Calibration Plate

Use the following options to describe the attributes of the calibration plate (grid type spacing and fiducial type) and to control the method the tool uses to locate grid points in the image.

Note: If you are specify any of the DataMatrix fiducial types, you can enable a timeout for the calibration operation. If the DataMatrix Timeout checkbox is checked, the tool will terminate the calibration operation after the specified timeout value has passed.

Parameter	Description
Feature Finder	This value specifies how the tool will search the calibration image for calibration vertex points. This method must match the type of calibration plate that you are using. Checkerboard VisionPro supports this mode for existing applications but does not recommend this for new applications. For checkerboard plates with Cognex 'L' fiducial marks or without a fiducial mark, use CheckerboardExhaustive or CheckerboardEfficient. For checkerboard plates with DataMatrix fiducials, use CheckerboardExhaustiveMultiRegion or CheckerboardEfficientMultiRegion. DotGrid VisionPro supports this mode for existing applications that use a grid-of-dots calibration plate. Cognex recommends checkerboard plates for all calibration applications. CheckerboardExhaustive This mode provides the most robust feature extraction possible for checkerboard plates (with or without the Cognex "L" fiducial marks) but requires the longest time to execute. Choose the CheckerboardEfficient mode for generally faster processing times. CheckerboardExhaustiveMultiRegion This mode provides the most robust feature extraction possible for checkerboard calibration plates with DataMatrix fiducial marks but requires the longest time to execute. Choose the CheckerboardEfficientMultiRegion mode for generally faster processing times. This method can tolerate partial occlusion of plate features from reflections or other issues, as long as the fiducial marks are visible. CheckerboardEfficient This mode provides generally good calibration results for checkerboard plates (with or without the Cognex "L" fiducial marks) in less time than CheckerboardExhaustive mode, provided certain conditions apply. See the section Feature Extraction Modes for details. CheckerboardEfficientMultiRegion This mode provides generally good calibration results for checkerboard plates with DataMatrix fiducial marks in less time than CheckerboardExhaustiveMultiRegion mode, provided certain conditions apply. See the section Feature Extraction Modes for details.
Fiducial Mark	This value specifies the type and characteristics of the fiducial marks on the calibration plate. Note: Not all combinations of feature finding and fiducial marks are valid. If you enter an invalid combination, the tool will generate an error at calibration time. DataMatrixWithGridPitch This specifies that the plate includes Cognex-compatible DataMatrix fiducial marks, each of which specifies the coordinates of the mark in the plate's 2D coordinate system and the grid pitch in mm. If you specify this mode, the tool ignores any grid pitch values that you supply. DataMatrix This specifies that the plate includes Cognex-compatible DataMatrix fiducial marks, each of which specifies the coordinates of the mark in the plate's 2D coordinate system. If you specify this mode, you must specify the grid pitch explicitly (PhysicalTileSizeX and PhysicalTileSizeY). If you use this mode and the fiducial marks include grid pitch information, that information is ignored; the tool uses the values that you specify DotGridAxes The use of this method is supported for legacy applications that use a grid-of-dots calibration plate. The origin and grid pitch are specified by a pattern of extra dots on the plate. StandardRectangles This specifies that the plate uses a single standard Cognex 'L' fiducial mark. None Use this value for calibration plates with no fiducial marks. The Calibration tool will use the tile vertex or dot center that is closest to the center of the image as the origin and will assign the positive x-axis and y-axis to the grid lines which are closest in angle to the x-axis and y-axis in the pixel coordinate space of the calibration image.
Tile Size X Tile Size Y	Enter the grid spacing for the calibration plate. For a checkerboard-style plate, this is the tile size. For a grid-of-dots calibration plate, this is the spacing between dot centers in the X- and Y-direction. Enter the grid spacing using real-world units of measurement you want to use for your vision application. For example, if you want to use inches for your application and your calibration plate uses tiles that are one-half inch in size, enter a value of 0.5. Note: If you are using a calibration plate that specifieds grid spacing, the tool replaces any grid spacing values that you have entered with those defined by the plate markings. The units (inches or mm) specified by the plate markings are discarded.
