mogrify -format jpeg *.tiff
To scale an image of a cockatoo to exactly 640 pixels in width and 480 pixels in height, use:
mogrify -geometry 640x480! cockatoo.miff
To create a single colormap for a sequence of bird images, use:
mogrify -colors 256 scenes/birds.*
-annotate "%m:%f %wx%h"
The color of the border is obtained from the X server and is defined as bordercolor (class borderColor). See X(1) for details.
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 remain unchanged. Refer to quantize(9) for more details.
If more than one image is specified on the command line, a single colormap is created and saved with each image.
Note, options -colormap, -dither, -colorspace, and -treedepth affect the color reduction algorithm.
Color reduction, by default, takes place in the RGB color space. Empirical evidence suggests that distances in color spaces such as YUV or YIQ correspond to perceptual color differences more closely than do distances in RGB space. These color spaces may give better results when color reducing an image. Refer to quantize(9) for more details.
The -colors or -monochrome option is required for this option to take effect.
By default, each image is commented with its file name. Use this option to assign a specific comment to the image. Optionally you can include the image filename, type, width, height, or scene number by embedding special format characters. Embed %f for filename, %m for magick, %w for width, %h for height, %s for scene number, or \n for newline. 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.
Specify +compress to store the binary image in an uncompressed format. The default is the compression type of the specified image file.
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.
To specify a percentage width or height instead, append %. For example to crop the image by ten percent on all sides of the image, use -crop 10%.
Use cropping to apply image processing options, or transmogrify, only a particular area of an image. Use -crop 0x0 to remove edges that are the background color.
This option specifies an image density when decoding a Postscript or Portable Document page. The default is 72 pixels per inch in the horizontal and vertical direction.
The basic strategy of dithering is to trade intensity resolution for spatial resolution by averaging the intensities of several neighboring pixels. Images which suffer from severe contouring when reducing colors can be improved with this option.
The -colors or -monochrome option is required for this option to take effect.
This option will convert any image to the image format you specify. See convert(1) for a list of image format types supported by ImageMagick.
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.
The color of the border is specified with the -mattecolor command line option.
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.
You can apply separate gamma values to the red, green, and blue channels of the image with a gamma value list delineated with commas (i.e. 1.7,2.3,1.2).
By default, the width and height are maximum values. That is, the image is expanded or contracted to fit the width and height value while maintaining the aspect ratio of the image. Append an exclamation point to the geometry to force the image size to exactly the size you specify. For example, if you specify 640x480! the image width is set to 640 pixels and height to 480. If only one factor is specified, both the width and height assume the value.
To specify a percentage width or height instead, append %. The image size is multiplied by the width and height percentages to obtain the final image dimensions. To increase the size of an image, use a value greater than 100 (e.g. 125%). To decrease an image's size, use a percentage less than 100.
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...). -label name assign a label to an image.
Use this option to assign a specific label to the image. Optionally you can include the image filename, type, width, height, or scene number in the label by embedding special format characters. Embed %f for filename, %m for magick, %w for width, %h for height, or %s for scene number. For example,
-label "%m:%f %wx%h"produces an image label of MIFF:bird.miff 512x480 for an image titled bird.miff and whose width is 512 and height is 480.
If the first character of string is @, the image label is read from a file titled by the remaining characters in the string.
When converting to Postscript, use this option to specify a header string to print above the image.
By default, color reduction chooses an optimal set of colors that best represent the original image. Alternatively, you can choose a particular set of colors with this option. This is useful when you want to create a sequence of images with one particular set of colors for each image.
Specify the percent change in brightness, the color saturation, and the hue separated by commas. For example, to increase the color brightness by 20% and decrease the color saturation by 10% and leave the hue unchanged, use: -modulate 20,-10.
The red, green, and blue intensities of an image are negated.
The principal function of noise peak elimination filter is to smooth the objects within an image without losing edge information and without creating undesired structures. The central idea of the algorithm is to replace a pixel with its next neighbor in value within a 3 x 3 window, if this pixel has been found to be noise. A pixel is defined as noise if and only if this pixel is a maximum or minimum within the 3 x 3 window.
This is a contrast enhancement technique.
