The View menu contains several options which allow the user to manipulate the current image.
Figure 6.1: The View Menu
Pan View: Centres the image on the last screen position where the mouse button was clicked in order to bring up the main menu. The program will only recognise a button event that has occured within the boundaries of the current image displayed on the screen. If the data is cyclical in the x-direction, the image will wrap around.
An error message (figure 6.2) will be displayed if for any reason, the current image cannot be panned, for example, a full size image of data from rotated data sets cannot be panned since because it is non-cyclical in both the x and y direction.
Figure 6.2: Error Message when panning not allowed
Zoom In: Allows the user to zoom in on an area by factors of 2, 4, 8 and 16. The zoom factor is selected from the menu shown in figure 6.3. Vertical sections are only enlarged in the horizontal plane. The program takes the last screen co-ordinates of the mouse was clicked to bring up the main menu as the central point to zoom in on.
Figure 6.3: The Zoom Factor Menu.
Zoom Out: The user can zoom out by factors of 2,4, 8, and 16. If the image is at its full size the user will not be allowed to zoom out any further and an error message will be displayed on the screen (figure 6.4) or if a zoom out factor has been selected such that the size of the image exceeds a value of 1 , a second error message will be displayed (figure 6.5). To close the error dialog box, click once using the left hand mouse button on the Okay button. Until the window is closed, the screen will not recieve any more events.
Figure 6.4: Zoom Out Error Message : when zoom out selected at full image size.
Figure 6.5: Error Message when image size exceeds 1.
Full View: Resets the image back to its original size.
Changing Variables whilst image not at full view
Refer to section 3.5.3