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[-adaptive-blur • -adaptive-resize • -adaptive-sharpen • -adjoin • -affine • -alpha • -annotate • -antialias • -append • -attenuate • -authenticate • -auto-orient • -average • -backdrop • -background • -bench • -bias • -black-point-compensation • -black-threshold • -blue-primary • -blur • -border • -bordercolor • -borderwidth • -cache • -caption • -channel • -charcoal • -chop • -clip • -clip-mask • -clip-path • -clone • -clut • -coalesce • -colorize • -colormap • -colors • -colorspace • -combine • -comment • -compose • -composite • -compress • -contrast • -contrast-stretch • -convolve • -crop • -cycle • -decipher • -debug • -deconstruct • -define • -delay • -delete • -density • -depth • -descend • despeckle • -displace • -display • -dispose • -dissolve • -distort • -dither • -draw • -edge • -emboss • -encipher • -encoding • -endian • -enhance • -equalize • -evaluate • -extent • -extract • -fill • -filter • -flatten • -flip • -floodfill • -flop • -font • -foreground • -format • -frame • -frame • -fuzz • -fx • -gamma • -gaussian-blur • -geometry • -gravity • -green-primary • -help • -iconGeometry • -iconic • -identify • -immutable • -implode • -insert • -intent • -interlace • -interpolate • -label • -lat • -layers • -level • -limit • -linear-stretch • -linewidth • -liquid-rescale • -list • -log • -loop • -magnify • -map • -map • -mask • -mattecolor • -mask • -median • -metric • -mode • -modulate • -monitor • -monochrome • -morph • -mosaic • -motion-blur • -name • -negate • -noise • -normalize • -opaque • -ordered-dither • -orient • -page • -paint • -path • -pause • -pause • -pen • -ping • -pointsize • -polaroid • -posterize • -preview • -print • -process • -profile • -quality • -quantize • -quiet • -radial-blur • -raise • -random-threshold • -recolor • -red-primary • -regard-warnings • -region • -remote • -render • -repage • -resample • -resize • -reverse • -roll • -rotate • -sample • -sampling-factor • -scale • -scene • -scenes • -screen • -seed • -segment • -separate • -sepia-tone • -set • -shade • -shadow • -shared-memory • -sharpen • -shave • -shear • -sigmoidal-contrast • -silent • -size • -sketch • -snaps • -solarize • -splice • -spread • -stegano • -stereo • -storage-type • -strip • -stroke • -strokewidth • -swap • -swirl • -text-font • -texture • -threshold • -thumbnail • -tile • -tile-offset • -tint • -title • -transform • -transparent • -transparent-color • -transpose • -transverse • -treedepth • -trim • -type • -undercolor • -unique-colors • -units • -unsharp • -update • -verbose • -version • -view • -vignette • -virtual-pixel • -visual • -watermark • -wave • -white-point • -white-threshold • -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.

adaptively blur pixels; descreasing its effect near edges.

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

resize image with data dependent triangulation.

See -resize for details about the geometry specification. The -adaptive-resize option defaults to data dependent triangulation. Use the -filter to choose a different resampling algorithm. Offsets, if present in the geometry string, are ignored, and the -gravity option has no effect.

adaptively sharpen pixels; increasng its effect near edges.

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

join images into a single multi-image file.

Enabled by default. -adjoin will try to save all images of an image sequence 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.

Set the 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.

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.

control and special operations of the alpha/matte channel of an image

Alpha sets a flag on an image indicating whether or not to use alpha channel data. Choose from these options:

   on
   off
   reset
   set

Activate to to use alpha channel data or deactivate to ignore any existing alpha channel data. Reset sets the alpha channel to fully opaque. Set sets the alpha channel to the intensity of the image.

The obsoleted -matte operation is equivelent to a "-alpha on, while the +matte operation is equivelent to the application of "-alpha on -alpha reset" operations.

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.

If the first character of text is @, the text is read from a file titled by the remaining characters in the string. Text in a file are literal, no embedded formatting characters are recognized.

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 current -background color setting. 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.

lessen (or intensify) when adding noise to an image.

decipher image with this password.

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

automatically orient (rotate) image from a digital camera.

