Image Magick provides a GUI and a command line interface that are
especially useful for displaying and manipulating images under Unix
and Linux.  It can also be installed under windows, but the advanced
features are not available from the GUI under windows.  (I have
never been successful in getting the command line interface to
work under windows... if you figure it out let me know!)

Image files come in many different formats.  When you specify an image
file as an argument to an Image Magick command, it will first look
at the filename extension to try and figure out what the format is.

For example, if you have a JPEG image in the file stoopid.jpg, you can
display it with the command

display stoopid.jpg

You can manually override the format by prepending a tag to the
filename that will tell Image Magick the format.  As a redundant
example, the above display command could also be given as

display jpg:stoopid.jpg

This explicitly tells Image Magick that the file format is JPEG.


Most of the image files on the course web site are "raw" files:  
they have no header and there is one byte per pixel.  To Image 
Magick, this format is called "gray."  In addition, since there 
is no header, you must tell Image Magick the size of the image.  

So, to display the image "lena.bin" found on the course web site, 
the command would be

display -size 256x256 gray:lena.bin

But this may give you an error.  The most probable cause is that
you installed Image Magick from binaries or built from source with
the default parameters and Image Magick is expecting 24-bit color
pixels.

In that case, you must also tell Image Magick that the image has
only one byte per pixel.  The correct command to display the image
in this case is:

display -depth 8 -size 256x256 gray:lena.bin

-----------------------

Once you have successfully displayed the image in this way, you can
left click on the image to bring up a very useful menu.  This menu
will enable you to perform a wide variety of image processing and
manipulation tasks.  You can also save the image in different
formats, edit it pixel by pixel, create overlays, annotations, and
extra layers, and so on.

Left click on the image again to close the menu.

The best way to gain familiarity with this GUI is to simply play
with it.

------------------------

Image Magick provides a variety of additional useful commands, but
the main one you will need for this course is the "convert" command.

This command converts an image from one format to another.  For
example, to convert "lena.bin" to a TIF file, you could type

convert -depth 8 -size 256x256 gray:lena.bin lena.tif

This will make the TIF file lena.tif.  You could display the TIF
file by typing

display lena.tif

(you don't have to specify the depth or the size because they
are already specified in the TIF file header)

If you wanted to name the TIF file lena.foo instead, you could type

convert -depth 8 -size 256x256 gray:lena.bin tif:lena.foo

This would make a TIF file called "lena.foo".  You could display
it with the command

display tif:lena.foo

----------------------

The information above will get you started with Image Magick and
shows you how to do everything you really need for ECE 5273.  Of
course, Image Magick can do a lot more!  When you install Image
Magick, be sure to also install the man pages.  To get started 
using the more advanced features of Image Magick, you should 
read the man pages for the various commands, e.g.

man display 
man convert

The other main Image Magick commands (that you can find out
about from their man pages) are:

animate
identify
montage
mogrify
composite

There is also a lot of useful information on the main Image Magick
man page; type

man ImageMagick

to see it!