Geometric Calibration – deprecated

Defining a Distortion Model

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Requirements Software operation Defining Calibration Tasks Definitions and Theory

Supported Systems

Supported Targets

Required Evidence

Test Setup

Calibration Procedure

User Interface

Use in Imatest IT

Module settings

Module outputs

Defining a Device

Defining Distortion

Defining the System of Devices

Defining the Target

Defining a Test Capture

Defining a Test Image

Homogenous Coordinates

Projective Camera Model

Multi-Camera Systems

Distortion Models

Coordinate Systems

Rotations and Translations


This component defines an initial estimate of the distortion model that functionally maps from the device’s image plane (which may exhibit geometric distortion due to optics) to an undistorted, rectilinear “virtual” image plane. 

Refer to the Distortion Model page to understand how these model definition fields relate to the mathematical form used for the distortion model. 

It is very important that the initial input distortion model matches well with the nominal distortion curve. Each actual device instance will have small variations from this curve and it is important to give the optimizer an appropriate starting point or else it might give too much preference to fitting the higher order coefficients, which might lose some subtleties of the curve shape. 

Note: Currently, all distortion models supported by this module are purely radial and polynomial-based. Future forms may require a different set of defining fields. 


Model Type

Supported values: Radial Polynomial, Radial Division Polynomial, Packed Radial Division Polynomial

Flag to indicate the nature of the polynomial mapping defined by the supplied coefficients. 


Polynomial Form

Supported values: Odd, Even, or All

Flag to indicate how the supplied coefficients relate to various polynomial powers. 



Supported values: array of 1 to 10 values

The initial coefficients