ImageMagick
ImageMagick(1) ImageMagick(1)
NAME ImageMagick - commandline utilities to create, edit, or convert
images
SYNOPSIS
animate [ options ... ] file [ [ options ... ] file ... ]
composite [ options ... ] image composite [ mask ] composited
conjure [ options ] script.msl [ [ options ] script.msl ]
convert [ [ options ... ] [ input_file ... ] ... [ output_file ] ]
display [ options ... ] file ... [ [options ... ]file ... ]
identify file [ file ... ]
import [ options ... ] file
mogrify [ options ... ] file ...
montage [ options ... ] file [ [ options ... ] file ... ] output_file
DESCRIPTION
ImageMagick provides a suite of commandline utilities for creating,
converting, editing, and displaying images:
Display is a machine architecture independent image processing and dis-
play program. It can display an image on any workstation display run-
ning an X server.
Import reads an image from any visible window on an X server and out-
puts it as an image file. You can capture a single window, the entire
screen, or any rectangular portion of the screen.
Montage creates a composite by combining several separate images. The
images are tiled on the composite image with the name of the image
optionally appearing just below the individual tile.
Convert converts an input file using one image format to an output file
with a differing image format.
Mogrify transforms an image or a sequence of images. These transforms
include image scaling, image rotation, color reduction, and others. The
transmogrified image overwrites the original image.
Identify describes the format and characteristics of one or more image
files. It will also report if an image is incomplete or corrupt.
Composite composites images to create new images.
Conjure interprets and executes scripts in the Magick Scripting Lan-
guage (MSL).
The ImageMagick utilities recognize the following image formats:
Name Mode Description
o 8BIM *rw- Photoshop resource format
o AFM *r-- TrueType font
o APP1 *rw- Photoshop resource format
o ART *r-- PF1: 1st Publisher
o AVI *r-- Audio/Visual Interleaved
o AVS *rw+ AVS X image
o BIE *rw- Joint Bi-level Image experts Group
interchange format
o BMP *rw+ Microsoft Windows bitmap image
o CAPTION *r+ Caption (requires separate size info)
o CMYK *rw- Raw cyan, magenta, yellow, and black
samples (8 or 16 bits, depending on
the image depth)
o CMYKA *rw- Raw cyan, magenta, yellow, black, and
matte samples (8 or 16 bits, depending
on the image depth)
o CUT *r-- DR Halo
o DCM *r-- Digital Imaging and Communications in
Medicine image
o DCX *rw+ ZSoft IBM PC multi-page Paintbrush
o DIB *rw+ Microsoft Windows bitmap image
o DPS *r-- Display Postscript
o DPX *r-- Digital Moving Picture Exchange
o EPDF *rw- Encapsulated Portable Document Format
o EPI *rw- Adobe Encapsulated PostScript
Interchange format
o EPS *rw- Adobe Encapsulated PostScript
o EPS2 *-w- Adobe Level II Encapsulated PostScript
o EPS3 *-w- Adobe Level III Encapsulated PostScript
o EPSF *rw- Adobe Encapsulated PostScript
o EPSI *rw- Adobe Encapsulated PostScript
Interchange format
o EPT *rw- Adobe Encapsulated PostScript with TIFF
preview
o FAX *rw+ Group 3 FAX
o FILE *r-- Uniform Resource Locator
o FITS *rw- Flexible Image Transport System
o FPX *rw- FlashPix Format
o FTP *r-- Uniform Resource Locator
o G3 *rw- Group 3 FAX
o GIF *rw+ CompuServe graphics interchange format
o GIF87 *rw- CompuServe graphics interchange format
(version 87a)
o GRADIENT *r-- Gradual passing from one shade to
another
o GRANITE *r-- Granite texture
o GRAY *rw+ Raw gray samples (8 or 16 bits,
depending on the image depth)
o H *rw- Internal format
o HDF -rw+ Hierarchical Data Format
o HISTOGRAM *-w- Histogram of the image
o HTM *-w- Hypertext Markup Language and a
client-side image map
o HTML *-w- Hypertext Markup Language and a
client-side image map
o HTTP *r-- Uniform Resource Locator
o ICB *rw+ Truevision Targa image
o ICM *rw- ICC Color Profile
o ICO *r-- Microsoft icon
o ICON *r-- Microsoft icon
o IMPLICIT *---
o IPTC *rw- IPTC Newsphoto
o JBG *rw+ Joint Bi-level Image experts Group
interchange format
o JBIG *rw+ Joint Bi-level Image experts Group
interchange format
o JP2 *rw- JPEG-2000 JP2 File Format Syntax
o JPC *rw- JPEG-2000 Code Stream Syntax
o JPEG *rw- Joint Photographic Experts Group
JFIF format
o JPG *rw- Joint Photographic Experts Group
JFIF format
o LABEL *r-- Text image format
o LOGO *rw- ImageMagick Logo
o M2V *rw+ MPEG-2 Video Stream
o MAP *rw- Colormap intensities (8 or 16 bits,
depending on the image depth) and
indices (8 or 16 bits, depending
on whether colors exceeds 256).
