Skip to page contents

[ –adjoin | –affine | –annotate | –antialias | –append | –authenticate | –average | –backdrop | –background | –bias | –blue-primary | –blur | –border | –bordercolor | –borderwidth | –cache | –channel | –charcoal | –chop | –clip –clone | –coalesce | –colorize | –colormap | –colors | –colorspace | –combine | –comment | –compose | –compress | –contrast | –convolve | –crop | –cycle | –debug | –deconstruct | –define | –delay | –delete | –density | –depth | –descend | despeckle | –displace | –display | –dispose | –dissolve | –dither | –draw | –edge | –emboss | –encoding | –endian | –enhance | –equalize | –evaluate | –extent | –extract | –fill | –filter | –flatten | –flip | –flop | –font | –foreground | –format | –format | –frame | –frame | –fuzz | –fx | –gamma | –gaussian | –geometry | –gravity | –green-primary | –help | –iconGeometry | –iconic | –immutable | –implode | –insert | –intent | –interlace | –label | –lat | –level | –limit | –linewidth | –list | –log | –loop | –magnify | –map | –map | –mask | –matte | –mattecolor | –median | –metric | –mode | –modulate | –monitor | –monochrome | –morph | –mosaic | –motion-blur | –name | –negate | –noise | –normalize | –opaque | –orient | –page | –paint | –pause | –pause | –pen | –ping | –pointsize | –posterize | –preview | –process | –profile | –quality | –quiet | –radial-blur | –raise | –random-threshold | –red-primary | –region | –remote | –render | –repage | –resample | –resize | –roll { | –rotate | –sample | –sampling-factor | –scale | –scene | –scenes | –screen | –segment | –separate | –sepia-tone | –set | –shade | –shadow | –shared-memory | –sharpen | –shave | –shear | –sigmoidal-contrast | –silent | –size | –snaps | –solarize | –splice | –spread | –stegano | –stereo | –strip | –stroke | –strokewidth | –support | –swap | –swirl | –text-font | –texture | –threshold | –thumbnail | –tile | –tint | –title | –transform | –transparent | –treedepth | –trim | –type | –undercolor | –update | –units | –unsharp | –verbose | –version | –view | –virtual-pixel | –visual | –watermark | –wave | –white-point | –window | –window-group | –write ]

Below is list of command-line options recognized by the ImageMagick command-line tools. If you want a description of a particular option, click on the option name in the navigation bar above and you will go right to it.

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 for all image format.

drawing transformation matrix.

This option provides a transformation matrix {s_x, r_x, r_y, s_y, t_x, t_y} for use by subsequent –draw or –transform options.

The transformation matrix has 3x3 elements, but three of them are omitted from the input because they are constant. The new coordinate { x^', y^' } of a pixel {x, y} in the transformed image is calculated using the following matrix equation:

                                |  sx  rx  0 |
  { x'  y'  1 } = { x  y  1 } * |  ry  sy  0 |
                                |  tx  ty  1 |

The size of the resulting image is set so that the rotated and scaled source image is exactly contained within the new image area. The t_x and t_y parameters subsequently shift the image pixels so that those that are moved out of the image area are cut off.

Since the transformation usually changes the image size, the origin of the transformation is the image center, not the upper left edge. Consequently, the coordinate values x and y differ from the pixel coordinates by image-width/2, or image-height/2, respectively.

As do the pixel coordinates, the transform matrix uses a left-handed coordinate system (positive direction is rightward resp. downward; positive rotation is clockwise).

Scaling by the factor s is accomplished with the matrix:

  {s, 0, 0, s, 0, 0}

Translation by a displacement {d_x, d_y} is accomplished with the matrix:

  {1, 0, 0, 1, dx, dy}

Rotation clockwise about the origin by an angle a is accomplished with the matrix:

  {cos(a), sin(a), -sin(a), cos(a), 0, 0}

A series of operations can be accomplished by using a matrix that is the multiple of the matrices for each operation.

annotate an image with text.

This is a convenience option for annotating your image with text. For more precise control over your text annotations, use –draw.

X-rotate and y-rotate give the angle of the text and x and y are offsets that give the location of the text relative to the upper left corner of the image.

remove pixel aliasing.

By default, objects are antialiased when drawn (e.g. lines, polygon, etc.). Use +antialias to disable antialiasing. Without antialiasing, you can avoid increasing the unique colors in an image, draw fixed width lines, or improve the rendering speed.

append a set of images.

This option creates a single image where the images in the original set are stacked top-to-bottom. If they are not of the same width, any narrow images will be expanded to fit using the background color. Use +append 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.

decrypt image with this password.

Use this option to supply a password for decrypting an image or an image sequence, if it is being read from a format such as PDF that supports encryption. Encrypting images being written is not supported.

average 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.

display the image centered on a backdrop.

This backdrop covers the entire workstation screen and is useful for hiding other X window activity while viewing the image. The color of the backdrop is specified as the background color. The color is specified using the format described under the –fill option.

the background color.

The color is specified using the format described under the –fill option.

add bias when convolving an image.

blue chromaticity primary point.

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 –resize for details about the geometry specification.

the border color.

The color is specified using the format described under the –fill option.

the border width.

(This option has been replaced by the –limit option).

the type of channel.

Choose from: Red, Green, Blue, Alpha, Cyan, Magenta, Yellow, Black, Opacity, Index, RGB, RGBA, CMYK, or CMYKA.

By default, ImageMagick applies operations all channels, except the opacity channel, in an image. Use this option to apply an operation to only select channels of an image. For example to only negate the alpha channel of an image, use

    -channel Alpha -negate

simulate a charcoal drawing.

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 –chopoption 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.

make a copy of an image (or images).

Specify the image by its index in the sequence. The first image is index 0. Negative indexes are relative to the end of the sequence, for example, -1 represents the last image of the sequence. Specify a range of images with a dash (e.g. 0-4). Separate indexes with a comma (e.g. 0,2). Use +clone make a copy of the last image in the image sequence.

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 fill color.

Specify the amount of colorization as a percentage. You can apply separate colorization values to the red, green, and blue channels of the image with a colorization value list delimited with commas (e.g. 0,0,50).

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.

preferred number of colors in the image.