Use this option to specify the dimensions of the Postscript page in pixels per inch or a TEXT page in pixels. The default for a Postscript page is to center the image on a letter page 612 by 792 pixels. The margins are 1/2" (i.e. 612x792+36+36). Other common sizes are:
Letter 612x 792
Tabloid 792x1224
Ledger 1224x 792
Legal 612x1008
Statement 396x 612
Executive 540x 720
A3 842x1190
A4 595x 842
A5 420x 595
B4 729x1032
B5 516x 729
Folio 612x 936
Quarto 610x 780
10x14 720x1008
For convenience you can specify the page size by media (e.g. A4, Ledger, etc.).
The page geometry is relative to the vertical and horizontal density of the Postscript page. See -density for details.
The default page dimensions for a TEXT image is 612x792.
Quality is 0 (worst) to 100 (best). The default is 75.
A negative x offset rolls the image left-to-right. A negative y offset rolls the image top-to-bottom.
Empty triangles left over from rotating the image are filled with the color defined as bordercolor (class borderColor). See X(1) for details.
Shearing slides one edge of an image along the X or Y axis, creating a parallelogram. An X direction shear slides an edge along the X axis, while a Y direction shear slides an edge along the Y axis. The amount of the shear is controlled by a shear angle. For X direction shears, x degrees> is measured relative to the Y axis, and similarly, for Y direction shears y degrees is measured relative to the X axis.
Empty triangles left over from shearing the image are filled with the color defined as bordercolor (class borderColor). See X(1) for details.
192x128
384x256
768x512
1536x1024
3072x2048
Finally, use this option to choose a particular resolution layer of a JBIG
image (e.g. -size 1024x768).
An optimal depth generally allows the best representation of the source image with the fastest computational speed and the least amount of memory. However, the default depth is inappropriate for some images. To assure the best representation, try values between 2 and 8 for this parameter. Refer to quantize(9) for more details.
The -colors or -monochrome option is required for this option to take effect.
This option enables you to perform undercolor removal and black generation on CMYK images-- images to be printed on a four-color printing system. You can control how much cyan, magenta, and yellow to remove from your image and how much black to add to it. The standard undercolor removal is 1.0x1.0. You'll frequently get better results, though, if the percentage of black you add to your image is slightly higher than the percentage of C, M, and Y you remove from it. For example you might try 0.5x0.7.
This information is printed: image scene number; image name; image size; the image class (DirectClass or PseudoClass); the total number of unique colors (if known); and the number of seconds to read and transform the image. Refer to miff(5) for a description of the image class.
If -colors is also specified, the total unique colors in the image and color reduction error values are printed. Refer to quantize(9) for a description of these values.
Options are processed in command line order. Any option you specify on the command line remains in effect until it is explicitly changed by specifying the option again with a different effect. For example, to mogrify two images, the first with 32 colors and the second with only 16 colors, use:
mogrify -colors 32 cockatoo.miff -colors 16 macaw.miff
Change - to + in any option above to reverse its effect. For example, specify +compress to store the binary image in an uncompressed format.
By default, the image format 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). See convert(1) for a list of valid image formats.
Specify file as - for standard input and output. If file has the extension .Z or .gz, the file is uncompressed with uncompress or gunzip respectively and subsequently compressed using with compress or gzip. Finally, precede the image file name with | to pipe to or from a system command.
Use an optional index enclosed in brackets after a file name to specify a desired subimage of a multi-resolution image format like Photo CD (e.g. img0001.pcd[4]).
Permission to use, copy, modify, distribute, and sell this software and its documentation for any purpose is hereby granted without fee, provided that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in supporting documentation, and that the name of E. I. du Pont de Nemours and Company not be used in advertising or publicity pertaining to distribution of the software without specific, written prior permission. E. I. du Pont de Nemours and Company makes no representations about the suitability of this software for any purpose. It is provided "as is" without express or implied warranty.
E. I. du Pont de Nemours and Company disclaims all warranties with regard to this software, including all implied warranties of merchantability and fitness, in no event shall E. I. du Pont de Nemours and Company be liable for any special, indirect or consequential damages or any damages whatsoever resulting from loss of use, data or profits, whether in an action of contract, negligence or other tortuous action, arising out of or in connection with the use or performance of this software.
David Pensak, E. I. du Pont de Nemours and Company, for providing a computing environment that made this program possible.
Paul Raveling, USC Information Sciences Institute, for the original idea of using space subdivision for the color reduction algorithm.