Image Processing Toolbox User's Guide

Overview Navigation

To get an overview of the image displayed in the Image Tool, use the Overview tool. The Overview tool displays a view of the entire image, scaled to fit, in a separate window. 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 window. 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.

For example, view an image in the Image Tool.

• imtool('moon.tif')
  

When the Image Tool starts, the Overview tool also starts, by default. You can also start the Overview tool by clicking the Overview button in the Image Tool toolbar or by selecting the Overview option from the Tools menu in the Image Tool. The following figure shows the Image Tool with the Overview tool. For more information about using the Overview tool, see these topics:

• Using the Overview Tool
• Specifying the Color of the Detail Rectangle
• Getting the Position and Size of the Detail Rectangle
• Printing the View of the Image in the Overview Tool

  

Image Tool with Overview Tool

Using the Overview Tool

To use the Overview tool to explore an image displayed in the Image Tool, follow this procedure:

1. Start 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.

1. The Image Tool opens the Overview tool, by default. If the Overview tool is already active, clicking the Overview button brings the tool to the front of the windows open on your screen.

2. Using the mouse, move the cursor into the detail rectangle. The cursor changes to the fleur shape, .
3. Press 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 might want to 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 Rectangle 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]. To paste this position vector into the MATLAB workspace or another application, right-click and select Paste from the context menu.

Printing the View of the Image in the Overview Tool

You can print the view of the image displayed in the Overview tool. Select the Print to Figure option from the Overview tool File menu. See Printing Images for more information.

Using Image Tool Navigation Aids

Panning the Image Displayed in the Image Tool

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