The actual number of colors in the image may be less than your request, but never more. Note, this is a color reduction option. Images with less unique colors than specified with this option will have any duplicate or unused colors removed. The ordering of an existing color palette may be altered. When converting an image from color to grayscale, convert the image to the gray colorspace before reducing the number of colors since doing so is most efficient. Refer to the color reduction algorithm for more details.

Note, options –dither, –colorspace, and –treedepth affect the color reduction algorithm.

the type of colorspace.

Choices are: CMYK, GRAY, HSL, HWB, OHTA, Rec601Luma, Rec709Luma, RGB, Transparent, XYZ, YCbCr, YIQ, YPbPr, or YUV.

Color reduction, by default, takes place in the RGB color space. Empirical evidence suggests that distances in color spaces such as YUV or YIQ correspond to perceptual color differences more closely than do distances in RGB space. These color spaces may give better results when color reducing an image. Refer to the color reduction algorithm for more details..

The Transparent color space behaves uniquely in that it preserves the matte channel of the image if it exists.

The –colors or –monochrome option, or saving to a file format which requires color reduction, is required for this option to take effect.

combine one or more images into a single image.

The grayscale value of the pixels of each image in the sequence is assigned in order to the specified channels of the combined image. The typical ordering would be image 1 = Red, 2 = Green, 3 = Blue, etc.

annotate an image with a comment.

Use this option to assign a specific comment to the image, when writing to an image format that supports comments. You can include the image filename, type, width, height, or other image attribute by embedding special format characters listed under the –format option. The comment is not drawn on the image, but is embedded in the image datastream via a "Comment" tag or similar mechanism. If you want the comment to be visible on the image itself, use the –draw option.

For example,

     -comment "%m:%f %wx%h"

produces an image comment of MIFF:bird.miff 512x480 for an image titled bird.miff and whose width is 512 and height is 480.

If the first character of string is @, the image comment is read from a file titled by the remaining characters in the string.

the type of image composition.

The description of composition uses abstract terminology in order to allow the the description to be more clear, while avoiding constant values which are specific to a particular build configuration. Each image pixel is represented by red, green, and blue levels (which are equal for a gray pixel). QuantumRange is the maximum integral value which may be stored in the red, green, or blue channels of the image. Each image pixel may also optionally (if the image matte channel is enabled) have an associated level of opacity (ranging from opaque to transparent), which may be used to determine the influence of the pixel color when compositing the pixel with another image pixel. If the image matte channel is disabled, then all pixels in the image are treated as opaque. The color of an opaque pixel is fully visible while the color of a transparent pixel color is entirely absent (pixel color is ignored).

By definition, raster images have a rectangular shape. All image rows are of equal length, and all image columns have the same number of rows. By treating the alpha channel as a visual "mask" the rectangular image may be given a "shape" by treating the alpha channel as a cookie-cutter for the image. Pixels within the shape are opaque, while pixels outside the shape are transparent. Pixels on the boundary of the shape may be between opaque and transparent in order to provide antialiasing (visually smooth edges). The description of the composition operators use this concept of image "shape" in order to make the description of the operators easier to understand. While it is convenient to describe the operators in terms of "shapes" they are by no means limited to mask-style operations since they are based on continuous floating-point mathematics rather than simple boolean operations.

The following composite operators are available:

use this type of pixel compression when writing the image.

Choices are: None, BZip, Fax, Group4, JPEG, JPEG2000, 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 of lossless JPEG is generally not recommended.

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.

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.

For a more pronounced effect you can repeat the option:

    convert rose: -contrast -contrast rose_c2.png

convolve image with the specified convolution kernel.

The kernel is specified as a comma-separated list of integers, ordered left-to right, starting with the top row. The order of the kernel is determined by the square root of the number of entries. Presently only square kernels are supported.

cut out a rectangular region of the image.

See –resize 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.

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.

Append an exclamation point to the geometry to force the page size to exactly the size you specify.

displace image colormap by amount.

Amount defines the number of positions each colormap entry is shifted.

enable debug printout.

The events parameter specifies which events are to be logged. It can be either None, All, Trace, or a comma-separated list consisting of one or more of the following domains: Annotate, Blob, Cache, Coder, Configure, Deprecate, Exception, Locale, Render, Resource, TemporaryFile, Transform, X11, or User. For example, to log cache and blob events, use.

    convert -debug "Cache,Blob" rose: rose.png

The User domain is normally empty, but developers can log user events in their private copy of ImageMagick.

Use the –log option to specify the format for debugging output.

Use +debug to turn off all logging.

Debugging may also be set using the MAGICK_DEBUG environment variable. The allowed values for the MAGICK_DEBUG environment variable are the same as for the –debug option.

break down an image sequence into constituent parts.

This option compares each image with the next in a sequence and returns the maximum bounding region of any pixel differences it discovers. This method can undo a coalesced sequence returned by the –coalesce option, and is useful for removing redundant information from a GIF or MNG animation.

The sequence of images is terminated by the appearance of any option. If the –deconstruct option appears after all of the input images, all images are deconstructed.

add coder/decoder specific options.

This option creates one or more definitions for coders and decoders to use while reading and writing image data. Definitions may be passed to coders and decoders to control options that are specific to certain image formats. If value is missing for a definition, an empty-valued definition of a flag will be created with that name. This is used to control on/off options. Use +define key to remove definitions previously created. Use +define "*" to remove all existing definitions.

The following definitions may be created:

  jp2:rate=value
    Specify the compression factor to use while writing JPEG-2000
    files. The compression factor is the reciprocal of the compression
    ratio. The valid range is 0.0 to 1.0, with 1.0 indicating lossless
    compression. If defined, this value overrides the -quality setting.
    The default quality setting of 75 results in a rate value of 0.06641.

  mng:need-cacheoff
    turn playback caching off for streaming MNG.

  ps:imagemask
    If the ps:imagemask flag is defined, the PS3 and EPS3 coders will
    create Postscript files that render bilevel images with the Postscript
    imagemask operator instead of the image operator.

For example, to create a postscript file that will render only the black pixels of a bilevel image, use:

    convert bilevel.tif -define ps:imagemask eps3:stencil.ps

display the next image after pausing.

This option is useful for regulating the animation of image sequences ticks/ticks-per-second seconds must expire before the display of the next image. The default is no delay between each showing of the image sequence. The default ticks-per-second is 100.

