...
Distortion measurements are described in Distortion: Methods and Modules. A few key points.
The optimization algorithm in Checkerboard is superior to the simple algorithm used in SFRplus. For critical measurements, always use Checkerboard.
For the Center center of distortion to be meaningful and its measurement to be robust, some distortion (typically enough to be visible) must be present.
The optimization algorithm in Checkerboard is superior to the simple algorithm used in SFRplus. For critical measurements, always use Checkerboard. center of distortion can’t always be calculated. We have seen a case of wave (or “mustache”) distortion where the image was visibly pincushion-distorted near the center and barrel-distorted near the corners, but overall TV distortion was very low. We were unable to calculate the center of distortion for this image. (It’s not impossible, but it will require some complex programming.)
Link
What is the center of the image? by R.G. Wilson and S. A. Shafer. Fifteen, count ’em fifteen optical centers. Do I hear a bid for sixteen? Going… going…