Calibrated values that describe the unavoidable image distortions intrinsic to the internal design characteristics of a camera or image acquisition system. Most electronic imaging applications involve the use of a lens or focusing device and a transducer, such as the grid of light-sensitive cells on a charge-coupled device (CCD) or a CMOS sensor within a digital camera. Geometrical effects such as barrel and pincushion distortions can be introduced by the lens and will depend on its design and focal length; moreover, the imaging sensor may not be perfectly aligned with the axis of the lens, leading to a small offset effect. The interior orientation parameters quantify such effects, which are different for each camera and lens. They are required chiefly when images taken with the camera are used to derive precise measurements. See also exterior orientation parameters.