Measure length of a laser line

[Netsroht]

Hello, we've got VBAI and we want to measure the length of units. We've got grey units on a grey background where the starting and the ending(edges) of our units are hard to find. So we aplly a laser beam onto our unit. So where the camera sees the line there's the unit. But our unit length is not always the same so the length of the line represents the length of the unit. We've tried with STRAITH EDGE, we've easily found the line but the line drwan by Vision Builder is always as long as the ROI. But is there another possibility to measure the length of the line Thanks in advance

[Vladimir_Drzik]

Hi

Can you post an image?

Vladimir

[Netsroht]

Hi, for some reason I am not able to post images. The link(possibly javascript) for "Add Attachments" is not working, probably blocked by our proxy server. But it's easy to describe. You can imagine, that your whole screen is dark grey and somewhere there you've got a white line. And we want to measure the length of this line. Finding this line is quite easy. We found out that Advanced Edge Detection knows the start and the end point of the line, but only, when you configure it. There you can see the different points it has found. But after finishing settings you only see the start and the end point of the whole edge found going from the start of ROI to the end of ROI, even if our line is way shorter. Hope, you understand what i mean. A grey screen with a white line.

[BruceAmmons]

I would consider thresholding the image to isolate the line, then using blob analysis to get the length of the line.  You would probably measure the max ferret diameter.

Bruce

[Netsroht]

Do you mean "Detect Objects" with "Blob Analysis". That's what I've tried yesterday and it seems, that it works quite good.

[CarlosOtiniano]

if still not solved the problem you can measure distance passing an RGB image to 8bit and extract a color plane insert VERTICAL CLAMP IMAQ function MIN which will measure the minimum height of the piece analyzed, this function block can be located within the MACHINE VISION path / MEASURE DISTANCES