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.

measure performance.

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

add bias when convolving an image.

use black point compensation.

force all pixels at or below the threshold into black while leaving all pixels above the threshold unchanged.

blue chromaticity primary point.

reduce image noise and reduce detail levels.

Convolve the image with a Gaussian or normal distribution. The formula is:

where r is the blur radius (r² = u² + v²), and σ is the standard deviation of the Gaussian distribution. As a guideline, set r to approximately 3σ. Specify a radius of 0 and ImageMagick selects a suitable radius for you.

This option differs from -gaussian-blur simply by taking advantage of the linear separable properties of the distribution. Here we apply a single-dimensional Gaussian matrix in the horizontal direction, then repeat the process in the vertical direction.

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).

assign a caption to an image.

define the image color channels later operators may be limited to.

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

To print a complete list of channel types, use the -list channel option.

You can specify the above as a comma separated list of channels, or concatenate the letters 'R', 'G', 'B', 'A', 'O', 'C', 'M', 'Y', 'K', to specify specific multiple channels for later operators to be applied to. For example to only negate the alpha channel of an image, use

    -channel Alpha -negate

By default, ImageMagick sets "-channel to the value 'RGB' to limit channel affected operators to all channels, except the opacity channel, in an image. Using the option "+channel will reset the value back to this default.

Operators that are affected by the "-channel setting include: "-blur, "-combine, "-contrast-stretch, "-evaluate, "-fx, "-gaussian-blur, "-motion-blur, "-negate, "-normalize, "-ordered-dither, "-radial-blur, "-random-threshold, "-separate, and -threshold.

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.

clip image as defined by this mask.

clip along a named path from the 8BImageMagick profile.

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.

Given two images, replace the channel values in the first image, with a lookup of its replacement value in second LUT gradient image.

The LUT image should be either a single row or column image of replacement colors. The lookup is controled by the -interpolate setting, especially for an LUT which is not the full length needed by the ImageMagick installed Quailty (Q) level. Good setings for this is the default 'bilinear' or 'bicubic' interpolation setting for a smooth color gradient, or 'integer' for a direct unsmoothed lookup of color values.

Also only the channel values defined by the -channel setting will have there values replaced.

This operator is especially suited to replacing a grayscale image with specific color gradient from the CLUT image.

Note that color replacements involving transparency (alpha/matte channel) will lookup the replacement alpha/matte value using the alpha/matte value of the original image. As such correct alpha channel lookup for a pure gray-scale original image will require a copy of that grayscale to be transfered into its alpha channel before applying the -clut operator. The special "-alpha set" operation can be used for this purpose.

Fully define the look of each frame of an GIF animation sequence, to form a 'film strip' like animation.

Overlay each image in an image sequence accoding to their -dispose meta-data, to re-produce the actual look of an animation at each point in the animation sequence. All images the same size, and are assigned appropriate GIF disposal settings so the animation will continues to work as expected as a GIF animation. Such frames are more easilly viewed, and processed, than the highly optimized GIF overlay images.

The animation can be re-optimized after processing using the -layers method 'optimize', though there is no gurantee that the restored GIF animation optimization will be better than the original.

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.

the image colorspace.

Choices are:

  CMY
  CMYK
  Gray
  HSB
  HSL
  HWB
  Lab
  Log
  OHTA
  Rec601Luma
  Rec601YCbCr
  Rec709Luma
  Rec709YCbCr
  RGB
  sRGB
  Transparent
  XYZ
  YCbCr
  YCC
  YIQ
  YPbPr
  YUV

To print a complete list of colorspaces, use the -list colorspace option.

For a more accurate color conversion to or from the RGB, CMYK, or grayscale colorspaces use the -profile option.

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. Comments in a file are literal, no embedded formatting characters are recognized.

the type of image composition.

The description of composition uses abstract terminology in order to allow 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 methods are available:

To print a complete list of composite operators, use the -list composite option.

There can be more methods listed, that what is shown above, many of these require special arguments, restricting there use to special composition operators, such as -blend, -dissolve, and -displace.

perform alpha composition on the current image sequence.

This is done according to the current -compose setting with the source image offset but the position given by -geometry

use this type of pixel compression when writing the image.

