Hardware manual

Impact Reference Guide Circle Edge Refinement
3-115 Datalogic Automation Inc.
Circle Edge Refinement
In the Measurement Drawer
The Circle Edge Refinement tool refines the center location and diameter of a circle based on an estimated
center and the number of segments to search. It indicates if the center and diameter are within an expected
range. This tool is primarily used to find the centers of the balls in a ball grid array (BGA).
Input Name What it is
Input Image Linked Image
Tool Origin The tool’s origin relative to the entire image space
Estimated Center
List
The list of estimated circle center point locations
Diameter Tolerance The diameter variation allowed. The parameters are minus, nominal, and
plus.
Circle Scan Type The type of circle and how the tool should find the edge
Circle Edge Detect
Type
First Edge, Center Edge, Best Edge: Finds one edge point per ROI, then
find fits the circle with least squared error
Best Two Edges, Best Three Edges, All Edges: finds multiple edge
points per ROI. See “Circle Edge Detect Type” on page 3-117.
Number of Line
Segments
How many circle edge segments the tool should use (minimum of 3)
Minimum Number
of Points
The least number of edge points the tool should use to refine the circle
Segment Length The minimum line segment length the tool should use to refine the circle
Outlier Enable See “Outlier Enable and Outlier Distance Threshold” on page 3-132
Outlier Distance
Threshold
See “Outlier Enable and Outlier Distance Threshold” on page 3-132
Edge Detection
Method
Gradient Edges or Grey Level Edges
Gradient detection generally provides more consistent results. In some
cases Gradient detection can pick up extra edges in a noisy image and
Grey Level detection may offer better control.
See “Edge Detection Method” on page 3-78.
Edge Detection
Sensitivity
The sensitivity level determines the transition level necessary for detec-
tion. A higher value detects more edges.
Fixed Gradient
Threshold Percent-
age
The gradient threshold value for Gradient Edges Detection Method
Fixed Grey Level
Threshold Percent-
age
The grey level threshold value for Grey Level Edges Detection Method