Confirmed, the error pop ups under linux too.
The plugin looks very useful, some comments/suggestions:
Shouldn’t the plugin respect the hierarchy and appear under Plugins, not in the Menu bar? Hijacking the Menu bar is, I guess, not a good idea (if everybody does that, then menu would be unusable as there is not a lot of space for other entries).
The example using the blob image in the plugin page is confusing as that particular image has an inverted LUT. The page talks about “maxima” (high in the 1D plots) when you see “minima” (dark greyscale values). I understand that the plugin uses the maxima, but virtually all watersheds procedures I have seen published standardise on the minima (dark) as seeds. Sure this is a matter of image polarity, but the inverted LUT of the blobs example makes it less straightforward to grasp.
What would be also useful, although not sure if it is worth implementing is having a polarity switch, so one can process minima or maxima as desired without having to close the plugin, invert the image and run the plugin again.
Thanks for making the plugin available.