Choices are: None, BZip, Fax, Group4, JPEG, JPEG2000, Lossless, LZW, RLE or Zip.

To print a complete list of compression types, use the -list compress option.

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 down-sampling 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

Improve the contrast in an image by stretching the range of intensity values. While doing so black-out at most black-point pixels and burn at most white-point pixels. Or, if percent is used, black-out at most black-point % pixels and burn at most 100% minus white-point% pixels.

The channels are stretched in concert. Specify -channel to normalize the RGB channels individually.

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.

By adding a exclamation character flag to the geometry argument, the cropped images virtual canvas page size and offset will be set as if the geometry argument was a viewport or window. This means the canvas page size will be set to exactly the same size you specified, the the image offset set relative to top left corner of the region cropped.

If the cropped image 'missed' the actual image on its virtual canvas, a special single pixel transparent 'missed' image is returned, and a 'crop missed' warning given.

displace image colormap by amount.

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

convert cipher pixels to plain pixels.

Get the passphrase from the specified filename.

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.

find areas that has changed between images

Given a sequence of images all the same size, such as produced by -coalesce, replace the second and later images, with a smaller image of just the area that changed relative to the previous image.

The resulting sequence of images can be used to optimize an animation sequence, though will not work correctly for GIF animations when parts of the animation can go from opaque to transparent.

This option is actually equivalent to the -layers method 'compare-any'.

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.
    A 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

Set attributes of the image registry by prefixing the value with registry:. For example, to set a temporary path to put work files, use:

  convert -define registry:temporary-path=/data/tmp ...

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.

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 +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. 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).

define the GIF disposal image setting for images that are being created or read in.

The layer disposal method defines the way each the displayed image is to be modified after the current 'frame' of an animation has finished being displayed (after its 'delay' period), but before the next frame on an animation is to be overlaid onto the display.

Here are the valid methods:

  Undefined    0   No disposal specified (usually equivalent to 'none').
  None         1   Do not dispose between frames. Just layer the next frame.
  Background   2   Overwrite the frames area with the background color.
  Previous     3   Overwrite the frames area with what was there prior to overlaying.

You can also use the numbers given above, which is what the GIF format uses internally to represent the above settings.

To print a complete list of dispose methods, use the -list dipose option.

Use +dispose, turn off the setting and prevent resetting the layer disposal methods of images being read in.

Use -set 'dispose' method to set the image disposal method for images already in memory.

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.

distort an image, using the given method and its required arguments.

The arguments is a single string containing a list of floating point numbers separated by commas or spaces. The number of floating point values need depends on the distortion method being used.

Choose from these distortion types:

To print a complete list of distortion methods, use the -list distort option.

Many of the above methods are based on how a set of individual coordinates should be translated when image is distorted. Such a coordinate list is given as a sequence of pairs of coordinates, source X,Y coordinate, followed immediataly by that points distorted X,Y coordinate (4 floating point values).

For example, to warp an image using 'perspective' distortion, you need a list of at least 4 coordinate pairs, or 16 numbers. These number could be thought of as representing the distortion of a quadraterial from the source image to the distorted image. Here is the perspective distortion of the built-in "rose:" image. Note the 4 sets of coordinate pairs.

  convert rose:  -virtual-pixel black \
       -distort Perspective '0,0,0,0  0,45,0,45   69,0,60,10  69,45,60,35' \
       rose_3d_rotated.gif

If more that the minimum number of coordinate pairs are given, then the distortion method will be 'least squares' fitted to produce the best result for all the coordinate pairs given. It also allows the use of image registration to find coordinate pairs. Using extra coordinate pairs can be used to improve the fit of a distorted image to another image or chart beyond the resolution of a pixel coordinate. Of course a bad coordinate pair can also make the 'fit' worse. Caution is always advised.

The output image size will by default be the same as the input image. This means that if the part of the distorted image falls outside the viewed areas of the 'distorted space', those parts will be clipped and lost. However if you use the plus form of the operator (+distort) the resulting image will be automatically adjusted to show the whole of the distorted image, using the smallest image possible, if it is posible for that distortion method. A 'virtual canvas' offset will also then be added to the resulting image to locate that image in 'distorted space'. Use a +repage, to remove this offset if it is unwanted.

