EE368B - Image and Video Compression

The computing resources for the class Image and Video Compression are provided by the ISE Laboratory, which is located at Packard Building 066. This page describes several things you will need to know to use this facility.

1 Logging In

To use the ISE Lab you must

• Register for class EE368B,

• Subscribe to the EE368B mailing list. You can subscribe by sending a message to majordomo@lists.stanford.edu containing the phrase
  
  subscribe ee368b

You will be given an account on the ISE computers. Your home account will be in /u/username -- where username is your leland/AFS user name.

When using any of the ISE machines, your home-directory (/u/username) is the same. The ISE home-directory is not mounted on the Sweet Hall machines. Hence, it is recommended that you put all of your work for this class in your ISE home directory.

• The ISE computers run the Common Desktop Environment (CDE). This is a relatively new graphical user interface that many Unix workstations are adopting. Documentation on how to use and customize CDE is in the lab.

• Login to one of the ISE lab computers using an initial password you can obtain from us (We will provide information about passwords in the class). When you login, you will be forced to change your password; it will say "you need to change your password, please type the new password". Then after you've typed the new password twice correctly, it will log you out immediately. Login again with the new password.

Your account will be setup with default .login, .cshrc, .emacs, etc files in /u/username. You will also have a matlab subdirectory with a startup.m file in it. The startup.m file defines a path for matlab that includes the Matlab toolbox functions.

• If you are on a console in the ISE lab, rather then telnetting in, open a terminal window by clicking on the little arrow above the paper-and-pencil icon on the left-hand side of the "front panel" that runs across the bottom of the screen, and click on "terminal".

• If you are on the console, type "xmodmap ~/.xmodmaprc" in the terminal window. This removes a spurious keyboard mapping that otherwise prevents XEmacs from letting you use the Meta key (which is labeled "Extend-char" on the keyboard). You will need to do this each and every time you login on the console of one of the ISE machines.

(You can't just put this into your .login file, because your .login file is not currently executed when you log in from an HP console. That may get changed, but for now, after you log in, give the above command in some shell. That command reads your file ~/.xmodmaprc, which has been set up already to contain the correct command for xmodmap to fix the problem.)

• Finally, create a .forward file in in /u/username so that mail gets forwarded properly. Your .forward file should contain one-line with the email address you normally use.

2 Running XEmacs

We suggest that you run the matlab tutorials and edit your matlab programs using "xemacs." Naturally, you may use any editor that you want, but we have organized the lab around the assumption that students will mainly be using xemacs. We have designed the tutorials with the expectations that:

• The XEmacs window will split the XEmacs window into two when you run the tutorials and homeworks. One part of the window will contain the text commands that are sent to matlab; the other buffer will contain the matlab program itself, running inside of a separate shell-process.

• To execute commands, you will send text lines from one buffer to the other.

We find this method useful because it helps you organize the commands that you send to the matlab process in the text window. To begin running XEmacs, do the following:

• Type "xemacs &" at the command prompt. This will open up an xemacs window.

• In the XEmacs window, type: "M-x run matlab" (M- refers to the meta key, that is bound on the HP keyboard to the extend char key next to the space bar). This will start a sub-process running matlab. This will appear in the window, and you will see the matlab splash screen appear briefly.

• If you already know how to use emacs, then you should read the file "/usr/local/class/psych221/emacs-hacks/ReadMe" for information about special control keys and mouse-assignments we have made to make the emacs/matlab interface work smoothly. This file describes some of the contents of the default ".emacs" file and the XEmacs-matlab interface.

If you are not familiar with emacs but you intend to use it, then this is a good time to try the emacs tutorial. Also, ask people in the class for help. Many people are quite familiar with emacs and it is an important research tool.

3 Hardware Peripherals

3.1 Printers

There are several HP printers and scanners in the ISE lab. These are to be used only for ISE lab classwork. Please don't abuse your ISE printing privilege. There is a substantial, but finite, amount of paper available; so, if you use it up, no one will be able to print. You can use the 'lp' and 'lpr' commands to print and 'lpstat' and 'lpq' to see the printer queues. See the lp and lpstat man pages (lpr and lpq don't have man pages). The default printer is called 'ise5si' and by default it prints in two-sided mode. Other printers are also available, including color printers for classes requiring color output. Not all printers are available from all machines; but, they can be reached from ise0. To see a list of all the available printers available from your current machine, type 'lpstat -a' on the current machine.

3.2 Scanners and Cameras

The laboratory also contains a color flatbed scanner, and students within certain classes will be use digital cameras. The scanner and the camera work with the HP Vectra, running Windows '95.

4 Details

4.1 ISE Lab Home Directories

Each ISE Lab user has a home directory local to the ISE computers. The pointer to that home directory is /u/username -- where username is the user's ISE Lab/Leland/AFS user name. This directory (/u/username) looks the same regardless of which ISE machine you are logged into. But it is local to the ISE computers, i.e., it is not mounted on the Sweet Hall machines. We recommend that you put all of your class work on the ISE computers under your home directory. Note that you'll eventually need to remove any files from your ISE home directory at some point after the class is over. The grace period after the class ends will depend somewhat on disk space utilization on the ISE machines, but it will probably be at least a month or two, though certainly no more than nine months.

4.2 Disk space

There is also a large temporary space in /tmp on each ISE computer for local temporary storage. Unlike /u/username, /tmp is separate on each machine. (There is a much smaller /usr/tmp on each machine -- please use /tmp instead.) Nevertheless, please do not abuse the space available in /tmp -- such as by filling it more than 50% full for very long. This space has to be shared by all users of the particular machine.

Each machine automounts user home directories. It is all in filesystems called /iseX/uY where X is 0 to 8 (for the 9 machines) and Y is 1,2,.... However, *nobody* should EVER use any of those /iseX/uY names. All pointers used should be of the form /u/username, where username is, er, the person's user name. A given user is subject to being moved to a new filesystem without notice.

Note that you'll eventually need to remove any files from your ISE home directory at some point after the class is over. The grace period after the class ends will depend somewhat on disk space utilization on the ISE machines. It will probably be at least a month or two, but no more than nine months.

There is also a large temporary space in /tmp on each ISE computer for local temporary storage. Unlike /u/username, /tmp is separate on each machine. (There is a much smaller /usr/tmp on each machine -- please use /tmp instead.) Nevertheless, please do not abuse the space available in /tmp -- such as by filling it more than 50% full for very long. This space has to be shared by all users of the particular machine.

4.3 Default Dot Files

If you ever need to see the default files that are created for new accounts on these machines, you can look in /usr/local/skel.

5 Problems

Finally, please report problems on ISE machines to action@ise.Stanford.EDU.