Demonstration of JPEG and JAVA

Demonstration of JPEG and JAVA for use in digital teaching files.

The demonstration teaching file case for the abstract below can be viewed as either an unknown or viewed with the diagnosis.

Note the following:

The images are optimally viewed on a 24 bit monitor (millions of colors). If viewed on a 256 color monitor, your WWW browser may "dither" the image, giving it a grainy appearance. If only a 256 color display is present on a Macintosh, this can be avoided by setting the monitor control panel to "256 grays" rather than "256 colors".
The inital image will be in JPEG form, regardless of your browser, compressed with a quality setting of 88.
If you have JAVA capability, clicking on "view image as cine" (just below the main image) will enable JAVA cine and gray-scale controls. You may need to allocate extra memory to your browser to run JAVA applets, and make sure that JAVA is enabled in the Netscape 3.0 or MS-Explorer 3.0 preferences.
The cine can be turned on/off, and the tabs below the lookup-table bar can be used to adjust the color table.
Known bugs/features in this version of the code (which are currently being addressed)
- it is best to adjust the gray-scale while the cine is turned on
- changes in gray scale may lag your adjustments by 10-20 seconds if you don't have a WWW browser that has a just-in-time JAVA compiler.
- if you change to "frame mode" from "cine mode", the cine must be turned on for the frames to appear.
- the image filtering portion of the JAVA code has been temporarily disabled, to allow modification to increase compatibility with a wider variety of WWW browsers.

An Internet-based, interactive nuclear medicine image display system implemented in the Java programming language. N.X. Phung, J.W. Wallis. Washington University School of Medicine, St. Louis, MO.

We have implemented an image display system also capable of manipulating and viewing cine nuclear medicine data, for use in both teaching files and on-call interpretation. It can be accessed from any platform running a Java-enabled World Wide Web browser-either locally via local network, or remotely via the Internet.

The image processing algorithms are implemented as separate modules, chained in an image producer-consumer design pattern. The user interface classes are Java Abstract Windowing Toolkit Component subclasses, and interact via a multiplexer class with image processing classes conforming to the Java Observer/Observable interface.

Features include a graphic user interface with interactive controls to select color scheme, brightness and contrast; tiled or cine viewing modes (with adjustable animation rate); convolution filters; drawing of regions of interest; and either JPEG or full quality (raw 16 bit pixel) image transmission formats. The system was evaluated for download speed (local and remote); and image quality was scored on a scale of 110 by three physicians (blinded to compression setting):

                        GI bleeding study	             Whole body bone
Compression setting     none  95    88    75    50    none  GIF   95    88    75    50
File size (kb)          642   47    27    18    13    672   147   76    42    26    18
Image quality (1-10)    10    10    10    9.3   8.7   9.5   9.5   9     8.5   5.5    4
Access time, ethernet(s)26          7                       1           1             
Access time, 28.8 modem 160         32                      75          22

A compression setting of 88 was deemed adequate for teaching purposes, resulting in a 15-20 fold compression when the 8bit compressed data are compared with the 16bit raw data. In summary, JPEG and JAVA have a definite role for online teaching (eg. see http://gamma.wustl.edu/abs97.html), and have great potential for use in networked picture archival and viewing systems.