You can alternatively specify a special "-set option:distort:viewport {geometry_string}" setting which will specify the size and the offset of the generated 'viewport' image of the distorted image space.

Colors are acquired from the source image according to the -interpolate color lookup setting, when the image is magnified. However if the viewed image is minified (image becomes smaller), a special area resampling function (added ImageMagick v6.3.5-9), is used to produce a higher quality image. For example you can use a 'perspective' distortion to view a infinitely tiled 'plane' all the way to the horizon.

For example...

  convert -size 90x90 pattern:checkerboard -normalize -virtual-pixel tile \
      -distort perspective  '0,0,5,45  89,0,45,46  0,89,0,89  89,89,89,89' \
      checks_tiled.jpg

Warning, infinitely tiled perspective images involving the horizon can be very slow to generate due to the use of the high quality 'area resampling' function (added ImageMagick v6.3.5-9). You can turn off 'area resampling' using a -filter setting of 'point', but the quality will suffer badly.

If an image generates invalid pixels, such as the 'sky' in the last 'perspective' distortion example, -distort will use the current -mattecolor setting for these pixels. If you do not what this 'sky' to be visible, set the color to match the rest of the ground.

Affine rotations and shears (such as 'SRT' distortion), tend to produce a cleaner result that the equivalent -rotate and/or -shear operation, with more control of due to the above settings. It is algorithmically slower, though in IM it may be faster.

Apply a Hilbert-Peano error diffusion dither to images when general color reduction is applied via an option, or automatically when saving to specific formats. This is enabled by default.

Dithering places two or more colors in neighbouring pixels so that to the eye a closer approximation of the images original color is reproduced. This reduces the number of colors needed to reproduce the image but at the cost of a lower level pattern of colors. Error diffusion dithers can use any set of colors (generated or user defined) to an image.

Use +dither to turn off dithering (the default), and to also render PostScript without text or graphic aliasing. Disabling dithering often (but not always) leads to faster process, a smaller number of colors, but more cartoon like image coloring. Generally resulting in 'color banding' effects in areas with color gradients.

The color reduction operators -colors, -monochrome, -map, and -posterize, apply dithering to images using the reduced color set they created. These operators are also used as part of automatic color reduction when saving images to formats with limited color support, such as GIF:, XBM:, and others, so dithering may also be used in these cases.

Alternativelly you can use -random-threshold to generate purely random dither. Or use -ordered-dither to apply threshold mapped dither patterns, using uniform color maps, rather than specific color maps.

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

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.

convert plain pixels to cipher pixels.

Get the passphrase from the specified filename.

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.

To print a complete list of endian type, use the -list endian option.

Use +endian to revert to unspecified endianness.

apply a digital filter to enhance a noisy image.

perform histogram equalization to the image.

Best results may come from equalizing the lightness channel as follows: ... -colorspace HSL -channel lightness -equalize -colorspace RGB ...

evaluate an arithmetic, relational, or logical expression.

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

To print a complete list of evaluate operators, use the -list evaluate option.

set the image size and offset. If the image is enlarged, unfilled areas are set to to the background color.

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.

This option accepts a color name, a hex color, or a numerical RGB, RGBA, HSL, HSLA, CMYK, or CMYKA specification. See Color Names for a description of how to properly specify the color argument.

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(255,255,255)" ...

See -draw for further details.

To print a complete list of color names, use the -list color option.

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
   Gaussian
   Quadratic
   Cubic
   Catrom
   Mitchell
   Lanczos
   Sinc
   Keys
   Parzen
   Welsh
   Bessel

If you do not select a filter with this option, the filter defaults to Mitchell for a colormapped image, a image with a matte channel, or if the image is enlarged. Otherwise the filter default to Lanczos.

Since options are evaluated in command line order, be sure to specify the -filter option before the -resize option.

To print a complete list of resize filters, use the -list filter option.

You can modify how the filter behaves as it scales your image with these settings:

-define filter:support=radius
Set the filter support radius.


-define filter:lobes=count
Set the number of lobes to use for the Sinc/Bessel filter.


