Using Image Tool Navigation Aids

Using Image Tool Navigation Aids

In this section...

“Navigating an Image Using the Overview Tool” on page 4-23 “Panning the Image Displayed in the Image Tool” on page 4-26 “Zooming In and Out on an Image in the Image Tool” on page 4-27 “Specifying the Magnification of the Image” on page 4-27

Navigating an Image Using the Overview Tool

If an image is large or viewed at a large magnification, the Image Tool displays only a portion of the entire image, including scroll bars to allow navigation around the image. To determine which part of the image is currently visible in the Image Tool, use the Overview tool. The Overview tool displays the entire image, scaled to fit. Superimposed over this view of the image is a rectangle, called the detail rectangle. The detail rectangle shows which part of the image is currently visible in the Image Tool. You can change the portion of the image visible in the Image Tool by moving the detail rectangle over the image in the Overview tool.

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4 Displaying and Exploring Images

Overview tool button

Overview tool

Detail rectangle

Image Tool with Overview Tool

The following sections provide more information about using the Overview tool.

•“Starting the Overview Tool” on page 4-24

•“Moving the Detail Rectangle to Change the Image View” on page 4-25

•“Specifying the Color of the Detail Rectangle” on page 4-25

•“Getting the Position and Size of the Detail Rectangle” on page 4-25

•“Printing the View of the Image in the Overview Tool” on page 4-26

Starting the Overview Tool

You can start the Overview tool by clicking the Overview button in the Image Tool toolbar or by selecting the Overview option from the Tools menu

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Using Image Tool Navigation Aids

in the Image Tool. You can also change the preferences, so the Overview tool will open automatically when you open the Image Tool. For more information on setting preferences, see iptprefs.

Moving the Detail Rectangle to Change the Image View

1Start the Overview tool by clicking the Overview button in the Image Tool toolbar or by selecting Overview from the Tools menu. The Overview tool opens in a separate window containing a view of the entire image, scaled to fit.

If the Overview tool is already active, clicking the Overview button brings the tool to the front of the windows open on your screen.

2Using the mouse, move the pointer into the detail rectangle. The pointer changes to a fleur, .

3Press and hold the mouse button to drag the detail rectangle anywhere on the image. The Image Tool updates the view of the image to make the specified region visible.

Specifying the Color of the Detail Rectangle

By default, the color of the detail rectangle in the Overview tool is blue. You can change the color of the rectangle to achieve better contrast with the predominant color of the underlying image. To do this, right-click anywhere inside the boundary of the detail rectangle and select a color from the Set Color option on the context menu.

Getting the Position and Size of the Detail Rectangle

To get the current position and size of the detail rectangle, right-click anywhere inside it and select Copy Position from the context menu. You can also access this option from the Edit menu of the Overview tool.

This option copies the position information to the clipboard. The position information is a vector of the form [xmin ymin width height]. You can paste this position vector into the MATLAB workspace or another application.

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