Image Processing Toolbox

Viewing the Images

By default, cpselect displays the entire base and input images in the Overview windows and displays a close up view of a portion of these images in the Detail windows. However, to find visual elements that are common to both images, you may want to change the section of the image displayed in the detail view or zoom in on a part of the image to view it in more detail. The following sections describe the different ways to change your view of the images.

• Using Scroll Bars to View Other Parts of an Image
• Using the Detail Rectangle to Change the View
• Moving the Image Displayed in the Detail Window
• Zooming In and Out on an Image
• Specifying the Magnification of the Images
• Locking the Relative Magnification of the Input and Base Images

Using Scroll Bars to View Other Parts of an Image

To view parts of an image that are not visible in the Detail or Overview windows, use the scroll bars provided in each window.

As you scroll the image in the Detail window, note how the Detail Rectangle moves over the image in the Overview window. The position of the Detail Rectangle always shows the portion of the image in the Detail window.

Using the Detail Rectangle to Change the View

To get a closer view of any part of the image, move the Detail Rectangle in the Overview window over that section of the image. cpselect displays that section of the image in the Detail window at a higher magnification than the overview window.

To move the Detail Rectangle:

1. Click on the default cursor button in the button bar.
2. Move the pointer into the Detail Rectangle. The cursor changes to the fleur shape, ,indicating the directions in which it can be moved.
3. Press and hold the mouse button to drag the Detail Rectangle anywhere on the image.

Note    As you move the Detail Rectangle over the image in the Overview window, the view of the image displayed in the Detail window changes.

Moving the Image Displayed in the Detail Window

To change the section of the image displayed in the Detail window, use the Hand tool to move the image in the window.

To use the Hand tool:

1. Click on the Hand tool button in the button bar.
2. Move the pointer over the image in the Detail window. The cursor changes shape, , indicating the directions in which it can be moved.
3. Press and hold the mouse button and drag the image in the Detail window.

Note    As you move the image in the Detail window, the Detail Rectangle in the Overview window moves.

Zooming In and Out on an Image

To enlarge an image to get a closer look or shrink an image to see the whole image in context, use the Zoom buttons on the button bar. (You can also zoom in or out on an image by changing the magnification. See Specifying the Magnification of the Images for more information.)

To zoom in or zoom out on the base or input images:

1. Click the appropriate "magnifying glass" button.

   

2. Move the pointer over the image you want to zoom in or out on. The cursor changes to the cross-hair cursor.

1. You can zoom in or out on either the input or the base images, in either the Detail or Overview windows. To keep the relative magnifications of the base and input images synchronized, click the Lock ratio check box. See Locking the Relative Magnification of the Input and Base Images for more information.

Note    If you zoom in close on the image displayed in the Overview window, the Detail Rectangle may no longer be visible.

1. You can use the zoom tool in two ways:
   • Position the cursor over a location in the image and click the mouse. With each click, cpselect changes the magnification of the image by a preset amount. (See Specifying the Magnification of the Images for a list of some of these magnifications.) cpselect centers the new view of the image on the spot where you clicked.
   • Alternately, you can position the cursor over a location in the image and, while pressing and holding the mouse button, draw a rectangle defining the area you want to zoom in or out on. cpselect magnifies the image so that the chosen section fills the Detail window. cpselect resizes the Detail Rectangle in the Overview window as well.

Note    When you zoom-in or -out on an image, notice how the magnification value changes.

Specifying the Magnification of the Images

To enlarge an image to get a closer look or to shrink an image to see the whole image in context, use the magnification edit box. (You can also use the Zoom buttons to enlarge or shrink an image. See Zooming In and Out on an Image for more information.)

To change the magnification of an image:

1. Move the cursor into the magnification edit box of the window you want to change. The cursor changes to the text entry cursor.

Note    Each Detail window and Overview window has its own magnification edit box.

2. Type a new value in the magnification edit box and press Enter, or click on the menu associated with the edit box and choose from a list of preset magnifications. cpselect changes the magnification of the image and displays the new view in the appropriate window.

   

Locking the Relative Magnification of the Input and Base Images

To keep the relative magnification of the input and base images automatically synchronized in the Detail or Overview windows, click on the Lock Ratio checkbox. The two Detail windows and the two Overview windows each have their own Lock ratio checkboxes.

When the Lock Ratio check box is selected, cpselect changes the magnification of both the input and base images when you zoom-in or -out on either one of the images or specify a magnification value for either of the images.

Starting the Control Point Selection Tool

Specifying Matching Control Point Pairs