ImageMagick - image manipulation

Version

5.5.7-4

Description

ImageMagick is a collection of tools for display and interactive manipulation of images.

The package includes tools for image conversion, annotation, compositing, animation, and creating montages. ImageMagick can read and write many of the more popular image formats (e.g. JPEG, TIFF, PNM, XPM, Photo CD, etc.).

For a full description of the ImageMagick package and the included modules

display - processes and displays images
import - captures X11 windows
animate - displays a sequence of images
montage - creates a composite image of separate images
mogrify - transforms an image or a sequence of images
convert - converts images to different formats
composite - composite images together
identify - describes the format and characteristics of images

see the official ImageMagick WWW page or the (locally available) ImageMagick page contained within the distribution package.

How to use

Some information you may find in the ImageMagick FAQ.

In order to test the following examples it is assumed that the ImageMagick source directory (not available at all dv.xx.dlr.de) is the current directory (/usr/local/contrib/src/ImageMagick).

In order to display an image on any workstation or terminal running X use the display command, e.g.

   display images/aquarium.miff

   display -monochrome -dither images/aquarium.miff

If the image colors are not correct use this command:

   display -visual default images/aquarium.miff

To display an image of a cockatoo specified with a World Wide Web (WWW) uniform resource locator (URL), use

   display ftp://wizards.dupont.com/images/cockatoo.jpg
   display http://www.wizards.dupont.com/cristy/images/magick.png

You can find other example images in the 'images' directory.

Be sure to read the manual pages for the

utilities and the official ImageMagick WWW page.

The ImageMagick utilities read and write MIFF images. Refer to the end of this message for more information about MIFF. Use convert to convert images to and from the MIFF format.

ImageMagick utilities recognizes many image formats including popular formats like TIFF, JPEG, PNG, PDF, Photo CD, and GIF. and for your convenience automatically converts most of these alien image format to MIFF at execution time. However, the MIFF image format has several advantages over most image formats (i.e. runlength encoding, digital signature on an image colormap, etc.). ImageMagick is designed to exploit these advantages. Whenever possible convert an alien image format to the MIFF format before using the various ImageMagick programs.

Other formats are also recognized. See CONVERT(1) for a list of valid image formats. You can specify a particular image format by prefixing the image filename with the image type and a colon (i.e. ps:image.ps).

ANIMATION

To prevent color flashing on visuals that have colormaps, animate creates a single colormap from the image sequence. This can be rather time consuming. You can speed this operation up by reducing the colors in the image before you `animate' them. Use `mogrify' to color reduce the images:

   mogrify -colors 256 scenes/dna.[0-9]*

Note, the image sequence in ImageMagick.animation.tar.Z (remark: on dv.go.dlr.de the contents of ImageMagick.animation.tar.Z is soft-linked into the scenes directory) is already reduced. Alternatively, you can use a Standard Colormap; or a static, direct, or true color visual. You can define a Standard Colormap with `xstdcmap'. For example, to use the "best" Standard Colormap, type:

   xstdcmap -best
   animate -map best scenes/dna.[0-9]*

or to use a true color visual:

   animate -visual truecolor scenes/dna.[0-9]*

Image filenames can appear in any order on the command line if the scene keyword is specified in the MIFF image. Otherwise the images display in the order they appear on the command line. A scene is specified when converting from another image format to MIFF by using the "scene" option with any filter. Be sure to choose a scene number other than zero. For example, to convert a TIFF image to a MIFF image as scene #2, type:

   convert -scene 2 image.tiff image.miff

NOTES

In the german computer magazin 'iX' (11/93) an informative article about ImageMagick is published.
Images do not display correctly on the IBM R6000 visual with 4096 colors (Sabine). However they do display correctly on the visual with 256 colors. Until IBM fixes their server, type xdpyinfo to determine the ID of the 256 color visual and type
```
   display -visual 0x???? image.miff
```
On the Stardent put
```
   *installColormap:  on
```
in your X resource file.
Some Digital and Tektronix servers have a bug. When converting from LSBFirst to MSBFirst X server (or visa-versa) you may get the error
Illegal unit size: 8 found in routine: _normalizeimagebits
On occasion, a window manager (twm) may get in strange state which will cause the display program to work improperly. Fix this by restarting the window manager.
If the image is displayed with incorrect colors, try using a different visual. Type xdpyinfo and choose an alternative visual (if one exists) by either visual class or visual id. For example, to specifically choose a PseudoColor visual on a server that supports it, type
```
   display -visual pseudocolor image.miff
```

MIFF IMAGE FORMAT

MIFF is an image format which I (the author of ImageMagick) developed. I like it because it

It is machine independent. It can be read on virtually any computer. No byte swapping is necessary.
It has a text header. Most image formats are coded in binary and you cannot easily tell attributes about the image. Use 'more' on MIFF image files and the attributes are displayed in text form.
It can handle runlength-encoded images. Although most scanned images do not benefit from runlength-encoding, most computer-generated images do. Images of mostly uniform colors have a high compression ratio and therefore take up less memory and disk space.
It allows a scene number to be specified. This allows you to specify an animation sequence out-of-order on the command line. The correct order is determined by the scene number of each image.
MIFF computes a digital signature for colormapped images. This is useful for animating a sequence of images on a colormapped X server. If all signatures match in the image sequence, computing a global colormap is not necessary.
There is a `montage' keyword allowing an image to act as a visual image directory. See display(1) for more details.

One way to get an image into MIFF format is to use `convert'. or read it from an X window using the 'import' program. Alternatively, type the necessary header information in a file with a text editor. Next, dump the binary bytes into another file. Finally, type

   cat header binary_image | display -write image.miff -

For example, suppose you have a raw red, green, blue image file on disk that is 640 by 480. The header file would look like this:

   id=ImageMagick columns=640 rows=480 :

The image file would have red, green, blue tuples (rgbrgbrgb...).

Refer to the display manual page for more details.