Most of these operators can be used with V6 and V7 and if not the version number is indicated next to the operator information.
There are 284 operators listed here
A
Adaptive blur - Adaptively blur pixels, with decreasing effect near the edges. (6&7)
Adaptive resize - Resize the image using data-dependent triangulation. (6&7)
Adaptive sharpen - Adaptively sharpen pixels, with increasing effect near edges. (6&7)
Adjoin - Join images into a single multi-image file. (6&7)
Affine - Set the drawing transformation matrix for combined rotating and scaling. (6)
Alpha - Gives control of the alpha/matte channel of an image. (6&7)
Alpha discrete - Treat the alpha channel independently (do not blend). (7)
Annotate - Annotate an image with text - angle option (6&7)
Antialias - Enable/Disable of the rendering of anti-aliasing pixels when drawing fonts and lines. (6&7)
Antialias off - Enable/Disable of the rendering of anti-aliasing pixels when drawing fonts and lines. (6&7)
Append - Join current images vertically or horizontally. (6&7)
Append horizontal - Join current images vertically or horizontally. (6&7)
Attenuate - Lessen (or intensify) when adding noise to an image. (6&7)
Authenticate - Decrypt a PDF with a password. (6&7)
Auto gamma - Automagically adjust gamma level of image. (6&7)
Auto level - Automagically adjust color levels of image. (6&7)
Auto orient - Automagically orient (rotate) an image created by a digital camera. (6&7)
Average - Average a set of images. (6)
B
Backdrop - Display the image centered on a backdrop. (6&7)
Background - (6&7)
Bench - Measure performance.
(6&7)
Bias - Add bias when convolving an image. (6&7)
Black threshold - (6&7)
Blackpoint compensation - Blackpoint compensation for a colour profile. (6&7)
Blend - Blend an image into another by the given percent. (6&7)
Blue primary - Set the blue chromaticity primary point. (6&7)
Blue shift - Simulate a scene at nighttime in the moonlight. Start with a factor of 1.5 (6&7)
Blur - Reduce image noise and reduce detail levels. (6&7)
Border - Surround the image with a border of color. (6&7)
Border color - Set the border color. (6&7)
Border width - The width of the border. (6&7)
Brightness contrast - Adjust the brightness and/or contrast of the image (6&7)
C
Cache - (6&7)
Caption - Assign a caption to an image. (6&7)
CDL - Color correct with a color decision list. (6&7)
Channel - Work on the specified image channel (6&7)
Charcol - Simulate a charcoal drawing. (6&7)
Chop - Remove pixels from the interior of an image. (6&7)
Clamp - Restrict image colors from 0 to the quantum depth. (6&7)
Clip - Apply the clipping path if one is present. (6&7)
Clip mask - Clip the image as defined by this mask. (6&7)
Clip path - Clip along a named path from the 8BImageMagick profile. (6&7)
Clone - Make a copy of an image (or images). (6&7)
Clut - Replace the channel values in the first image using each corresponding channel in the second image as a color lookup table. (6&7)
Coalesce - Fully define the look of each frame of an GIF animation sequence, to form a 'film strip' animation. (6&7)
Color matrix - Apply a color correction to the image (6&7)
Colorize - Colorize the image by an amount specified by value using the color specified by the most recent -fill setting. (6&7)
Colormap - Define the colormap type. (6&7)
Colors - Set the preferred number of colors in the image. (6&7)
Colorspace - Set the image colorspace. (6&7)
Combine - Combine one or more images into a single image. (6&7)
Comment - Embed a comment in an image. (6&7)
Compare - Mathematically and visually annotate the difference between two images. (6&7)
Complex - Perform complex mathematics on an image sequence (6&7)
Compose - Set the type of image composition. (6&7)
Composite - Perform alpha composition on the current image sequence. (6&7)
Compress - Use pixel compression specified by type when writing the image. (6&7)
Contrast - Enhance or reduce the image contrast. (6&7)
Contrast stretch - Increase the contrast in an image by stretching the range of intensity values. (6&7)
Convolve - Convolve an image with a user supplied convolution kernel. (6&7)
Crop - Cut out one or more rectangular regions of the image. (6&7)
Cycle - Displace image colormap by amount. (6&7)
D
Debug - Enable debug printout. (6&7)
Decipher - Decipher and restore pixels that were previously transformed by -encipher. (6&7)
Deconstruct - Find areas that has changed between images (6)
Define - add specific global settings generally used to control coders and image processing operations (6&7)
Delay - Display the next image after pausing. (6&7)
