image.
-cycle
amount
displace image colormap by amount.
Amount
defines the number of positions each colormap entry is shifted.
-debug
events
enable debug printout.
The
events
parameter specifies which events are to be logged. It can be either
None
,
All
,
Trace
, or a comma-separated list consisting of one or more of the following domains:
Annotate
,
Blob
,
Cache
,
Coder
,
Configure
,
Deprecate
,
Exception
,
Locale
,
Render
,
Resource
,
TemporaryFile
,
Transform
,
X11
, or
User
. For example, to log cache and blob events, use.
convert -debug "Cache,Blob" rose: rose.png
The
User
domain is normally empty, but developers can log user events in their private copy of ImageMagick.
Use the
#log
-log
option to specify the format for debugging output.
Use
#debug
+debug
to turn off all logging.
Debugging may also be set using the
MAGICK_DEBUG
../www/resources.html#environment
environment variable
.  The allowed values for the
MAGICK_DEBUG
environment variable are the same as for the
#debug
-debug
option.
-deconstruct
break down an image sequence into constituent parts.
This option compares each image with the next in a sequence and returns the maximum bounding region of any pixel differences it discovers. This method can undo a coalesced sequence returned by the
#coalesce
-coalesce
option, and is useful for removing redundant information from a GIF or MNG animation.
The sequence of images is terminated by the appearance of any option. If the
#deconstruct
-deconstruct
option appears after all of the input images, all images are deconstructed.
-define
key
{
=value
}
,..
add coder/decoder specific options.
This option creates one or more definitions for coders and decoders to use while reading and writing image data.  Definitions may be passed to coders and decoders to control options that are specific to certain image formats. If
value
is missing for a definition, an empty-valued definition of a flag will be created with that name. This is used to control on/off options.  Use
#define"
+define key
to remove definitions previously created. Use
#define
+define "*"
to remove all existing definitions..
The following definitions may be created:.
jp2:rate=value
Specify the compression factor to use while writing JPEG-2000
files. The compression factor is the reciprocal of the compression
ratio. The valid range is 0.0 to 1.0, with 1.0 indicating lossless
compression. If defined, this value overrides the -quality setting.
The default quality setting of 75 results in a rate value of 0.06641.
mng:need-cacheoff
turn playback caching off for streaming MNG.
ps:imagemask
If the ps:imagemask flag is defined, the PS3 and EPS3 coders will
create Postscript files that render bilevel images with the Postscript
imagemask operator instead of the image operator.
For example, to create a postscript file that will render only the black pixels of a bilevel image, use:.
convert bilevel.tif -define ps:imagemask eps3:stencil.ps
-delay
seconds
display the next image after pausing.
This option is useful for regulating the animation of image sequences
delay/100
seconds 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.
You can specify a delay range (e.g.
-delay 10-500
) which sets the minimum and maximum delay.
-delete
index
delete the image, specified by its index, from the image sequence.
Use
+delete
to delete the last image in the current image sequence.
-density
width
-density
width
x
height
horizontal and vertical resolution in pixels of the image.
This option specifies the image resolution to store while encoding a raster image or the canvas resolution while rendering (reading) vector formats such as Postscript, PDF, WMF, and SVG into a raster image. Image resolution provides the unit of measure to apply when rendering to an output device or raster image. The default unit of measure is in dots per inch (DPI). The
#units
-units
option may be used to select dots per centimeter instead.
The default resolution is 72 dots per inch, which is equivalent to one point per pixel (Macintosh and Postscript standard). Computer screens are normally 72 or 96 dots per inch while printers typically support 150, 300, 600, or 1200 dots per inch. To determine the resolution of your display, use a ruler to measure the width of your screen in inches, and divide by the number of horizontal pixels (1024 on a 1024x768 display).
If the file format supports it, this option may be used to update the stored image resolution. Note that Photoshop stores and obtains image resolution from a proprietary embedded profile. If this profile is not stripped from the image, then Photoshop will continue to treat the image using its former resolution, ignoring the image resolution specified in the standard file header.
The density option is an attribute and does not alter the underlying raster image. It may be used to adjust the rendered size for desktop publishing purposes by adjusting the scale applied to the pixels. To resize the image so that it is the same size at a different resolution, use the
#resample
-resample
option.
-depth
value
depth of the image.
This is the number of bits in a color sample within a pixel. The only acceptable values are 8 or 16. Use this option to specify the depth of raw images whose depth is unknown such as GRAY, RGB, or CMYK, or to change the depth of any image after it has been read.
-descend
obtain image by descending window hierarchy.
-despeckle
reduce the speckles within an image.
-displace
horizontal-scale
-displace
horizontal-scale
x
vertical-scale
shift image pixels as defined by a displacement map.
With this option,
composite image
is used as a displacement map. Black, within the displacement map, is a maximum positive displacement. White is a maximum negative displacement and middle gray is neutral. The displacement is scaled to determine the pixel shift. By default, the displacement applies in both the horizontal and vertical directions. However, if you specify
mask
,
composite image
is the horizontal X displacement and
mask
the vertical Y displacement.
-display
host:display[.screen]
specifies the X server to contact.
This option is used with convert for obtaining image or font from this X server. See
X(1)
.
-dispose
method
GIF disposal method.
The Disposal Method indicates the way in which the graphic is to be treated after being displayed.
Here are the valid methods:.
Undefined       No disposal specified.
None            Do not dispose between frames.
Background      Overwrite the image area with the background color.
Previous        Overwrite the image area with what was there prior to rendering the image.
-dissolve
percent
dissolve an image into another by the given percent.
The opacity of the composite image is multiplied by the given percent, then it is composited over the main image.
-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
-colors
or
#monochrome
-monochrome
option is required for this option to take effect.
Use
#dither
+dither
to turn off dithering and to render PostScript without text or graphic aliasing. Disabling dithering often (but not always) leads to decreased processing time.
-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 shapes, text, transformations, and pixel operations. The shape primitives are.
point           x,y
line            x0,y0 x1,y1
rectangle       x0,y0 x1,y1
roundRectangle  x0,y0 x1,y1 wc,hc
arc             x0,y0 x1,y1 a0,a1
ellipse         x0,y0 rx,ry a0,a1
circle          x0,y0 x1,y1
polyline        x0,y0  ...  xn,yn
polygon         x0,y0  ...  xn,yn
Bezier          x0,y0  ...  xn,yn
path            path specification
image           operator x0,y0 w,h filename
The text primitive is.
text            x0,y0 string
The text gravity primitive is.
gravity         NorthWest, North, NorthEast, West, Center,
East, SouthWest, South, or SouthEast
The text gravity primitive only affects the placement of text and does not interact with the other primitives.  It is equivalent to using the
#gravity
-gravity
commandline option, except that it is limited in scope to the
#draw
-draw
option in which it appears.
