Can IMAQ Vision inspect this fuzziness scratch?

[shenhao]

Hi!
The image below is the surface of a fiber. We can see that there is a fuzziness scratch on the surface. I try to inspect it using IMAQ Vision 6.0,
My inspect step is:
1. use laplacian to enhance the image.
2. autothreshold using entropy.
3. remove the noises and pick-up the scratch.
but when i am going to step 2, i find that after thresholding noises and scratch are connected, can't be divide easily.
Does anyone give me some suggestion? Thanks a lot!

[Remzi]

Hi,
If you are just trying to inspect the existence of the scratch, in vision assistant (if available) you might try other threshold methods or manual threshold.

Remzi A.
National Instruments

[RManion]

Hi shenhao,

I have played around with this image, and have had moderate success by performing low pass filtering prior to the laplacian, and advanced morphology (skeleton) after thresholding.

By filtering first, though we reduce the strength of the scratch, we also remove a great deal of noise. The skeleton operation assists in separating the noise from the scratch.

You might also want to try an equalizing look up table and playing with a custom convolution... Good luck, this is definitely a tough problem to solve.

Hope this helps though,

Robert