Use > to change the image delay only if its current value exceeds the given delay. < changes the image delay only if current value is less than the given delay. For example, if you specify 30> and the image delay is 20, the image delay does not change. However, if the image delay is 40 or 50, the delay it is changed to 30. Enclose the given delay in quotation marks to prevent the < or > from being interpreted by your shell as a file redirection.

delete the image, specified by its index, from the image sequence.

Use +delete to delete the last image in the current image sequence.

horizontal and vertical resolution in pixels of the image.

This option specifies the image resolution to store while encoding a raster image or the canvas resolution while rendering (reading) vector formats such as Postscript, PDF, WMF, and SVG into a raster image. Image resolution provides the unit of measure to apply when rendering to an output device or raster image. The default unit of measure is in dots per inch (DPI). The –units option may be used to select dots per centimeter instead.

The default resolution is 72 dots per inch, which is equivalent to one point per pixel (Macintosh and Postscript standard). Computer screens are normally 72 or 96 dots per inch while printers typically support 150, 300, 600, or 1200 dots per inch. To determine the resolution of your display, use a ruler to measure the width of your screen in inches, and divide by the number of horizontal pixels (1024 on a 1024x768 display).

If the file format supports it, this option may be used to update the stored image resolution. Note that Photoshop stores and obtains image resolution from a proprietary embedded profile. If this profile is not stripped from the image, then Photoshop will continue to treat the image using its former resolution, ignoring the image resolution specified in the standard file header.

The density option is an attribute and does not alter the underlying raster image. It may be used to adjust the rendered size for desktop publishing purposes by adjusting the scale applied to the pixels. To resize the image so that it is the same size at a different resolution, use the –resample option.

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.

obtain image by descending window hierarchy.

reduce the speckles within an image.

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).

GIF disposal method.

The Disposal Method indicates the way in which the graphic is to be treated after being displayed.

Here are the valid methods:

  Undefined       No disposal specified.
  None            Do not dispose between frames.
  Background      Overwrite the image area with the background color.
  Previous        Overwrite the image area with what was there prior to rendering the image.

dissolve 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. Disabling dithering often (but not always) leads to decreased processing time.

annotate an image with one or more graphic primitives.

Use this option to annotate an image with one or more graphic primitives. The primitives include shapes, text, transformations, and pixel operations. The shape primitives are:

   point           x,y
   line            x0,y0 x1,y1
   rectangle       x0,y0 x1,y1
   roundRectangle  x0,y0 x1,y1 wc,hc
   arc             x0,y0 x1,y1 a0,a1
   ellipse         x0,y0 rx,ry a0,a1
   circle          x0,y0 x1,y1
   polyline        x0,y0  ...  xn,yn
   polygon         x0,y0  ...  xn,yn
   Bezier          x0,y0  ...  xn,yn
   path            path specification
   image           operator x0,y0 w,h filename

The text primitive is.

   text            x0,y0 string

The text gravity primitive is.

   gravity         NorthWest, North, NorthEast, West, Center,
                   East, SouthWest, South, or SouthEast

The text gravity primitive only affects the placement of text and does not interact with the other primitives. It is equivalent to using the –gravity commandline option, except that it is limited in scope to the –draw option in which it appears.

The transformation primitives are.

   rotate          degrees
   translate       dx,dy
   scale           sx,sy
   skewX           degrees
   skewY           degrees

The pixel operation primitives are.

   color           x0,y0 method
   matte           x0,y0 method

The shape primitives are drawn in the color specified in the preceding –fill option. For unfilled shapes, use –fill none. You can optionally control the stroke with the –stroke and –strokewidth options.

Point requires a single coordinate.

Line requires a start and end coordinate.

Rectangle expects an upper left and lower right coordinate.

RoundRectangle has the upper left and lower right coordinates and the width and height of the corners.

Circle has a center coordinate and a coordinate for the outer edge.

Use Arc to inscribe an elliptical arc within a rectangle. Arcs require a start and end point as well as the degree of rotation (e.g. 130,30 200,100 45,90).

Use Ellipse to draw a partial ellipse centered at the given point with the x-axis and y-axis radius and start and end of arc in degrees (e.g. 100,100 100,150 0,360).

Finally, polyline and polygon require three or more coordinates to define its boundaries. Coordinates are integers separated by an optional comma. For example, to define a circle centered at 100,100 that extends to 150,150 use:

   -draw 'circle 100,100 150,150'

Paths (See Paths) represent an outline of an object which is defined in terms of moveto (set a new current point), lineto (draw a straight line), curveto (draw a curve using a cubic Bezier), arc (elliptical or circular arc) and closepath (close the current shape by drawing a line to the last moveto) elements. Compound paths (i.e., a path with subpaths, each consisting of a single moveto followed by one or more line or curve operations) are possible to allow effects such as donut holes in objects.

Use image to composite an image with another image. Follow the image keyword with the composite operator, image location, image size, and filename:

   -draw 'image Over 100,100 225,225 image.jpg'

You can use 0,0 for the image size, which means to use the actual dimensions found in the image header. Otherwise, it will be scaled to the given dimensions. See –compose for a description of the composite operators.

Use text to annotate an image with text. Follow the text coordinates with a string. If the string has embedded spaces, enclose it in single or double quotes.

For example,

   -draw 'text 100,100 "Works like magick!"'

annotates the image with Works like magick! for an image titled bird.miff

If the first character of string is @, the text is read from a file titled by the remaining characters in the string. See the –annotate option for another convenient way to annotate an image with text.

Rotate rotates subsequent shape primitives and text primitives about the origin of the main image. If the –region option precedes the –draw option, the origin for transformations is the upper left corner of the region.

Translate translates them.

Scale scales them.

SkewX and SkewY skew them with respect to the origin of the main image or the region.

The transformations modify the current affine matrix, which is initialized from the initial affine matrix defined by the –affine 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 –affineoption. 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 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.

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.

Drawing primitives conform to the Magick Vector Graphics format.

detect edges within an image.

emboss an image.

specify the text encoding.

Choose from AdobeCustom, AdobeExpert, AdobeStandard, AppleRoman, BIG5, GB2312, Latin 2, None, SJIScode, Symbol, Unicode, Wansung.

specify endianness (MSB or LSB) of the image.