The transformation primitives are.
rotate          degrees
translate       dx,dy
scale           sx,sy
skewX           degrees
skewY           degrees
The pixel operation primitives are.
color           x0,y0 method
matte           x0,y0 method
The shape primitives are drawn in the color specified in the preceding
#stroke
-stroke
option. Except for the
line
and
point
primitives, they are filled with the color specified in the preceding
#fill
-fill
option. For unfilled shapes, use
#fill
-fill none
.
Point
requires a single coordinate.
Line
requires a start and end coordinate.
Rectangle
expects an upper left and lower right coordinate.
RoundRectangle
has the upper left and lower right coordinates and the width and height of the corners.
Circle
has a center coordinate and a coordinate for the outer edge.
Use
Arc
to inscribe an elliptical arc within a rectangle. Arcs require a start and end point as well as the degree of rotation (e.g. 130,30 200,100 45,90).
Use
Ellipse
to draw a partial ellipse centered at the given point with the x-axis and y-axis radius and start and end of arc in degrees (e.g. 100,100 100,150 0,360).
Finally,
polyline
and
polygon
require three or more coordinates to define 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'
Paths
(See
http://www.w3.org/TR/SVG/paths.html
Paths
) represent an outline of an object which is defined in terms of moveto (set a new current point), lineto (draw a straight line), curveto (draw a curve using a cubic Bezier), arc (elliptical or circular arc) and closepath (close the current shape by drawing a line to the last moveto) elements. Compound paths (i.e., a path with subpaths, each consisting of a single moveto followed by one or more line or curve operations) are possible to allow effects such as
donut holes
in objects.
Use
image
to composite an image with another image. Follow the image keyword with the composite operator, image location, image size, and filename:.
-draw 'image Over 100,100 225,225 image.jpg'
You can use 0,0 for the image size, which means to use the actual dimensions found in the image header. Otherwise, it will be scaled to the given dimensions. See
#compose
-compose
for a description of the composite operators.
Use
text
to annotate an image with text. Follow the text coordinates with a string. If the string has embedded spaces, enclose it in single or double quotes.  Optionally you can include the image filename, type, width, height, or other image attribute by embedding special format character. See
#comment
-comment
for details.
For example,.
-draw 'text 100,100 "%m:%f %wx%h"'
annotates the image with
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 text is read from a file titled by the remaining characters in the string.
Rotate
rotates subsequent shape primitives and text primitives about the origin of the main image. If the
#region
-region
option precedes the
#draw
-draw
option, the origin for transformations is the upper left corner of the region.
Translate
translates them.
Scale
scales them.
SkewX
and
SkewY
skew them with respect to the origin of the main image or the region.
The transformations modify the current affine matrix, which is initialized from the initial affine matrix defined by the
#affine
-affine
option. Transformations are cumulative within the
#draw
-draw
option. The initial affine matrix is not affected; that matrix is only changed by the appearance of another
#affine
-affine
option. If another
#draw
-draw
option appears, the current affine matrix is reinitialized from the initial affine
matrix.
Use
color
to change the color of a pixel to the fill color (see
#fill
-fill
). Follow the pixel coordinate with a method:.
point
replace
floodfill
filltoborder
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, whereas
filltoborder
recolors any neighbor pixel that is not the border color. 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, whereas
filltoborder
changes the matte value of any neighbor pixel that is not the border color (
#bordercolor
-bordercolor
). Finally
reset
changes the matte value of all pixels.
You can set the primitive color, font, and font bounding box color with
#fill
-fill
,
#font
-font
, and
#box
-box
respectively.  Options are processed in command line order so be sure to use these options
before
the
#draw
-draw
option.
-edge
radius
detect edges within an image.
-emboss
radius
emboss an image.
-encoding
type
specify the text encoding.
Choose from
AdobeCustom
,
AdobeExpert
,
AdobeStandard
,
AppleRoman
,
BIG5
,
GB2312
,
Latin 2
,
None
,
SJIScode
,
Symbol
,
Unicode
,
Wansung
.
-endian
type
specify endianness (
MSB
or
LSB
) of the image.
Use
#endian
+endian
to revert to unspecified endianness.
-enhance
apply a digital filter to enhance a noisy
image.
-equalize
perform histogram equalization to the image.
-evaluate
operator constant
evaluate an arithmetic, relational, or logical expression.
Choose from:
Add
,
And
,
Divide
,
LeftShift
,
Max
,
Min
,
Multiply
,
Or
,
RightShift
,
Set
,
Subtract
, or
Xor
.
-extract
width
-extract
width
x
height
{{+-}
offset
}
extract area from image.
-fill
color
color to use when filling a graphic primitive.
Colors are represented in ImageMagick in the same form used by SVG:.
name                 (
identify -list color
to see names)
#RGB                 (R,G,B are hex numbers, 4 bits each)
#RRGGBB              (8 bits each)
#RRRGGGBBB           (12 bits each)
#RRRRGGGGBBBB        (16 bits each)
#RGBA                (4 bits each)
#RRGGBBAA            (8 bits each)
#RRRGGGBBBAAA        (12 bits each)
#RRRRGGGGBBBBAAAA    (16 bits each)
rgb(r,g,b)           (r,g,b are decimal numbers)
rgba(r,g,b,a)        (r,g,b,a are decimal numbers)
Enclose the color specification in quotation marks to prevent the "#" or the parentheses from being interpreted by your shell.
For example,
convert -fill blue ...
convert -fill "#ddddff" ...
convert -fill "rgb(65000,65000,65535)" ...
The shorter forms are scaled up, if necessary by replication. For example,
#3af
,
#33aaff
, and
#3333aaaaffff
are all equivalent.
See
#draw
-draw
for further details.
-filter
type
use this type of filter when resizing an image.
Use this option to affect the resizing operation of an image (see
#resize
-resize
). Choose from these filters:.
Point
Box
Triangle
Hermite
Hanning
Hamming
Blackman
Gaussian
Quadratic
Cubic
Catrom
Mitchell
Lanczos
Bessel
Sinc
The default filter is automatically selected to provide the best quality while consuming a reasonable amount of time. The
Mitchell
filter is used if the image supports a palette, supports a matte channel, or is being enlarged, otherwise the
Lanczos
filter is used.
