Cheese is unusable and transparent with nvidia global FXAA active
I encountered the initial problem a while ago, and had assumed it was a settings issue with Linux Mint itself, or possibly Cinnamon (see the thread at https://forums.linuxmint.com/viewtopic.php?f=47&t=349718). However, having just encountered the same issue with Firefox (see https://forums.linuxmint.com/viewtopic.php?p=2066885#p2066885), I have come to learn the two issues were related, and caused by the same thing - global FXAA in the nVidia binary driver. There were two fixes - one was to disable hardware acceleration in Firefox (which fixed FF but not Cheese), the other was to disable global FXAA from the nVidia settings (which fixed both Cheese and Firefox).
I understand this is probably not the best place to report this issue as it appears to be more of a bug with nVidia's drivers than an actual problem with Cheese, but since it impacts Cheese, I figured it couldn't hurt to at least let you know.