o MAT *-w+ MATLAB image format
o MATTE *-w+ MATTE format
o MIFF *rw+ Magick image format
o MNG *rw+ Multiple-image Network Graphics
o MONO *rw- Bi-level bitmap in least-significant-
-byte-first order
o MPC -rw- Magick Persistent Cache image format
o MPEG *rw+ MPEG-1 Video Stream
o MPG *rw+ MPEG-1 Video Stream
o MPR *r-- Magick Persistent Registry
o MSL *r-- Magick Scripting Language
o MTV *rw+ MTV Raytracing image format
o MVG *rw- Magick Vector Graphics
o NETSCAPE *r-- Netscape 216 color cube
o NULL *r-- Constant image of uniform color
o OTB *rw- On-the-air bitmap
o P7 *rw+ Xv thumbnail format
o PAL *rw- 16bit/pixel interleaved YUV
o PALM *rw- Palm Pixmap format
o PBM *rw+ Portable bitmap format (black and white)
o PCD *rw- Photo CD
o PCDS *rw- Photo CD
o PCL *-w- Page Control Language
o PCT *rw- Apple Macintosh QuickDraw/PICT
o PCX *rw- ZSoft IBM PC Paintbrush
o PDB *r-- Pilot Image Format
o PDF *rw+ Portable Document Format
o PFA *r-- TrueType font
o PFB *r-- TrueType font
o PFM *r-- TrueType font
o PGM *rw+ Portable graymap format (gray scale)
o PICON *rw- Personal Icon
o PICT *rw- Apple Macintosh QuickDraw/PICT
o PIX *r-- Alias/Wavefront RLE image format
o PLASMA *r-- Plasma fractal image
o PM *rw- X Windows system pixmap (color)
o PNG *rw- Portable Network Graphics
o PNM *rw+ Portable anymap
o PPM *rw+ Portable pixmap format (color)
o PREVIEW *-w- Show a preview an image enhancement,
effect, or f/x
o PS *rw+ Adobe PostScript
o PS2 *-w+ Adobe Level II PostScript
o PS3 *-w+ Adobe Level III PostScript
o PSD *rw- Adobe Photoshop bitmap
o PTIF *rw- Pyramid encoded TIFF
o PWP *r-- Seattle Film Works
o RAS *rw+ SUN Rasterfile
o RGB *rw+ Raw red, green, and blue samples (8 or
16 bits, depending on the image depth)
o RGBA *rw+ Raw red, green, blue, and matte samples
(8 or 16 bits, depending on the image
depth)
o RLA *r-- Alias/Wavefront image
o RLE *r-- Utah Run length encoded image
o ROSE *rw- 70x46 Truecolor test image
o SCT *r-- Scitex HandShake
o SFW *r-- Seattle Film Works
o SGI *rw+ Irix RGB image
o SHTML *-w- Hypertext Markup Language and a
client-side image map
o STEGANO *r-- Steganographic image
o SUN *rw+ SUN Rasterfile
o SVG *rw+ Scalable Vector Gaphics
o TEXT *rw+ Raw text
o TGA *rw+ Truevision Targa image
o TIF *rw+ Tagged Image File Format
o TIFF *rw+ Tagged Image File Format
o TILE *r-- Tile image with a texture
o TIM *r-- PSX TIM
o TTF *r-- TrueType font
o TXT *rw+ Raw text
o UIL *-w- X-Motif UIL table
o UYVY *rw- 16bit/pixel interleaved YUV
o VDA *rw+ Truevision Targa image
o VICAR *rw- VICAR rasterfile format
o VID *rw+ Visual Image Directory
o VIFF *rw+ Khoros Visualization image
o VST *rw+ Truevision Targa image
o WBMP *rw- Wireless Bitmap (level 0) image
o WMF *r-- Windows Metafile
o WPG *r-- Word Perfect Graphics
o X *rw- X Image
o XBM *rw- X Windows system bitmap (black
and white)
o XC *r-- Constant image uniform color
o XCF *r-- GIMP image
o XML *r-- Scalable Vector Gaphics
o XPM *rw- X Windows system pixmap (color)
o XV *rw+ Khoros Visualization image
o XWD *rw- X Windows system window dump (color)
o YUV *rw- CCIR 601 4:1:1
Modes:
* Native blob support
r Read
w Write
+ Multi-image
Support for some of these formats require additional programs or
libraries. README tells where to find this software.