-flatten
flatten a sequence of images.
The sequence of images is replaced by a single image created by composing each image after the first over the first image.
The sequence of images is terminated by the appearance of any option. If the
#flatten
-flatten
option appears after all of the input images, all images are flattened.
-flip
create a
mirror image
.
reflect the scanlines in the vertical direction.
-flop
create a
mirror image
.
reflect the scanlines in the horizontal direction.
-font
name
use this font when annotating the image with text.
You can tag a font to specify whether it is a PostScript, TrueType, or OPTION1 font. For example,
Arial.ttf
is a TrueType font,
ps:helvetica
is PostScript, and
x:fixed
is X11.
-foreground
color
define the foreground color.
The color is specified using the format described under the
#fill
-fill
option.
-format
type
the image format type.
When used with the
mogrify
utility, this option will convert any image to the image
/www/formats.html
format
you specify.  For a list of image format types supported by ImageMagick, see the output of this command:
identify -list format
.
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
-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
.
-format
string
output formatted image characteristics.
When used with the
identify
utility, use this option to print information about the image in a format of your choosing. You can include the image filename, type, width, height, Exif data, or other image attributes by embedding special format characters:.
%b   file size
%c   comment
%d   directory
%e   filename extension
%f   filename
%h   height
%i   input filename
%k   number of unique colors
%l   label
%m   magick
%n   number of scenes
%o   output filename
%p   page number
%q   quantum depth
%r   image class and colorspace
%s   scene number
%t   top of filename
%u   unique temporary filename
%w   width
%x   x resolution
%y   y resolution
%@   bounding box
%#   signature
\n   newline
\r   carriage return
For example,
-format "%m:%f %wx%h"
displays
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 format is read from a file titled by the remaining characters in the string.
You can also use the following special formatting syntax to print Exif information contained in the file:.
%[EXIF:tag]
Where "tag" can be one of the following:.
*  (print all Exif tags, in keyword=data format)
!  (print all Exif tags, in tag_number data format)
#hhhh (print data for Exif tag #hhhh)
ImageWidth
ImageLength
BitsPerSample
Compression
PhotometricInterpretation
FillOrder
DocumentName
ImageDescription
Make
Model
StripOffsets
Orientation
SamplesPerPixel
RowsPerStrip
StripByteCounts
XResolution
YResolution
PlanarConfiguration
ResolutionUnit
TransferFunction
Software
DateTime
Artist
WhitePoint
PrimaryChromaticities
TransferRange
JPEGProc
JPEGInterchangeFormat
JPEGInterchangeFormatLength
YCbCrCoefficients
YCbCrSubSampling
YCbCrPositioning
ReferenceBlackWhite
CFARepeatPatternDim
CFAPattern
BatteryLevel
Copyright
ExposureTime
FNumber
IPTC/NAA
ExifOffset
InterColorProfile
ExposureProgram
SpectralSensitivity
GPSInfo
ISOSpeedRatings
OECF
ExifVersion
DateTimeOriginal
DateTimeDigitized
ComponentsConfiguration
CompressedBitsPerPixel
ShutterSpeedValue
ApertureValue
BrightnessValue
ExposureBiasValue
MaxApertureValue
SubjectDistance
MeteringMode
LightSource
Flash
FocalLength
MakerNote
UserComment
SubSecTime
SubSecTimeOriginal
SubSecTimeDigitized
FlashPixVersion
ColorSpace
ExifImageWidth
ExifImageLength
InteroperabilityOffset
FlashEnergy
SpatialFrequencyResponse
FocalPlaneXResolution
FocalPlaneYResolution
FocalPlaneResolutionUnit
SubjectLocation
ExposureIndex
SensingMethod
FileSource
SceneType
Surround the format specification with quotation marks to prevent your shell from misinterpreting any spaces and square brackets.
-frame
width
-frame
width
x
height
{+-}
outer-bevel-width
{+-}
inner-bevel-width
surround the image with an ornamental border.
See
#geometry
-geometry
for details about the geometry specification. The
#frame
-frame
option is not affected by the
#gravity
-gravity
option.
The color of the border is specified with the
#mattecolor
-mattecolor
command line option.
-frame
include the X window frame in the imported image.
-fuzz
distance
{
%
}
colors within this distance are considered equal.
A number of algorithms search for a target color. By default the color must be exact. Use this option to match colors that are close to the target color in RGB space. For example, if you want to automatically trim the edges of an image with
#trim
-trim
but the image was scanned and the target background color may differ by a small amount. This option can account for these differences.
The
distance
can be in absolute intensity units or, by appending
%
as a percentage of the maximum possible intensity (255, 65535, or 4294967295).
-fx
expression
apply a mathematical expression an image or image channels.
For example, to extract the matte channel of the image (this is the negative to what is commonly thought of as the alpha channel mask of the image), use:.
convert drawn.png -fx 'a' +matte matte.png
Mathematic operators include.
constants: QuantumRange, Opaque, Transparent, Pi
standard operators (in order of precedence):
^ (power), *, /, % (modulo), +, -,
, =,
& (binary AND), | (binary OR), : (binary XOR)
math function name:
abs(), acos(), asin(), atan(), ceil(), cos(), exp(), floor(), log(), ln(),
max(), min(), rand(), sign(), sin(), sqrt(),  tan()
color names: red, cyan, black, etc
symbols:
u  = first image in sequence
v  = second image in sequence
i  = column offset
j  = row offset
p  = pixel to use (absolute or relative to current pixel)
w  = width of this image
h  = height of this image
r  = red value (from RGBA), of a specific or current pixel
g  = green   ''
b  = blue    ''
a  = alpha   ''
c  = cyan value of CMYK color of pixel
y  = yellow    ''
m  = magenta   ''
k  = black     ''
intensity = pixel intensity
luminosity = pixel luminosity
Specify the image source using an image index represented by
u
, starting at zero for the first image, (eg:
u[3]
is the fourth image in the image sequence). A negative image index counts images from the end of the current image sequence, therefore
u[-1]
refers to the last image in the sequence.
Without an index
u
or
v
represent the first and second image of the sequence. If no image is specified, the
u
image is used.
For example to reduce the intensity of the red channel by 50%, use.
convert image.png -channel red -fx 'u/2.0' image.jpg
The pixels are processed one at a time, but a different pixel of a image can be specified with a pixel index represented by
p
. For example,.
p[-1].g      Green value of pixel to the immediate left of current
p[-1,-1].r   Red value, diagonally left and up from current pixel
To specify an absolute position, use braces, rather than brackets.
p{12,34}.b   is the blue pixel at image location 12,34
The other symbols specify the value you wish to retrieve.
