| iTool User's Guide: Working with Images |

## Displaying Images

The iImage tool's primary design is to visualize image data, though the tool is capable of much more once the data is displayed. The iImage tool also allows you to manipulate and edit the displays. The first task is to display the image data.

Your options for invoking the iImage tool are:

- At the IDL Command Line without arguments or keywords

- At the IDL Command Line with arguments or keywords

For more information on accepted arguments and keywords, see IIMAGE.

- Through the File New Visualization iImage menu option in the IDL Development Environment

- Through the File New iImage menu option in an iTool

To visualize image data in the iImage tool:

1. Image data can be loaded into the data manager. Image data of any supported type can also be directly visualized into the iImage tool using File Open or the File Open icon at the top left of your iImage window, and the File Open Dialog appears.

2. Select the desired image file from your directory structure. For example here we will visualize an`examples/data` file named `afrpolitsm.png`. Select the file name and click Open.

Figure 10-1: A JPEG File Visualized Using the iImage Tool

Figure 10-1: A JPEG File Visualized Using the iImage Tool

Note The `examples/data` subdirectory of your IDL distribution contains a text file named `index.txt`. This file lists all data files available in the example directory and also lists their dimensions and values.

### Displaying Multiple Images

You can use the window layout dialog to provide for multiple image display within your window. To add another image to the window containing the image you just visualized:

1. From the iImage window displaying the political map of Africa JPEG image, select Window Layout.

Figure 10-2: The Window Layout Dialog

Figure 10-2: The Window Layout Dialog

The Window Layout dialog contains these items:

- Dimensions — Allows you to enter specific window dimensions.

- Layout — Allows you to pick from a scroll-down list of layout options and grids.

- Preview — Gives you a visual preview of the selected layout.

For more information on working with window layouts, see Window Layouts.

2. Select a layout, in this case select Gridded and then enter 2 and 1 for Columns and Rows and then OK.

3. The window now displays a two by two arrangement of views. You will notice the original political map of Africa image is shifted to the top-left view. Select and highlight the top-right view.

4. Select File Open or the File Open icon at the top left of your iImage window, and from the File Open Dialog select the `examples/data` image named `africavlc.png` and click Open.

5. The second image of the African continent now appears in the top-right view.

Figure 10-3: Displaying Multiple Images in iImage

Figure 10-3: Displaying Multiple Images in iImage

IDL Online Help (March 01, 2006)