Opening Images

Fslview currently only opens files of type AVW. This format consists of 2 files a header file (.hdr) and an image data file (.img). To read an AVW file select the Open option from the File menu. A file opening dialog will appear. It will list all directories and all files with an "hdr" extension. Select the "hdr" file that you want to load and press the Open button.

The image will then be opened in Ortho view (Coronal, Sagittal and Axial views displayed simultaneously). The image name will be displayed in the Overlay Listview. Since it was the first image loaded it will be the Main Image, in the Overlay Listview it will be marked with a small set of arrows.()

To then load a second overlay select the Add option from the File menu. A file opening dialog will appear.The image file to be added must have the same dimensions as the Main Image otherwise a "Cannot load incompatible overlay" message will appear.

When the second overlay is added its name will also appear in the Overlay Listview. Since it is not the Main Image it will not be marked with a set of arrows. The Overlay Listview control can be used to change the transparency of images, change the order in which they are drawn, make them visible or invisible and lock or unlock them. For more information on how to perform these operations refer to the Overlay Listview documentation.

The images can be viewed in 3 separate types of view via the View menu. These view types are as follows:-

• Ortho - the default view showing Axial, Orthagonal and Sagittal slices.
• Lightbox - shows all slices simultaneously, currently shows only Axial slices.
• Single - shows only a single slice but mode can be switched between Axial, Orthagonal and Sagittal.

Moving the mouse over a slice while holding down the Left mouse button will cause the cursor to move around the image. The cursor position and value can be viewed on the Cursor Toolbar. It is also possible to move the cursor to any position by altering the values in the Cursor Toolbar. The Fslview has linked cursor behaviour so as the cursor is moved around in one view it also moves in all other currenly open views. So, for example, when clicking on an image in the lightbox view the cursor will be automatically moved on any open Ortho views.