|
Options are processed in command line order. Any option you specify on
the command line remains in effect for the set of images that follows,
until the set is terminated by the appearance of any option or -noop.
Some options only affect the decoding of images and others only the encoding.
The latter can appear after the final group of input images.
This is a combined list of the commandline options used by the ImageMagick
utilities (animate, composite, convert, display, identify,
import, mogrify and montage).
In this document, angle brackets ("<>") enclose variables, and curly
brackets ("{}") enclose optional parameters. For example,
"-fuzz <distance>{%}" means you can use the
option "-fuzz 10"
or "-fuzz 2%".
| 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 to force this
behavior.
|
|
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 to stack images left-to-right. The set of images
is terminated by the appearance of any option.
If the -append
option appears after all of the input images, all images are appended.
|
|
The set of images
is terminated by the appearance of any option.
If the -average
option appears after all of the input images, all images are averaged. |
| 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 in the "Color Names"
section of X(1).
Refer to
X Resources
for details.
|
|
The color is specified using the format described in the "Color Names"
section of X(1). |
| blur the image with a gaussian operator |
|
Blur with the given radius and
standard deviation (sigma).
|
| surround the image with a border of color |
|
See -geometry for details
about the geometry specification.
|
|
The color is specified using the format described in the "Color Names"
section of X(1). |
| set the color of the annotation bounding box |
|
The color is specified using the format described in the "Color Names"
section of X(1). |
|
See -draw for further
details.
|
| megabytes of memory available to the pixel cache |
|
Image pixels are stored in memory until 80 megabytes of memory have been
consumed. Subsequent pixel operations are cached on disk. Operations to
memory are significantly faster but if your computer does not have a sufficient
amount of free memory you may want to adjust this threshold value.
|
|
Choose from: Red, Green, Blue, Opacity,
Cyan, Magenta, Yellow, or Black.
|
|
Use this option to extract a particular channel from the image.
Matte,
for example, is useful for extracting the opacity values from an image.
|
| simulate a charcoal drawing |
|
-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 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 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 option removes entire rows and columns,
and moves the remaining corner blocks leftward and upward to close the gaps.
|
| 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 feature requires the XML library. If the XML library
is not present, the option is ignored. |
| 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
option appears after all of the input images, all images are coalesced. |
| 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).
|
|
Choose between shared or private.
|
|
This option only applies when the default X server visual is PseudoColor
or GRAYScale. Refer to -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. |
| 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 for
more details.
|
|
Note, options -dither, -colorspace, and -treedepth
affect the color reduction algorithm.
|
|
Choices are: 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.
|
| annotate an image with a comment |
|
Use this option to assign a specific comment to the image. You can include the
image filename, type, width, height, or other image attribute by embedding
special format characters:
|
%b file size
%c comment
%d directory
%e filename extention
%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
%s scene number
%t top of filename
%u unique temporary filename
%w width
%x x resolution
%y y resolution
%# signature
\n newline
\r carriage return
-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.
|
| the type of image composition |
|
[This option is not used by convert but this section
is included because it describes the composite operators that are used
by the -draw option of convert.]
|
|
By default, each of the composite image pixels are replaced by the
corresponding image tile pixel. You can choose an alternate composite
operation:
|
Over
In
Out
Atop
Xor
Plus
Minus
Add
Subtract
Difference
Multiply
Bumpmap
Copy
CopyRed
CopyGreen
CopyBlue
CopyOpacity
|
How each operator behaves is described below.
|
- Over
-
The result will be the union of the two image shapes, with opaque areas of
composite image obscuring image in the region of overlap.
- In
-
The result is simply composite image cut by the shape
of image.
None of the image data of image will be in the result.
- Out
-
The resulting image is composite image with the shape
of image cut out.
- Atop
-
The result is the same shape as image image,
with composite image
obscuring image where the image shapes overlap. Note this differs
from over because the portion of composite image outside
image's shape does not appear in the result.
- Xor
-
The result is the image data from both composite image and
image
that is outside the overlap region. The overlap region will be blank.
- Plus
-
The result is just the sum of the image data. Output values are
cropped to 255 (no overflow). This operation is independent of the
matte channels.
- Minus
-
The result of composite image - image, with underflow
cropped to
zero. The matte channel is ignored (set to 255, full coverage).
- Add
-
The result of composite image + image, with overflow wrapping
around (mod 256).
- Subtract
-
The result of composite image - image, with underflow wrapping
around (mod 256). The add and subtract operators can be
used to perform reversible transformations.
- Difference
-
The result of abs(composite image - image). This is useful
for comparing two very similar images.
- Multiply
-
The result of composite image * image. This is useful for
the creation of drop-shadows.
- Bumpmap
-
The result image shaded by composite image.
- Copy
-
The resulting image is image replaced with composite image.
Here the matte information is ignored.
- CopyRed
-
The resulting image is the red layer in image replaced with the red
layer in composite image. The other layers are copied untouched.
- CopyGreen
-
The resulting image is the green layer in image replaced with the green
layer in composite image. The other layers are copied untouched.
- CopyBlue
-
The resulting image is the blue layer in image replaced with the blue
layer in composite image. The other layers are copied untouched.
