Drawing on an IMAQ image

[AndrewIons01]

Dear All

I am trying to incorporate a piece of code into my vi that will allow me to draw a box on an image. The box however, must be able to be created based off of the image pixels from a camera. I am currently using a piece of code that allows me to click and drag a box. 

What I'm saying, is that if i have an image from the camera that is 500x500 pixels (for example) and a beam is at the position  (250,250), i would like to draw a box around this of a user determined size. If I wanted a box that was 100 image pixels wide, I could draw/create a box that has points at (150,350), (350,150), (350,350), (150,150). The beam is at the centre of the box. 

I have tried to use the IMAQ draw on image VI but this seems to change the pixel values, I don't want it to do this as these images are then manipulated (centroid calculation etc). 

does anyone have any idea how I might do this or any advice?

The VI i am using currently is attached below, I did not write this particular vi. I believe it was written by Ben64.  

Best Wishes

Andrew

[hy_]

HI,

If you do not want to alter the image, you can use a separate front panel object and place it on top of the graph.

[RamonG]

Have you considered creating a rectangular ROI? This is non destructive and can be moved on the UI.

[AndrewIons01]

Hi both

thank you so much for the replies. 

I will try this solution and see how it goes.

can I then take the image output of that image then display it onto an intensity graph with the box drawn on it. 

Best Wishes 

Andrew

[RamonG]

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@AndrewIons01 wrote:

can I then take the image output of that image then display it onto an intensity graph with the box drawn on it. 

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Using an intensity graph seems a bit convoluted when you are already using IMAQ. Is there a reason for this?

[AndrewIons01]

Hi 

we are using intensity graphs as it was what we decided to use early on in the project. Another reason is because it will show me exactly how far a beam has travelled. 

Best Wishes

Andrew

[RamonG]

Then how about using 2 cursors? This will show lines across the whole length and width but it is non-destructive.

[AndrewIons01]

Hi 

Ramon

This sounds great, is it possible to define the gap between the cursors by a set amount i.e. can i use a numeric indicator to pre-define a width and height?

Best wishes

Andrew

[RamonG · Accepted solution]

Yes, you can programmatically set cursors.

[AndrewIons01]

Brilliant thank you so much, this works a treat.