Surface area calculation with 3D Convex Hull and interpretation of results

Hi all (and more specifically @ThomasBoudier)

I’d like to calculate surface area of a mosquito antenna, images taken as a confocal stack. I’m trying to use the 3D Convex Hull plugin to do this, but don’t understand the units of the results or if I’m even using it correctly.

My current workflow is:
Image>Stacks>3D Project
Analyze>3D Convex Hull>Measure All

Here is a link to an example image, and I’ve attached the results I’m getting from the workflow above.

Obtaining the surface area of the small projections is less important to me than calculating the surface area of the cylindrical core. Is this a the correct workflow to be able to measure surface area, and how do I convert these results to mm^2/mm^3?

Thanks so much,

Margo

Hi @margo,

First to answer your question about this 3D Convex Hull, this plugin is not mine and I do not know where to find it :wink: . I would guess about the results : columns with voxels should refer to pixels number, with volume it should refer to units, the last 3 columns refer to shape factors. You can change the image calibration of your image and see what values are changing.

Second, to answer your question about measuring the surface area of the cylindrical core, I do not understand why you do a 3D projection, your image is already a stack. The simplest thing to do would be to a Z projection and measure the width and height of your cylinder, then you can compute its area, more accurately I guess than a 3D measurement.

Hope this helps

Best,

Thomas