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<< Click to Display Table of Contents >> Navigation: NxLib API > Commands > CollectPattern > Parameters > Refinement |
Extracting sub pixel accurate center points of the calibration pattern in blurred and distorted raw images is not a trivial task. Therefore the CollectPattern command now provides a refinement procedure to increase the accuracy of the point centers when a camera model already exists. The procedure will use the known camera geometry to compensate blur and distortions in the point detection process.
Refinement will improve pattern detection accuracy especially when the camera lenses exhibit a significant amount of distortion, blur or both.
Because refinement cannot be done without calibration data there is also a "Delayed" refinement option which will buffer the image data together with each pattern observation. For all patterns collected with "Delayed" refinement the Calibrate command will automatically perform the refinement of the point centers after an initial estimate of the calibration data has been computed. This will improve the accuracy of the camera calibration. NxView's calibration dialog will use "Delayed" refinement by default.
Note: Collecting patterns with "Immediate" refinement will fail when no calibration data is loaded or the calibration data does not match the camera geometry. Use "None" or "Delayed" refinement when collecting patterns for camera calibration.
String |
"None" |
Do not use pattern point refinement. |
"Immediate" |
Refine pattern point coordinates immediately during |
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"Delayed" |
Buffer image data together with the pattern observation in order to perform the point refinement after a new camera calibration has been computed. This is useful when collecting camera calibration patterns for the Calibrate command. |
"Immediate"
Note: When the Projector parameter is enabled, refinement is not supported and will automatically be set to "None".