- CopyOpacity
-
The resulting image is the matte layer in image replaced with the matte
layer in composite image. The other layers are copied untouched.
|
The image compositor requires a matte, or alpha channel in the image
for some operations. This extra channel usually defines a mask which
represents a sort of a cookie-cutter for the image. This is the case
when matte is 255 (full coverage) for pixels inside the shape, zero
outside, and between zero and 255 on the boundary. For certain
operations, if image does not have a matte channel, it is initialized
with 0 for any pixel matching in color to pixel location (0,0), otherwise
255 (to work properly borderwidth must be 0).
|
| the type of image compression |
|
Choices are: None, BZip, Fax,
Group4,
JPEG, Lossless,
LZW, RLE or Zip.
|
|
Specify +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. |
| 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>{+-}<y>{%}
|
| preferred size and location of the cropped image |
|
See -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 instead.
|
|
To specify a percentage width or height to be removed instead, append
%. For example
to crop the image by ten percent (five percent on each side of the image),
use -crop 10%.
|
|
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 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 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.
|
| displace image colormap by amount |
|
Amount defines the number of positions each colormap entry is
shifted.
|
| break down an image sequence into constituent parts |
|
The sequence of images
is terminated by the appearance of any option.
If the -deconstruct
option appears after all of the input images, all images are deconstructed. |
| 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.
|
| 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 dots per inch in the horizontal
and vertical direction. This option is used in concert with -page.
|
|
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.
|
| obtain image by descending window hierarchy |
| reduce the speckles within an image |
|
-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.
|
| specifies the X server to contact |
|
This option is used with convert for
obtaining image or font from this X server. See X(1).
|
|
Here are the valid methods:
|
0 No disposal specified.
1 Do not dispose between frames.
2 Overwrite frame with background color
from header.
3 Overwrite with previous frame.
| 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. |
| 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.
|
|
Use +dither to turn off dithering and to render Postscript without
text or graphic aliasing.
|
| 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 x,y
line x0,y0 x1,y1
rectangle x0,y0 x1,y1
roundRectangle x0,y0 w,h 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
color x0,y0 method
matte x0,y0 method
text x0,y0 string
image operator x0,y0 w,h filename
|
Point requires a single coordinate.
Line requires a start and end coordinate, while
rectangle
expects an upper left and lower right coordinate.
RoundRectangle has a center coordinate, a width and
height, and the width and height of the corners.
Circle has a center coordinate and a coordinate for
the outer edge. Use Arc to circumscribe an 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'
|
See Paths.
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 color to change the color of a pixel to the fill color (see
-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).
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 other image attribute by embedding special format character.
See -comment for details.
|
-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.
|
|
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'
|
See -compose for a description of the composite operators.
|
|
If the first character of string is @, the text is read from
a file titled by the remaining characters in the string.
|
|
You can set the primitive color, font, and font bounding box
color with
-fill, -font, and -box respectively. Options
are processed in command line order so be sure to use these
options before the -draw option.
|
| detect edges within an image |
| specify endianness (MSB or LSB) of output image |
|
Use +endian to revert to unspecified endianness.
|
| apply a digital filter to enhance a noisy image |
| perform histogram equalization to the image |
| color to use when filling a graphic primitive |
|
The color is specified using the format described in the "Color Names"
section of X(1). |
|
See -draw for further
details.
|
| use this type of filter when resizing an image |
|
Use this option to affect the resizing operation of an image (see
-geometry).
Choose from these filters:
|
Point
Box
Triangle
Hermite
Hanning
Hamming
Blackman
Gaussian
Quadratic
Cubic
Catrom
Mitchell
Lanczos
Bessel
Sinc
|
The default filter is Lanczos
|
| 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
option appears after all of the input images, all images are flattened. |
|
reflect the scanlines in the vertical direction.
|
|
reflect the scanlines in the horizontal direction.
|
| 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 OPTION1.
|
| define the foreground color |
|
The color is specified using the format described in the "Color Names"
section of X(1). |
|
This option will convert any image to the image format you specify.
See ImageMagick(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.
|
| output formatted image characteristics |
|
Use this option to print information about the image in a format of your
choosing. You can include the image filename, type, width, height,
or other image attributes by embedding special format characters: |
%b file size
%c comment
%d directory
%e filename extention
%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
%s scene number
%t top of filename
%u unique temporary filename
%w width
%x x resolution
%y y resolution
%# signature
\n newline
\r carriage return
-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. |
|
-frame <width>x<height>+<outer bevel width>+<inner bevel width>
|
| surround the image with an ornamental border |
|
See -geometry for details
about the geometry specification.
The -frame option is not affected by the -gravity option.
|
|
The color of the border is specified with the
-mattecolor command
line option.
|
| include the X window frame in the imported image |
| 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 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 or 65535).
|
| 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
(e.g., 1.7/2.3/1.2).
|
|
Use +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).
|
| blur the image with a gaussian operator |
|
Use the given radius and standard deviation (sigma).
|
|
-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 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.
|
|
When used with animate and display, offsets are handled in
the same manner as in X(1) and the -gravity option is not used.