Delete - Delete the image, specified by its index, from the image sequence. (6&7)
Density - Set the horizontal and vertical resolution of an image for rendering to devices. (6&7)
Depth - Depth of the image. (6&7)
Descend - Obtain image by descending window hierarchy. (6&7)
Deskew - Straighten an image. A threshold of 40% works for most images. (6&7)
Despeckle - Reduce the speckles within an image. (6&7)
Direction - Render text right-to-left or left-to-right. (6&7)
Displace - Shift image pixels as defined by a displacement map. (6&7)
Display - Specifies the X server to contact. (6&7)
Dispose - Define the GIF disposal image setting for images that are being created or read in. (6&7)
Dissimilarity threshold - Maximum RMSE for subimage match (default 0.2). (6&7)
Dissolve - Dissolve an image into another by the given percent. (6&7)
Distort - Distort an image, using the given method and its required arguments. (6&7)
Distribute cache - Launch a distributed pixel cache server. (6&7)
Dither - Apply a Riemersma or Floyd-Steinberg error diffusion dither to images. (6&7)
Dither - (6&7)
Draw arc - Annotate an image with one or more graphic primitives. (6&7)
Duplicate - Duplicate an image one or more times. (6&7)
E
Edge - Detect edges within an image. (6&7)
Emboss - Emboss an image. (6&7)
Encipher - Encipher pixels for later deciphering by -decipher. (6&7)
Encoding - Specify the text encoding. (6&7)
Endian - Specify endianness (MSB or LSB) of the image. (6&7)
Enhance - Apply a digital filter to enhance a noisy image. (6&7)
Equalize - Perform histogram equalization on the image channel-by-channel. (6&7)
Evaluate - (6&7)
Evaluate sequence - Alter channel pixels by evaluating an arithmetic, relational, or logical expression over a sequence of images. (6&7)
Exit - Stop processing at this point (7)
Extent - Set the image size and offset. (6&7)
Extract - Extract the specified area from image. (6&7)
F
Family - Set a font family for text. (6&7)
Features - Display (cooccurrence matrix) texture measure features for each channel in the image in each of four directions (horizontal, vertical, left and right diagonals) for the specified distance. (6&7)
FFT - Implements the forward discrete Fourier transform (DFT). (6&7)
Fill - Color to use when filling a graphic primitive. (6&7)
Filter - Filter to be used during resize. (6&7)
Flatten - This is a simple alias for the -layers method "flatten". (6&7)
Flip - Create a mirror image. (6&7)
Floodfill - Floodfill the image with color at the specified offset. (6&7)
Flop - Reflect the image in the horizontal direction. (6&7)
Font - Set the font to be used with draw, annotate etc. (6&7)
Foreground - Define the foreground color. (6&7)
Format - Output formatted image characteristics. (6&7)
Frame - A frame around the image (6&7)
Function - Apply a function to channel values. (6&7)
Fuzz - Fuzz can be used to select a range of colours and in the example is used with transparent. (6&7)
Fx - The Fx special effects image operator is used to apply a mathematical expression to an image or image channels. (6&7)
G
Gamma - Level of gamma correction. (6&7)
Gaussian blur - Blur the image with a Gaussian operator. (6&7)
Geometry - Geometry sets the coordinates for the modification. (6&7)
Gravity - Gravity sets the location of the modification. (6&7)
Grayscale - Convert image to grayscale. (6&7)
Green primary - Green chromaticity primary point. (6&7)
H
Hald clut - Apply a Hald color lookup table to the image. (6&7)
Help - Display the help file (6&7)
Highlight color - When comparing images, emphasize pixel differences with this color. (6&7)
I
Icon Geometry - Specify the icon geometry. (6&7)
Iconic - Iconic animation (6&7)
Identify - Identify the format and characteristics of the image. (6&7)
IFT - Implements the inverse discrete Fourier transform (DFT). (6&7)
Immutable - Make image immutable. (6&7)
Implode - Implode image pixels about the center. (6&7)
Insert - Insert the last image into the image sequence. (6&7)
Intensity - Method to generate intensity value from pixel. (6&7)
Intent - Use this type of rendering intent when managing the image color. (6&7)
Interlace - The type of interlacing scheme. (6&7)
Interline spacing - The space between two text lines. (6&7)
Interpolate - Set the pixel color interpolation method to use when looking up a color based on a floating point or real value. (6)
Interword spacing - The space between words. (6&7)
K
Kerning - The space between letters. (6&7)
L
Label - Not displayed but added to the image. (6&7)
Lat - Perform local adaptive threshold. (6&7)
