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How to create ROI


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There is no way (that I know of) that you can manually select an annular triangular ROI manually over an image display in LV Vision in a single easy step. You can select a circle, oval, annulus (tire shape) rectangle, rotated rectangle.

You can select the triangle itself by using the Polygon Tool (don't use the Closed Free hand Tool, the adjoing lines won't be straight).

post-2680-1241805611.jpg?width=400

You can write code so that the user first selects the outer triangle, then selects the inner triangle, and you form the resultant ROI as {Outer-Inner}.

N.

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Such a simple request yet not as trivial as it first seems.

Nevilles idea will most certainly work if you trust whoever is drawing the triangles. Hopefully you can go with that. But if you want a programmatic method, more complicated, but less demanding on the user you might try the following.....

1. "Threshold" the image (I'm looking at your blue icons) to get it in black and white.

3. "Fill holes" so that the center part of your triangle is fully blocked (i.e. you have a solid triangle). This is your major mask.

4. Scale your mask down by a factor (say 5%). And invert. This is your minor mask.

5. Combine both masks.

6. Apply the mask to your original image.

You should now just have the white triangle without drawing anything.

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  • 1 year later...

There is no way (that I know of) that you can manually select an annular triangular ROI manually over an image display in LV Vision in a single easy step. You can select a circle, oval, annulus (tire shape) rectangle, rotated rectangle.

You can select the triangle itself by using the Polygon Tool (don't use the Closed Free hand Tool, the adjoing lines won't be straight).

post-2680-1241805611.jpg?width=400

You can write code so that the user first selects the outer triangle, then selects the inner triangle, and you form the resultant ROI as {Outer-Inner}.

N.

Hello! I am new to this forum. But I have a problem that seems I cannot resolve the way I want.

I also want to create a R.O.I. method, but without VISION and IMAQ modules. I am working on an image processing project, in which I want to use only the default functions (Full Development) in LabView (either 8.5 or 2009). The only things I can find on the internet is only ROI with VISION. Can you give me some hints on this?

Thanks a lot.

Laurentiu A.

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Hello! I am new to this forum. But I have a problem that seems I cannot resolve the way I want.

I also want to create a R.O.I. method, but without VISION and IMAQ modules. I am working on an image processing project, in which I want to use only the default functions (Full Development) in LabView (either 8.5 or 2009). The only things I can find on the internet is only ROI with VISION. Can you give me some hints on this?

See the other thread.

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See the other thread.

You can create and ROI like you want. Draw two triangles using Polygon, one inside the other (holding down the Ctrl key allows you to add another ROI to the image control). Read the ROI property to get the data for the ROI. There should be two contours listed in the order they were drawn. If the inner triangle was drawn second, then read out that contour and set the Contour Type (Contour ID) to 1 (Internal) and the write it back.

There is a bug present in LabVIEW that doesn't keep the Contour Type (Contour ID) value when you read it from the ROI property, but it does write it properly.

post-1423-064436300 1278703192_thumb.png

post-1423-032119300 1278703192_thumb.png

Triangle Outline.vi

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