2D Circle

Operator Function

Find circles in the input image using circular calipers and output the center point and radius of the circle.

Parameter Introduction

Input Parameters

Parameter	Range	Default Value	Description	Illustration
Input Image	0-8	0	IM number for image input

Calculation Parameters

Parameter	Range	Default Value	Description	Illustration
Caliper			Set the range of the search area
Transition	Positive/Negative/All	All	Identify the direction of grayscale change, including: Positive: Transition from black to white Negative: Transition from white to black All: Both transitions
Selection	First/Last/Best	Best	Select points that meet the threshold, including: First: The first point found that meets the threshold Last: The last point that meets the threshold Best: The point with the largest threshold change
Threshold	1-255	10.000	Threshold setting for gradient change
Standard Deviation	0.4-100	2.000	Standard deviation for smoothing gradient changes
Fitting Method	Least Squares/Minimum Enclosing Circle	Minimum Enclosing Circle	Least Squares: Use all feature points to fit the optimal solution Minimum Enclosing Circle: The smallest circle ensuring all points are inside the circle

Result Display

Parameter	Range	Default Value	Description	Illustration
Circle	true/false	false	If enabled, display the found circle on the IM image
Circle Center	true/false	false	If enabled, display the found circle center on the IM image
Edge Points	true/false	false	If enabled, display the found caliper contour points on the IM image

Output Parameters

Name	Type	Range	Description
Result	bool	true/false	true for success false for failure
Warning	bool	true/false	true indicates a warning false indicates no warning
Message	string		Output success, error, or warning messages. Empty if no error or warning.
Time	float		Operator execution time, unit: ms
Circle	circle2d	Found circle information	Center point circularity

Exception Troubleshooting

No.	Exception Information	Corresponding Parameter	Solution
1	Caliper out of bounds		Increase the number of calipers
2	Not enough fitting points found
3	Input image is empty		Check if the input image is empty

Example Introduction

Engineering Design

1. Select the Load Image tool to load the required 2D image to IM0.

2. Select the 2D Circle tool.

Tool Usage

1. Select the input image for the operation. The image number must match the IM number where the image is located in the project.

2. Use the caliper to select the area where the circle needs to be found.

::: Warning Tips 1. Use the ROI controller on the image window to drag or scale the caliper; 2. Directly modify the circle center or caliper parameters in the calculation parameters to set the caliper; :::

3. Set the parameters.

4. Check the content you want to display in the result display section.

5. Click Test to check if the image window and parameters meet expectations.

6. If there are no issues, click Save. Run the operator in the run list, and then view the running results in the corresponding IM.