NI Vision Tutorial - basic fundamentals

[CarlosOtiniano]

I worked with pattern matching, work fine but when I was looking objects revolved over 360 degrees you lose control, tracking patterns have this limit with objects that rotate more than one revolution on its axis

[Klemen]

Hello,

if an object rotates 360 deg (let's say around its axis), it rotates back to the the initial position. The number of full rotations have no effect on this.

Did you train the pattern for full rotation, e.g. 0 to 360 or -180 to 180 deg?

Thing that could affect the detection:

- non-uniform contrast change

- scale change

- perspective/affine transformation

In my experience the NI pattern matching works very well under the right circumstances.

Best regards,

K

[alexandresantos]

Hello friend

I would to know if possible get a accuracy of 1mm using NI Vision.

I am taking width measurement from a steel strip under movement which it could be from 750 to 1900mm width.

I am researching a camera from Basler or Ximea. Advices about the best camera will be welcome.

Thanks,

Alexandre

[Klemen]

Hello,

have you looked at the following link?

http://digital.ni.com/public.nsf/allkb/29D716D6F4F1FBC386256AE700727AF6

Best regards,
K

[alexandresantos]

Hello friend

Thanks for the link, It made me more concious about the importance of selection of lens and CCD.

I know that for my project, 90% of the sucess is the correct choice for CCD and lens. Because this I am searching more literature like that.

If you know, please send me.

Thanks,

Alexandre.

[Klemen]

Don't forget the proper scene illumination also...

There are quite a few guidelines on the web, you should have no problem searching for them. Also, the camera and lens manufacturer clould (should) probably help with any additional questions?

Best regards,

K

[CarlosOtiniano]

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Klemen escribió:

Hello,

if an object rotates 360 deg (let's say around its axis), it rotates back to the the initial position. The number of full rotations have no effect on this.

Did you train the pattern for full rotation, e.g. 0 to 360 or -180 to 180 deg?

Thing that could affect the detection:

- non-uniform contrast change

- scale change

- perspective/affine transformation

In my experience the NI pattern matching works very well under the right circumstances.

Best regards,

K

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You can tell me how to configure  for full rotation, e.g. 0 to 360 or -180 to 180 deg?

[Klemen]

Hello.

Here you go:

Best regards,

K

[kaus]

Sir, I need to detect triangles in an image. How do i proceed? IMaq has inbuilt func for detect shapes for circle and rectangle but not fot triangle.

[muks]

Kaus,

You are just hijacking threads which is not going to help much. Please start a new thread and try particle analysis as suggested in the other thread.  Also in your NEW thread post an image if possible