The convert program is a member of the ImageMagick(1) suite of tools. Use it to convert between image formats as well as resize an image, blur, crop, despeckle, dither, draw on, flip, join, re-sample, and much more.
For more information about the convert command, point your browser to file:///usr/share/doc/imagemagick-6-common/html/www/convert.html (on debian system you may install the imagemagick-6-doc package) or http://www.imagemagick.org/script/convert.php.
Image Settings: -adjoin join images into a single multi-image file -affine matrix affine transform matrix -alpha option activate, deactivate, reset, or set the alpha channel -antialias remove pixel-aliasing -authenticate value decrypt image with this password -attenuate value lessen (or intensify) when adding noise to an image -background color background color -bias value add bias when convolving an image -black-point-compensation use black point compensation -blue-primary point chromaticity blue primary point -bordercolor color border color -caption string assign a caption to an image -cdl filename color correct with a color decision list -channel type apply option to select image channels -clip clip along the first path from the 8BIM profile -clip-mask filename associate a clip mask with the image -clip-path id clip along a named path from the 8BIM profile -colors value preferred number of colors in the image -colorspace type alternate image colorspace -comment string annotate image with comment -compose operator set image composite operator -compress type type of pixel compression when writing the image -decipher filename convert cipher pixels to plain pixels -define format:option define one or more image format options -delay value display the next image after pausing -density geometry horizontal and vertical density of the image -depth value image depth -direction type render text right-to-left or left-to-right -display server get image or font from this X server -dispose method layer disposal method -dither method apply error diffusion to image -encipher filename convert plain pixels to cipher pixels -encoding type text encoding type -endian type endianness (MSB or LSB) of the image -family name render text with this font family -features distance analyze image features (e.g. contrast, correlation) -fill color color to use when filling a graphic primitive -filter type use this filter when resizing an image -flatten flatten a sequence of images -font name render text with this font -format "string" output formatted image characteristics -fuzz distance colors within this distance are considered equal -gravity type horizontal and vertical text placement -green-primary point chromaticity green primary point -intensity method method to generate intensity value from pixel -intent type type of rendering intent when managing the image color -interlace type type of image interlacing scheme -interline-spacing value set the space between two text lines -interpolate method pixel color interpolation method -interword-spacing value set the space between two words -kerning value set the space between two letters -label string assign a label to an image -limit type value pixel cache resource limit -loop iterations add Netscape loop extension to your GIF animation -mask filename associate a mask with the image -matte store matte channel if the image has one -mattecolor color frame color -metric type measure differences between images with this metric -moments report image moments -monitor monitor progress -orient type image orientation -page geometry size and location of an image canvas (setting) -ping efficiently determine image attributes -pointsize value font point size -precision value maximum number of significant digits to print -preview type image preview type -quality value JPEG/MIFF/PNG compression level -quiet suppress all warning messages -red-primary point chromaticity red primary point -regard-warnings pay attention to warning messages -remap filename transform image colors to match this set of colors -respect-parentheses settings remain in effect until parenthesis boundary -sampling-factor geometry horizontal and vertical sampling factor -scene value image scene number -seed value seed a new sequence of pseudo-random numbers -size geometry width and height of image -statistic type geometry replace each pixel with corresponding statistic from the neighborhood -stretch type render text with this font stretch -stroke color graphic primitive stroke color -strokewidth value graphic primitive stroke width -style type render text with this font style -support factor resize support: > 1.0 is blurry, < 1.0 is sharp -synchronize synchronize image to storage device -taint declare the image as modified -texture filename name of texture to tile onto the image background -tile-offset geometry tile offset -treedepth value color tree depth -transparent-color color transparent color -undercolor color annotation bounding box color -units type the units of image resolution -verbose print detailed information about the image -view FlashPix viewing transforms -virtual-pixel method virtual pixel access method -weight type render text with this font weight -white-point point chromaticity white point
Image Operators: -adaptive-blur geometry adaptively blur pixels; decrease effect near edges -adaptive-resize geometry adaptively resize image with data dependent triangulation -adaptive-sharpen geometry adaptively sharpen pixels; increase effect near edges -annotate geometry text annotate the image with text -auto-gamma automagically adjust gamma level of image -auto-level automagically adjust color levels of image -auto-orient automatically orient image -bench iterations measure performance -black-threshold value force all pixels below the threshold into black -blue-shift factor simulate a scene at nighttime in the moonlight -blur geometry reduce image noise and reduce detail levels -border geometry surround image with a border of color -brightness-contrast geometry improve brightness / contrast of the image -canny geometry detect edges in the image -charcoal radius simulate a charcoal drawing -chop geometry remove pixels from the image interior -clamp keep pixel values in range (0-QuantumRange) -clip clip along the first path from the 8BIM profile -clip-mask filename associate a clip mask with the image -clip-path id clip along a named path from the 8BIM profile -colorize value colorize the image with the fill color -color-matrix matrix apply color correction to the image -connected-component connectivity connected-components uniquely labeled -contrast enhance or reduce the image contrast -contrast-stretch geometry improve contrast by `stretching' the intensity range -convolve coefficients apply a convolution kernel to the image -cycle amount cycle the image colormap -deskew threshold straighten an image -despeckle reduce the speckles within an image -distort method args distort images according to given method ad args -draw string annotate the image with a graphic primitive -edge radius apply a filter to detect edges in the image -emboss radius emboss an image -enhance apply a digital filter to enhance a noisy image -equalize perform histogram equalization to an