Note, a format delineated with + means that if more than one image is
specified, it is composited into a single multi-image file. Use +adjoin
if you want a single image produced for each frame.
Your installation might not support all of the formats in the list. To
get an up-to-date listing of the formats supported by your particular
configuration, run "convert -list format".
Raw images are expected to have one byte per pixel unless ImageMagick
is compiled in 16-bit mode. Here, the raw data is expected to be stored
two bytes per pixel in most-significant-byte-first order. You can tell
if ImageMagick was compiled in 16-bit mode by typing "convert" without
any options, and looking for "Q:16" in the first line of output.
OPTIONS
Options are processed in command line order. Any option you specify on
the command line remains in effect for the set of images that follows,
until the set is terminated by the appearance of any option or -noop.
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 <dis-
tance>{%}" means you can use the option "-fuzz 10" or "-fuzz 2%".
-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 to
force this behavior.
-affine <matrix>
drawing transform matrix
This option provides a transform matrix {sx,rx,ry,sy,tx,ty} for
use by subsequent -draw or -transform options.
-antialias
remove pixel aliasing
-append
append a set of images
This option creates a single image where the images in the orig-
inal set are stacked top-to-bottom. If they are not of the same
width, any narrow images will be expanded to fit using the back-
ground 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.
-average
average a set of images
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.
-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 in the "Color
Names" section of X(1). Refer to "X Resources", below, for
details.
-background <color>
the background color
The color is specified using the format described in the "Color
Names" section of X(1).
-blur <radius>x<sigma>
blur the image with a gaussian operator
Blur with the given radius and standard deviation (sigma).
-border <width>x<height>
surround the image with a border of color
See -geometry for details about the geometry specification.
-bordercolor <color>
the border color
The color is specified using the format described in the "Color
Names" section of X(1).
-borderwidth <geometry>
the border width
-box <color>
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.
-cache <threshold>
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.
-channel <type>
the type of channel
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.
-charcoal <factor>
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.
-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 feature requires the XML library. If the XML library
is not present, the option is ignored.
-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 option appears after all of the input images,
all images are coalesced.
-colorize <value>
colorize the image with the pen color
Specify the amount of colorization as a percentage. You can
apply separate colorization values to the red, green, and blue
channels of the image with a colorization value list delineated
with slashes (e.g. 0/0/50).
-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 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. Refer to quan-
tize for more details.
Note, options -dither, -colorspace, and -treedepth affect the
color reduction algorithm.
-colorspace <value>
the type of colorspace
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 pre-
serves the matte channel of the image if it exists.
The -colors or -monochrome option is required for this option to
take effect.
-comment <string>
annotate an image with a comment
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
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
[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
.in 20
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
.in 20
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
.in 20
The resulting image is composite image with the shape of
image cut out.
Atop
.in 20
The result is the same shape as image image, with compos-
ite image obscuring image where the image shapes overlap.
Note this differs from over because the portion of compos-
ite image outside image's shape does not appear in the
result.
Xor
.in 20
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
.in 20
The result is just the sum of the image data. Output val-
ues are cropped to 255 (no overflow). This operation is
independent of the matte channels.
