Using pattern matching to locate measurement tools

[rbergs]

I may be using the completely wrong tools to do this, but here is what I want to do:

I would like to use Labview to locate an object in a field of view, and apply measurement tools to the object.  Basically, find a blob, and measure the blob.

What I have done is used the pattern matching tools to find the object (which works EXTREMELLY well), but the measurement tools, such as 'clamp' and other line tools do not 'follow' the location of the pattern match.  I may misunderstand its purpose, but the pattern matching retangle has a point associated with it.  My understanding is that I could use this as an origin of sorts to 'locate' the area I want the measurement tools to do their job.  I have some experience with Adept Vision, and I know that you can set up coordinate systems, I figure there is something like this in Labview, I just may be using the wrong tool.

I have an application that while the object I am interested in will generally be in the same location, it will change slightly side to side and vertically.  What I would like to do is set the camera up and be able to find the area I am interested in, take a measurement and go on with life.

The pattern matching works very well by itself.  The measurements tools (clamp and the like) work well by themselves.  What I would like to do is combine them so that the measurement will be taken no matter how the object is oriented and where it is within the view area.

Is there a better tool to use, or is there a command or something that I am missing?  I am using Vision Assistant 8.0 and Labview 8.0.

Thanks

[Vivek_N]

Hello rbergs,

From what I understood, it looks like you need to take measurements of an object that appears in different orientations within an image. Setting up a coordinate system for the 'blob' that you detect in the image requires the Vision Development Module. By setting up a coordinate system, you will be able to take measurements irrespective of the orientation of the blob.

Do you have the Vision Development Module? If so, you can use the IMAQ Coordinate system functions that can be found in the Functions palette : Vision and Motion >> Machine Vision >> Coordinate System.

I hope this helps.

[rbergs]

I checked in my installation of Labview, and the command/VI is there.

Is the coordinate system commands available in the Vision Assistant, or only in Labview proper? 

[Vivek_N]

Hello rbergs,

There are no specific coordinate system commands to be used in the Vision Assistant. You can however make your application work in LabVIEW. I would suggest taking a look at the 'Simple Calibration Example.vi' (one of the LabVIEW shipping examples). This VI builds a coordinate system for an object in an image, and applies to different images. I hope this helps.