motion tracing camera controlled by a stepper motor

[Y.L.]

Hi, i'm trying to build a motion tracing camera controlled by a stepper motor. Could you please give me some tips?

[JR_A.]

You would probably need an IMAQ frame grabber board to capture the images from your camera and then you could use the Vision toolkit to determine where the object is in the frame. It could then tell which direction it is moving and you could then use a Motion Control card to control the stepper motors to move your camera. I'd recommend taking a look at the Vision Products and the Motion Products.

Regards,

JR A.
Application Engineering
National Instruments

[Y.L.]

JR A.,
I have a IMAQ PCI-1409 board. Could you be more specific what Vision toolkit do I need i order to determine where the object is in the frame?

Thank you

[JR_A.]

Sure. The IMAQ boards come with NI-IMAQ which is the hardware driver which allows you to acquire images but it does not provide functions for image analysis. That is where the 'IMAQ Vision' comes in. It is a toolkit which give you processing algorithms such as particle analysis, filtering, pattern matching... and much more. The toolkit is available in a LabVIEW version or a Measurement Studio version (which can be used with C++ or VB as well). Take a look at the sight for Vision for more info.

Cheers,

JR A.
Application Engineer
National Instruments

[Y.L.]

JR A., I have got IMAQ Vision for LabVIEW.Could you tell me which function or method is the one to determine whether the image is inside the frame or not?

Thank you

[JR_A.]

Well, there are a lot of different ways that you could do it depending on your system and your images. I'd recommend looking at the IMAQ Vision Help and at the example programs. You could do pattern matching to find the object that you are looking for and then you would know it's location. Or you could subtract on image from the previous and then threshold and do binary analysis or particle analysis to find the new position. Take a look at the examples and that should give you a better idea.

Cheers,

JR A.
Application Engineer
National Instruments

[Y.L.]

Hi, could you tell me where I can find examples of image subtraction? I couldn't find any from the examples.
Thank you.

[JR_A.]

There isn't a subtraction example but there is an addition example which would give you the idea of how to use to Operators functions. It can be found in the IMAQ Vision examples under Functions->Operators.

JR A.

[Y.L.]

Hi JR A, The example helps a lot. Thank you. Do you know any examples of binary analysis or particle analysis to find object positions?

Thank you