# Attach Calibration Data to Run-time Images

As your vision application executes, the Checkerboard Calibration tool attaches the precomputed transformation to the coordinate space tree of each run-time image. Vision tools that analyze the run-time image in the calibrated coordinate space can generate results in desired physical units relative to your application environment:

The camera, lens and physical relationship between the camera and the scene under inspection must be the same for both calibration and run-time operations. If any of these elements change you must re-calibrate your vision application.

In addition to providing the ability to work directly in calibrated physical coordinates, the Checkerboard Calibration tool can generate calibrated coordinate spaces that work for linear and nonlinear vision applications:

- Linear coordinate spaces let your application correct the effects of aspect-ratio distortion caused by non-square camera pixels.
- Nonlinear coordinate spaces let your application correct for the effect of optical and perspective distortion.