Calibration Errors

At each stage in calibration it is advisable to visualise the residuals on the data in order to determine the adequacy of the set of fitted model parameters in describing the data. Several utilities are provided by "calib plots" for this purpose.

• graph tool. Pop up a new graph Tv for current use.
• rdist. Graph the radial residula errors in the graph Tv. Left camera residuals are in red and right camera residuals are in blue. Any effects due to radial distortion will manifest themselves as a systematic curving of these distributions. With a small amount of experience this plot can be used to visually varify the adequacy of a calibration.
• epi-err. Plot a histogram of errors perpendicular to the epi-polars. As this measure is completely independent of 3D model assumptions, this distribution can be used to estimate the mean location accuracy of calibration features.
• x-err. Plot a histogram of errors in the x direction (and therefore approximately along the epi-polars).

Additional information regarding statistical distributionc can also be viewed in the Histogram Tool.

The additional fucntionality is also provided.

• 3D geom. Install the current 3D geometry used in the calibration for viewing in the Tina system 3D Tv tool.
• model proj. Project the current model view and display hypothesis results (see below).