Vision

[eskay]

Hi

I am with a project to locate a continuous line( a form of defect) in a metal sheet.
I am attaching a sample of the image.
The work i have done
1)image enhancements
2) canny edge detection

Located lines along X-Y axis without any inclination.
Can anyone suggest a possible technique to overlay the line contour on the sheet irrespective of inclination

Bye
Ganesh

[Scott_R]

Hello Ganesh,

If I understand correctly, you are trying to draw a line on your image that will indicate where the line defects are occurring in the metal sheet. Is this what you are trying to do?

If you are using LabVIEW, there is a "Show Results" option in the Settings input to the Find Horizontal/Vertical Edge VIs. By setting that to show the results, the edge that is detected will be highlighted on the image.

What environment are you developing your application in? Are you using LabVIEW, Visual Basic, Visual C++, or CVI? What versions of the IMAQ driver and Vision toolkit are you using?

Regards,
Scott R.
Applications Engineer
National Instruments

[eskay]

Hi Scott,
Yes i am supposed to detect lines(form of defect,scratch) on the metal sheet.
The lines can be horizontal,vertical and also inclined and even corrugated.
Am using LabVIEW 7.1 on Win XP,
I couldnt find out the VI u are referring to ?
I did particle filtering and could somewhat find out line defects.
If possible can u suggest any alternate solution

Cheers
Ganesh

[Scott_R]

Ganesh,

Those VIs should have been installed when you installed the Vision Development Module. What version of the Vision software do you have installed on your system? Try opening the Function Palette and navigating to All Functions >> NI Measurements >> Vision >> Machine Vision >> Locate Edges. Try using those two VIs with the inputs that I mentioned earlier.

What about trying to use a histogram with intensity measurements? You could perform a histogram on the image and then look for any pixels that are darker than the rest of your image.

Regards,
Scott R.
Applications Engineer
National Instruments