Panning and Zooming

Summary:


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Panning an Image

Panning an image means changing the section of the image to be displayed in the main display window. The purple pan window shows the entire area of the loaded image. A green box cursor in the pan window shows the area of the image currently being displayed in the main display window. If the green box cursor does not fill the entire pan window (i.e., the image zoom is > 1), it may be relocated to another area in the pan window by moving the mouse to that area and clicking the middle mouse button. Alternatively, it may be moved by clicking and dragging the left mouse button while on or within its perimeter. Similarly, pan window itself may be repositioned by clicking and dragging the left mouse button while on or within its perimeter (but outside the green box cursor). The Pan window may be removed from the image display by means of the Panner/Magnifier sub-menu within the File or Zoom Pull-down Menus.

The image may also be panned by clicking the middle mouse button in the main display window after moving the cursor. The image will then be centered at the current mouse location.

Zooming an Image

Zooming an image means changing the number of display pixels per image pixel. At Zoom = 1, there is one display pixel per image pixel. At Zoom 2, there are 2 display pixels per image pixel in both x and y. Note that non-square (and even non-integer) mappings are possible.

Arbitrary zooms may be selected by moving the mouse to the corner of the green box cursor in the pan window, and clicking and dragging the left mouse button. More typically useful zooms may be selected by clicking the middle mouse button without moving the mouse. Each click will increase the zoom by a factor of two. Other common zoom factors may be selected with the Zoom Pull-down Menu or the Zoom 1, x2, and x1/2 command buttons.


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Last Updated May 23, 1995