A pixel outside the boundary of the image has a value dictated by the
#virtual-pixel
-virtual-pixel
option setting.
The
#channel
-channel
setting can be used to specify the output channel of the result. If no output channel is given the result is set over all channels, except the opacity channel. For example, suppose you want to replace the red channel of alpha.png with the average of the green channels from the images alpha.png and beta.png, use:.
convert alpha.png beta.png -channel red -fx '(u.g+v.g)/2' gamma.png
Note that all the original images in the current image sequence are replaced by the updated
alpha.png
image.
-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
. Gamma less than 1.0 darkens the image and gamma greater than 1.0 lightens it. Large adjustments to image gamma may result in the loss of some image information if the pixel quantum size is only eight bits (quantum range 0 to 255).
You can apply separate gamma values to the red, green, and blue channels of the image with a gamma value list delimited with commas (e.g.,
1.7,2.3,1.2
).
Use
#gamma
+gamma
value
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).
-gaussian
radius
-gaussian
radius
x
sigma
blur the image with a Gaussian operator.
Use the given radius and standard deviation (sigma).
-geometry
width
-geometry
width
x
height
{
+-
}
x
{
+-
}
y
preferred size and location of the Image window.
By default, the window size is the image size and the location is chosen by you when it is mapped.
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 the width is specified, the width assumes the value and the height is chosen to maintain the aspect ratio of the image. Similarly, if only the height is specified (e.g.,
#geometry
-geometry x256
, the width is chosen to maintain the aspect ratio.
If the
x
is negative, the offset is measured leftward from the right edge of the screen to the right edge of the image being displayed. Similarly, negative
y
is measured between the bottom edges. The offsets are not affected by
%
; they are always measured in pixels.
-gravity
type
direction primitive gravitates to when annotating the image.
Choices are:
NorthWest
,
North
,
NorthEast
,
West
,
Center
,
East
,
SouthWest
,
South
,
SouthEast
.
The direction you choose specifies where to position the text when annotating the image. For example, a gravity of
Center
forces the text to be centered within the image. By default, the image gravity is
NorthWest
. See
#draw
-draw
for more details about graphic primitives.  Only the text primitive is affected by the
#gravity
-gravity
option.
The
#gravity
-gravity
option is also used in concert with the
#geometry
-geometry
option and other options that take
geometry
as a parameter, such as the
#crop
-crop
option. See
#geometry
-geometry
for details of how the
#gravity
-gravity
option interacts with the
x
and
y
parameters of a geometry specification.
When used as an option to
../www/composite.html
composite
,
#gravity
-gravity
gives the direction that the image gravitates within the composite.
When used as an option to
../www/montage.html
montage
,
#gravity
-gravity
gives the direction that an image gravitates within a tile. The default gravity is
Center
for this purpose.
-green-primary
x,y
green chromaticity primary point.
-help
print usage instructions.
-iconGeometry
geometry
specify the icon geometry.
Offsets, if present in the geometry specification, are handled in the same manner as the
#geometry
-geometry
option, using X11 style to handle negative offsets.
-iconic
iconic animation.
-identify
describe the format and characteristics of the image.
-immutable
make image immutable.
-implode
factor
implode image pixels about the center.
-insert
index
insert the last image into the image sequence.
This option takes last image in the current image sequence and inserts it at the given index. If a negative index is used, the insert position is calculated before the last image is removed from the sequence. As such
-insert -1
will result in no change to the image sequence.
The
+insert
option is equivalent to
-insert -1
. In other words, insert the last image, at the end of the current image sequence. Consequently this has no effect on the image sequence order.
-intent
type
use this type of rendering intent when managing the image color.
Use this option to affect the the color management operation of an image (see
#profile
-profile
).  Choose from these intents:
Absolute, Perceptual, Relative, Saturation
.
The default intent is undefined.
-interlace
type
the type of interlacing scheme.
Choices are:
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 PNG
or
GIF
or
progressive JPEG
image.
-label
name
assign a label to an image.
Use this option to assign a specific label to the image, when writing to an image format that supports labels, such as TIFF, PNG, MIFF, or PostScript. You can include the the image filename, type, width, height, or other image attribute by embedding special format character. A label is not drawn on the image, but is embedded in the image datastream via a
Label
tag or similar mechanism. If you want the label to be visible on the image itself, use the
#draw
-draw
option. See
#comment
-comment
for details.
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
-font
.
When creating a montage, by default the label associated with an image is displayed with the corresponding tile in the montage. Use the
#label
+label
option to suppress this behavior.
-lat
width
-lat
width
x
height
{
+-
}
offset
{
%
}
perform local adaptive thresholding.
Perform local adaptive thresholding using the specified width, height, and offset. The offset is a distance in sample space from the mean, as an absolute integer ranging from 0 to the maximum sample value or as a percentage.
-level
black_point
-level
black_point
{,
white_point
}{
%
}{,
gamma
}
adjust the level of image contrast.
Give one, two or three values delimited with commas: black-point, white-point, gamma (e.g. 10,250,1.0 or 2%,98%,0.5). The black and white points range from 0 to QuantumRange or from 0 to 100%; if the white point is omitted it is set to QuantumRange-black_point. If a
%
sign is present anywhere in the string, the black and white points are percentages of QuantumRange. Gamma is an exponent that ranges from 0.1 to 10.; if it is omitted, the default of 1.0 (no gamma correction) is assumed.
-limit
type value
pixel cache resource limit.
Choose from:
Area
,
Disk
,
File
,
Map
,
or Memory.
The value for File is in number of files. The Disk limit is in Gigabytes and and the values for the other resources are in Megabytes. By default the limits are 768 files, 1024MB memory, 4096MB map, and unlimited disk, but these are adjusted at startup time on platforms that can provide information about available resources. When the limit is reached, ImageMagick will fail in some fashion, or take compensating actions if possible. For example,
-limit memory 32 -limit map 64
limits memory.  When the pixel cache reaches the memory limit it uses memory mapping. When that limit is reached it goes to disk. If disk has a hard limit, the program will fail.
Resource limits may also be set using
../www/resources.html#environment
environment variables
. The environment variables
MAGICK_AREA_LIMIT
,
MAGICK_DISK_LIMIT
,
MAGICK_FILES_LIMIT
,
MAGICK_MEMORY_LIMIT
, and
MAGICK_MAP_LIMIT
, may be used to set the limits for disk space, open files, heap memory, and memory map size, respectively.