Minus
.in 20
The result of composite image - image, with underflow
cropped to zero. The matte channel is ignored (set to
255, full coverage).
Add
.in 20
The result of composite image + image, with overflow wrap-
ping around (mod 256).
Subtract
.in 20
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
.in 20
The result of abs(composite image - image). This is use-
ful for comparing two very similar images.
Multiply
.in 20
The result of composite image * image. This is useful for
the creation of drop-shadows.
Bumpmap
.in 20
The result image shaded by composite image.
Copy
.in 20
The resulting image is image replaced with composite
image. Here the matte information is ignored.
CopyRed
.in 20
The resulting image is the red layer in image replaced
with the red layer in composite image. The other layers
are copied untouched.
CopyGreen
.in 20
The resulting image is the green layer in image replaced
with the green layer in composite image. The other layers
are copied untouched.
CopyBlue
.in 20
The resulting image is the blue layer in image replaced
with the blue layer in composite image. The other layers
are copied untouched.
CopyOpacity
.in 20
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).
-compress <type>
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.
Use the -quality option to set the compression level to be used
by JPEG, PNG, MIFF, and MPEG encoders. Use the -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 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 dis-
tance 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 dis-
tance is measured upward between the bottom edges.
If the x and y offsets are omitted, a set of tiles of the speci-
fied 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 enable debug printout
-deconstruct
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.
-delay <1/100ths of a second>
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.
-density <width>x<height>
vertical and horizontal resolution in pixels of the image
This option specifies an image density when decoding a
PostScript or Portable Document page. The default is 72 dots per
inch in the horizontal and vertical direction. This option is
used in concert with -page.
-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>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 dis-
placement. 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
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 <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 or -monochrome option is required for this option to
take effect.
Use +dither to turn off dithering and to render Postscript with-
out text or graphic aliasing.
-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, transforma-
tions, 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 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 option. Except for the line and point primi-
tives, they are filled with the color specified in the preceding
-fill option. For unfilled shapes, use -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 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'
Paths (See 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) ele-
ments. Compound paths (i.e., a path with subpaths, each consist-
ing 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 for a descrip-
tion of the composite operators.
Use text to annotate an image with text. Follow the text coordi-
nates with a string. If the string has embedded spaces, enclose
it in double quotes. Optionally you can include the image file-
name, type, width, height, or other image attribute by embedding
special format character. See -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 origen of the main image. If the -region option
precedes the -draw option, the origen 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 origen 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 option. Transformations are cumulative within the -draw
option. The initial affine matrix is not affected; that matrix
is only changed by the appearance of another -affine option. If
another -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). 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 tar-
get 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 primi-
tive 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.
You can set the primitive color, font, and font bounding box
color with -fill, -font, and -box respectively. Options are pro-
cessed in command line order so be sure to use these options
before the -draw option.
-edge <radius>
detect edges within an image
-emboss
emboss an image
-encoding <type>
specify the font encoding
Choose from AdobeCustom, AdobeExpert, AdobeStandard, AppleRoman,
BIG5, GB2312, Latin 2, None, SJIScode, Symbol, Unicode, Wansung.
-endian <type>
specify endianness (MSB or LSB) of output image
Use +endian to revert to unspecified endianness.
-enhance
apply a digital filter to enhance a noisy image
-equalize
perform histogram equalization to the image
-fill <color>
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.
-filter <type>
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
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.
-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, True-
type, or OPTION1 font. For example, Arial.ttf is a Truetype
font, ps:helvetica is Postscript, and x:fixed is OPTION1.
-foreground <color>
define the foreground color
The color is specified using the format described in the "Color
Names" section of X(1).
-format <type>
the image format type
This option will convert any image to the image format you spec-
ify. See ImageMagick(1) for a list of image format types sup-
ported by ImageMagick.
By default the file is written to its original name. However,
if the filename extension matches a supported format, the exten-
sion is replaced with the image format type specified with -for-
mat. 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
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
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.
-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.
-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 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).
-gamma <value>
level of gamma correction
The same color image displayed on two different workstations may
look different due to differences in the display monitor. Use
gamma correction to adjust for this color difference. Reasonable
values extend from 0.8 to 2.3.
