Section 2

Getting Started

 

 

The IISS supports an extensive command line start-up syntax for specifying the number of cells, their dimensions, and their contents. The complete syntax description can be found in Section 8. Here we give brief examples to familiarize the user with command line notation for getting data into frames of the IISS.


2.1 Quickstart Examples

2.1.1 Viewing A Single Image

A simple way to use the Image SpreadSheet as a one cell interactive image viewer (with roam and zoom capabilities) is to invoke the IISS with an image filename in a self-describing file format such as JPEG or GIF:

iiss andrew.jpg
iiss lena.gif

2.1.2 Viewing Several Images

A list of filenames on the command line can be used to specify a sequence of images to read in the order specified, such as:

iiss andrew.jpg lena.gif Images/tree.sun
iiss *.tiff 'Stack0001Frame #'
iiss metafilename_with_imagefiles

In the first example, the image files can be specified in any order and each image can be of any dimension (i.e. all of the images do not have to be of the same type or size). Note that you will need to use the right arrow key to step through the images manually one at a time, or use the c-key to automatically cycle through the images.

In the second example, the *.tiff file reference uses the Unix shell (csh) for pattern expansion and matches any filename with the suffix .tiff. This enables reading many common files into a sequence of frames within a given cell in a convenient way. The second expansion 'Stack0001Frame #' uses the IISS expression parser and matches all files which have the common prefix Stack0001Frame followed by one space and then a multidigit number. The files are then ordered according to the value of the number for example Stack0001Frame 1, Stack0001Frame 2, ... Stack0001Frame 100. In this example using, iiss Stack0001Frame* , would give a DIFFERENT ordering.

In the third example above, the individual image filenames are not specified on the command line but instead a meta-filename is provided. This metafile contains a list of image files. This is convenient when you want to read a lot of image files (without having to type this list out each time) as in an animation sequence and want to specify a particular order in which to view these files.

2.1.3 Viewing An IISS Header File

After reading several files into the Image Spreadsheet and organizing them in an informative way you can save the spreadsheet configuration (using the Savesheet button in the Options Panel, as described in the following Sections) in an IISS header file that will usually have the suffix *.iss. The IISS will also prompt you to save your session information when you exit the program to avoid losing a lot of valuable work. You can restore a previously save spreadsheet configuration using the command shown below. Note that as a convenience you do not need to type the standard suffix part of the filename.

iiss toms_ozone.iss
iiss toms_ozone


2.2 Multi-Cell Image Display Example

A multi-cell image display can be created using two methods:

  1. Graphical user interface approach - Start the iiss and populate the frames with image data using the Read Panel.
  2. Command line argument approach - Start the iiss with detailed command line arguments to specify the size of the sheet and which data sets to read into specified cells and frames.

In this relatively detailed example, we show how to create a 2x2 image spreadsheet and populate the first row of the sheet with unformatted (or raw) data from a satellite instrument known as the Total Ozone Mapping Spectrometer (TOMS) that measures the daily global distribution of ozone in the upper atomsphere. The datasets in this example do not contain any header information and are referred to as raw or unformatted image format. Typically, image files are in some self-describing file format and satellite datasets contain detailed parameters specified in a hierarchical data format (HDF). For simplicity, we have created data files without header information to illustrate this example.

The first method is the simplest way to read the TOMS ozone datasets. You can start up the IISS with 4 empty cells each window of the desired size using the command: iiss -s 340 359. Then use the interactive GUI Read Panel to browse and select files to be placed in each appropriate frame or several frames.

The second method is to use the command line arguments described below. The command line approach gives more control on start up and can be placed into a start up script file. First, change directory to $IISS_HOME/examples/toms. Assuming that the iiss program is found in one of the users current path directories ($PATH UNIX Shell variable), a list of command line arguments used by the IISS can be seen by typing the command, iiss -h, which gives the usage parameters. In order to read the TOMS data in our example, the IISS is invoked with the following command line arguments:

     iiss -q 2 2 -s 340 359 -H 340 -f -tl 78 -Q1,1 toms.79* -Q1,2 toms.80*

These options have the following meaning:

When the IISS user interface is displayed you should see a four cell spreadsheet with images in the top two cells and on the left will be the Options Panel. Notice the matrix glyph at the top of the panel. Move the mouse cursor into the SpreadSheet window, into cell A1 which contains data for January 1979. Then press the right-arrow key on the keyboard (directly below the Page Down key). The cursor will change to a watch symbol as the program reads in the next frame of data (A1[[2]]). When the new data is displayed the cursor will change back to an arrow shape. You may finish reading the data for cell A1 by pressing the right arrow key until the first frame is again displayed.

WARNING: The SpreadSheet stores all image data in memory (RAM); do not load the memory space beyond capactiry, or the program is likely to be killed by the operating system. As an example, if your data is 512 x 512, 8 bits deep, each frame occupies 0.25MB, so on a system with 16 MB, the SpreadSheet would be limited to fewer than 64 frames.

Use the up and down arrow keys to traverse the sequence of frames. Finally, using the mouse, click on the Exit button in the Options Panel and answer Yes to the confirmation dialog.

Notice that some feedback messages have been sent to the text-window in which you typed the iiss command. These messages contain warnings or error notifications, so if the program appears to exhibit incorrect behavior, check the messages for clues.

Next invoke IISS with the same arguments as above with the addition of two more options before the -Q1,1 argument:

     iiss -s 340 359 -H 340 -f -tl 78 -o toms.map -of -Q1,1 toms.79* -Q1,2 toms.80*

The overlay image will be applied to each frame. In order to use a meaningful colormap or Look Up Table (LUT) move the cursor into cell A1 and press the d key. After the Display Panel appears, select the toms.cd.levels.bcm colormap in the ColorMap browser. The Display Panel can be closed using the button in the top right corner of the form.


2.3 User Interface Model in the IISS

Just as the exit functionality can be accessed in different ways (typically three mechanisms), most other functionality within the IISS can also be accessed using three methods:

  1. Graphical User Interface (GUI) panels or forms,
  2. Pop-up menus, or
  3. Keyboard accelerator keys.

Each of the three mechanisms is usually available simultaneously in most modes within the IISS. The Options Panel including the cell glyph (upper portion) and all top level functionality accessible via the buttons is shown below. Each button usually brings up a sub-panel such as the Read and Formula Panels.


2.4 Exiting from the IISS

There are three ways to exit from the IISS application:

  1. Panel button selection - click on Exit button in Options Panel
  2. Select Exit item from within the Main Menu
  3. Keyboard input within a frame window - type Esc-key

When you have finished using the IISS, select the Exit button from the Options Panel. The Options Panel (shown below) can be made visible or hidden using menu item selection from within a cell (Main Menu->panels->Options Panel). Menu items are displayed by holding the Right Mouse Button down inside a frame/cell of the IISS. The Main Menu items are shown below.

Alternatively, you can use menus to exit from the IISS. Move the cursor into one of the four cells and hold down the right mouse button. A pop-up menu will appear. Move the mouse down to the final menu entry Exit and release the mouse button to start the exit dialog.

In the third method of exiting from the IISS, press the Escape key while the cursor is inside a frame window. Note that the cursor location determines input focus and can be moved around the screen using the mouse input device.

WARNING: The user is always asked for confirmation on quitting, but currently the user will not be automatically prompted to save the state of the current IISS session before exiting the program.


2.5 Getting Help

There is online documentation on the use of the IISS. The online user manual is the document you are reading now. Selecting the Help button in the Options Panel brings up the keyboard Help Panel shown below. These keyboard functions are also shown in tabular form in Appendix D.