You can use the option
#list
-list resource
to list the limits.
-linewidth
the line width for subsequent draw operations.
-list
type
the type of list.
Choices are:
Coder
,
Color
,
Delegate
,
Format
,
Magic
,
Module
,
Resource
, or
Type
.
This option lists information about the ImageMagick configuration.
-log
string
Specify format for debug log.
This option specifies the format for the log printed when the
#debug
-debug
option is active.
You can display the following components by embedding special format characters:.
%d   domain
%e   event
%f   function
%l   line
%m   module
%p   process ID
%r   real CPU time
%t   wall clock time
%u   user CPU time
%%   percent sign
\n   newline
\r   carriage return
For example:.
convert -debug coders -log "%u %m:%l %e" in.gif out.png
The default behavior is to print all of the components.
-loop
iterations
add Netscape loop extension to your GIF animation.
Set iterations to zero to repeat the animation an infinite number of times, otherwise the animation repeats itself up to
iterations
times.
-magnify
factor
magnify the image.
-map
filename
choose a particular set of colors from this image.
[
convert
or
mogrify
].
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
+map
to reduce all images in the image sequence that follows to a single optimal set of colors that best represent all the images. The sequence of images is terminated by the appearance of any option. If the
#map
+map
option appears after all of the input images, all images are mapped.
-map
type
display image using this type.
[
animate
or
display
].
Choose from these
Standard Colormap
types:.
best
default
gray
red
green
blue
The
X server
must support the
Standard Colormap
you choose, otherwise an error occurs.  Use
list
as the type and
display
searches the list of colormap types in
top-to-bottom
order until one is located. See
xstdcmap(1)
for one way of creating Standard Colormaps.
-mask
filename
Specify a clipping mask.
The image read from the file is used as a clipping mask. It must have the same dimensions as the image being masked.
If the mask image contains an alpha channel, the opacity of each pixel is used to define the mask. Otherwise, the intensity (gray level) of each pixel is
used.
Use
#mask
+mask
to remove the clipping mask.
It is not necessary to use
#clip
-clip
to activate the mask;
#clip
-clip
is implied by
#mask
-mask
.
-matte
store matte channel if the image has one.
If the image does not have a matte channel, create an opaque one.
Use
#matte
+matte
to ignore the matte channel and to avoid writing a matte channel in the output file.
-mattecolor
color
specify the color to be used with the
#frame
-frame
option.
The color is specified using the format described under the
#fill
-fill
option.
-median
radius
apply a median filter to the image.
-metric
type
measure differences between images with this metric.  Choose from MAE, MSE, PSE, PSNR, or RMSE.
-mode
value
mode of operation.  Choose from these styles:
Frame, Unframe, or Concatenate
-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.  Hue is the percentage of absolute rotation from the current position. For example 50 results in a counter-clockwise rotation of 90 degrees, 150 results in a clockwise rotation of 90 degrees, with 0 and 200 both resulting in a rotation of 180 degrees.  .
To increase the color brightness by 20% and decrease the color saturation by 10% and leave the hue unchanged, use:
#module
-module 120,90
.  .
-flop
monitor progress.
-monochrome
transform the image to black and white.
-morph
frames
morphs an image sequence.
Both the image pixels and size are linearly interpolated to give the appearance of a meta-morphosis from one image to the next.
The sequence of images is terminated by the appearance of any option. If the
#morph
-morph
option appears after all of the input images, all images are morphed.
-mosaic
create a mosaic from an image or an image sequence.
The
#page
-page
option can be used to establish the dimensions of the mosaic and to locate the images within the mosaic.
The sequence of images is terminated by the appearance of any option. If the
#mosaic
-mosaic
option appears after all of the input images, all images are included in the mosaic.
-name
name an image.
-negate
replace every pixel with its complementary color.
The red, green, and blue intensities of an image are negated. White becomes black, yellow becomes blue, etc.  Use
#negate
+negate
to only negate the grayscale pixels of the image.
-noise
radius|type
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 pixel 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 pixel window.
Use
radius
to specify the width of the neighborhood.
Use
#noise
+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 fill color within the image.
The color is specified using the format described under the
#fill
-fill
option.
See
#fill
-fill
for more details.
-page
widthxheight
{
+-
}
x
{
+-
}
y
{
%
}{
!
}{
}{
}
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:.
11x17         792  1224
Ledger       1224   792
Legal         612  1008
Letter        612   792
LetterSmall   612   792
ArchE        2592  3456
ArchD        1728  2592
ArchC        1296  1728
ArchB         864  1296
ArchA         648   864
A0           2380  3368
A1           1684  2380
A2           1190  1684
A3            842  1190
A4            595   842
A4Small       595   842
A5            421   595
A6            297   421
A7            210   297
A8            148   210
A9            105   148
A10            74   105
B0           2836  4008
B1           2004  2836
B2           1418  2004
B3           1002  1418
B4            709  1002
B5            501   709
C0           2600  3677
C1           1837  2600
C2           1298  1837
C3            918  1298
C4            649   918
C5            459   649
C6            323   459
Flsa          612   936
Flse          612   936
HalfLetter    396   612
For convenience you can specify the page size by media (e.g. A4, Ledger, etc.). Otherwise,
#page
-page
behaves much like
#geometry
-geometry
(e.g.
#page
-page letter+43+43
).
This option is also used to place subimages when writing to a multi-image format that supports offsets, such as GIF89 and MNG. When used for this purpose the offsets are always measured from the top left corner of the canvas and are not affected by the
#gravity
-gravity
option. To position a GIF or MNG image, use
#page
-page
{+-}x{+-}y
(e.g.  -page +100+200). When writing to a MNG file, a
#page
-page
option appearing ahead of the first image in the sequence with nonzero width and height defines the width and height values that are written in the
MHDR
chunk.  Otherwise, the MNG width and height are computed from the bounding box that contains all images in the sequence. When writing a GIF89 file, only the bounding box method is used to determine its dimensions.
For a PostScript page, the image is sized as in
#geometry
-geometry
and positioned relative to the lower left hand corner of the page by {+-}
x
offset
{+-}
y
offset
. Use
#page
-page 612x792
, for example, to center the image within the page. If the image size exceeds the PostScript page, it is reduced to fit the page. The default gravity for the
#page
-page
option is
NorthWest
, i.e., positive
x
and
y
offset
are measured rightward and downward from the top left corner of the page, unless the
#gravity
-gravity
option is present with a value other than
NorthWest
.
The default page dimensions for a TEXT image is 612x792.