You can apply separate gamma values to the red, green, and blue
channels of the image with a gamma value list delineated with
slashes (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).
-gaussian <radius>x<sigma>
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 speci-
fication. 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 redi-
rection.
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 South-
West, 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. To specify
the dimensions of the composite image, use the -resize option.
When used as a convert, import or mogrify option, -geometry is
synonymous with -resize and 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. To specify the dimensions of the montage, use the -resize
option.
-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 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 direc-
tion 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.
-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 option, using X11 style to
handle negative offsets.
-iconic
iconic animation
-immutable
make image immutable
-implode <factor>
implode image pixels about the center
-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). 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 pro-
gressive JPEG image.
-label <name>
assign a label to an image
Use this option to assign a specific label to the image. Option-
ally you can include the image filename, type, width, height, or
other image attribute by embedding special format character. See
-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.
-level <value>
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.
-linewidth
the line width for subsequent draw operations
-list <type>
the type of list
Choices are: Delegate, Format, Magic, Module, or Type.
This option lists entries from the ImageMagick configuration
files.
-loop <iterations>
add Netscape loop extension to your GIF animation
A value other than zero forces the animation to repeat itself up
to iterations times.
-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 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.
-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, oth-
erwise 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 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.
-matte 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.
-mattecolor <color>
specify the color to be used with the -frame option
The color is specified using the format described in the "Color
Names" section of X(1).
-median <radius>
apply a median filter to the image
-mode <value>
mode of operation
-modulate <value>
vary the brightness, saturation, and hue of an image
Specify the percent change in brightness, the color saturation,
and the hue separated by commas. For example, to increase the
color brightness by 20% and decrease the color saturation by 10%
and leave the hue unchanged, use: -modulate 120,90.
-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 option appears after all of the input
images, all images are morphed.
-mosaic
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.
-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 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 informa-
tion 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
-noop NOOP (no option)
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.
-normalize
transform image to span the full range of color values
This is a contrast enhancement technique.
-opaque <color>
change this color to the pen color within the image
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.
-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.
-pen <color>
specify the pen color for drawing operations
The color is specified using the format described in the "Color
Names" section of X(1).
-ping efficiently determine image characteristics
-pointsize <value>
pointsize of the Postscript, OPTION1, or TrueType font
-preview <type>
image preview type
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 <command>
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.
-profile <filename>
add ICM, IPTC, or generic profile to image
-profile filename adds an ICM (ICC color management), IPTC
(newswire information), or a generic profile to the image.
Use +profile icm, +profile iptc, or +profile profile_name to
remove the respective profile. Use identify -verbose to find
out what profiles are in the image file. Use +profile "*" to
remove all profiles.
To extract a profile, the -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 quality is 75. Use the
-sampling_factor option to specify the factors for chroma down-
sampling.
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 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, other-
wise 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-abso-
lute-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 com-
pression is always lossless.
For further information, see the PNG specification.
-raise <width>x<height>
lighten or darken image edges
This will create a 3-D effect. See -geometry for details
details about the geometry specification. Offsets are not used.
Use -raise to create a raised effect, otherwise use +raise.
-region <width>x<height>{+-}<x>{+-}<y>
apply options to a portion of the image
The x and y offsets are treated in the same manner as in -crop.
-remote
perform a remote operation
The only command recognized at this time is the name of an image
file to load.
-resize <width>x<height>{%}{@}{!}{<}{>}
resize an image
This is an alias for the -geometry option and it behaves in the
same manner. If the -filter option precedes the -resize option,
the specified filter is used.
There are some exceptions:
When used as a composite option, -resize conveys the preferred
size of the output image, while -geometry conveys the size and
placement of the composite image within the main image.
When used as a montage option, -resize conveys the preferred
size of the montage, while -geometry conveys information about
the tiles.
-roll {+-}<x>{+-}<y>
roll an image vertically or horizontally
See -geometry for details the geometry specification. The x and
y offsets are not affected by the -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 misinter-
preted as a file redirection.
Empty triangles left over from rotating the image are filled
with the color defined as background (class backgroundColor).
See X(1) for details.
-sample <geometry>
scale image with pixel sampling
See -geometry for details about the geometry specification.