-define filter:blur=factor
Scale the X axis of the filter (and its window). Use > 1.0 for blurry or < 1.0 for sharp.


-define filter:window=filter
The IIR (infinite impulse response) filters are windowed (brought down to zero) with these filters: Hanning, Hamming, Blackman, or Kaiser. The bessel and sinc filters are by default blackman-windowed. Choose from these windowing functions:

   Blackman
   Hanning
   Hamming
   Kaiser

For example, to get a 8 lobe Lanczos-Bessel filter:

  convert image.png  -define filter:window=bessel -define filter:lobes=8 \
          -filter bessel -resize 150%   image.jpg

a simple alias for the -layers method "flatten"

create a mirror image.

reflect the scanlines in the vertical direction.

floodfill the image with color at the specified offset. Using -fuzz to floodfill pixels which only change by a small amount.

create a mirror image.

reflect the scanlines in the horizontal direction.

set the font to use when annotating images with text, or creating labels.

To print a complete list of fonts, use the -list font option (for versions prior to 6.3.6, use 'type' instead of 'font').

In addition to the fonts specified by the above pre-defined list, you can also specify a font from a specific source. For example Arial.ttf is a TrueType font file, ps:helvetica is PostScript font, and x:fixed is X11 font.

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 converts 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.

See Format and Print Image Properties for an explanation on how to specify the argument to this option.

surround the image with an ornamental border.

See -resizefor 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 to an image or image channels.

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

See FX, The Special Effects Image Operator for a detailed discussion of this option.

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.

Convolve the image with a Gaussian or normal distribution. The formula is:

where r is the blur radius (r² = u² + v²), and σ is the standard deviation of the Gaussian distribution. As a guideline, set r to approximately 3σ. Specify a radius of 0 and ImageMagick selects a suitable radius for you.

preferred size and location of the image.

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. Or you can use -list with a 'Gravity' option to get a complete list of -gravity settings available in your ImageMagick installation.

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.

identify the format and characteristics of 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 color reduction algorithm for a description of these values.

If -verbose preceds this option, copious amounts of image properties are displayed including image statistics, profiles, image histogram, and others.

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 color management operation of an image (see -profile). Choose from these intents: Absolute, Perceptual, Relative, Saturation.

The default intent is undefined.

To print a complete list of rendering intents, use the -list intent option.

the type of interlacing scheme.

Choose from:

  none
  line
  plane
  partition
  JPEG
  GIF
  PNG

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.

To print a complete list of interlacing schemes, use the -list interlace option.

The pixel color interpolation method to use when looking up a color basied on a floating point or real value.

When looking up the color of a pixel using a non-interger floating point value, you typically fall in between the pixel colors defined by the source image. This setting determines how the color is determined from the colors of the pixels surrounding that point. That is how to determine the color of a point that falls between two, or even four different colored pixels.

  integer:           The color of the top-left pixel (floor function)
  nearest-neighbor:  The nearest pixel to the lookup point (rounded function)
  average:           The average color of the surrounding four pixels
  bilinear           A double linear interpolation of pixels (the default)
  mesh               Divide area into two flat triangular interpolations
  bicubic            Fitted bicubic-spines of surrounding 16 pixels
  spline             Direct spline curves (colors are blurred)
  filter             Use resize -filter settings

This is most important for distortion operators such as -distort, -implode, -transform and -fx.

To print a complete list of interpolation methods, use the -list interpolate option.

See also -virtual-pixel, for control of the lookup for positions outside the boundaries of the image.

assign a label to an image.

Use this option to assign a specific label to the image, as it is read in or created. You can use the -set operation to re-assign a the labels of images already read in. Image formats such as TIFF, PNG, MIFF, supports saving the label information with the image.

When saving an image to a PostScript file, any label assigned to an image will be used as a header string to print above the postscript image.

You can include the image filename, type, width, height, or other image attribute by embedding special format character. See -format for details of the percent escape codes.

For example,

  -label "%m:%f %wx%h"  bird.miff

assigns an image label of MIFF:bird.miff 512x480 to the "bird.miff" image and whose width is 512 and height is 480, as it is read in. If a +label option was used instead, any existing label present in the image would be used. You can remove all labels from an image by assigning the empty string.