Use +endian to revert to unspecified endianness.

apply a digital filter to enhance a noisy image.

perform histogram equalization to the image.

evaluate an arithmetic, relational, or logical expression.

Choose from: Add, And, Divide, LeftShift, Max, Min, Multiply, Or, RightShift, Set, Subtract, or Xor.

set the image extent. The pixels scale or location do not change. If the image is enlarged, unfilled areas are set to black.

See –resize for details about the geometry specification.

extract the specified area from image. The option is most useful for extracting a subregion of a very large raw image. Note, these two command are equivalent:

  convert -size 16000x16000 -depth 8 -extract 640x480+1280+960 image.rgb image.png
  convert -size 16000x16000 -depth 8 image.rgb[640x480+1280+960]' image.rgb image.png

color to use when filling a graphic primitive.

Colors are represented in ImageMagick in the same form used by SVG:

  name                 (identify -list color to see names)
  #RGB                 (R,G,B are hex numbers, 4 bits each)
  #RRGGBB              (8 bits each)
  #RRRGGGBBB           (12 bits each)
  #RRRRGGGGBBBB        (16 bits each)
  #RGBA                (4 bits each)
  #RRGGBBAA            (8 bits each)
  #RRRGGGBBBAAA        (12 bits each)
  #RRRRGGGGBBBBAAAA    (16 bits each)
  rgb(r,g,b)           (r,g,b are decimal numbers)
  rgba(r,g,b,a)        (r,g,b,a are decimal numbers)

Enclose the color specification in quotation marks to prevent the "#" or the parentheses from being interpreted by your shell.

For example,

  convert -fill blue ...
  convert -fill "#ddddff" ...
  convert -fill "rgb(65000,65000,65535)" ...

The shorter forms are scaled up, if necessary by replication. For example, #3af, #33aaff, and #3333aaaaffff are all equivalent.

See –draw for further details.

use this type of filter when resizing an image.

Use this option to affect the resizing operation of an image (see –resize). Choose from these filters:

   Point
   Box
   Triangle
   Hermite
   Hanning
   Hamming
   Blackman
   Gaussian
   Quadratic
   Cubic
   Catrom
   Mitchell
   Lanczos
   Bessel
   Sinc

The default filter is automatically selected to provide the best quality while consuming a reasonable amount of time. The Mitchell filter is used if the image supports a palette, supports a matte channel, or is being enlarged, otherwise the Lanczos filter is used.

flatten 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.

create a mirror image.

reflect the scanlines in the vertical direction.

create a mirror image.

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 X11.

define the foreground color.

The color is specified using the format described under the –fill option.

the image format type.

When used with the mogrify utility, this option will convert any image to the image format you specify. For a list of image format types supported by ImageMagick, see the output of this command: identify -list format.

By default the file is written to its original name. However, if the filename extension matches a supported format, the extension is replaced with the image format type specified with –format. 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.

When used with the identify utility, use this option to print information about the image in a format of your choosing. You can include the image filename, type, width, height, Exif data, or other image attributes by embedding special format characters:

   %O   page offset
   %P   page width and height
   %b   file size
   %c   comment
   %d   directory
   %e   filename extension
   %f   filename
   %g   page geometry
   %h   height
   %i   input filename
   %k   number of unique colors
   %l   label
   %m   magick
   %n   number of scenes
   %o   output filename
   %p   page number
   %q   quantum depth
   %r   image class and colorspace
   %s   scene number
   %t   top of filename
   %u   unique temporary filename
   %w   width
   %x   x resolution
   %y   y resolution
   %z   image depth
   %@   bounding box
   %#   signature
   %%   a percent sign
   \n   newline
   \r   carriage return

For example,

   -format "%m:%f %wx%h"

displays MIFF:bird.miff 512x480 for an image titled bird.miff and whose width is 512 and height is 480.

If the first character of string is @, the format is read from a file titled by the remaining characters in the string.

You can also use the following special formatting syntax to print Exif information contained in the file:

   %[EXIF:tag]

Where "tag" can be one of the following:

   *  (print all Exif tags, in keyword=data format)
   !  (print all Exif tags, in tag_number data format)
   #hhhh (print data for Exif tag #hhhh)
   ImageWidth
   ImageLength
   BitsPerSample
   Compression
   PhotometricInterpretation
   FillOrder
   DocumentName
   ImageDescription
   Make
   Model
   StripOffsets
   Orientation
   SamplesPerPixel
   RowsPerStrip
   StripByteCounts
   XResolution
   YResolution
   PlanarConfiguration
   ResolutionUnit
   TransferFunction
   Software
   DateTime
   Artist
   WhitePoint
   PrimaryChromaticities
   TransferRange
   JPEGProc
   JPEGInterchangeFormat
   JPEGInterchangeFormatLength
   YCbCrCoefficients
   YCbCrSubSampling
   YCbCrPositioning
   ReferenceBlackWhite
   CFARepeatPatternDim
   CFAPattern
   BatteryLevel
   Copyright
   ExposureTime
   FNumber
   IPTC/NAA
   ExifOffset
   InterColorProfile
   ExposureProgram
   SpectralSensitivity
   GPSInfo
   ISOSpeedRatings
   OECF
   ExifVersion
   DateTimeOriginal
   DateTimeDigitized
   ComponentsConfiguration
   CompressedBitsPerPixel
   ShutterSpeedValue
   ApertureValue
   BrightnessValue
   ExposureBiasValue
   MaxApertureValue
   SubjectDistance
   MeteringMode
   LightSource
   Flash
   FocalLength
   MakerNote
   UserComment
   SubSecTime
     SubSecTimeOriginal
   SubSecTimeDigitized
   FlashPixVersion
   ColorSpace
   ExifImageWidth
   ExifImageLength
   InteroperabilityOffset
   FlashEnergy
   SpatialFrequencyResponse
   FocalPlaneXResolution
   FocalPlaneYResolution
   FocalPlaneResolutionUnit
   SubjectLocation
   ExposureIndex
   SensingMethod
   FileSource
   SceneType

Surround the format specification with quotation marks to prevent your shell from misinterpreting any spaces and square brackets.

surround the image with an ornamental border.

See –geometryfor 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, 65535, or 4294967295).

apply a mathematical expression an image or image channels.