-sample ignores the -filter selection if the -filter option is
present. Offsets, if present in the geometry string, are
ignored, and the -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 omit-
ted, 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 2x1to specify the 4:2:2
downsampling method
-scale <geometry>
scale the image.
See -geometry for details about the geometry specification.
-scale uses a simpler, faster algorithm, and it ignores the
-filter selection if the -filter option is present. Offsets, if
present in the geometry string, are ignored, and the -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.
-seed <value>
pseudo-random number generator seed value
-segment <cluster threshold>x<smoothing threshold>
segment an image
Segment an image by analyzing the histograms of the color compo-
nents and identifying units that are homogeneous with the fuzzy
c-means technique.
Specify cluster threshold as the number of pixels in each clus-
ter must exceed the the cluster threshold to be considered
valid. Smoothing threshold eliminates noise in the second
derivative of the histogram. As the value is increased, you can
expect a smoother second derivative. The default is 1.5. See
"Image Segmentation", below, for details.
-shade <azimuth>x<elevation>
shade the image using a distant light source
Specify azimuth and elevation as the position of the light
source. Use +shade to return the shading results as a grayscale
image.
-shadow <radius>x<sigma>
shadow the montage
-shared_memory
use shared memory
This option specifies whether the utility should attempt 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>x<sigma>
sharpen the image
Use a gaussian operator of the given radius and standard devia-
tion (sigma).
-shave <width>x<height>
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, cre-
ating 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 mea-
sured relative to the X axis.
Empty triangles left over from shearing the image are filled
with the color defined as background (class backgroundColor).
See X(1) for details.
-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 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 <factor>
negate all pixels above the threshold level
Specify factor as the percent threshold of the intensity (0 -
99.9%).
This option produces a solarization effect seen when exposing a
photographic film to light during the development process.
-spread <amount>
displace image pixels by a random amount
Amount defines the size of the neighborhood around each pixel to
choose a candidate pixel to swap.
-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 stegano-
graphic 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.
-stroke <color>
color to use when stroking a graphic primitive
The color is specified using the format described in the "Color
Names" section of X(1).
See -draw for further details.
-strokewidth <value>
set the stroke width
See -draw for further details.
-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 (type-
writer style) formatted text. The default is 14 point Courier.
You can tag a font to specify whether it is a Postscript, True-
type, 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>
threshold the image
Create a bi-level image such that any pixel intensity that is
equal or exceeds the threshold is reassigned the maximum inten-
sity otherwise the minimum intensity.
-tile <filename>
tile image when filling a graphic primitive
-tile <geometry>
layout of images [montage]
-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 file-
name, 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
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 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 in the "Color
Names" section of X(1).
-treedepth <value>
tree depth for the color reduction algorithm
Normally, this integer value is zero or one. A zero or one tells
display to choose 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 quantize for more
details.
The -colors or -monochrome option 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 to make -trim remove edges that
are nearly the same color as the corner pixels.
-type <type>
the image type
Choose from: Bilevel, Grayscale, Palette, PaletteMatte, True-
Color, TrueColorMatte, ColorSeparation, ColorSeparationMatte, or
Optimize.
Normally, when a format supports different subformats such as
grayscale and truecolor, the encoder will try to choose an effi-
cient subformat. The -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.pgm -type TrueColor bird.jpg
Similarly, using -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 dis-
played image accordingly.
-units <type>
the type of image resolution
Choose from: Undefined, PixelsPerInch, or PixelsPerCentimeter.
-unsharp <radius>x<sigma>
sharpen the image with an unsharp mask operator
Use the given radius and standard deviation (sigma).
-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 miff for a description of the
image class.
If -colors is also specified, the total unique colors in the
image and color reduction error values are printed. Refer to
quantize for a description of these values.
-view <string>
FlashPix viewing parameters
-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>x<saturation>
percent brightness and saturation of a watermark
-wave <amplitude>x<wavelength>
alter an image along a sine wave
Specify amplitude and wavelength of the wave.
-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 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 to reduce the number of colors.
-window_group
specify the window group
-write <filename>
write an image sequence [convert, composite]
The image sequence following the -write filenameoption is writ-
ten out, and then 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
filename option.