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, or during the final processing in the creation of a image montage.

The label font can be specified with -font, and the other font attribute settings.

If the first character of string is @, the image label is read from a file titled by the remaining characters in the string. Labels in a file are literal, no embedded formatting characters are recognized.

perform local adaptive threshold.

Perform local adaptive threshold 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.

handle multiple images forming a set of image layers or animation frames.

Perform various image operation methods to a ordered sequence of images which may represent either a set of overlaid 'image layers', a GIF disposal animation, or a fully-'coalesced' animation sequence.

To print a complete list of layer types, use the -list layers option.

See also the -coalesce operator, and the GIF -dispose setting.

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 other limits are in in bytes. 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 32mb -limit map 64mb

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 fails.

Resource limits may also be set using environment variables. Set the environment variables MAGICK_AREA_LIMIT, MAGICK_DISK_LIMIT, MAGICK_FILE_LIMIT, MAGICK_MEMORY_LIMIT, and MAGICK_MAP_LIMIT limits for image area, disk space, open files, heap memory, and memory map respectively.

You can use the option -list resource to list the current limits.

Linear with saturation stretch.

the line width for subsequent draw operations.

rescale image with seam-carving.

print a list of supported option arguments. Choose from these list types:

  coder
  color
  configure
  delegate
  font
  format
  log
  magic
  module
  resource
  threshold

The above are just the special lists generated from various sources. In addition to these are many other lists, generally used as part of the parsing of command line options as compiled into the current ImageMagick version you are using. For example type "-list list" to get a completely listing of all the "-list" arguments available.

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.

reduce the number of colors in an image to the colors used by this image.

[convert or mogrify].

If the -dither setting is enabled (the default) then the given colors are dithered over the image as necessary, otherwise the closest color (in RGB colorspace) is selected to replace that pixel in the image.

As a side effect of applying a -map of colors across all images in the current image sequence, all the images will have the same color table. That means that when saved to a file format such as GIF, it will use that color table as a single common or global color table, for all the images, without requiring extra local color tables.

Use +map to reduce all images in the current image sequence to use a common color map over all the images. This is equivalent to appending all the images together (without extra background colors) and color reducing those images using -colors with a 256 color limit, then -map those colors over the original list of images. This ensures all the images follow a single color map.

If the number of colors over all the images is less than 256, then +map should not perform any color reduction or dithering, as no color changes are needed. In that case, its only effect is to force the use of a global color table. This is recommended after using either -colors or -ordered-dither to reduce the number of colors in an animated image sequence.

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.

pixel map. Here are the valid components of a map:

[stream].

  r        red pixel component
  g        green pixel component
  b        blue pixel component
  a        alpha pixel component (0 is transparent)
  o        opacity pixel component (0 is opaque)
  i        grayscale intensity pixel component
  c        cyan pixel component
  m        magenta pixel component
  y        yellow pixel component
  k        black pixel component
  p        pad component (always 0)

You can specify as many of these components as needed in any order (e.g. bgr). The components can repeat as well (e.g. rgbr).

Composite the image pixels as defined by the mask.

Use +mask to remove the image mask.

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.

output to STDERR a measure of the differences between images, according the to given metric.

Choose from:

 AE    absolute number of differnet pixels
 MAE   mean absolute error (normalized), average channel error distance
 MEPP  mean error per pixel (normalized mean error, normalized peak error)
 MSE   mean error squared, average of the channel error squared
 PAE   peak absolute (normalize peak absolute)
 PSNR  peak signal to noise ratio
 RMSE  root mean squared (normalized root mean squared)

The 'AE' or absolute count of pixels that are different, can be controled using a -fuzz factor to ignore pixels which only changed by a small amount. The 'PAE' can be used to find the size of the -fuzz factor needed to make all pixels 'similar'.

The 'MEPP' metric returns three different metrics ('MAE', 'MAE' normalized, and 'PAE' normalized) from the single comparision run.

To print a complete list of metrics, use the -list metrics option.

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

[montage].

Use the -list option with a 'Mode' argument for a list of -mode arguments available in your ImageMagick installation.