02-12-2013 10:06 AM
Hi,
I'm trying to write a program to fit a circle to an image (from an avi), however when running the IMAQ find circular edge v3.vi I get the error message:
'Error -1074395720 occurred at IMAQ Find Circular Edge 3
Possible reason
IMAQ Vision: Invalid ROI.'
I'm using the IMAQ Construct ROI vi to define the ROI and I'm pretty sure the output ROI is in the correct format for the IMAQ find circular edge v3 vi.
I've attached my program (Labview 2011)
Any thoughts?
Many thanks
Rory
Solved! Go to Solution.
02-13-2013 05:39 AM
Hi Rory,
Welcome to the NI Forums.
'IMAQ Find Circular Edge 3' expects an ROI of type 'Annulus'. There are a number of functions in labVIEW for converting ROI types such as 'IMAQ Convert ROI to Annulus'. However, as the Find Circular Edge VI doesn't JUST require the annulus but bounding box and other details as well, there is a strange solution to this issue.
Drop "IMAQ Convert ROI to Annulus" down and pass the ROI through. Then drop down "Convert Annulus to ROI" (yes, really) and pass the output of that in to "Find Circular Edge".
This is a strange, circular workaround but it seems to force the ROI type to change to annulus and therefore works.
Let me know if you have any further questions.
Many thanks,
02-13-2013 05:46 AM
Thanks a lot Eden I'll give that a try. It does seem strange thaty in the help files it makes no mention of what type of ROI is required.
Rory
02-13-2013 09:02 AM
Works perfectly - thanks very much!
10-14-2013 05:31 PM
hey, this is what i was looking for, and youre answer is just awesome.. Kudos for you my friend.
12-10-2021 01:10 PM - edited 12-10-2021 01:14 PM
Same problem at first. Drop down "Convert Annulus to ROI" by following the answer and pass the output of that in to "Find Circular Edge", the error of "Invalid ROI" disappeared indeed.
However, the output images did not give me the expected circles.