For example, to extract the matte channel of the image (this is the negative to what is commonly thought of as the alpha channel mask of the image), use:

  convert drawn.png -fx 'a' +matte matte.png

Mathematic operators include.

  constants: QuantumRange, Opaque, Transparent, Pi
  standard operators (in order of precedence):
      ^ (power), *, /, % (modulo), +, -, <, >, =,
      & (binary AND), | (binary OR), : (binary XOR) 
  math function name:
      abs(), acos(), asin(), atan(), ceil(), cos(), exp(), floor(), log(), ln(),
      max(), min(), rand(), sign(), sin(), sqrt(),  tan()
  color names: red, cyan, black, etc
  symbols:
      u  = first image in sequence
      v  = second image in sequence
      i  = column offset
      j  = row offset
      p  = pixel to use (absolute or relative to current pixel)
      w  = width of this image
      h  = height of this image
      r  = red value (from RGBA), of a specific or current pixel
      g  = green   ''
      b  = blue    ''
      a  = alpha   ''
      c  = cyan value of CMYK color of pixel
      y  = yellow    ''
      m  = magenta   ''
      k  = black     ''
      intensity = pixel intensity
      luminosity = pixel luminosity

Specify the image source using an image index represented by u, starting at zero for the first image, (eg: u[3] is the fourth image in the image sequence). A negative image index counts images from the end of the current image sequence, therefore u[-1] refers to the last image in the sequence.

Without an index u or v represent the first and second image of the sequence. If no image is specified, the u image is used.

For example to reduce the intensity of the red channel by 50%, use.

  convert image.png -channel red -fx 'u/2.0' image.jpg

The pixels are processed one at a time, but a different pixel of a image can be specified with a pixel index represented by p. For example,

   p[-1].g      Green value of pixel to the immediate left of current
   p[-1,-1].r   Red value, diagonally left and up from current pixel

To specify an absolute position, use braces, rather than brackets.

  p{12,34}.b   is the blue pixel at image location 12,34

The other symbols specify the value you wish to retrieve.

A pixel outside the boundary of the image has a value dictated by the –virtual-pixel option setting.

The –channel setting can be used to specify the output channel of the result. If no output channel is given the result is set over all channels, except the opacity channel. For example, suppose you want to replace the red channel of alpha.png with the average of the green channels from the images alpha.png and beta.png, use:

  convert alpha.png beta.png -channel red -fx '(u.g+v.g)/2' gamma.png

Note that all the original images in the current image sequence are replaced by the updated alpha.png image.

level of gamma correction.

The same color image displayed on two different workstations may look different due to differences in the display monitor. Use gamma correction to adjust for this color difference. Reasonable values extend from 0.8 to 2.3. Gamma less than 1.0 darkens the image and gamma greater than 1.0 lightens it. Large adjustments to image gamma may result in the loss of some image information if the pixel quantum size is only eight bits (quantum range 0 to 255).

You can apply separate gamma values to the red, green, and blue channels of the image with a gamma value list delimited with commas (e.g., 1.7,2.3,1.2).

Use +gamma 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).

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.

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.

direction primitive gravitates to when annotating the image.

Choices are: NorthWest, North, NorthEast, West, Center, East, SouthWest, South, SouthEast.

The direction you choose specifies where to position the text when annotating the image. For example, a gravity of Center forces the text to be centered within the image. By default, the image gravity is NorthWest. See –draw for more details about graphic primitives. Only the text primitive is affected by the –gravity option.

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.

green chromaticity primary point.

print usage instructions.

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 animation.

make image immutable.

implode image pixels about the center.

insert the last image into the image sequence.

This option takes last image in the current image sequence and inserts it at the given index. If a negative index is used, the insert position is calculated before the last image is removed from the sequence. As such –insert -1 will result in no change to the image sequence.

The +insert option is equivalent to –insert -1. In other words, insert the last image, at the end of the current image sequence. Consequently this has no effect on the image sequence order.

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, when writing to an image format that supports labels, such as TIFF, PNG, MIFF, or PostScript. You can include the the image filename, type, width, height, or other image attribute by embedding special format character. See –format 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.

A label is not drawn on the image, but is embedded in the image datastream via a Label tag or similar mechanism. If you want the label to be visible on the image itself, use the –draw option.

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.

When creating a montage, by default the label associated with an image is displayed with the corresponding tile in the montage. Use the +label option to suppress this behavior.

perform local adaptive thresholding.

Perform local adaptive thresholding using the specified width, height, and offset. The offset is a distance in sample space from the mean, as an absolute integer ranging from 0 to the maximum sample value or as a percentage.

adjust the level of image contrast.

Give one, two or three values delimited with commas: black-point, white-point, gamma (e.g. 10,250,1.0 or 2%,98%,0.5). The black and white points range from 0 to QuantumRange or from 0 to 100%; if the white point is omitted it is set to QuantumRange-black_point. If a % sign is present anywhere in the string, the black and white points are percentages of QuantumRange. Gamma is an exponent that ranges from 0.1 to 10.; if it is omitted, the default of 1.0 (no gamma correction) is assumed.

pixel cache resource limit.

Choose from: Area, Disk, File, Map, or Memory.

The value for File is in number of files. The Disk limit is in Gigabytes and and the values for the other resources are in Megabytes. By default the limits are 768 files, 1024MB memory, 4096MB map, and unlimited disk, but these are adjusted at startup time on platforms that can provide information about available resources. When the limit is reached, ImageMagick will fail in some fashion, or take compensating actions if possible. For example,

  -limit memory 32 -limit map 64

limits memory. When the pixel cache reaches the memory limit it uses memory mapping. When that limit is reached it goes to disk. If disk has a hard limit, the program will fail.

Resource limits may also be set using environment variables. The environment variables MAGICK_AREA_LIMIT, MAGICK_DISK_LIMIT, MAGICK_FILES_LIMIT, MAGICK_MEMORY_LIMIT, and MAGICK_MAP_LIMIT, may be used to set the limits for disk space, open files, heap memory, and memory map size, respectively.

You can use the option –list resource to list the limits.

the line width for subsequent draw operations.

the type of list.

Choices are: Coder, Color, Delegate, Format, Magic, Module, Resource, or Type.

This option lists information about the ImageMagick configuration.

Specify format for debug log.

This option specifies the format for the log printed when the –debug option is active.

