Show HN: Slideo – Synchronize Slides with Video Using Computer Vision (OpenCV)

I made this tool to prepare for exams more efficiently. It is written in rust and uses OpenCV to detect and match features in slides (provided as PDF) and video frames. The matching algorithm is described in [1].

The PDF pages can appear anywhere in the video frames, in any order. Rotation, translation, scaling and obstruction is fully supported due to the feature extractor (ORB) being rotation/scale/transformation invariant.

[1] https://github.com/hediet/slideo/blob/master/BACKGROUND.md

There's many old videos on media.ccc.de with very low quality, standard definition camcorder and without slide capture or at maximum grainy vga captured slides. Might it be possible to take re-render those to FHD or even 4K with everything upscaled and the projector replaced? Would need some additional magic to recognize laser pointers, mouse pointers and the presenter walking in front of the screen, but might be worth it for some of the more timeless talks.

Great idea! I have watched some lectures/talks online with terrible camera work (e.g. panning to the speaker when they are asking the audience to read the slide).

Another solution I've seen was to play a simultaneous video feed of the slides only. Not particularly efficient. Would love to see something like this instead for instructional content!

This is awesome! I can imagine something like this in the text-based video editor we are developing. One usage could be automatic frame alignment for moving objects.

I see only one timestamp for each slide. So I was wondering on how will it handle case when presenter move back and forth for some slide?