ImageViewer:
Author: Christopher Zakian
Contact: czakian@indiana.edu

1. OVERVIEW
   The purpose of this image viewer is to let the user view PNM images; either
   from the command line, or as an application started from another program.
   As such, the image viewer can be called with either an image input stream or
   with a file name. 
       Great care and effort has been made to keep the code as compact and
   simple as possible. To this end, the image viewer uses Java's 
   Java Advanced Imaging library (JAI). These libraries do not come in the
   standard Java libraries. To use the image viewer, you can use the jarfiles
   provided under the jai directory. To use these jars, compile the image viewer
   with the provided Makefile. Be sure to have the jai directory in the same 
   directory as your Makefile and ImageViewer.java file.
   Alternatively, you can download and install the JAI to your machine 
   as per Java's instructions at:
   http://java.sun.com/products/java-media/jai/INSTALL-1_1_2.html
       This program has been tested with .ppm images up to 48.0MB 
  and 4096x4096 pixels. Additionally,There is no reason that the image viewer 
  couldn't display other image formats supported by JAI; however, these formats
   have not been tested since they are outside of the scope of this project.
   for more information on image formats supported by JAI see:
   http://java.sun.com/products/java-media/jai/forDevelopers/jai1_0_1guide-unc/Acquisition.doc.html	 

2. INSTRUCTIONS FOR USE

   on Linux:
   Compile the code with:
   $ make
   then run it with a file name:
   $ java ImageViewer MyPic.ppm 
   or with an input stream:
   $ java ImageViewer <  MyPic.ppm

   TODO: instructions for windows and mac

3. TECHNICAL INFORMATION
   
   a. Important notes:
   
      For JAI.create:
      the "fileload" and "stream" options must not be changed unless you intend
      to change the operation being done. These strings are op names which are 
      used to create a RenderedOP. For more information on how JAI uses op names
      refer the the resources at the bottom.

      For DisplayJAI:
      This method of of displaying the output image was chosen over using JAI's
      ScrollingImagePanel because the ScrollingImagePanel has been deprecated,
      and that it does not get the correct insets for the Image. Currently there
      is no non deprecated equivalent to the ScrollingImagePanel.
      Adding DisplayJAI(which has no scroll bars) to a JScrollPane has the
      equivalent effect, but with proper insets for the Image. Keep an eye out 
      for a replacement of the ScrollingImagePanel in new releases of the JAI.

  b. Building the JAI from source code:
     
     1. get the source code from the svn repository:	
     	svn checkout https://svn.java.net/svn/jai-core~svn trunk

     2. read the README-build.html file in the trunk. 

     3. cd to the trunk directory in a terminal

     4. run ant
     the build should commence. 

     5. locate the jars by going to: build -> linuxi586 -> opt -> lib -> ext

     There should be three jar files: jai_codec, jai_core, and mlibwrapper.

     Copy these jars into the image viewer's jai directory and you are finished.

  c. Resources:

     It is suprisingly hard to find documentation on the JAI so here are the
     resources I found most helpful in creating this program:

     JAI API:
     http://download.oracle.com/docs/cd/E17802_01/products/products/java-media/jai/forDevelopers/jai-apidocs/

     Programming in Java Advanced Imaging (put out by Sun):
     http://java.sun.com/products/java-media/jai/forDevelopers/jai1_0_1guide-unc/JAITOC.fm.html

     List of Operation Names (the "fileload" and "stream" options are used in this program):
     http://java.sun.com/products/java-media/jai/forDevelopers/jai1_0_1guide-unc/Programming-environ.doc.html#55112