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Measure Distance Between Pixels in Image Viewer App

The Image Viewer app enables you to measure the Euclidean distance between two pixels using the Distance tool. The Distance tool displays the line, the endpoints, and label with the distance measurement. The tool specifies the distance in data units determined by the XData and YData properties, which is pixels, by default. You can save the endpoint locations and distance information.

Determine Distance Between Pixels Using Distance Tool

After you open an image in Image Viewer, open the Distance tool by clicking Distance tool button in the Image Viewer toolbar or selecting Measure Distance from the Tools menu. For more information about opening an image in Image Viewer, see Open Image Viewer App.

Measure distance with a click-and-drag approach. When you move the pointer over the image, the pointer changes to cross hairs . Position the cross hairs at the first endpoint, hold down the mouse button, drag the cross hairs to the second endpoint, and release the button.

The figure shows a distance line with the line endpoints and distance measurement label.

Grayscale image of the moon, showing a distance line with length 189.65 pixels


You can also use a Distance tool with a figure, such as displayed using imshow, by using the imdistline function.

Export Endpoint and Distance Data

To save the endpoint locations and distance information, right-click the Distance tool and choose the Export to Workspace option from the context menu. The Distance tool opens the Export to Workspace dialog box. You can use this dialog box to specify the names of the variables used to store this information.

Export to Workspace dialog box

After you click OK, the Distance tool creates the variables in the workspace, as in the following example.

  Name          Size            Bytes  Class     Attributes

  distance      1x1                 8  double              
  point1        1x2                16  double              
  point2        1x2                16  double 

Customize the Appearance of the Distance Tool

Using the Distance tool context menu, you can customize many aspects of the Distance tool appearance and behavior. Position the pointer over the line and right-click to access these context menu options.

  • Toggle the distance tool label on and off using the Show Distance Label option.

  • Change the color used to display the Distance tool line using the Set color option.

  • Constrain movement of the tool to either horizontal or vertical using the Constrain drag option.

  • Delete the distance tool object using the Delete option.

See Also


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