You can display the following components by embedding special format characters:

   %d   domain
   %e   event
   %f   function
   %l   line
   %m   module
   %p   process ID
   %r   real CPU time
   %t   wall clock time
   %u   user CPU time
   %%   percent sign
   \n   newline
   \r   carriage return

For example:

  convert -debug coders -log "%u %m:%l %e" in.gif out.png

The default behavior is to print all of the components.

add Netscape loop extension to your GIF animation.

Set iterations to zero to repeat the animation an infinite number of times, otherwise the animation repeats itself up to iterations times.

magnify the image.

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.

display image using this type.

[animate or display].

Choose from these Standard Colormap types:

  best
  default
  gray
  red
  green
  blue

The X server must support the Standard Colormap you choose, otherwise an error occurs. Use list as the type and display searches the list of colormap types in top-to-bottom order until one is located. See xstdcmap(1) for one way of creating Standard Colormaps.

Specify a clipping mask.

The image read from the file is used as a clipping mask. It must have the same dimensions as the image being masked.

If the mask image contains an alpha channel, the opacity of each pixel is used to define the mask. Otherwise, the intensity (gray level) of each pixel is used.

Use +mask 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.

specify the color to be used with the –frame option.

The color is specified using the format described under the –fill option.

apply a median filter to the image.

measure differences between images with this metric. Choose from MAE, MSE, PSE, PSNR, or RMSE.

mode of operation. Choose from these styles: Frame, Unframe, or Concatenate

vary the brightness, saturation, and hue of an image.

Specify the percent change in brightness, the color saturation, and the hue separated by commas. Hue is the percentage of absolute rotation from the current position. For example 50 results in a counter-clockwise rotation of 90 degrees, 150 results in a clockwise rotation of 90 degrees, with 0 and 200 both resulting in a rotation of 180 degrees. .

To increase the color brightness by 20% and decrease the color saturation by 10% and leave the hue unchanged, use: –module 120,90. .

monitor progress.

transform the image to black and white.

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.

create a mosaic from an image or an image sequence.

The –page option can be used to establish the dimensions of the mosaic and to locate the images within the mosaic.

The sequence of images is terminated by the appearance of any option. If the –mosaic option appears after all of the input images, all images are included in the mosaic.

simulate motion blur.

Blur with the given radius, standard deviation (sigma), and angle. The angle given is the angle toward which the image is blurred. That is the direction people would consider the object is coming from.

name an image.

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

transform image to span the full range of color values.

This is a contrast enhancement technique.

change this color to the fill color within the image.

The color is specified using the format described under the –fill option.

See –fill for more details.

specify orientation of the image pixels.

Choose from these orientations:

  bottom-left
  bottom-right
  left-bottom
  left-top
  right-bottom
  right-top
  top-left
  top-right
  undefined

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).

This option is also used to place subimages when writing to a multi-image format that supports offsets, such as GIF89 and MNG. When used for this purpose the offsets are always measured from the top left corner of the canvas and are not affected by the –gravity option. To position a GIF or MNG image, use –page{+-}x{+-}y (e.g. -page +100+200). When writing to a MNG file, a –page option appearing ahead of the first image in the sequence with nonzero width and height defines the width and height values that are written in the MHDR chunk. Otherwise, the MNG width and height are computed from the bounding box that contains all images in the sequence. When writing a GIF89 file, only the bounding box method is used to determine its dimensions.

For a PostScript page, the image is sized as in –geometry 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.

Use +page to remove the page settings for an image.

simulate an oil painting.

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.

efficiently determine image characteristics.

pointsize of the PostScript, OPTION1, or TrueType font.

reduce the image to a limited number of color levels.

image preview type.

Use this option to affect the preview operation of an image (e.g. convert file.png -preview Gamma Preview:gamma.png). Choose from these previews:

  Rotate
  Shear
  Roll
  Hue
  Saturation
  Brightness
  Gamma
  Spiff
  Dull
  Grayscale
  Quantize
  Despeckle
  ReduceNoise
  Add Noise
  Sharpen
  Blur
  Threshold
  EdgeDetect
  Spread
  Shade
  Raise
  Segment
  Solarize
  Swirl
  Implode
  Wave
  OilPaint
  CharcoalDrawing
  JPEG

The default preview is JPEG.

process a sequence of images using a process module.

The command argument has the form module=arg1,arg2,arg3,...,argN where module is the name of the module to invoke (e.g. "analyze") and arg1,arg2,arg3,...,argN are an arbitrary number of arguments to pass to the process module.

The sequence of images is terminated by the appearance of any option.

If the –process option appears after all of the input images, all images are processed.

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 –strip 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

JPEG/MIFF/PNG compression level.

For the JPEG and MPEG image formats, quality is 0 (lowest image quality and highest compression) to 100 (best quality but least effective compression). The default is to use the estimate quality of your input image otherwise 75. Use the –sampling-factor option to specify the factors for chroma downsampling.

For the MIFF image format, quality/10 is the zlib compression level, which is 0 (worst but fastest compression) to 9 (best but slowest). It has no effect on the image appearance, since the compression is always lossless.

For the JPEG-2000 image format, quality is mapped using a non-linear equation to the compression ratio required by the Jasper library. This non-linear equation is intended to loosely approximate the quality provided by the JPEG v1 format. The default quality value 75 results in a request for 16:1 compression. The quality value 100 results in a request for non-lossy compression.

For the MNG and PNG image formats, the quality value sets the zlib compression level (quality / 10) and filter-type (quality % 10). Compression levels range from 0 (fastest compression) to 100 (best but slowest). For compression level 0, the Huffman-only strategy is used, which is fastest but not necessarily the worst compression.

If filter-type is 4 or less, the specified filter-type is used for all scanlines:

  0: none
  1: sub
  2: up
  3: average
  4: Paeth

If filter-type is 5, adaptive filtering is used when quality is greater than 50 and the image does not have a color map, otherwise no filtering is used.

If filter-type is 6, adaptive filtering with minimum-sum-of-absolute-values is used.

Only if the output is MNG, if filter-type is 7, the LOCO color transformation and adaptive filtering with minimum-sum-of-absolute-values are used.

The default is quality is 75, which means nearly the best compression with adaptive filtering. The quality setting has no effect on the appearance of PNG and MNG images, since the compression is always lossless.

For further information, see the PNG specification.

