What's the differences between "IMAQ Find Circular Edge.vi" and "IMAQ Detect Circles.vi"

[leq_82]

Hello,All

 Both VI "IMAQ Find Circular Edge.vi" and "IMAQ Detect Circles.vi" can detect circular, both can get the coordinate of circular's center and the radius,but I 'm not clear about the differences,the respective advantages and the disadvantages.In which case I use "IMAQ Detect Circles.vi" is better?and vice versa.Thanks!

[leq_82]

Does anyone clear?I am looking forward to hearing from you soon.Thanks!

[udka · Accepted solution]

Below are my inferences:

IMAQ Find Circular Edge.vi and IMAQ Detect Circles.vi can be used to detect circle. The main difference between them is how they get the edge points and do a circle fit:

IMAQ Find Circular Edge.vi: Internally uses Spoke which uses annular ROI and along the search lines specified identifies edge points and then does Circle fit on the points obtained.(Ref: http://zone.ni.com/reference/en-XX/help/370281AD-01/nivisionconcepts/edge_detection_concepts/)

IMAQ Detect Circles.vi: Uses Curve extraction and contour analysis algorithm to identify the curves and detect the circle (Ref: http://zone.ni.com/reference/en-XX/help/370281AD-01/nivisionconcepts/contour_analysis_concepts/)

-Apart from above one more difference is type of images on which algorithm can be used: IMAQ Detect Circles.vi works only on U8 images whereas IMAQ Find Circular Edge.vi works on below types (Ref: http://zone.ni.com/reference/en-XX/help/370281U-01/imaqvision/imaq_find_circular_edge_3/)

[leq_82]

uday,Thanks!