This option is used in concert with
#density
-density
.
Use
#page
+page
to remove the page settings for an image.
-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
.
-pause
seconds
pause between animation loops [animate].
Pause for the specified number of seconds before repeating the animation.
-pause
seconds
pause between snapshots [import].
Pause for the specified number of seconds before taking the next snapshot.
-ping
efficiently determine image characteristics.
-pointsize
value
pointsize of the PostScript, OPTION1, or TrueType font.
-posterize
levels
reduce the image to a limited number of color levels.
-preview
type
image preview type.
Use this option to affect the preview operation of an image (e.g.
convert file.png -preview Gamma Preview:gamma.png
). Choose from these previews:.
Rotate
Shear
Roll
Hue
Saturation
Brightness
Gamma
Spiff
Dull
Grayscale
Quantize
Despeckle
ReduceNoise
Add Noise
Sharpen
Blur
Threshold
EdgeDetect
Spread
Shade
Raise
Segment
Solarize
Swirl
Implode
Wave
OilPaint
CharcoalDrawing
JPEG
The default preview is
JPEG
.
-process
command
process a sequence of images using a process module.
The command argument has the form
module=arg1,arg2,arg3,...,argN
where
module
is the name of the module to invoke (e.g.  "analyze") and arg1,arg2,arg3,...,argN are an arbitrary number of arguments to pass to the process module.
The sequence of images is terminated by the appearance of any option.
If the
#process
-process
option appears after all of the input images, all images are processed.
-profile
filename
add ICM, IPTC, or generic profile to image.
#profile
-profile filename
adds an ICM (ICC color management), IPTC (newswire information), or a generic profile to the image
Use
#profile
+profile icm
,
#profile
+profile iptc
, or
#profile
+profile profile_name
to remove the respective profile. Use
identify -verbose
to find out what profiles are in the image file. Use
#strip
-strip
to remove all profiles.
To extract a profile, the
#profile
-profile
option is not used. Instead, simply write the file to an image format such as
APP1, 8BIM, ICM,
or
IPTC
.
For example, to extract the Exif data (which is stored in JPEG files in the
APP1
profile), use.
convert cockatoo.jpg exifdata.app1
-quality
value
JPEG/MIFF/PNG compression level.
For the JPEG and MPEG image formats, quality is 0 (lowest image quality and highest compression) to 100 (best quality but least effective compression). The default is to use the estimate quality of your input image otherwise 75. Use the
#sampling-factor
-sampling-factor
option to specify the factors for chroma downsampling.
For the MIFF image format, quality/10 is the zlib compression level, which is 0 (worst but fastest compression) to 9 (best but slowest). It has no effect on the image appearance, since the compression is always lossless.
For the JPEG-2000 image format, quality is mapped using a non-linear equation to the compression ratio required by the Jasper library. This non-linear equation is intended to loosely approximate the quality provided by the JPEG v1 format. The default quality value 75 results in a request for 16:1 compression. The quality value 100 results in a request for non-lossy compression.
For the MNG and PNG image formats, the quality value sets the zlib compression level (quality / 10) and filter-type (quality % 10). Compression levels range from 0 (fastest compression) to 100 (best but slowest). For compression level 0, the Huffman-only strategy is used, which is fastest but not necessarily the worst compression.
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, adaptive filtering with
minimum-sum-of-absolute-values
is used.
Only if the output is MNG, if filter-type is 7, the LOCO color transformation and adaptive filtering with
minimum-sum-of-absolute-values
are used.
The default is quality is 75, which means nearly the best compression with adaptive filtering. The quality setting has no effect on the appearance of PNG and MNG images, since the compression is always lossless.
For further information, see the
http://www.w3.org/pub/WWW/TR
PNG
specification.
When writing a JNG image with transparency, two quality values are required, one for the main image and one for the grayscale image that conveys the alpha channel. These are written as a single integer equal to the main image quality plus 1000 times the opacity quality. For example, if you want to use quality 75 for the main image and quality 90 to compress the opacity data, use
#quality
-quality 90075
.
-quiet
suppress all error or warning messages.
-radial-blur
angle
radial blur the image.
-raise
widthxheight
lighten or darken image edges.
This will create a 3-D effect. See
#geometry
-geometry
for details details about the geometry specification. Offsets are not used.
Use
#raise
-raise
to create a raised effect, otherwise use
#raise
+raise
.
-red-primary
x,y
red chromaticity primary point.
-region
widthxheight
{
+-
}
x
{
+-
}
y
apply options to a portion of the image.
The
x
and
y
offsets are treated in the same manner as in
#crop
-crop
.
-remote
perform a remote operation.
The only command recognized at this time is the name of an image file to load.
-render
render vector operations.
Use
#render
+render
to turn off rendering vector operations. This is useful when saving the result to vector formats such as MVG or SVG.
-repage
size and location of an image canvas.
This option is like
#page
-page
but acts as an image operator rather than a setting.
Use "+repage" to eliminate page size and location data.
-resample
horizontalxvertical
Resample image to specified horizontal and vertical resolution.
Resize the image so that its rendered size remains the same as the original at the specified target resolution. For example, if a 300 DPI image renders at 3 inches by 2 inches on a 300 DPI device, when the image has been resampled to 72 DPI, it will render at 3 inches by 2 inches on a 72 DPI device.  Note that only a small number of image formats (e.g. JPEG, PNG, and TIFF) are capable of storing the image resolution. For formats which do not support an image resolution, the original resolution of the image must be specified via
#density
-density
on the command line prior to specifying the resample resolution.
Note that Photoshop stores and obtains image resolution from a proprietary embedded profile. If this profile exists in the image, then Photoshop will continue to treat the image using its former resolution, ignoring the image resolution specified in the standard file header.
-resize
width
-resize
width
{
%
}{
@
} {
!
} {
<
} {
>
}
resize an image.
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 the width is specified, the width assumes the value and the height is chosen to maintain the aspect ratio of the image. Similarly, if only the height is specified (e.g.,
-resize x256
, the width is chosen to maintain the aspect ratio.
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 specify the maximum area in pixels of an image.
Use
<
to change the dimensions of the image
only
if its width or height exceeds the geometry specification.
>
resizes the image
only
if both of its dimensions are less than the geometry specification.  For example, if you specify
640x480
and the image size is 256x256, the image size does not change. However, if the image is 512x512 or 1024x1024, it is resized to 480x480. Enclose the geometry specification in quotation marks to prevent the
<
or
>
from being interpreted by your shell as a file redirection.