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. |
|
When used as a composite option, -geometry
gives the dimensions of the image and its location with respect
to the composite image. If the -gravity option is present
with NorthEast, East, or SouthEast gravity, the x
represents the distance from the right edge of the image to the right edge of
the composite image. Similarly, if the -gravity option is present
with SouthWest, South, or SouthEast gravity, y
is measured between the bottom edges. Accordingly, a positive offset will
never point in the direction outside of the image. The
offsets are not affected by "%"; they are always measured in pixels. |
|
When used as a convert, import or mogrify option,
-geometry
specifies the size of the output image. The offsets, if present, are ignored.
|
|
When used as a montage option, -geometry specifies the image
size and border size for each tile; default is 256x256+0+0. Negative
offsets (border dimensions) are meaningless. The -gravity
option affects the placement of the image within the tile; the default
gravity for this purpose is Center. If the "%" sign appears in
the geometry specification, the tile size is the specified percentage of
the original dimensions of the first tile.
|
| 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 or other
graphic primitive when annotating
the image. For example Center gravity forces the text to be centered
within the image. By default, the image gravity is NorthWest.
See -draw for more details about graphic primitives.
|
|
The -gravity option is also used in concert with the -geometry
option and other options that take <geometry> as a parameter, such
as the -crop option. See -geometry for details of how the
-gravity option interacts with the
<x> and <y> parameters of a geometry
specification. |
|
When used as an option to composite, -gravity
gives the direction that the image gravitates within the composite.
|
|
When used as an option to montage, -gravity gives the direction
that an image gravitates within a tile. The default gravity is Center
for this purpose.
|
| specify the icon geometry |
|
Offsets, if present in the geometry specification, are handled in
the same manner as the -geometry option, using X11 style to handle
negative offsets. |
| implode image pixels about the center |
| 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).
Choose from these intents:
Absolute, Perceptual, Relative, Saturation
|
|
The default intent is undefined.
|
| 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.
|
| 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 other image attribute
by embedding special format character. See -comment for details.
|
-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.
|
| adjust the level of image contrast |
|
Give three point values delineated with commas: black, mid, and white
(e.g. 10,1.0,65000). The white and black points range from 0 to MaxRGB
and mid ranges from 0 to 10.
|
| the line width for subsequent draw operations |
|
Choices are: Delegate, Format, Magic,
Module, or Type.
|
|
This option lists entries from the ImageMagick configuration files.
|
| add Netscape loop extension to your GIF animation |
|
A value other than zero forces the animation to repeat itself up to
iterations
times.
|
| 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 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
option appears after all of the input images, all images are mapped. |
|
display image using this type. |
|
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. |
|
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 opacity channel, the opacity of each pixel is
used to define the mask. Otherwise, the intensity (gray level) of each
pixel is used. |
|
Use +mask to remove the clipping mask. |
|
It is not necessary to use -clip to activate the mask; -clip
is implied by -mask. |
| store matte channel if the image has one |
|
If the image does not have a matte channel, create an opaque one.
|
|
Use +matte to ignore the matte channel and to avoid writing a
matte channel in the output file. |
|
The color is specified using the format described in the "Color Names"
section of X(1). |
| apply a median filter to the image |
| 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 120,90.
|
| transform the image to black and white |
|
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
option appears after all of the input images, all images are morphed. |
| create a mosaic from an image sequence |
|
The -page option is used to locate the images within the mosaic. |
|
The sequence of images
is terminated by the appearance of any option.
If the -mosaic
option appears after all of the input images, all images are included
in the mosaic. |
| 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
to only negate the grayscale pixels of the image.
|
| 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 followed by a noise type to add noise to an image. Choose
from these noise types:
|
Uniform
Gaussian
Multiplicative
Impulse
Laplacian
Poisson
|
The -noop option can be used to terminate a group of images
and reset all options to their default values, when no other option is
desired. |
| transform image to span the full range of color values |
|
This is a contrast enhancement technique.
|
| change this color to the pen color within the image |
|
The color is specified using the format described in the "Color Names"
section of X(1). |
|
See -fill for more details.
|
|
-page <width>x<height>{+-}<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 behaves much like
-geometry (e.g. -page letter+43+43>).
|
|
To position a GIF image, use -page{+-}<x>{+-}<y>
(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
{+-}<xoffset>{+-}<y
offset>. Use
-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
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 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.
|
|
Each pixel is replaced by the most frequent color in a circular neighborhood
whose width is specified with radius.
|
| pause between animation loops [animate] |
|
Pause for the specified number of seconds before repeating the
animation. |
| pause between snapshots [import] |
|
Pause for the specified number of seconds before taking the next
snapshot. |
| specify the pen color for drawing operations |
|
The color is specified using the format described in the "Color Names"
section of X(1). |
| efficiently determine image characteristics |
| pointsize of the Postscript, OPTION1, or TrueType font |
|
Use this option to affect the preview operation of an image (e.g.
convert
-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 a sequence of images |
|
The sequence of images
is terminated by the appearance of any option. |
If the -process
option appears after all of the input images, all images are processed. |