Layers - Handle multiple images forming a set of image layers or animation frames. (6&7)
Level - Adjust the level of image channels. (6&7)
Level colors - Adjust the level of an image using the provided dash seperated colors. (6&7)
Limit - Set the resource limit. (6&7)
Linear stretch - Linear with saturation stretch. (6&7)
Linewidth - Linewidth is depreciated use strokewidth. (6&7)
Liquid rescale - Rescale image with seam-carving. (6&7)
List - List some operator options (6&7)
Log - Specify the format for the debug log. (6&7)
Loop - Add Netscape loop extension to your GIF animation. (6&7)
Lowlight color - When comparing images, de-emphasize pixel differences with this color. (6&7)
M
Magnify - magnify the image. (6&7)
Map - Display image using a specified type. (6)
Mask - Composite the image pixels as defined by the mask. (6)
Mattecolor - Sets the color for -frame (6&7)
Median - Apply a median filter to the image. (6&7)
Metric - Output to STDERR a measure of the differences between images according to the type given metric. (6&7)
Mode - Mode of operation. (6&7)
Modulate - Vary the brightness, saturation, and hue of an image. (6&7)
Moments - Report image moments. (6&7)
Monitor - Monitor progress. (6&7)
Monochrome - Transform the image to black and white. (6&7)
Morph - Morphs an image sequence. (6&7)
Morphology - apply a morphology method to the image. (6&7)
Mosaic - A simple alias for the -layers method "mosaic". (6&7)
Motion blur - (6&7)
N
Name - Name an image. (6&7)
Negate - Replace every pixel with its complementary color. (6&7)
Noise - Add and remove noise (6&7)
Normalize - Increase the contrast in an image by stretching the range of intensity values. (6&7)
O
Opaque - Opaque using fill for the replacement colour and -fuzz to select a range. (6&7)
Ordered dither - Dither the image using a pre-defined ordered dither threshold map specified, and a uniform color map with the number of levels per color channel. (6&7)
Orient - Specify orientation of a digital camera image. (6&7)
P
Page - Set the size and location of an image on the larger virtual canvas. (6&7)
Page - Set the size and location of an image on the larger virtual canvas. (6&7)
Paint - Oil paint effect. (6&7)
Path - Write images to this path on the disk. (6&7)
Pause - Pause between animation loops. (6&7)
Perceptible - set each pixel whose value is less than |epsilon| to -epsilon or epsilon (whichever is closer) otherwise the pixel value remains unchanged. (6&7)
Ping - Efficiently determine image characteristics. (6&7)
Pointsize - Set the font size to be used with draw, annotate etc. (6&7)
Polaroid - Polaroid effect. (6&7)
Poly - Combines multiple images according to a weighted sum of polynomials; one floating point weight (coefficient) and one floating point polynomial exponent (power) for each image expressed as comma separa (6&7)
Posterize - Reduce the image to a limited number of color levels. (6&7)
Precision - Set the maximum number of significant digits to be printed. (6&7)
Preview - Image preview type. (6&7)
Print - Interpret string and print to console. (6&7)
Process - Process the image with a custom image filter. (6&7)
Profile - Manage ICM, IPTC, or generic profiles in an image. (6&7)
Q
Quality - Specify the output image quality. (6&7)
Quantize - Reduce colors in this colorspace. (6&7)
Quite - Suppress all warning messages. (6&7)
R
Radial blur - Blur around the center of the image. (6&7)
Raise - Lighten or darken image edges. (6&7)
Raise - Lighten or darken image edges. (6&7)
Read - Explicit read of an image, rather than an implicit read. (7)
Read mask - Prevent updates to image pixels specified by the mask (7)
Red primary - Set the red chromaticity primary point. (6&7)
Regard warnings - Pay attention to warning messages. (6&7)
Region - Set a region in which subsequent operations apply. (6&7)
Remap - Reduce the number of colors in an image to the colors used by this image. (6&7)
Remote - Perform a remote operation. (6&7)
Render - Render vector operations. (6&7)
Repage - Adjust the canvas and offset information of the image. (6&7)
Resample - Resample image to specified horizontal and vertical resolution. (6&7)
Resize - Resize the image and leave EXIF data etc. (6&7)
Respect parenthases - Settings remain in effect until parenthesis boundary. (6&7)
Reverse - Reverse the order of images in the current image list. (6&7)
Roll - (6&7)
Rotate - Rotate the image (6&7)
S
Sample - Scale image using pixel sampling. (6&7)
Scale - Different type of resizing an image (6&7)
Scene - Set scene number. (6&7)
Screen - Specify the screen to capture. (6&7)