If the
#filter
-filter
option precedes the
#resize
-resize
option, the specified filter is used.
-roll {
+-
}
x
{
+-
}
y
roll an image vertically or horizontally.
See
#geometry
-geometry
for details the geometry specification. The
x
and
y
offsets are not affected by the
#gravity
-gravity
option.
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
-rotate "-90>"
and the image size is 480x640, the image is not rotated. However, if the image is 640x480, it is rotated by -90 degrees. If you use
>
or
<
, enclose it in quotation marks to prevent it from being misinterpreted as a file redirection.
Empty triangles left over from rotating the image are filled with the color defined as
background
. The color is specified using the format described under the
#fill
-fill
option.
-sample
geometry
scale image using pixel sampling.
See
#geometry
-geometry
for details about the geometry specification.
#sample
-sample
ignores the
#filter
-filter
selection if the
#filter
-filter
option is present. Offsets, if present in the geometry string, are ignored, and the
#gravity
-gravity
option has no effect.
-sampling-factor
horizontal-factor
x
vertical-factor
sampling factors used by JPEG or MPEG-2 encoder and YUV decoder/encoder.
This option specifies the sampling factors to be used by the JPEG encoder for chroma downsampling. If this option is omitted, the JPEG library will use its own default values. When reading or writing the YUV format and when writing the M2V (MPEG-2) format, use
#sampling-factor
-sampling-factor 2x1
to specify the 4:2:2 downsampling method.
-scale
geometry
scale the image.
See
#geometry
-geometry
for details about the geometry specification.
#scale
-scale
uses a simpler, faster algorithm, and it ignores the
#filter
-filter
selection if the
#filter
-filter
option is present. Offsets, if present in the geometry string, are ignored, and the
#gravity
-gravity
option has no effect.
-scene
value
set scene number.
This option sets the scene number of an image or the first image in an image sequence.
-scenes
value-value
range of image scene numbers to read.
Each image in the range is read with the filename followed by a period (
.
) and the decimal scene number. You can change this behavior by embedding a
%d, %0Nd, %o, %0No, %x, or %0Nx printf
format specification in the file name. For example,.
montage -scenes 5-7 image.miff
makes a montage of files image.miff.5,
image.miff.6, and image.miff.7, and.
animate -scenes 0-12 image%02d.miff
animates files image00.miff, image01.miff, through image12.miff.
-screen
specify the screen to capture.
This option indicates that the GetImage request used to obtain the image should be done on the root window, rather than directly on the specified window. In this way, you can obtain pieces of other windows that overlap the specified window, and more importantly, you can capture menus or other popups that are independent windows but appear over the specified window.
-segment
cluster-threshold
x
smoothing-threshold
segment an image.
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
#segm
"Image Segmentation"
for details.
-separate
separate an image channel into a grayscale image.  Specify the channel with
#channel
-channel
.
-sepia-tone
threshold
simulate a sepia-toned photo.
Specify
threshold
as the percent threshold of the intensity (0 - 99.9%).
This option applies a special effect to the image, similar to the effect achieved in a photo darkroom by sepia toning.  Threshold ranges from 0 to QuantumRange and is a measure of the extent of the sepia toning.  A threshold of 80% is a good starting point for a reasonable tone.
-set
attribute value
pixel cache resource limit.
Choose from:
Area
,
Disk
,
File
,
Map
,
or Memory.
-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
+shade
to return the shading results as a grayscale image.
-shadow
percent-opacity
{
xsigma
}{
+-
}
x
{
+-
}
y
{
%
}
simulate an image shadow.
-shared-memory
use shared memory.
This option specifies whether the utility should attempt to use shared memory for pixmaps. ImageMagick must be compiled with shared memory support, and the display must support the
MIT-SHM
extension. Otherwise, this option is ignored. The default is
True
.
-sharpen
radius
{
xsigma
}
sharpen the image.
Use a Gaussian operator of the given radius and standard deviation (sigma).
-shave
widthxheight
{
%
}
shave pixels from the image edges.
Specify the width of the region to be removed from both sides of the image and the height of the regions to be removed from top and bottom.
-shear
x-degrees
x
y-degrees
shear the image along the X or Y axis.
Use the specified 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 with the
#fill
-background
options. The color is specified using the format described under the
#fill
-fill
option.
-sigmoidal-contrast
contrast
x
mid-point
image lightness rescaling using sigmoidal contrast enhancement.
Increase the contrast of the image using a sigmoidal transfer function without saturating highlights or shadows.
Contrast
indicates how much to increase the contrast (0 is none; 3 is typical; 20 is a lot);
mid-point
indicates where midtones fall in the resultant image (0 is white; 50% is middle-gray; 100% is black).  By default the image contrast is increased, use
+sigmoidal-contrast
to decrease the contrast.
-silent
operate silently.
-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
-size
with an offset 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).
-snaps
value
number of screen snapshots.
Use this option to grab more than one image from the X server screen, to create an animation sequence.
-solarize
threshold
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.
-splice
width
x
height
{
+-
}
x
{
+-
}
y
{
%
}
splice the background color into the image.
See
#geometry
-geometry
for details about the geometry specification.
-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.
-stegano
offset
hide watermark within an image.
Use an offset to start the image hiding some number of pixels from the beginning of the image. Note this offset and the image size. You will need this information to recover the steganographic image (e.g. display -size 320x256+35 stegano:image.png).
-stereo
composite two images to create a stereo anaglyph.
The left side of the stereo pair is saved as the red channel of the output image. The right side is saved as the green channel. Red-green stereo glasses are required to properly view the stereo image.
-strip
strip the image of any profiles or comments.
-stroke
color
color to use when stroking a graphic primitive.
The color is specified using the format described under the
#fill
-fill
option.
See
#draw
-draw
for further details.
-strokewidth
value
set the stroke width.
See
#draw
-draw
for further details.
-swap
index,index
swap the positions of two images in the image sequence.
For example,
#swap
-swap 0,2
swaps the first and the third images in the current image sequence.  Whereas,
#swap
+swap
swaps the last two image.
-swirl
degrees
swirl image pixels about the center.
Degrees
defines the tightness of the swirl.
-text-font
name
font for writing fixed-width text.
Specifies the name of the preferred font to use in fixed (typewriter style) formatted text. The default is 14 point
Courier
.
You can tag a font to specify whether it is a PostScript, TrueType, or OPTION1 font. For example,
Courier.ttf
is a TrueType font and
x:fixed
is OPTION1.
-texture
filename
name of texture to tile onto the image background.
