Countour around blob

Hello,

I’m switching to GL 3.2 because I need to use some shaders.
At the same time I’m loosing a line width, which I really need.
So I’m looking for alternative solutions.

Essentially I have blobs, that are detected via open CV.
I then draw these blobs on the screen.

Since I can’t do it with vectors anymore, I thought maybe there is some sort of matte-choker or blur effect, that I could use to grow these shapes. Or maybe even “glow” effect. Then I could just fill them in different color and draw behind my actual blobs essentially creating a contour around them.

Any ideas ?

Thanks
M

Maybe you could use openCV dilate?
https://docs.opencv.org/3.4/d4/d86/group__imgproc__filter.html#ga4ff0f3318642c4f469d0e11f242f3b6c
This method is availble using ofxCV via the namespace an implemented as in the link, but also using ofxOpenCV as:

    `grayDiff.dilate();`

The number of iterations (so how much it dilates) is not exposed, but easy to add.