Parameter	Description
Feature Finder	This value specifies how the tool will search the calibration image for calibration vertex points. This method must match the type of calibration plate that you are using. Checkerboard VisionPro supports this mode for existing applications but does not recommend this for new applications. For checkerboard plates with Cognex 'L' fiducial marks or without a fiducial mark, use CheckerboardExhaustive or CheckerboardEfficient. For checkerboard plates with DataMatrix fiducials, use CheckerboardExhaustiveMultiRegion or CheckerboardEfficientMultiRegion. DotGrid VisionPro supports this mode for existing applications that use a grid-of-dots calibration plate. Cognex recommends checkerboard plates for all calibration applications. CheckerboardExhaustive This mode provides the most robust feature extraction possible for checkerboard plates (with or without the Cognex "L" fiducial marks) but requires the longest time to execute. Choose the CheckerboardEfficient mode for generally faster processing times. CheckerboardExhaustiveMultiRegion This mode provides the most robust feature extraction possible for checkerboard calibration plates with DataMatrix fiducial marks but requires the longest time to execute. Choose the CheckerboardEfficientMultiRegion mode for generally faster processing times. This method can tolerate partial occlusion of plate features from reflections or other issues, as long as the fiducial marks are visible CheckerboardEfficient This mode provides generally good calibration results for checkerboard plates (with or without the Cognex "L" fiducial marks) in less time than CheckerboardExhaustive mode, provided certain conditions apply. See the section Feature Extraction Modes for details. CheckerboardEfficientMultiRegion This mode provides generally good calibration results for checkerboard plates with DataMatrix fiducial marks in less time than CheckerboardExhaustiveMultiRegion mode, provided certain conditions apply. See the section Feature Extraction Modes for details.
Fiducial Mark	This value specifies the type and characteristics of the fiducial marks on the calibration plate. Note: Not all combinations of feature finding and fiducial marks are valid. If you enter an invalid combination, the tool will generate an error at calibration time. DataMatrixWithGridPitch This specifies that the plate includes Cognex-compatible DataMatrix fiducial marks, each of which specifies the coordinates of the mark in the plate's 2D coordinate system and the grid pitch in mm. If you specify this mode, the tool ignores any grid pitch values that you supply. DataMatrix This specifies that the plate includes Cognex-compatible DataMatrix fiducial marks, each of which specifies the coordinates of the mark in the plate's 2D coordinate system. If you specify this mode, you must specify the grid pitch explicitly (PhysicalTileSizeX and PhysicalTileSizeY). If you use this mode and the fiducial marks include grid pitch information, that information is ignored; the tool uses the values that you specify. DotGridAxes The use of this method is supported for legacy applications that use a grid-of-dots calibration plate. The origin and grid pitch are specified by a pattern of extra dots on the plate. StandardRectangles This specifies that the plate uses a single standard Cognex 'L' fiducial mark. None Use this value for calibration plates with no fiducial marks. The Calibration tool will use the tile vertex or dot center that is closest to the center of the image as the origin and will assign the positive x-axis and y-axis to the grid lines which are closest in angle to the x-axis and y-axis in the pixel coordinate space of the calibration image.
Tile Size X Tile Size Y	Enter the grid spacing for the calibration plate. For a checkerboard-style plate, this is the tile size. For a grid-of-dots calibration plate, this is the spacing between dot centers in the X- and Y-direction. Enter the grid spacing using real-world units of measurement you want to use for your vision application. For example, if you want to use inches for your application and your calibration plate uses tiles that are one-half inch in size, enter a value of 0.5. Note: If you are using a calibration plate that specifieds grid spacing, the tool replaces any grid spacing values that you have entered with those defined by the plate markings. The units (inches or mm) specified by the plate markings are discarded.