When writing a JNG image with transparency, two quality values are required, one for the main image and one for the grayscale image that conveys the alpha channel. These are written as a single integer equal to the main image quality plus 1000 times the opacity quality. For example, if you want to use quality 75 for the main image and quality 90 to compress the opacity data, use –quality 90075.

suppress all error or warning messages.

radial blur the image.

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.

random threshold the image.

red chromaticity primary point.

apply options to a portion of the image.

The x and y offsets are treated in the same manner as in –crop.

perform a remote operation.

The only command recognized at this time is the name of an image file to load.

render vector operations.

Use +render to turn off rendering vector operations. This is useful when saving the result to vector formats such as MVG or SVG.

size and location of an image canvas.

This option is like –page but acts as an image operator rather than a setting.

Use "+repage" to eliminate page size and location data.

Resample image to specified horizontal and vertical resolution.

Resize the image so that its rendered size remains the same as the original at the specified target resolution. For example, if a 300 DPI image renders at 3 inches by 2 inches on a 300 DPI device, when the image has been resampled to 72 DPI, it will render at 3 inches by 2 inches on a 72 DPI device. Note that only a small number of image formats (e.g. JPEG, PNG, and TIFF) are capable of storing the image resolution. For formats which do not support an image resolution, the original resolution of the image must be specified via –density on the command line prior to specifying the resample resolution.

Note that Photoshop stores and obtains image resolution from a proprietary embedded profile. If this profile exists in the image, then Photoshop will continue to treat the image using its former resolution, ignoring the image resolution specified in the standard file header.

resize an image.

By default, the width and height are maximum values. That is, the image is expanded or contracted to fit the width and height value while maintaining the aspect ratio of the image. Append an exclamation point to the geometry to force the image size to exactly the size you specify. For example, if you specify 640x480! the image width is set to 640 pixels and height to 480.

If only the width is specified, the width assumes the value and the height is chosen to maintain the aspect ratio of the image. Similarly, if only the height is specified (e.g., –resize x256, the width is chosen to maintain the aspect ratio.

To specify a percentage width or height instead, append %. The image size is multiplied by the width and height percentages to obtain the final image dimensions. To increase the size of an image, use a value greater than 100 (e.g. 125%). To decrease an image's size, use a percentage less than 100.

Use @ to specify the maximum area in pixels of an image.

Use > to change the dimensions of the image only if its width or height exceeds the geometry specification. < resizes the image only if both of its dimensions are less than the geometry specification. For example, if you specify 640x480> and the image size is 256x256, the image size does not change. However, if the image is 512x512 or 1024x1024, it is resized to 480x480. Enclose the geometry specification in quotation marks to prevent the < or > from being interpreted by your shell as a file redirection.

If the –filter option precedes the –resize option, the image is resized with the specified filter.

If the –support option precedes the –resize option, the image is resized with the specified support.

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.

apply Paeth image rotation to the image.

Use > to rotate the image only if its width exceeds the height. < rotates the image only if its width is less than the height. For example, if you specify –rotate "-90>" and the image size is 480x640, the image is not rotated. However, if the image is 640x480, it is rotated by -90 degrees. If you use > or <, enclose it in quotation marks to prevent it from being misinterpreted as a file redirection.

Empty triangles left over from rotating the image are filled with the color defined as background. The color is specified using the format described under the –fill option.

scale image using 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 factors used by JPEG or MPEG-2 encoder and YUV decoder/encoder.

This option specifies the sampling factors to be used by the JPEG encoder for chroma downsampling. If this option is omitted, the JPEG library will use its own default values. When reading or writing the YUV format and when writing the M2V (MPEG-2) format, use –sampling-factor 2x1 to specify the 4:2:2 downsampling method.

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.

set scene number.

This option sets the scene number of an image or the first image in an image sequence.

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.

specify the screen to capture.

This option indicates that the GetImage request used to obtain the image should be done on the root window, rather than directly on the specified window. In this way, you can obtain pieces of other windows that overlap the specified window, and more importantly, you can capture menus or other popups that are independent windows but appear over the specified window.

segment an image.

Segment an image by analyzing the histograms of the color components and identifying units that are homogeneous with the fuzzy c-means technique.

Specify cluster threshold as the number of pixels in each cluster must exceed the the cluster threshold to be considered valid. Smoothing threshold eliminates noise in the second derivative of the histogram. As the value is increased, you can expect a smoother second derivative. The default is 1.5. See "Image Segmentation" for details.

separate an image channel into a grayscale image. Specify the channel with –channel.

simulate a sepia-toned photo.

Specify threshold as the percent threshold of the intensity (0 - 99.9%).

This option applies a special effect to the image, similar to the effect achieved in a photo darkroom by sepia toning. Threshold ranges from 0 to QuantumRange and is a measure of the extent of the sepia toning. A threshold of 80% is a good starting point for a reasonable tone.

set an image attribute.

Attributes of interest include delay and page.

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.

simulate an image shadow.

use shared memory.

This option specifies whether the utility should attempt to use shared memory for pixmaps. ImageMagick must be compiled with shared memory support, and the display must support the MIT-SHM extension. Otherwise, this option is ignored. The default is True.

sharpen the image.

Use a Gaussian operator of the given radius and standard deviation (sigma).

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 the image along the X or Y axis.

Use the specified positive or negative shear angle.

Shearing slides one edge of an image along the X or Y axis, creating a parallelogram. An X direction shear slides an edge along the X axis, while a Y direction shear slides an edge along the Y axis. The amount of the shear is controlled by a shear angle. For X direction shears, x-degrees is measured relative to the Y axis, and similarly, for Y direction shears y-degrees is measured relative to the X axis.

Empty triangles left over from shearing the image are filled with the color defined with the –background options. The color is specified using the format described under the –fill option.

image lightness rescaling using sigmoidal contrast enhancement.

Increase the contrast of the image using a sigmoidal transfer function without saturating highlights or shadows. Contrast indicates how much to increase the contrast (0 is none; 3 is typical; 20 is a lot); mid-point indicates where midtones fall in the resultant image (0 is white; 50% is middle-gray; 100% is black). By default the image contrast is increased, use +sigmoidal-contrast to decrease the contrast.

operate silently.

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).

number of screen snapshots.

