Arc Finder Properties Fit Mode Fit Mode specifies the mode used by the tool to calculate and return values for the found arc. There are three modes for fitting hypotheses to a valid arc entity. l Both: The Arc Finder calculates and returns both the arc center and the arc radius. This is the default mode, which will typically provide the most accurate results. l Center: The Arc Finder calculates the arc center. The returned center point values are the tool center (i.e. Arc X and Arc Y). l Radius: The Arc Finder calculates the arc radius. The returned Radius value is the tool radius.
Minimum Arc Percentage Minimum Arc Percentage sets the minimum percentage of arc contours that need to be matched for an arc hypothesis to be considered as valid. ACEUser's Guide, 3.6.x, 18316-000 Rev A Page 392 Object Definition Opening The radius of the found arc, Arc X and Arc Y being the center of the circular arc described by the found arc Rotation The rotation of the region of interest Average Contrast Average contrast between light and dark pixels on either side of the found arc, expressed in grey- level values. Fit Quality Normalized average error between the calculated arc or line entity and the actual edges matched to the found entity.
Fit quality ranges from 0 to 1, with 1 being the best quality. A value of 1 means that the average error is 0. Conversely, a value of 0 means that the average matched error is equal to Conformity Tolerance. Match Quality Percentage of edges actually matched to the found arc. Match Quality ranges from 0 to 1, with 1 being the best quality. A value of 1 means that edges were matched for every point along the found entity. Similarly, a value of 0.2 means edges were matched to 20% of the points along the found entity.