-write <filename>
write the image to a file [display]
If filename already exists, you will be prompted as to whether
it should be overwritten.
By default, the image is written in the format that it was read
in as. To specify a particular image format, prefix filename
with the image type and a colon (e.g., ps:image) or specify the
image type as the filename suffix (e.g., image.ps). See con-
vert(1) for a list of valid image formats. Specify file as -
for standard output. If file has the extension .Z or .gz, the
file size is compressed using compress or gzip respectively.
Precede the image file name with | to pipe to a system command.
Use -compress to specify the type of image compression.
The equivalent X resource for this option is writeFilename
(class WriteFilename). See "X Resources", below, for details.
FILES AND FORMATS
By default, the image format is determined by its magic number, i.e.,
the first few bytes of the file. To specify a particular image format,
precede the filename with an image format name and a colon
(i.e.ps:image) or specify the image type as the filename suffix. The
magic number takes precedence over the filename suffix and the prefix
takes precedence over the magic number and the suffix in input files.
The prefix takes precedence over the filename suffix in output files.
To read the "built-in" formats (GRANITE, H, LOGO, NETSCAPE, PLASMA, and
ROSE) use a prefix (including the colon) without a filename or suffix.
To read the XC format, follow the colon with a color specification. To
read the CAPTION format, follow the colon with a text string or with a
filename prefixed with the at symbol (@).
When you specify X as your image type, the filename has special mean-
ing. It specifies an X window by id, name, or root. If no filename is
specified, the window is selected by clicking the mouse in the desired
window.
Specify input_file as - for standard input, output_file as - for stan-
dard output. If input_file has the extension .Z or .gz, the file is
uncompressed with uncompress or gunzip respectively. If output_file has
the extension .Z or .gz, the file is compressed using with compress or
gzip respectively.
Finally, when running on platforms that allow it, precede the image
file name with | to pipe to or from a system command (this feature is
not available on VMS, Win32 and Macintosh platforms).
Use an optional index enclosed in brackets after an input file name to
specify a desired subimage of a multi-resolution image format like
Photo CD (e.g. img0001.pcd[4]) or a range for MPEG images (e.g.
video.mpg[50-75]). A subimage specification can be disjoint (e.g.
image.tiff[2,7,4]). For raw images, specify a subimage with a geometry
(e.g. -size 640x512 image.rgb[320x256+50+50]). Single images are writ-
ten with the filename you specify. However, multi-part images (e.g., a
multi-page PostScript document with +adjoin specified) are written with
the filename followed by a period (.) and the 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,
image%02d.miff
writes files image00.miff, image01.miff, etc.
When running a commandline utility, you can prepend an at sign @ to a
filename to read a list of image filenames from that file. This is con-
venient in the event you have too many image filenames to fit on the
command line.
ENVIRONMENT
DISPLAY
To get the default host, display number, and screen.
SEE ALSO
animate(1), display(1), animate(1), display(1), identify(1), import(1),
montage(1), mogrify(1), composite(1)
COPYRIGHT
Copyright (C) 2002 ImageMagick Studio
Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and associated documentation files ("ImageMag-
ick"), to deal in ImageMagick without restriction, including without
limitation the rights to use, copy, modify, merge, publish, distribute,
sublicense, and/or sell copies of ImageMagick, and to permit persons to
whom the ImageMagick is furnished to do so, subject to the following
conditions:
The above copyright notice and this permission notice shall be included
in all copies or substantial portions of ImageMagick.
The software is provided "as is", without warranty of any kind, express
or implied, including but not limited to the warranties of mer-
chantability, fitness for a particular purpose and noninfringement.In
no event shall ImageMagick Studio be liable for any claim, damages or
other liability, whether in an action of contract, tort or otherwise,
arising from, out of or in connection with ImageMagick or the use or
other dealings in ImageMagick.
Except as contained in this notice, the name of the ImageMagick Studio
LLC shall not be used in advertising or otherwise to promote the sale,
use or other dealings in ImageMagick without prior written authoriza-
tion from the ImageMagick Studio.
AUTHORS
John Cristy, ImageMagick Studio LLC,
Glenn Randers-Pehrson, ImageMagick Studio LLC.
ImageMagick Date: 2002/02/15 01:00:00 ImageMagick(1)
