tracking motion

[Emily Lyng]

Hi all,

I'm new to LabView, using version 8 of both LabView and Vision.  I'm working on tracking crab motion.  I created a vi that will give me the xy pixel co-ordinates of the crab.  I need this to repeat every 5 seconds and give me the output in a table, with the time, and I'm a bit stuck 🙂  Ideally I'd like it to convert the location to real life values also, I'll be looking at things like velocity at different times of day.

I'm looking at lots of examples and trying things out, but thought this may be something someone with experience could accomplish very quickly...

I appreciate any help or advice you can give me.  Below is what i have so far.

http://img187.imageshack.us/img187/8100/crabposition3ah8.gif

Emily

[SatishK]

Hi Emily

From looking at your code it seems like was generated from Vision Assistant. Assuming that you are using Vision Assistant 8.0, look at "Image Calibration" under the Image menu. It will allow you to calibrate your images so that you can provide a relationship between the pixel coordinates and real world coordinates. Once you do this, the real world measurements that you get from Particle Analysis will be in the units that you set up.

Regards,

Satish Kumar
R & D,
National Instruments

[Emily Lyng]

Thanks Satish for your fast response.

I found it so can now calibrate.  I also managed to get the repeat every 5 seconds part accomplished, it was easier than I expected - just a while loop and a time delay.  Still working on getting the co-ordinates out in a table form, at the moment they come as 2D array which is not stored anywhere, so I need to transform it as I need to be able to plot the co-ordinates with time.  In Vision assistant the results come this way but not when I convert to a LabView vi, and for this project it would be better if I can simply save the results displayed on the front panel, either continuously or after the study time is over.  I found some more good examples though so I'm playing and learning as I go 🙂

Emily

Message Edited by Emily Lyng on 08-02-2006 03:22 AM

[Emily Lyng]

I fixed it 🙂

Thanks again for the calibration tip Satish

Emily

[K_seeker]

Emily,

I did a small project similar to what you are working on. In my case it were rat(s)in a enclosed space. I am assuming that the crabs your watching is also in an enclosed space, like a tank or such. Will you have just one crab or more than one? In case you are observing multple crabs,How are you going to differentiate between multiple crabs? Also your code will have to take care of the scenario when one crab would like to climb up on another. Other than position, do you also need to extract the direction in which the crab is facing. (Some subjects under investigation can move in reverse direction for short distances).

Let me se if I can locate my LV code. Good Luck.

[Emily Lyng]

The crabs are in an enclosed space.  At the moment there are four arenas with one crab in each, we don't need to worry about differentiating between them at this stage, although its something I'm interested in perhaps for future studies.  I have created code in vision assisstant for the four regions of interest, but not sure how to get them working together.  I'd like to take the analysis further in LabView rather than just export the xy co-ordinates, we'd like to look at things like velocity and periodicity of activity.

It would be wonderful if you could find your file - thanks!

Emily