image -evaluate operator value evaluate an arithmetic, relational, or logical expression -extent geometry set the image size -extract geometry extract area from image -fft implements the discrete Fourier transform (DFT) -flip flip image vertically -floodfill geometry color floodfill the image with color -flop flop image horizontally -frame geometry surround image with an ornamental border -function name apply a function to the image -gamma value level of gamma correction -gaussian-blur geometry reduce image noise and reduce detail levels -geometry geometry preferred size or location of the image -grayscale method convert image to grayscale -hough-lines geometry identify lines in the image -identify identify the format and characteristics of the image -ift implements the inverse discrete Fourier transform (DFT) -implode amount implode image pixels about the center -interpolative-resize geometry resize image using 'point sampled' interpolation -lat geometry local adaptive thresholding -layers method optimize or compare image layers -level value adjust the level of image contrast -level-colors color,color level image with the given colors -linear-stretch geometry improve contrast by `stretching with saturation' the intensity range -liquid-rescale geometry rescale image with seam-carving -magnify double the size of the image with pixel art scaling -mean-shift geometry delineate arbitrarily shaped clusters in the image -median geometry apply a median filter to the image -mode geometry make each pixel the 'predominant color' of the neighborhood -modulate value vary the brightness, saturation, and hue -monochrome transform image to black and white -morphology method kernel apply a morphology method to the image -motion-blur geometry simulate motion blur -negate replace each pixel with its complementary color -noise geometry add or reduce noise in an image -normalize transform image to span the full range of colors -opaque color change this color to the fill color -ordered-dither NxN add a noise pattern to the image with specific amplitudes -paint radius simulate an oil painting -perceptible epsilon pixel value less than |epsilon| become epsilon or -epsilon -polaroid angle simulate a Polaroid picture -posterize levels reduce the image to a limited number of color levels -print string interpret string and print to console -profile filename add, delete, or apply an image profile -quantize colorspace reduce colors in this colorspace -radial-blur angle radial blur the image -raise value lighten/darken image edges to create a 3-D effect -random-threshold low,high random threshold the image -region geometry apply options to a portion of the image -render render vector graphics -repage geometry size and location of an image canvas -resample geometry change the resolution of an image -resize geometry resize the image -roll geometry roll an image vertically or horizontally -rotate degrees apply Paeth rotation to the image -sample geometry scale image with pixel sampling -scale geometry scale the image -segment values segment an image -selective-blur geometry selectively blur pixels within a contrast threshold -sepia-tone threshold simulate a sepia-toned photo -set property value set an image property -shade degrees shade the image using a distant light source -shadow geometry simulate an image shadow -sharpen geometry sharpen the image -shave geometry shave pixels from the image edges -shear geometry slide one edge of the image along the X or Y axis -sigmoidal-contrast geometry lightness rescaling using sigmoidal contrast enhancement -sketch geometry simulate a pencil sketch -solarize threshold negate all pixels above the threshold level -sparse-color method args fill in a image based on a few color points -splice geometry splice the background color into the image -spread amount displace image pixels by a random amount -strip strip image of all profiles and comments -swirl degrees swirl image pixels about the center -threshold value threshold the image -thumbnail geometry create a thumbnail of the image -tile filename tile image when filling a graphic primitive -tint value tint the image with the fill color -transform affine transform image -transparent color make this color transparent within the image -transpose flip image vertically and rotate 90 degrees -transverse flop image horizontally and rotate 270 degrees -trim trim image edges -type type image type -unique-colors discard all but one of any pixel color -unsharp geometry sharpen the image -vignette geometry soften the edges of the image in vignette style -wave geometry alter an image along a sine wave -wavelet-denoise threshold removes noise from the image using a wavelet transform -white-threshold value force all pixels above the threshold into white
Image Sequence Operators: -append append an image sequence top to bottom (use +append for left to right) -clut apply a color lookup table to the image -coalesce merge a sequence of images -combine combine a sequence of images -compare mathematically and visually annotate the difference between an image and its reconstruction -complex operator perform complex mathematics on an image sequence -composite composite image -copy geometry offset, copy pixels from one area of an image to another -crop geometry cut out a rectangular region of the image -deconstruct break down an image sequence into constituent parts -evaluate-sequence operator evaluate an arithmetic, relational, or logical expression -flatten flatten a sequence of images -fx expression apply mathematical expression to an image channel(s) -hald-clut apply a Hald color lookup table to the image -morph value morph an image sequence -mosaic create a mosaic from an image sequence -poly terms build a polynomial from the image sequence and the corresponding terms (coefficients and degree pairs) -process arguments process the image with a custom image filter -separate separate an image channel into a grayscale image -smush geometry smush an image sequence together -write filename write images to this file
Image Stack Operators: -clone indexes clone an image -delete indexes delete the image from the image sequence -duplicate count,indexes duplicate an image one or more times -insert index insert last image into the image sequence -reverse reverse image sequence -swap indexes swap two images in the image sequence
Miscellaneous Options: -debug events display copious debugging information -distribute-cache port distributed pixel cache spanning one or more servers -help print program options -log format format of debugging information -list type print a list of supported option arguments -version print version information
Use any setting or operator as an output-option. Only a limited number of setting are input-option. They include: -antialias, -caption, -density, -define, -encoding, -font, -pointsize, -size, and -texture as well as any of the miscellaneous options.
By default, the image format of `file' is determined by its magic number. To specify a particular image format, precede the filename with an image format name and a colon (i.e. ps:image) or specify the image type as the filename suffix (i.e. image.ps). Specify 'file' as '-' for standard input or output.