Making Measurements

A measurement can show, for example, the distance between two points in an image.

Tip:

To check the units of measurement, hold your mouse pointer over the annotation. A tooltip is displayed (see image above) that displays details about the annotation.
To manage annotations (show/hide, change colors, delete, display values/units), you can display the list of measurements. See Using the Screen Options.

Note: Units of measurement are Standard International (SI) units, millimeters (mm) for length, and degrees (°) for angles.

The following types of measurements are available in the Drawings & Annotations toolbar in the Measurements icon group:

Straight line measurement
Multi-segment line (Polyline) measurement
Angle
Orthogonal (Perpendicular) measurement on a line, axis or plane

Note: If a white triangle is displayed in the lower corner of the icon, you can access the different tools in the icon group. See Using Icon Groups.

To add a measurement to an image, follow these steps:

Open the image in the Image Viewing Workspace or Darkroom mode.
In the Drawings & Annotations toolbar, in the Measurement icon group, select one of the following.

Tip: You can show or hide measurements using the Display Measurements Window option in the Screen Options menu.

To draw a straight line measurement...	Click . On the image, click to set the beginning and end points of the line. The line is displayed with its measurement (in millimeters.)
To draw a multi-segment line (polyline) measurement...	Click . On the image, click to set the start point. Move the mouse pointer to the first intermediate point of the line, and click again. A line segment is displayed with its measurement (in millimeters). Repeat step 3 to create as many segments as you want. Double-click to create the final endpoint. Measurements are displayed for each segment of the polyline. The total length is displayed in the tooltip and measurements list.
To draw an angle measurement...	Click . On the image, click to create the start point of your angle (A). Click to set the midpoint (B). A line is displayed. Click to set the end point (C). A second line is displayed, with the angle between the two lines shown in degrees. The angle is automatically calculated and displayed on the image and in the measurements list. The sequence of clicks for drawing angles is shown below.
To draw an orthogonal (perpendicular) line...	Note: This function only works with an existing line measurement. Click . On the image, move the mouse pointer over an existing line measurement. The pointer displays as a “+” to show that the orthogonal measurement tool is active. Click on the existing measurement line to set the orthogonal line start point. The pointer can only be moved in the plane perpendicular to the line of intersection along A or B. Move the pointer away from the starting line measurement and click again to set the end point for your orthogonal measurement. A perpendicular (orthogonal) line is displayed, with its length (in millimeters). A: Move the pointer in this direction to set the length of the new perpendicular line (red). B: In this direction, the pointer is constrained to move only along the plane of the starting line measurement (green). You can draw the new line measurement beyond the range of the starting line measurement; it will still move along the same perpendicular plane.