-threshold
value
{
green,blue,opacity
}{
%
}
threshold the image.
Create an image such that any pixel sample that is equal to, or exceeds the threshold, is reassigned the maximum intensity otherwise the minimum intensity.
If the green or blue value is omitted, these channels use the same value as the first one provided. If all three color values are the same, the result is a bi-level image. If the opacity threshold is omitted, OpaqueOpacity will be used and any partially transparent pixel will become fully transparent. If only a single 0 is provided, auto-thresholding will be performed.
To generate an all-black or all-white image with the same dimensions as the input image, you can use.
convert -threshold 65535 in.png black.png
convert -threshold 0,0 in.png white.png
-thumbnail
width
{%}
-thumbnail
widthxheight
{
%
}{
@
}{
!
}{
}{
}
create a thumbnail of the image.
This is exactly like
#resize
-resize
, except that any image profiles present are also removed as they are of little importance to small image thumbnails.
-tile
filename
tile image when filling a graphic primitive.
-tile
geometry
layout of images [
montage
].
-tint
value
tint the image with the fill color.
Specify the amount of tinting as a percentage.  Pure colors like black, white red, yellow, will not be affected by -tint. Only mid-range colors such as the various shades of grey.
-title
string
assign title to displayed image [
animate, display, montage
].
Use this option to assign a specific title to the image. This is assigned to the image window and is typically displayed in the window title bar. Optionally you can include the image filename, type, width, height, Exif data, or other image attribute by embedding special format characters described under the
#format
-format
option.
For example,.
-title "%m:%f %wx%h"
produces an image title of
MIFF:bird.miff 512x480
for an image titled
bird.miff
and whose width is 512 and height is 480.
-transform
transform the image.
This option applies the transformation matrix from a previous
#affine
-affine
option.
convert -affine 2,2,-2,2,0,0 -transform bird.ppm bird.jpg
-transparent
color
make this color transparent within the image.
The color is specified using the format described under the
#fill
-fill
option. The color to use for image transparency in colormap image formats, such as GIF. As a side effect, fully-opaque colors of this value may also become transparent, depending on the format.
-treedepth
value
tree depth for the color reduction algorithm.
Normally, this integer value is zero or one. A value of zero or one causes the use of an 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 the
../www/quantize.html
color reduction algorithm
for more details.
The
#colors
-colors
or
#monochrome
-monochrome
option, or writing to an image format which requires color reduction, is required for this option to take effect.
-trim
trim an image.
This option removes any edges that are exactly the same color as the corner pixels. Use
#fuzz
-fuzz
to make
#trim
-trim
remove edges that are nearly the same color as the corner pixels.
-type
type
the image type.
Choose from:
Bilevel
,
Grayscale
,
Palette
,
PaletteMatte
,
TrueColor
,
TrueColorMatte
,
ColorSeparation
,
ColorSeparationMatte
, or
Optimize
.
Normally, when a format supports different subformats such as grayscale and truecolor, the encoder will try to choose an efficient subformat. The
#type
-type
option can be used to overrride this behavior. For example, to prevent a JPEG from being written in grayscale format even though only gray pixels are present, use.
convert bird.p-type TrueColor bird.jpg
Similarly, using
#type
-type TrueColorMatte
will force the encoder to write an alpha channel even though the image is opaque, if the output format supports transparency.
-update
seconds
detect when image file is modified and redisplay.
Suppose that while you are displaying an image the file that is currently displayed is over-written.
display
will automatically detect that the input file has been changed and update the displayed image accordingly.
-units
type
the units of image resolution.
Choose from:
Undefined
,
PixelsPerInch
, or
PixelsPerCentimeter
. This option is normally used in conjunction with the
#density
-density
option.
-unsharp
radius
-unsharp
radius
x
sigma
{
+amount
}{
+threshold
}
sharpen the image with an unsharp mask operator.
The
#unsharp
-unsharp
option sharpens an image. The image is convolved with a Gaussian operator of the given radius and standard deviation (sigma). For reasonable results, radius should be larger than sigma. Use a radius of 0 to have the method select a suitable radius.
The parameters are:.
radius:    The radius of the Gaussian, in pixels,  not
counting the center pixel (default 0).
sigma:     The standard deviation of the Gaussian, in
pixels (default 1.0).
amount:    The percentage of the difference between the
original and the blur image that is added back
into the original (default 1.0).
threshold: The threshold, as a fraction of QuantumRange, needed
to apply the difference amount (default 0.05).
-use-pixmap
use the pixmap.
-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; and the number of seconds to read and transform the image. Refer to
../www/miff.html
MIFF
for a description of the image class.
If
#colors
-colors
is also specified, the total unique colors in the image and color reduction error values are printed. Refer to
quantize.html
quantize
for a description of these values.
-version
print ImageMagick version string.
-view
string
FlashPix viewing parameters.
-virtual-pixel
method
specify contents of "virtual pixels".
This option defines "virtual pixels" for use in operations that can access pixels outside the boundaries of an image.
Choose from these methods:.
Constant:  Use the image background color.
Edge:      Extend the edge pixel toward infinity (default).
Mirror:    Mirror the image.
Tile:      Tile the image.
This option affects operations that use virtual pixels such as
#blur
-blur
,
#sharpen
-sharpen
,
#wave
-wave
, etc.
-visual
type
animate images using this X visual type.
Choose from these visual classes:.
StaticGray
GrayScale
StaticColor
PseudoColor
TrueColor
DirectColor
default
visual id
The X server must support the visual you choose, otherwise an error occurs. If a visual is not specified, the visual class that can display the most simultaneous colors on the default screen is chosen.
-watermark
brightness
percent brightness of a watermark.
-wave
amplitude
-wave
amplitude
x
wavelength
alter an image along a sine wave.
Specify
amplitude
and
wavelength
of the wave.
-white-point
x,y
chromaticity white point.
-window
id
make image the background of a window.
id
can be a window id or name. Specify
root
to select X's root window as the target window.
By default the image is tiled onto the background of the target window. If
backdrop
or
#geometry
-geometry
are specified, the image is surrounded by the background color. Refer to
X RESOURCES
for details.
The image will not display on the root window if the image has more unique colors than the target window colormap allows. Use
#colors
-colors
to reduce the number of colors.
-window-group
specify the window group.
-write
filename
write an image sequence.
The image sequence following the
#write
-write
filename
option is written out, and processing continues with the same image in its current state if there are additional options. To restore the image to its original state after writing it, use the
#write
+write
filename
option.
Use
#compress
-compress
to specify the type of image compression.
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