Can I automatically detect and compute the size of a microhardness "dent" from a bitmap image with IMAQ? If yes, can you take a look at my image and explain the steps?

[PatS]

Ocassionally the dents are defined perfectly and/or there may be some artifacts near the edge of the image. I've attached two sample files. Any help would be appreciated.

Thanks...

[BruceAmmons]

Pat,

I think it can be done. I have a couple of suggestions.

Can you improve your lighting? That always makes it easier to do the analysis. You can experiment with a few techniques to get better definition of the larger dent.

I used "Find Straight Line" with very low parameter values (contrast = 8, filter width and steepness = 2) and it did a pretty good job of finding the edges of the larger dent, even with the bad lighting.

There are a few other issues, such as locating the dent, that would still need to be addressed. I don't know if it would always be in the center or if you would have to search for it.

Hopefully this will get you started.

Bruce

[cld]

Pat,
I was able to do multiple edge detection from different directions and get the edges of the square. My settings were around Contrast = 8, Filter Width =3,Steepness = 2, Line Spacing =2. To decrease your search region, you could do some form of thresholding and remove small and border objects. From this, get the location of the blob,and create an ROI around it. This may be hard with the smaller objects, but is an idea.
I hope this helps!
Chris D.
NI Applications Eningeer