How to speed up your annotations using the volume interpolation tool in webKnossos

Albane le Tournoulx de la Villegeorges
Published in
2 min readJun 23, 2022


Hi there!

Today, I want to introduce an essential feature that was recently added to webKnossos: the interpolation tool for volume annotations.

The concept is pretty simple, but it will definitely save you a lot of time. All you have to do is to draw on one slice, move forward by a few slices, draw again… and webKnossos will interpolate the segments between the two annotated slices.

Now, let’s have a step-by-step look at how it works.

First, use the brush or lasso tools to annotate a segment. Scroll down a few slices, and annotate the segment again.

Annotating a segment on one slice, scrolling down a few slices, and annotating again.

Then, click on the volume interpolation button. Let webKnossos do its work… and have a look at the slices between your two annotations: the cell has been segmented on each of these slices!

Clicking on the interpolation button: webKnossos will segment the cell on each slice between the two originally annotated ones.

Finally, use the traditional volume annotation tools (brush, eraser, lasso…) to finetune the annotation as needed.

Finetuning the annotation with the annotation tools in webKnossos.

We hope this feature will help you annotate faster. Stay up to date with the new webKnossos features by following us on Twitter!