ROI descriptor

[F.N]

We want to use the IMAQ read LCD  to read the screen on a digital thermometer. We need a ROI descriptor but we do not know what is suitable for that. PLEASE HELP!

Thank you

[AH-NI]

Hi F.N,

I hope you are well. 

One of the easier ways of creating a Region of Interest (ROI) descriptor is to use the IMAQ Construct ROI VI as it allows you to select the ROI convieniently as it saves time creating code to perform the same task.

Essentially a dialog box will pop up allowing you to select the Region that you are interesting in analysing.

More information can be found here:

http://zone.ni.com/reference/en-XX/help/370281P-01/nivisionlvbasics/define_regions_of_interest/

and 

http://zone.ni.com/reference/en-XX/help/370281P-01/imaqvision/imaq_constructroi/

Kind Regards,

[F.N]

Thank you. We attempted that and so far it looks fine but the problem now is that we did not convert the image to grayscale. How would that be done?

[RutsT]

I can't see your VI, but I asume you used a 'create IMAQ.vi' in your program? You can wire a control to the Image Type input. If you use a control you can choose for grayscale.

Does this help you? Otherwise you will have to convert it in another way, but please let me know if this already works.

Kind regards

Ruts

[F.N]

We have now converted to grayscale, but the problem is still the ROI - we're told to use the "IMAQ Get LCD ROI", but as an input into that icon we now need another ROI descriptor. As we are taking pictures as a sequence, it would interrupt the program if we ask every time for the user to define the ROI

[RutsT]

Also on this topic, would you please share your VI. This would make it a lot easier to see what's the problem.

[Phil_]

Why don't you use the image control to define your ROI?

You can use a property node from your image display to output a ROI. You can then define this ROI with the tools on the side of the image display.

[F.N]

This is our vi. The problem is that we need a suitable ROI descriptor for the IMAQ get LCD ROI. Thank you

[F.N]

What do you mean by image control? How would we find it?

[Phil_]

The thing on your front panel that is showing the picture from your camera!

Double click on it (so it takes you to the corresponding block diagram indicator), right click, create, property node, ROI.