Script - Stop the processing of command line arguments as image operations, and read all further options from the given file or pipeline. (7)
Seed - Seed a new sequence of pseudo-random numbers. (6&7)
Segment - Segment the colors of an image. (6&7)
Selective blur - Selectively blur pixels within a contrast threshold. (6&7)
Separate - Separate an image channel into a grayscale image. (6&7)
Sepia tone - Sepia effect. (6&7)
Set - Set an image attribute for all images in the current image sequence, after they have been created or read in. (6&7)
Shade - Shade the image using a distant light source. (6&7)
Shadow - Simulate an image shadow. (6&7)
Shared memory - Use shared memory. (6&7)
Sharpen - sharpen the image. (6&7)
Shave - Shave pixels from the image edges. (6&7)
Shear - Shear the image along the x-axis and/or y-axis. (6&7)
Sigmoidal contrast - Increase the contrast without saturating highlights or shadows. (6&7)
Silent - Operate silently. (6&7)
Similarity threshold - Minimum RMSE for subimage match. (6&7)
Size - Set the width and height of the image. (6&7)
Sketch - Simulate a pencil sketch. (6&7)
Smush - It does more than just append with a overlap. It appends images with shape, and allowing one shape to fit into another shape. (6&7)
Snaps - Set the number of screen snapshots. (6&7)
Solarize - Negate all pixels above the threshold level. (6&7)
Sparse color - Color the given image using the specified points of color, and filling the other intervening colors using the given methods. (6&7)
Splice - Splice the current background color into the image. (6&7)
Spread - Displace image pixels by a random amount. (6&7)
Stegano - Hide watermark within an image. (6&7)
Stereo - Composite two images to create a stereo anaglyph. (6&7)
Storage type - Pixel storage type. (6&7)
Stretch - Set a type of stretch style for fonts. (6&7)
Strip - Strip the image of any profiles or comments. (6&7)
Stroke - Color to use when stroking a graphic primitive. (6&7)
Strokewidth - Strokewidth sets the line width. (6&7)
Style - Set a font style for text - limited options (6&7)
Swap - Swap the positions of two images in the image sequence. (6&7)
Swirl - Swirl image pixels about the center. (6&7)
T
Taint - Mark the image as modified even if it isn't. (6&7)
Text font - Font for writing fixed-width text. (6&7)
Texture - Name of texture to tile onto the image background. (6&7)
Threshold - Apply simultaneous black/white threshold to the image. (6&7)
Thumbnail - Resize and thumbnail have the same effect but thumbnail strips the EXIF data etc. (6&7)
Tile - Set the tile image used for filling a subsequent graphic primitive. (6&7)
Tile offset - Specify the offset for tile images, relative to the background image it is tiled on. (6&7)
Tint - Tint the image with the fill color. (6&7)
Title - Assign a title to displayed image. (6&7)
Transform - Transform the image. (6)
Transparent - Make this color transparent within the image. (6&7)
Transparent color - Set the transparent colour. (6&7)
Transparent inverted - Make all colours except this color transparent within the image. (6&7)
Transpose - Mirror the image along the top-left to bottom-right diagonal. (6&7)
Transverse - Mirror the image along the images bottom-left top-right diagonal. (6&7)
Treedepth - Tree depth for the color reduction algorithm. (6&7)
Trim - Trim an image. (6&7)
Type - The image type. (6&7)
U
Undercolor - Set the color of the annotation bounding box. (6&7)
Unique colors - Discard all but one of any pixel color from the image. (6&7)
Units - The units of image resolution. (6&7)
Unsharp - Sharpen the image with an unsharp mask operator. (6&7)
Update - Detect when image file is modified and redisplay. (6&7)
V
Verbose - Print detailed information about the image when this option preceds the -identify option or info: (6&7)
Version - Print ImageMagick version. (6&7)
View - FlashPix viewing parameters. (6&7)
Vignette - soften the edges of the image in vignette style. (6&7)
Virtual pixel - Specify contents of virtual pixels. (6&7)
Visual - Animate images using this X visual type. (6&7)
W
Watermark - Watermark an image using the given percentages of brightness and saturation. (6&7)
Wave - Shear the columns of an image into a sine wave. (6&7)
Weight - Set a font weight for text. (6&7)
White point - Chromaticity white point. (6&7)
White threshold - Force to white all pixels above the threshold while leaving all pixels at or below the threshold unchanged. (6&7)
Window - Make the image the background of a window. (6&7)
Window-group - Specify the window group. (6&7)
Write - Write an image sequence. (6&7)
Write mask - Prevent pixels from being written. (7)