I added a Pairwise Image Comparison Cell

[meawoppl]

This cell presents both the current image in the pipeline and the previous image that it saw. It is not stateless, and hence has the thread unsafe flag.

Also a tiny cleanup detail of changing several ecto process returns from 0 to ecto::OK.

[vrabaud]

though I kindof agree we need something like that, I would rather have a logic that is more on the ecto side: having some kind of templated cell that does a sliding window. No ?

[meawoppl]

I am not exactly sure what you are suggesting. All this one does is store an internal copy of the last image seen, and then present both images.

This could be pretty easily used to create a video difference stream, or image quality metrics etc.