Defining image scale

Image scale is the ratio of the size of the objects in the image to the size of the objects on the ground. This parameter is optional, except when you want to import GPS/INS observations and use them during the automatic tie point measurements.

The image scale equation is:

scale = d/D = f/H
where:
Note: Entering the incorrect image scale may cause the computation of the math model (the bundle adjustment) to fail.
Parent topic: Understanding camera calibration data
Previous topic: Defining decentering distortion
Next topic: Defining earth radius

© PCI Geomatics Enterprises, Inc.®, 2026. All rights reserved.