Just to let you see what mogrify can do:
-bash-2.05b$ /usr/local/bin/mogrify
Version: ImageMagick 5.5.7 07/23/03 Q16
http://www.imagemagick.org
Copyright: Copyright (C) 2003 ImageMagick Studio LLC
Usage: /usr/local/bin/mogrify [options ...] file [ [options ...] file ...]
Where options include:
-affine matrix affine transform matrix
-antialias remove pixel-aliasing
-authenticate value decrypt image with this password
-background color background color
-black-threshold value
forces all pixels below the threshold into black
-blue-primary point chomaticity blue primary point
-blur radius blur the image
-border geometry surround image with a border of color
-bordercolor color border color
-channel type extract a particular color channel from image
-charcoal radius simulate a charcoal drawing
-chop geometry remove pixels from the image interior
-colorize value colorize the image with the fill color
-colors value preferred number of colors in the image
-colorspace type alternate image colorspace
-comment string annotate image with comment
-compress type image compression type
-contrast enhance or reduce the image contrast
-convolve coefficients
apply a convolution kernel to the image
-crop geometry preferred size and location of the cropped image
-cycle amount cycle the image colormap
-debug events display copious debugging information
-delay value display the next image after pausing
-density geometry horizontal and vertical density of the image
-depth value image depth
-despeckle reduce the speckles within an image
-display server get image or font from this X server
-dispose method Undefined, None, Background, Previous
-dither apply Floyd/Steinberg error diffusion to image
-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
-encoding type text encoding type
-endian type LSB or MSB
-enhance apply a digital filter to enhance a noisy image
-equalize perform histogram equalization to an image
-extract geometry extract area from image
-fill color color to use when filling a graphic primitive
-filter type use this filter when resizing an image
-flip flip image in the vertical direction
-flop flop image in the horizontal direction
-font name render text with this font
-format type image format type
-frame geometry surround image with an ornamental border
-fuzz distance colors within this distance are considered equal
-gamma value level of gamma correction
-gaussian geometry gaussian blur an image
-geometry geometry perferred size or location of the image
-green-primary point chomaticity green primary point
-implode amount implode image pixels about the center
-interlace type None, Line, Plane, or Partition
-help print program options
-label name assign a label to an image
-lat geometry local adaptive thresholding
-level value adjust the level of image contrast
-limit type value Disk, Map, or Memory resource limit
-list type Color, Delegate, Format, Magic, Module, Resource, or Type
-log format format of debugging information
-loop iterations add Netscape loop extension to your GIF animation
-map filename transform image colors to match this set of colors
-mask filename set the image clip mask
-matte store matte channel if the image has one
-median radius apply a median filter to the image
-modulate value vary the brightness, saturation, and hue
-monochrome transform image to black and white
-negate replace every pixel with its complementary color
-noop do not apply options to image-noise radius 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
-page geometry size and location of an image canvas
-paint radius simulate an oil painting
-fill color color for annotating or changing opaque color
-ordered-dither channeltype LOWxHIGH
ordered dither the image
-pointsize value font point size
-profile filename add ICM or IPTC information profile to image
-quality value JPEG/MIFF/PNG compression level
-raise value lighten/darken image edges to create a 3-D effect
-random-threshold channeltype LOWxHIGH
random threshold the image
-red-primary point chomaticity red primary point
-region geometry apply options to a portion of the image
-resample geometry change the resolution of an image
-resize geometry perferred size or location of 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
-sampling-factor geometry
horizontal and vertical sampling factor
-scale geometry scale the image
-scene number image scene number
-seed value pseudo-random number generator seed value
-segment values segment an image
-shade degrees shade the image using a distant light source
-sharpen radius sharpen the image
-shear geometry slide one edge of the image along the X or Y axis
-size geometry width and height of image
-solarize threshold negate all pixels above the threshold level
-spread amount displace image pixels by a random amount
-stroke color graphic primitive stroke color
-strokewidth value graphic primitive stroke width
-swirl degrees swirl image pixels about the center
-texture filename name of texture to tile onto the image background
-threshold value threshold the image
-thumbnail geometry create a thumbnail of the image
-tile filename tile image when filling a graphic primitive
-transform affine transform image
-transparent color make this color transparent within the image
-treedepth value color tree depth
-trim trim image edges
-type type image type
-undercolor color annotation bounding box color
-units type PixelsPerInch, PixelsPerCentimeter, or Undefined
-unsharp geometry sharpen the image
-verbose print detailed information about the image
-version print version information
-view FlashPix viewing transforms
-virtual-pixel method
Constant, Edge, Mirror, or Tile
-wave geometry alter an image along a sine wave
-white-point point chomaticity white point
-white-threshold value
forces all pixels above the threshold into white
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.