Use this option to grab more than one image from the X server screen, to create an animation sequence.

negate all pixels above the threshold level.

Specify factor as the percent threshold of the intensity (0 - 99.9%).

This option produces a solarization effect seen when exposing a photographic film to light during the development process.

splice the background color into the image.

See –geometry for details about the geometry specification.

displace image pixels by a random amount.

Amount defines the size of the neighborhood around each pixel to choose a candidate pixel to swap.

hide watermark within an image.

Use an offset to start the image hiding some number of pixels from the beginning of the image. Note this offset and the image size. You will need this information to recover the steganographic image (e.g. display -size 320x256+35 stegano:image.png).

composite two images to create a stereo anaglyph.

The left side of the stereo pair is saved as the red channel of the output image. The right side is saved as the green channel. Red-green stereo glasses are required to properly view the stereo image.

strip the image of any profiles or comments.

color to use when stroking a graphic primitive.

The color is specified using the format described under the –fill option.

See –draw for further details.

set the stroke width.

See –draw for further details.

resize support: > 1.0 is blurry, < 1.0 is sharp.

swap the positions of two images in the image sequence.

For example, –swap 0,2 swaps the first and the third images in the current image sequence. Whereas, +swap swaps the last two image.

swirl image pixels about the center.

Degrees defines the tightness of the swirl.

font for writing fixed-width text.

Specifies the name of the preferred font to use in fixed (typewriter style) formatted text. The default is 14 point Courier.

You can tag a font to specify whether it is a PostScript, TrueType, or OPTION1 font. For example, Courier.ttf is a TrueType font and x:fixed is OPTION1.

name of texture to tile onto the image background.

threshold the image.

Create an image such that any pixel sample that is equal to, or exceeds the threshold, is reassigned the maximum intensity otherwise the minimum intensity.

If the green or blue value is omitted, these channels use the same value as the first one provided. If all three color values are the same, the result is a bi-level image. If the opacity threshold is omitted, OpaqueOpacity will be used and any partially transparent pixel will become fully transparent. If only a single 0 is provided, auto-thresholding will be performed.

To generate an all-black or all-white image with the same dimensions as the input image, you can use.

  convert -threshold 65535 in.png black.png
  convert -threshold 0,0 in.png white.png

create a thumbnail of the image.

This is exactly like –resize, except that any image profiles present are also removed as they are of little importance to small image thumbnails.

tile image when filling a graphic primitive.

layout of images [montage].

repeat composite operation across and down image [composite].

tint the image with the fill color.

Specify the amount of tinting as a percentage. Pure colors like black, white red, yellow, will not be affected by -tint. Only mid-range colors such as the various shades of grey.

assign title to displayed image [animate, display, montage].

Use this option to assign a specific title to the image. This is assigned to the image window and is typically displayed in the window title bar. Optionally you can include the image filename, type, width, height, Exif data, or other image attribute by embedding special format characters described under the –format option.

For example,

  -title "%m:%f %wx%h"

produces an image title of MIFF:bird.miff 512x480 for an image titled bird.miff and whose width is 512 and height is 480.

transform 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

make this color transparent within the image.

The color is specified using the format described under the –fill option. The color to use for image transparency in colormap image formats, such as GIF. As a side effect, fully-opaque colors of this value may also become transparent, depending on the format.

tree depth for the color reduction algorithm.

Normally, this integer value is zero or one. A value of zero or one causes the use of an optimal tree depth for the color reduction algorithm.

An optimal depth generally allows the best representation of the source image with the fastest computational speed and the least amount of memory. However, the default depth is inappropriate for some images. To assure the best representation, try values between 2 and 8 for this parameter. Refer to the color reduction algorithm for more details.

The –colors or –monochrome option, or writing to an image format which requires color reduction, is required for this option to take effect.

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.

the image type.

Choose from: Bilevel, Grayscale, Palette, PaletteMatte, TrueColor, TrueColorMatte, ColorSeparation, ColorSeparationMatte, or Optimize.

Normally, when a format supports different subformats such as grayscale and truecolor, the encoder will try to choose an efficient subformat. The –type option can be used to overrride this behavior. For example, to prevent a JPEG from being written in grayscale format even though only gray pixels are present, use.

  convert bird.p-type TrueColor bird.jpg

Similarly, using –type TrueColorMatte will force the encoder to write an alpha channel even though the image is opaque, if the output format supports transparency.

set the color of the annotation bounding box.

The color is specified using the format described under the –fill option.

See –draw for further details.

detect when image file is modified and redisplay.

Suppose that while you are displaying an image the file that is currently displayed is over-written. display will automatically detect that the input file has been changed and update the displayed image accordingly.

the units of image resolution.

Choose from: Undefined, PixelsPerInch, or PixelsPerCentimeter. This option is normally used in conjunction with the –density option.

sharpen the image with an unsharp mask operator.

The –unsharp option sharpens an image. The image is convolved with a Gaussian operator of the given radius and standard deviation (sigma). For reasonable results, radius should be larger than sigma. Use a radius of 0 to have the method select a suitable radius.

The parameters are:

  radius:    The radius of the Gaussian, in pixels,  not counting the center
             pixel (default 0).
  sigma:     The standard deviation of the Gaussian, in pixels (default 1.0).
  amount:    The percentage of the difference between the original and the blur
             image that is added back into the original (default 1.0).
  threshold: The threshold, as a fraction of QuantumRange, needed to apply the
             difference amount (default 0.05).

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.

print ImageMagick version string.

FlashPix viewing parameters.

specify contents of "virtual pixels".

This option defines "virtual pixels" for use in operations that can access pixels outside the boundaries of an image.

Choose from these methods:

  background:  The area surrounding the image is the background color.
  edge:        Extend the edge pixel toward infinity (default).
  mirror:      Mirror the image.
  tile:        Tile the image.
  transparent: The area surrounding the image is the transparent blackness.

This option affects operations that use virtual pixels such as –blur, –sharpen, –wave, etc.

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.

percent brightness of a watermark.

alter an image along a sine wave.

Specify amplitude and wavelength of the wave.

chromaticity white point.

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.

specify the window group.

write an image sequence.

The image sequence following the –write filename option is written out, and processing continues with the same image in its current state if there are additional options. To restore the image to its original state after writing it, use the +write filename option.

Use –compress to specify the type of image compression.