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Ellipse measurement tool


Ellipse button

How to measure an ellipse

First click 2 points to define the major (long) axis of the ellipse. Next click any 3rd point that lies on the ellipse.

How to measure an ellipseHow to measure an ellipse

Tip: while you are moving the mouse to the second and third position, lengths and angles are displayed in the status bar at the bottom of the Digimizer window.

Ellipse measurements

The surface area, perimeter, length, width, roundness, average intensity and hue are displayed in the Measurements list window (*).

When the option Show result after finalizing measurement is selected, then the length and width are displayed in a small window next to the object.

  • Roundness is defined by (4*PI*Area) / (Perimeter*Perimeter) and is a number between 0 and 1. Values closer to 1 indicate a more 'round' object. A circle has a roundness of 1.
  • Definition of length and width:

    Length is length of the major axis of the ellipse (defined by point 1 and 2 in the image above).

    Width is the length of the (perpendicular) minor axis of the ellipse (calculated by Digimizer, not shown in the image above).

Summary statistics for all areas, perimeters, lengths, widths and average intensities measured with the Ellipse tool are displayed in the Statistics window.

*Only the parameters selected in the Measurements List Columns options box are displayed in the Measurements list window.

Lock tool

Lock buttonWhen the lock is Open, the program returns to Select mode after performing a measurement using the Ellipse tool. Close the lock when you need to perform several measurements with the same tool. See Lock tool.

See also