Point Finder Adaptive thresholds set a sensitivity level based on image content. This provides flexibility to variations in image lighting conditions and variations in contrast during the Search process. l Adaptive Low Sensitivity uses a low sensitivity adaptive threshold for detecting edges. It detects strongly defined edges and eliminates noise, at the risk of losing significant edge segments. l Adaptive Normal Sensitivity sets a default sensitivity threshold for detecting edges. l Adaptive High Sensitivity detects a great amount of low-contrast edges and noise. l Fixed Value sets an absolute value for the sensitivity to contrast.
A typical situation for the use of a fixed value is a setting in which there is little variance in lighting con- ditions. Fixed Value Contrast Threshold sets the minimum contrast needed for an edge to be detected in an input image. The threshold value expresses the step in grey-level val- ues required to detect edges. o Higher values reduce sensitivity to contrast. This reduces noise and the amount of low-contrast edges. o Lower values increase sensitivity and add a greater amount of edge at the expense of adding more noise. This may generate false detections and/or slow down the search process.
Interpolate Position Interpolate Position sets the mode used by the tool to compute a point hypothesis. By default, Interpolate Position is disabled. When Enabled, you can select one of the following modes l Corner: The tool will compute a hypothesis that fits a corner point to interpolated lines from connected edges. l Intersection: The tool will compute a hypothesis that is an intersection between the search axis and connected edges of an interpolated line. Positioning Level Positioning Level sets the effort level of the instance positioning process. A value of 0 will provide coarser positioning and lower execution time.
Conversely, a value of 10 will provide high accuracy positioning of Point instances. Subsampling Level Subsampling Level sets the subsampling level used to detect edges that are used by the tool to generate hypotheses. l High values provide a coarser search with a shorter execution time. l Lower values can provide a more refined search with slower execution time. ACEUser's Guide, 3.6.x, 18316-000 Rev A Page 597