How to correct purple fringing in a video?

[daniel47]

Does anyone have any experience with fixing purple fringing from a cheap/badly focused camera lens?
There’s obviously no direct filter for this but I was thinking there could be a combination that works good enough to improve the clip. Thinking out loud, maybe selecting only the purple areas/channel then desaturating then dragging the shadows way down? Anyone know how to do this?

Here’s a random frame that has quite a lot of this purple fringing on all the dark edges to the brightbackground (there’s also at least a saturation and sharpening that make it a bit more visible).

[shotcut]

Mask: Chroma Key Video Filter

The video filters beginning with “Mask:” let you select a portion of the image or video in which to apply other video filters. There are a few different ones, and this one lets you choose the portion of the image by a color and a distance from the chosen color. [image] See the “Tip” above. To really make this work you add additional video filters that affect the selected color range followed by the Mask: Apply video filter, which combines every thing in between. So, the order of the filters is…

[daniel47]

I always forget this filter exists, I think overall it does the job quite nicely. I need to tweak a bit the purple and its range and I’m done.
The alpha channel adjust and alpha channel view filters are also quite helpful.