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- Activate Ruler Tool by Tools > Measurement > Ruler
Draw a line to calibrate on the scale which is a part of the image.
Note For more accurate resultresults, it is recommended to use a calibration line as long as possible.
- Right-click on the calibration line and select Calibrate
- Enter the length of the calibration line in a physical unit in the dialog shown and select OK
The calibration line is shown in a physical unit now, and all next measurement that will be drawn will be shown in a physical unit.
Note The measurement calibration can only be done for images individually, so you should calibrate multiple uncalibrated images separately if you have more than one uncalibrated image.