Find a corner point

asked 2014-01-24 02:48:02 -0600

zawpai gravatar image

Hi Anyone,

Could you please take a look my imagesOrigin.jpg, Find.jpg? First image is the original one and second image indicates AOI. Actually, I would like to find the corner point, but I don't know which function/command I need to use.

Does anyone guide me to do this?

Regards

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Comments

Since you are actually using electronics, of which models are always exactly the same (up to some micrometers in precision) I would suggest using template based matching, see where highest response is and then define your corners based on the maximal output.

StevenPuttemans gravatar imageStevenPuttemans ( 2014-01-24 03:31:17 -0600 )edit

What do you exactly mean with "corner point"? Your red arrows in the image "find.jpg" are not really pointing to a corner, right?

Basically, finding corner structures in openCV can be done with "goodFeaturesToTrack" for example. The function evaluates the eigen values of the hessian matrix.

JohannesZ gravatar imageJohannesZ ( 2014-01-24 06:47:11 -0600 )edit

He wants to detect a corner that is in 'feature' way of speaking not a specific corner but two large horizontal and vertical bars crossing. I do not think that the goodFeaturesToTrack algorithm will do what you think here.

StevenPuttemans gravatar imageStevenPuttemans ( 2014-01-24 06:57:58 -0600 )edit

Hi StevenPuttemans and JohannesZ, Thanks for your information. If I use "template matching", I will need to teach 4 corners of the chip because my camera can't cover all kinds of chips. Camera's FOV is very small. Another disadvantage of using "template matching" is that the calculation for chip body may not precise if the corner is not the center of AOI. So, I want to detect two lines based on my AOI and I can get 4 corners and the orientation of the chip. But, I don't know how to find the line. Regards

zawpai gravatar imagezawpai ( 2014-01-26 18:59:06 -0600 )edit

If you can find the 4 corners, then just connect them and you have the line? I do not see the problem there? Or do you want to retrieve the mathematical formulation of that line?

StevenPuttemans gravatar imageStevenPuttemans ( 2014-01-27 01:58:42 -0600 )edit

Hi StevenPuttemans, I know how to calculate the line formula. But, I don't know how to get all corner points.

zawpai gravatar imagezawpai ( 2014-01-27 02:48:03 -0600 )edit