The magic of Kronos

(AKA Why My Rolling Shutter Fix Didn’t Match with RollingShutter)
WARNING: doesn’t come to any solution.

My last post was about trying to recreate The Foundry’s RollingShutter plugin, using the new Kronos 2 technology instead of the old one, which the discontinued plugin was left with. And while the proposed solution benefitted from Regularized motion estimation, when switching back to Local it was clear that RollingShutter still won over it. So there’s something missing that I didn’t recreate, and have yet to figure out. Continue reading “The magic of Kronos”

RollingShutter never left us

(AKA How to Correct Rolling Shutter in NukeX Without Plugins)

As you may know, The Foundry had a really good plugin for Nuke and After Effects called RollingShutter, used to try and remove the so-called effect that most of current cameras’ sensors introduce in the footage.

Every other popular rolling shutter fix uses the “global skew” method mentioned in the video, even After Effects’ Warp Stabilizer and Rolling Shutter Repair in its default setting (the Pixel Motion mode suggests a more accurate approach). This method is fundamentally wrong unless the camera is just panning and nothing moves in the shot.

Exaggerated ripple artefact

This is not to say that Warp stabilized footage doesn’t look good: in fact, RollingShutter sometimes introduces disgusting ripple artefacts around edges, while its counterparts don’t. But when it comes to matchmoving and compositing CG over real, knowing accurately where each part of the image would be in real life instead of a rough overall estimate, is key for a good result*.

RollingShutter has been discontinued, its latest Nuke version being released before Nuke 7. Even though it’s based on Kronos, it contains its own copy of it, which means that while Kronos technology keeps being improved, RollingShutter can’t take advantage of it. First it was GPU acceleration —I can live without that, but now Kronos 2 offers motion vectors with less artefacts.

Time to make our own improved RollingShutter.

Proposed method

Continue reading “RollingShutter never left us”