Why would anyone want to invert colors in video, you may ask?
Well, let me ask you this: why wouldn’t they want?
More seriously, I do that for a very specific reason: my bad eyesight makes it so that I can’t read black text on a white background. You know, the kind of text you occasionally find in books, or in slides. The kind of slides, you’ll find almost everywhere while watching College de France many lectures. Like in Dario Mantovani’s Usages juridiques du passé (dans la pensée des juristes romains).
To read this slide, I need the background to be dark and the text to be light.
Under macOS, I could easily invert colors of the whole screen, but that’d be impractical as that’d also invert colors in all my other windows that are already dark.
Here is how I invert only the colors of a video under macOS (see here for Windows).
- Install IIna, a free fork of VLC optimized for macOS. It’s a great app, really.
- Open the video you want to invert and go to Video->Video Filters.
- In the window that opens, click the + sign at the bottom left and select Negative. Click Add.
- Back to the first window. Click the Save button that is next to the new line with your filter and give your filter a name.
- Done. From now, with any video you play in IIna, you just need to go to Video-> Saved Video Filters, and click your filter. Or you can define your own custom keyboard shortcut in the Filter window.
My deepest apologies to Dario Mantovani for the treatment I put him through, but I’m sure he’ll understand that I was more interested in being able to read his slides than to look at him during his lectures 😉